Environmental Research Laboratories publication abstracts [microform] / U.S. Department of Commerce, National Oceanic and Atmospheric Administration, Environmental Research Laboratories

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US. DEPARTMENT OF COMMERCE
Robert A.Mosbacher, Secretary

National Oceanic and Atmospheric Administration
John A. Knauss, Under Secretary for
Oceans and Atmosphere/Adnnnistrator

Environmental Research Laboratories
Joseph O. Fletcher, Director

Environmental Research Laboratories

Publication
Abstracts

FY 1989

PENNSYLVANIA
LINIVERII

WR io 1880

DOCUMENTS COLLI61
us- Depository C

October 1989
Boulder, Colorado

FOREWORD

As the research arm of the National Oceanic and Atmospheric Administration
(NOAA) , the Environmental Research Laboratories (ERL) support the present
responsibilities and the development of future services of NOAA. Programs
include investigation of ocean processes and their interactions with the
atmosphere; studies of the ocean environment as it is affected by waste
disposal and development of energy and food resources; fundamental studies of
the upper atmosphere and space environments; atmosphere and ocean research on
weather and climate change; research on severe local storms, hurricanes, and
tsunamis; studies of cloud processes; research on the environmental effects of
regional and global pollution; and development of equipment, instruments,
systems, and facilities for these programs.

A principal measure of the success of a research laboratory is its output ot
scientific and technical papers and reports. The listings (including
abstracts when available) in the following pages are an index of such ERL
output for the period October 1, 1988, through September 30, 1989. This
document includes all known articles published in journals for FY 1988 and
those reports published within the official series of the Laboratories, as
well as conference proceedings and other reports. It also includes
publications by ERL-University cooperative institutes and by contractors
funded by ERL.

Joseph 0. Fletcher, Director
Environmental Research Laboratories
Boulder, Colorado

in

A GUIDE FOR USERS

Abstracts for this volume were submitted print ready by each Laboratory. If
no abstract accompanied the original publication, the words "No abstract"
follow the bibliographic entry.

Sections are arranged alphabetically by Laboratory. Some Laboratories have
included an addendum listing publications inadvertently omitted from the
FY 1988 volume.

Entries within the Laboratory sections are arranged alphabetically by author.
ERL authors' names are typed in all capital letters.

An author index starts on p. 197. A guide for using the index is on p . 195.

Availability of Publications

Papers published in scientific and technical journals are available through
the journals.

NOAA Technical Reports, Technical Memorandums, and Data Reports are available
from

National Technical Information Service (NTIS)

U.S. Department of Commerce

5285 Port Royal Road

Springfield, VA 22161

(703) 487-4600

FTS: Access code + 202 + 487-4600

The NTIS order number is in parentheses following the report number in the
bibliographic entry. Example: NOAA TM ERL ARL-119 (PB83-204347) .

Questions may be addressed to

Programs Office, R/El

National Oceanic and Atmospheric Administration

Environmental Research Laboratories

325 Broadway

Boulder, CO 80303

(303) 497-6212

FTS: Access Code + 320-6212

IV

CONTENTS

Index

code* Page

FOREWORD -- iii

A GUIDE FOR USERS -- iv

AERONOMY LABORATORY

AIR RESOURCES LABORATORY

ATLANTIC OCEANOGRAPHIC AND
METEOROLOGICAL LABORATORY

FORECAST SYSTEMS LABORATORY

GEOPHYSICAL FLUID DYNAMICS LABORATORY

GREAT LAKES ENVIRONMENTAL RESEARCH
LABORATORY

NATIONAL SEVERE STORMS LABORATORY

PACIFIC MARINE ENVIRONMENTAL LABORATORY

SPACE ENVIRONMENT LABORATORY

WAVE PROPAGATION LABORATORY

APPENDIX: FEDERAL- STATE COOPERATIVE PROGRAM IN
WEATHER MODIFICATION RESEARCH

ABOUT THE AUTHOR INDEX

AUTHOR INDEX

AL

1

AR

21

AO

57

FS

74

GF

84

GL

96

NS

110

PM

131

SE

147

WP

158

AP

187

195

..

197

*See AUTHOR INDEX, p. 197.

Digitized by the Internet Archive

in 2012 with funding from

LYRASIS Members and Sloan Foundation

http://archive.org/details/environmentalresOOenvi

ERL Publication Abstracts
FY 1989

AERONOMY LABORATORY

AL-001
Anthes, Richard A., Ying-Hwa Kuo, Eirh-Yu Hsie, Simon Low-Nam, and T.W. Bettge. Estimation of skill and
uncertainty in regional numerical models. Q. J.R. Meteorological Society 115:763-806 (1989).

The results from 72-hour simulations and forecasts from the Penn State/NCAR limited-area model, in which
a number of numerical and physical factors are varied, are analyzed to understand the contribution to
model error or uncertainty introduced by these factors. The factors include the initial conditions,
horizontal resolution (80 km and 1 60 km) and domain size, lateral boundary conditions, and physical
parametrizations. The results are compared with those of a global forecast model (the NCAR Community
Climate Model). The simulations and forecasts are verified both for 12 individual cases and for the en-
semble average of the 12 cases, using several objective measures of skill. The differences in these skill
scores between models are tested for their significance. The use of observed lateral boundary conditions
(LBC) exerts a strong control on the growth of errors over a domain size 3600x4800 km . Objective
measures of error show little growth beyond about 36 hours, so that 72-hour errors are nearly as low as
the 36-hour errors. On these time and space scales, the quality of the LBC is more important than any
other factor tested in the temporal evolution of the model errors. The results show that the large-scale
atmospheric motions have a major effect on the evolution of small-scale features in the model. Small
variations in initial conditions have little effect on the model skill beyond 12-24 hours. Of all the
factors examined, small uncertainties or errors in the initial conditions have the least effect on model
skill beyond 12 hours. Latent heating effects associated with condensation and precipitation, and sen-
sible and latent heat fluxes from the surface have a statistically significant effect on model skill.
However, relatively simple parametrizations of these effects produce nearly the same skill as do more com-
plex schemes for the cases studied here. There is a large variation in model skill from case to case;
some cases are easier to forecast than others. Also, there is much greater variation in different model
performances for a single case than when averaged over all 12 cases. The concept of climatological use
and verification of regional models is introduced. The climatological skill of the control model version
which includes all physical processes appears to be quite good. The skill scores of the ensemble average
simulation are considerably better than the average scores for individual cases, the model has small bias
errors, and the horizontal structure of the model-simulated atmosphere is similar to the observed struc-
ture for scales of motion resolved by the upper-air observational network over the United States.

AL-002

BALSLEY, B.B., and D.A. CARTER. Mountain waves in the tropical Pacific atmosphere: A comparison of ver-
tical wind fluctuations over Pohnpei and Christmas Island using VHF wind profilers. Journal of the
Atmospheric Sciences 46:2698-2715 (1989).

We compare vertical wind fluctuations observed by VHF radar wind profilers in the tropical troposphere
over a large, mountainous island (Pohnpei, at 7°N, 157°E) and a large, low-profile atoll (Christmas
Island, at 2°N, 158°W). The major differences in the two data sets appears to be due to the frequent oc-
currence of mountain waves over Pohnpei and to their absence over Christmas Island. These waves are
generated continuously at low levels over Pohnpei by the steady ENE trade winds acting on the 800m high
terrain, and can extend at least in the lower stratosphere. We find the occurrence of mountain waves at
middle- and upper-tropospherlc levels over Pohnpei to be governed primarily by a "critical-layer"
relationship between the winds aloft and the near-surface winds: a reversal in the direction of the upper
level winds relative to the lower-level trade winds precludes the upward propagation of mountain waves,
whereas a non-reversed wind profile allows the waves to propagate freely in the lower stratosphere, and
possibly to much higher heights, depending on the phase of the QB0.

AL-003

BALSLEY, B.B., W.L. ECKLUND, D.A. CARTER, K.S. GAGE, R. Mugica, A. Mabres, R. Rodriguez, S.K. Avery,
E.J. Violette, and R.F. Woodman. The ST radar under construction at Piura, Peru (5°S, 81 °W) . Conference
Proceedings, 4th MST Radar Workshop, Kyoto, Japan, November 29-December 2, 1988. Handbook for MAP 28:510
(1989).

No abstract.

AL-004

Burkholder , J.B., P.D. Hammer , C.J. HOWARD, and A. Goldman. Infrared line intensity measurements in
the v = 0-1 band of the CIO radical. Journal of Geophysical Research 94(D2) :225-2234 (1989).

Line intensities of the CIO radical in the fundamental vibrational band, v = 0-1, have been measured
using a high-resolution Fourier transform spectrometer coupled to a long path length absorption cell. The
CIO infrared absorption spectra were recorded at 0.0004 cm unapodized resolution in 50 coadded scans at
total pressures less than or equal to 0.4 Torr, He buffer gas. Spectra were recorded at calibrated [C10]
over the range 4x10 to 1.4 x 10 molecule cm , using two different chemical sources of CIO: CI + 0,
and NO + 0C10. The band intensity was measured as S = 9.68 ± 1.45 cm atm (95? confidence level) at
296 K, which is in agreement with a recent C10 band intensity determination using the concentration inde-
pendent Herman-Wallis method of band intensity analysis (Burkholder et al., 1987a). This value of the C10
band intensity is a factor of 2 greater than the value recently reported by Kostiuk et al. (1986). A N-
collisional broadening coefficient of Y° = 0.093+0.018 cm atm (95? confidence level) was determined
from spectra recorded with 10 Torr N added. A source of systematic error in the use of the CI + 0, reac-
tion as a quantitative source of C10 radicals is discussed.

AL-005

CARROLL, M.A., E. P. Condon, D.D. DUNLAP, G.L. Gregory, B.A. Ridley, G.W. Sachse , and M. Trainer.
Measurements of NO over the eastern Pacific Ocean and southwestern United States during the spring 1984
NASA GTE aircraft program. Journal of Geophysical Research 94:5043-5067 (1989).

Measurements of NO, NO (NO + N0-), 0.. and CO are presented from seven aircraft flights made over the
eastern Pacific Ocean and the southwestern United States in spring of 1984. The sampling region was
characterized by large- and small-scale variability for all of the measurements, likely as a result of
vigorous synoptic-scale meteorology and the influence of tropopause folds. Median values for NO, NO , 0_,
and CO from the flights made over the ocean in the region of 5.8-7.6 km were 10 parts per trillion by
volume (pptv), 32 pptv, 46 parts per billion by volume (ppbv) and 120 ppbv, respectively. Corresponding
values from two flights made over the continent at similar altitudes were 66 pptv, 38 pptv, 42 pptv, and
111 ppbv. There was a strong tendency for NO or NO to be correlated positively with 0- and to be an-
ticorrelated with dew-point/frost-point measurements. No significant overall correlation occurred between

NO and CO for the ocean data. The variability of NO was such that regions of net destruction and
regions of net production of 0 were sampled both over the ocean and over the continent. However, in the
middle free troposphere over the ocean, net 0_ destruction was predominant.

AL-006

CARROLL, M.A., E.P. Condon, G.L. Gregory, G.F. Hill, B.A. Ridley, G.W. Sachse, and A.L. Torres. An
intercomparison of results from ferrous sulphate and photolytic converter techniques for measurements
of NO made during the NASA GTE/CITE 1 aircraft program. Journal of Geophysical Research 93:15, 803~
15.81T (1988).

Two techniques designed for measurements of NO (NO + N0_) were intercompared during aircraft flights
made in the spring of 1984 in the middle free troposphere over the eastern Pacific Ocean and southwestern
United States. One NO chemiluminescence instrument was equipped with a ferrous sulphate converter,
another with a photolytic converter. The ferrous sulphate-equipped instrument was apparently much less
specific for NO-. It registered levels about 3 times larger than the photolytic converter and gave N0-/N0
ratios that were much larger than photochemical calculations would indicate as reasonable. Additionally,

the results imply that active NO was only 10-20? of total odd nitrogen in the middle free troposphere.

AL-007

CARROLL, M.A., G.L. Gregory, B.A. Ridley, and G.W. Sachse. NO and NO- in the troposphere: Technique
and measurements in regions of a folded tropopause. Journal of Geophysical Research 93:15,813-15,830
(1988).

During the 1984 spring program of the NASA Global Tropospheric Experiment, measurements of NO, N0-, 0,,
and CO were made during two aircraft flights that encountered tropopause fold events. The technique used
to measure NO (NO + N0_) is described. In the neighborhood of both tropopause fold events, CO and 0,
were strongly anticorrelated. In one fold, encountered over the eastern Pacific Ocean at night, NO was
positively correlated with the stratospheric origin of the air mass. In this fold at altitudes between
5.5 and 6.0 km, NO reached mixing ratios near 150 parts per trillion by volume (pptv) considerably larger
than the levels of 10-50 pptv in the air external to the fold. In contrast, in a daytime encounter with a
fold over the southwestern United States at altitudes of 6.7-8.8 km, NO did not correlate well with CO,

0,, or dew point, but remained roughly constant at levels of 100-200 pp6v. Outside of the fold, in a
region of strong convection activity, NO peaked to just over 500 pptv. It appears that mixing of tropos-
pheric air containing elevated NO weakened the expected trends for the fold over the continent compared
to the fold over the ocean, and therefore NO may not always be a good tracer of air of recent
stratospheric origin. However, the observations emphasize that the stratospheric source of NO acts to
introduce NO over a short period and through a large vertical region of the troposphere, not just near
the tropopause, as is assumed in many tropospheric models.

AL-008

CARTER, D.A., B. B. BALSLEY, W.L. ECKLUND, K.S. GAGE, A.C. Riddle, R. Garello, and M. Crochet.
Investigations of internal gravity waves using three vertically directed closely-spaced wind profilers.
Journal of Geophysical Research 94( D6) :8633"8642 (1989).

A network of three wind profilers spaced about 5 km apart was operated in southern France during the
Alpine Experiment (ALPEX) program. The wind profilers measured vertical motions, and the experiment was
designed to study traveling internal waves by comparing the vertical velocity fluctuations observed at
each station. The measured phase velocities, together with the observed periods, were used to deduce the
horizontal wavelength of the waves. Only a relatively few cases of monochromatic waves could be iden-
tified using this array. Most of the waves that were detected had phase velocities opposite to the
prevailing wind and had the speeds required to cause trapping as the intrinsic frequency was Doppler
shifted upward to the Brunt-Vaisala frequency.

AL-009

CARTER, D.A., P.E. Currier, and W.L. ECKLUND. A PC-based radar controller/signal processor. Conference
Proceedings, 1th MST Radar Workshop, Kyoto, Japan, November 29-December 2, 1988. Handbook for
MAP 28:609-610 (1989).

No abstract.

AL-010

CLARK, W.L., and J.L. GREEN. Flatland data analysis system. Conference Proceedings, 4th MST Radar
Workshop, Kyoto, Japan, November 29-December 2, 1988. Handbook for MAP 28:665-668 (1989).

No abstract.

AL-01 1

CLARK, W.L., J.L. GREEN, and J.M. WARN0CK. Monitoring VHF radar system performance using cosmic noise.
Conference Proceedings, 1th MST Radar Workshop, Kyoto, Japan, November 29-December 2, 1988. Handbook
for MAP 28:593-596 (1989).

No abstract.

AL-01 2

Currier, P.E., and W.L. ECKLUND. Ground clutter suppression at UHF by the use of surface wind measure-
ments. Conference Proceedings, 4th MST Radar Workshop, Kyoto, Japan, November 29-December 2, 1988.
Handbook for MAP 28:641-642 (1989).

No abstract.

AL-01 3

Currier, P.E., W.L. ECKLUND, D.A. CARTER, J.M. WARN0CK, and B.B. BALSLEY. Temperature profiling within
an acoustic source and a UHF wind profiler. Conference Proceedings, 4th MST Radar Workshop, Kyoto,
Japan, November 29-December 2, 1988. Handbook for MAP 28:528 (1989).

No abstract.

AL-01 4

Dabberdt, W.F., H. Cole, K.S. GAGE, W.L. ECKLUND, and W.L. Smith. Determination of boundary-layer
fluxes with an integrated sounding system. Proceedings, Western Pacific International Meeting and
Workshop on TOGA C0ARE, Noumea, New Caledonia, May 24-30, (1989).

An important atmospheric goal of TOGA COARE is to determine the exchange of momentum, and sensible and
latent heat in the western Pacific over the time scales of convective storms, westerly bursts and lower
frequency events. TOGA COARE will also require detailed moisture budget studies in support of improved
understanding of sub-gridscale processes and the evaluation of model parameterization schemes. Present
f ield-deployable measurement systems do not provide observations on the temporal and spatial scales neces-
sary to properly address these and other issues. We present the concept of the so-called Boundary-Layer
Integrated Sounding System (BLISS) as a means to provide these measurements. The BLISS consists of a
suite of demonstrated in situ and remote sensing subsystems which together provide the measurements to
sense directly or retrieve high-resolution profiles of winds, temperature and moisture and associated
fluxes. Individual subsystems under consideration include: surface meteorological station; UHF Doppler
wind profiling radar; radio acoustic sounder; infrared interferometer-spectrometer; microwave radiometer;
and an Omega-VLF radiosonde system for in situ but low frequency profiles to -20mb. Other features of the
integral system include a central data acquisition and processing counter, real-time satellite telemetry
link, and rugged, easily transported base station. We estimate the cost to be sufficiently modest to
enable deployment of a network of order 10-15 systems in support of TOGA COARE.

AL-015

Dlugokencky , E.J., and C.J. HOWARD. Studies of NO, radical reactions with some atmospheric organic com-
pounds at low pressures. The Journal of Physical Chemistry 93:1091-1096 (1989).

Rate constants for the reactions of NO, with trans-2-butene (1), isoprene (2),a-pinene (3), and acetal-
dehyde (4) have been measured as a function of temperature at low pressures in a fast flow system with LIF
detection of the NO, reactant and N0? product. Rate constants for reaction 1 were found to be independent
of pressure from 0.44 to 4.5 Torr, and the Arrhenius plot was curved. The data were fit by the four- ^
parameter equation, k (T = 201-378 K) = (1.78 + 0.36) x 10_ exp[-(530 ± 100)/T] + (1.28 ± 0.26) x 10
exp[(570 ± 110) /T] (where all the error limits arethe 95? confidence levels including a factor for sys-
tematic error, and the units are cm molecule s ). The. data for isoprene were fit by a normal
Arrhenius equation, k (T = 251-381 K) = (3-30 ± 0.45) x 10_ exp[-(450 ± 70)/T]. The Arrhenius plots for
a-pinene and acetaldenyde were linear, and the fits gave k (T = 261-384 K) = (1.19 ± 0.31) x 10
exp[(490 ± 70)/T] and k.(T = 264-374 K) = (1.44 ± 0.18) x TO exp[(-l860 ± 300)/T]. The efficiencies
for the conversion of NO, to N0? were determined for reactions of trans-2-butene and isoprene at low pres-
sures and room temperature in He, N , and 0. carrier gases, and at 360 K in 1 Torr of He. The measured
yields of NO. decreased with increasing size of the organic reactant, with increasing pressure, with
decreasing temperature, and with increasing deactivation efficiency of the carrier gas. These observa-
tions and the temperature dependencies of the rate constants indicate that reactions 1-3 proceed by way of
an addition mechanism. From the analysis used to determine the N0?.vields, N0? fluorescence quenching
ratecpnstants were determined for isoprene, k = (3.5 ± 1.1 ) x 10 , and trans-2-butene, k = (3.0 ± 0.9)
x 10 .

AL-016

Eaton, F., J. Brown, W.L. CLARK, D. Favier, K.S. GAGE, J.L. GREEN, W. Hatch, J. Hines, E. Murphy,
G. Nastrom, W. Peterson, T.E. VANZANDT, and J.M. WARNOCK. Comparisons of the transverse coherence
length and isoplanatic angle from measurements taken with the Flatlands very high frequency radar, opti-
cal techniques, and thermosondes. Preprints, Conference on Optics, Electro-Optics, and Laser
applications in Science and Engineering, Los Angeles, CA, January 15-20, 1989. The International
Society for Optical Engineering, Bellingham, WA (1980).

Comparisons are made of the transverse coherence length (r0) and isoplanatic angle (e0) derived from

measurements taken with the Flatlands very high frequency (VHF) radar, an r0 system, an isoplanometer , and

temperature fluctuation sensors mounted on a thermosonde. The measurements were conducted at the

Flatlands location near Urbana, Illinois, from 7-13 June 1988. The site was selected because of the lack

of orographic effects on airflow and the refractive index structure parameter (C 2). The radar was

n0

operated with alternating beams in the north and east directions at 20° zenith angle in order to avoid

contamination by specular reflections. Contributions of the refractive index structure parameter (C2)

from different altitudes above ground to the integrated-path r0 and 60 values are presented and discussed.

Diurnal variations of r0 and 60 obtained from the suite of instruments are shown with particular emphasis

on the "neutral" events. Measured results are compared to results from the Aeronomy Laboratory's

theoretical model of C2.
n

AL-017

ECKLUND, W.L. Hardware design for MST, ST and lower troposphere/boundary layer radars. Conference
Proceedings, 4th MST Radar Workshop, Kyoto, Japan, November 29-December 2, 1988. Handbook for MAP
28:518-521 (1989).

No abstract.

AL-018

ECKLUND, W.L. A microstrip antenna array for UHF wind profiling. Conference Proceedings, 1th MST Radar
Workshop, Kyoto, Japan, November 29-December 2, 1988. Handbook for MAP 28:529 (1989).

No abstract.

AL-019

ECKLUND, W.L., D.A. CARTER, B.B. BALSLEY, and P.E. Currier. A 915 MHz boundary layer wind profiler.
Conference Proceedings, 4th MST Radar Workshop, Kyoto, Japan, November 29-December 2, 1988. Handbook
for MAP 28:556-561 (1989).

No abstract.

AL-020

ECKLUND, W.L., D.A. CARTER, B.B. BALSLEY, K.S. GAGE, and P.E. Currier. Recent developments in lower
tropospheric wind profiling. Preprint volume, First European Wind Profiler Workshop, Trappes, France,
March 6-8, 1989, C33-C4iJ (1989).

A small UHF wind-profiling radar has been developed at NOAA's Aeronomy Laboratory. This radar provides
high-resolution wind profiles from near the surface upward to 2-3 km in clear air. Since the radar is
very sensitive to heavy clouds and rain, it can be used to monitor the height of the melting layer and the
vertical extent of hydrometeors . The small radar also provides temperature profiles up to 1 km when
operated with an acoustic source in the RASS mode.

AL-021

ECKLUND, W.L., K.S. GAGE, D.A. CARTER, and B.B. BALSLEY. Status and plans for the Pohnpei, F.S.M. (7°N,
157°E) ST radar. Conference Proceedings, 4th MST Radar Workshop, Kyoto, Japan, November 29-
December 2, 1988. Handbook for MAP 28:493 (1989).

No abstract.

AL-022

ECKLUND, W.L., J.L. GREEN, D.A. CARTER, W.L. CLARK, P.E. Currier, J.M. WARNOCK, and K.S. GAGE.
Summertime observations in Illinois using two wind profilers. Preprints, 24th Conference on Radar
Meteorology, Tallahassee, FL, March 27-31, 1989. American Meteorological Society, Boston, MA, 701-704
(1989).

No abstract.

AL-023

ECKLUND, W.L., K. Moran , P.E. Currier, B. Weber, D.A. CARTER, and D. Wuertz. A comparison of wind
profilers operating at 915, 405, and 50 MHz. Conference Proceedings, 4th MST Radar Workshop, Kyoto,
Japan, NovemDer 29-December 2, 1988. Handbook for MAP 28:413-415 (1989).

No abstract.

AL-024

FAHEY, D.W., J. Austin, J.G. Anderson, C.B. Farmer, L.E. Heidt, R.L. Jones, K.K. KELLY, D.M. MURPHY,
M.H. Proffitt, A.F. TUCK, and J.F. Vedder. Lagrangian photochemical modeling studies of the 1987
Antarctic spring vortex. 1. Comparison with AAOE observations. Journal of Geophysical Research
94:1 1 ,529-1 1 ,558 (1989).

In this paper, results from a photochemical model integrated along ensembles of 8-day air parcel trajec-
tories are used to simulate the latitude and vertical composition gradients observed from the ER-2
aircraft during the 1987 Airborne Arctic Ozone Experiment (AAOE). The photochemical model used includes
heterogeneous chemical reactions when polar stratospheric clouds are inferred, from local temperature and
pressure to be present. The model results were found to be very sensitive to NO mixing ratios and the
frequency of polar stratospheric clouds (PSCs). Trajectories often showed instantaneous (adiabatic) cool-
ing rates of up to 30 K d with air parcels even at high latitudes spending substantial periods outside
modeled clouds. This leads to a photochemical "balance" in the model calculations between the perturba-
tions to the composition caused by the heterogeneous reactions and the restoring effects of HN0o

destruction. For the period of interest (early September 1987), the model was able to simulate well both
the latitude gradient of CIO on the 428 K potential temperature surface and the CIO vertical gradient at
72°S. The model simulated well the NO and NO concentrations at high latitudes inside the dehydrated,
denitrified region, although NO values outside were significantly overestimated. There is evidence from
the chlorine and the nitrogen species partitioning in the model that even outside the denitrified,
dehydrated region the chemical composition is perturbed. It is argued that heterogeneous processing on
type I PSCs has occurred in this outer region, but without denitrif ication or dehydration. Model results
imply that the BrO observations made from the ER-2 within the dehydrated, denitrified region are consis-
tent with there being approximately 5 parts per trillion by volume of BrO at 428 K in spring. Within the
high CIO region, ozone destruction rates are calculated to exceed 2% d with approximately 80? due to the
CIO dimer mechanism.

AL-025

FAHEY, D.W., K.R. Chan, G.V. Ferry, K.K. KELLY, M. Loewenstein, D.M. MURPHY, L.R. Poole, and J.C.
Wilson. In situ measurements of total reactive nitrogen, total water, and aerosol in a polar
stratospheric cloud in the Antarctic. Journal of Geophysical Research 94:11,299-11,315 (1989).

Measurements of total reactive nitrogen (NO ), total water, and aerosol were made as part of the
Airborne Antarctic Ozone Experiment during August and September 1987. The measurements were made using
instruments located on board the NASA ER-2 aircraft, which conducted 12 flights over the Antarctic con-
tinent, reaching pressure altitudes of 20 km at 72°S latitude. The data presented here focus on a flight
during which a polar stratospheric cloud (PSC) was encountered, containing concentrations of 0.8- to 2.6-
ym diameter aerosol particles greater than 1 cm . The temperatures in the cloud ranged as low as 184 K
near 65-mbar pressure, but they remained above the frost point of water ice, except for short intervals.
From knowledge of the vapor pressures over nitric acid condensates, the appearance of aerosol above the
background level is consistent with the formation of the trihydrate phase, HNO ,'3H_0. The anisoklnetic
feature of the NO sample probe enhances the concentration of large aerosol particles in the inlet by a
factor of ~9. NO levels above 20 parts per billion by volume (ppbv) observed in the PSC indicate that
aerosol NO species contribute substantially to the NO signal. The amount of aerosol HNO -SH^O necessary
to enhance the NO signal to observed levels is calculated from aerosol impaction theory and is found to
be in satisfactory agreement with the observed aerosol volume. In addition, using the saturation vapor
pressures and an estimate of available HNO, in the cloud, the predicted volume of HNO -3H 0 also shows
satisfactory agreement with the directly measured aerosol volume. These results indicate that substantial
aerosol volume containing HNO, and H_0 is formed at temperatures above the frost point in the Antarctic
stratosphere in the winter ana spring months. Such aerosol formation is thought to be the prerequisite
for the production of active chlorine in heterogeneous reactions and for the large-scale removal of NO
through aerosol sedimentation.

AL-026

Fritts, D.C., T. Tsuda , T.E. VANZANDT, S.A. Smith, T. Sato, S. Fukao , and S. Kato. Momentum flux in the
troposphere and lower stratosphere using the MU radar. Conference Proceedings, 4th MST Radar Workshop,
Kyoto, Japan, November 29-December 2, 1988. Handbook for MAP 28:353~354 (1989).

No abstract.

AL-027

GAGE, K.S., B.B. BALSLEY, D.A. CARTER, W.L. ECKLUND, and J.R. MCAFEE. The Christmas Island ST radar
(2°N, 157°W), Conference Proceedings, 4th MST Radar Workshop, Kyoto, Japan, November 29-
December 2, 1988. Handbook for MAP 28:498-499 (1989).

No abstract.

AL-028

GAGE, K.S., B.B. BALSLEY, W.L. ECKLUND, D.A. CARTER, and J.R. MCAFEE. Wind profiler related research in
the tropical Pacific. Proceedings, Western Pacific International Meeting and Workshop on TOGA/COARE,
Noumea, New Caledonia, May 24-30, 1989.

This paper is broadly concerned with the application of wind profiling Doppler radar technology to
tropical atmospheric research. Examples of the use of wind profilers in the tropics are drawn from the
Aeronomy Laboratory's wind profilers located on Pohnpei (7°N, 158°E) and Christmas Island (2°N, 157°W).
The Pohnpei wind profiler was constructed in 1984 and has been used exclusively to observe vertical mo-
tions. The Christmas Island wind profiler has observed horizontal and vertical velocities routinely

since 1986. These two wind profilers form part of a planned trans-Pacific network of wind-profiling
radars that will eventually span the tropical Pacific.

AL-029

GAGE, K.S., B.B. BALSLEY, W.L. ECKLUND, R.F. Woodman, and S.K. Avery. A trans-Pacific network of wind-
profiling Doppler radars for tropical atmospheric research. Conference Proceedings, 4th MST Radar
Workshop, Kyoto, Japan, November 29-December 2, 1988. Handbook for MAP 28:44-55 (1989).

No abstract.

AL-030

GAGE, K.S.

W.L. ECKLUND, B.B. BALSLEY, J. Soegijo, M. Pardede, and S.M. Notosuyidno. A proposed ST

radar for Biak, Indonesia (1°S, 136°E). Conference Proceedings, 4th MST Radar Workshop, Kyoto, Japan,

November 29-December 2, 1'

Handbook for MAP 28:516 (T

I).

No abstract.

AL-031

GAGE, K.S., W.L. ECKLUND, and D.A. CARTER. Convection waves observed using a VHF wind-profiling Doppler

radar during the pre-STORM experiment. Preprints, 24th Conference on Radar Meteorology,

Tallahassee, FL, March 27-31, 1989. American Meteorological Society, Boston, MA, 705-708 (1989).

No abstract.

AL-032

GAGE, K.S., W.L. ECKLUND, and D.A. CARTER. A first look at convection waves observed by an ST radar.
Conference Proceedings, 4th MST Radar Workshop, Kyoto, Japan, November 29-December 2, 1988. Handbook
for MAP 28:384-393 (1989).

No abstract.

AL-033

GAGE, K.S., and G.D. Nastrom. A simple model for the enhanced frequency spectrum of vertical velocity

based on tilting of atmospheric layers by lee waves. Conference Proceedings, 4th MST Radar Workshop,

Kyoto, Japan, November 29-December 2, 1988. Handbook for MAP 28:292-298 (1989).

No abstract.

AL-034

GOLDAN, P.G., R. Fall, W.C. KUSTER, and F.C. FEHSENFELD. Uptake of COS by Growing Vegetation:
tropospheric sink. Journal of Geophysical Research 93:14,186-14,192 (1988).

A Major

Laboratory measurements of the uptake of COS by soybeans, corn, wheat, and alfalfa under conditions of
controlled illumination, temperature, and C0? concentration, and at COS concentrations spanning those
typically found in the troposphere (~500 parts per trillion by volume), indicate that the major uptake
pathway is through open stomata. Similarities between the uptake resistances observed for COS and C0?
provide a means of estimating global COS uptake from estimates of global terrestrial primary plant produc-
tivity. With an estimated annual plant uptake of 0.2-0.6 Tg COS (Tg =10 g), this appears to be the
largest global sink for this major tropospheric sulfur reservoir species. With this vegetative sink in-
cluded, estimated known sources and sinks appear to be in approximate balance.

AL-035

Goldman, A., J.B. Burkholder, C.J. HOWARD, R. Escribano, and A.G. Maki. Spectroscopic constants for the
infrared band of HN0„. Journal of Molecular Spectroscopy 131 : 195 -200 (1988).

3'

-1

High-resolution infrared measurements have been made on the vQ band of HN0. from 41 4 to 500 cm ' . Over
2300 transitions have been measured, assigned, and fit to obtain 15 rovibrational constants for the vq = 1
state that reproduce the. observed spectrum with a RMS deviation of 0.0004 cm . The band center for vq is
at 458.2287 ± 0.0005 cm .

AL-036

GREEN, J.L., R.R. Beland, J.H. Brown, W.L. CLARK, F.D. Eaton, L.D. Favier, K.S. GAGE, W.H. Hatch,
J.R. Hines, E.A. Murphy, G.D. Nastrom, W.A. Peterson, T.E. VANZANDT, and J.M. WARNOCK. Comparisons of
refractivity turbulence estimates from the Flatland VHF radar with other measurement techniques.
Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL, March 27-31, 1989. American
Meteorological Society, Boston, MA, 709-712 (1989).

No abstract.

AL-037

GREEN, J.L., and W.L. CLARK. The Flatland radar antenna steering implementation. Conference
Proceedings, 4th MST Radar Workshop, Kyoto, Japan, November 29-December 2, 1988. Handbook for MAP
28:522 (1989).

No abstract.

AL-038

GREEN, J.L. , and W.L. CLARK. Flatland radar on-line signal processing and radar control system.
Conference Proceedings, 4th MST Radar Workshop, Kyoto, Japan, November 29-December 2, 1988. Handbook
for MAP 28:604-608 (1989).

No abstract.

AL-039

GREEN, J.L., T.E. VANZANDT, K.S. GAGE, J.M. WARNOCK, W.L. CLARK, and G.D. Nastrom. The status of the
Flatland radar and recent studies. Conference Proceedings, 4th MST Radar Workshop, Kyoto, Japan,
November 29-December 2, 1988. Handbook for MAP 28:500-502 (1989).

No abstract.

AL-040 l8

Greenblatt, G.D. and C.J. HOWARD. Oxygen atom exchange in the interaction of OH with several small
molecules. The Journal of Physical Chemistry 93:1035-1042 (1989).

i ft
Oxygen atom exchange between OH and several oxygen-containing molecules was studied in a flow tube by

using laser magnetic resonance detection of the reagent OH and product OH. No significant exchange

was observed for 0 , HO, CO, CO , NO, 0CS, and S02 at 298 and 400 K, and upger liming to the exchange

rate coefficients are reported^ ,The rate coefficients for^the^reactionsof ,0H and OH with CO were

found to be (1.49 ± 0.15) x 10 i and (1.44 ± 0.15) x 10 cm molecule s , respectively ,_at 298 K.

NO and NO were found to exchange rapidly with k = (1.8 ± 0.6) x 10 and (1.0 ± 0.4) x 10 cm

molecule s , respectively at 298 K. On the basis of a simple model of adductf prmation k^ values for

the OH + NO and N0p association reactions were estimated to be S(3-6 ± 1.2) x 10 and SO. 5 ± 0.6) x

10 cm molecule s , respectively. Error limits are 95? confidence limits.

AL-041

Hofmann, D.J., J.M. Rosen, J.W. Harder, and J.V. Hereford. Balloon-borne measurements of aerosol, con-
densation nuclei, and cloud particles in the stratosphere at McMurdo Station, Antarctica, during the
spring of 1987. Journal of Geophysical Research 94 : 1 1 ,253-1 1 , 269 (1989).

Measurements of the vertical profile of particles with condensation nuclei counters and eight channel
aerosol detectors at McMurdo Station, Antarctica, in 1987 verified observations made in 1986 concerning
the absence of upwelling in the polar vortex and the presence of a condensation nuclei layer in conjunc-
tion with the ozone hole region. New observations of a bimodal aerosol size distribution, consisting of a
large-particle (=1 pm) mode mixed in with the small-particle sulfate mode, at temperatures below -79°C are
consistent with the presence of nitric acid-water particles at low concentrations. Higher concentrations
of large particles were observed in association with nacreous clouds. An unusual particle layer which
contained enhanced concentrations of both the small-particle (sulfate) mode and the large-particle (nitric
acid) mode was detected at temperatures below -85°C, suggesting simultaneous nucleation and growth
phenomena. The vortex condensation nuclei layer was observed to form at the same time as the ozone hole,
indicating that formation of the layer is triggered by photochemical processes and may be important in
controlling ozone depletion above 22 km.

AL-042

Hofmann, D.J., S. SOLOMON. Ozone destruction through heterogeneous chemistry following the eruption of
El Chichdn. Journal of Geophysical Research 91 : 5029 -5041 (1989).

It is now well established that heterogeneous reactions provide an important mechanism for Antarctic
ozone depletion. Recent laboratory studies suggest that the same reactions that occur on HN0_/H20 ice
clouds in the cold Antarctic stratosphere can also take place on sulfuric acid particles (e.g., volcanic
and background aerosols) typical of lower latitudes, albeit at slower rates. The reduction in stratos-
pheric ozone observed at northern mid-latitudes in late 1982 through 1983 following the volcanic eruption
of El ChichcSn is investigated in terms of ozone loss through heterogeneous chemistry on the aerosol which
formed in the stratosphere. The rates of the relevant heterogenous reactions are believed to be criti-
cally dependent on ( 1 ) the aerosol surface area density and (2) the percent by weight sulfuric acid in the
liquid particles. Direct measurements of both of these important quantities for El Chich6n aerosol are
described and used as a basis for model calculations of their possible effects on ozone and other trace
species. The observed volcanic particle surface area reached a maximum at mid-latitudes of about 50
urn cm (above a typical background value of about 0.75) at an altitude of 18-20 km in early 1983. This
enhancement of surface area is about the same as that encountered in stratospheric clouds in the
Antarctic, suggesting a possible basis for ozone depletion through heterogeneous chemistry. Observations
of N0? and HNO, also suggest that heterogenous reactions on both background and volcanic aerosol play a
significant role in partitioning reactive nitrogen species in middle an high latitudes in winter. It is
shown that heterogenous reactions similar to those occurring in Antarctica may have been responsible for
at least a portion of the anomalous ozone reduction observed at mid-latitudes in early 1983.

AL-043

Judasz, T.J., and B.B. BALSLEY. Improved theoretical and experimental models for the coaxial colinear
antenna. IEEE Transactions on Antennas and Propagation 37:289-296 (1989).

An improved theoretical model of the coaxial colinear (COCO) antenna is presented. Uniform and tapered
current distributions have been obtained experimentally and theoretically on end-fed coaxial colinear an-
tennas. There is reasonable agreement between theory and measurements. The linear systems of equations
of the theoretical model are solved using a preconditioned conjugate gradient method. The gains of a few
COCO antennas relative to equivalent lengths of half-wave dipoles are given.

AL-044

Keene, W.C., R.W. Talbot, M.O. Andreae, K. Beecher , H. Berresheim, M. Castro, J.C. Farmer, J.N.
Galloway, M.R. Hoffmann, S-M. Li, J.R. Maben, J.W. Munger, R.B. NORTON, A. A. P. Pszenny, H. Puxbaum,
H. Westberg, and W. Winiwarter. An intercomparison of measurement systems for vapor and particulate
phase concentrations of formic and acetic acids. Journal of Geophysical Research 94:6457-6471 (1989).

During June 1986, eight systems for measuring vapor phase and four for measuring particulate phase con-
centrations of formic acid (HC00H) and acetic acid (CH,C00H) were intercompared in central Virginia.
HC00H and CH C00H vapors were sampled by condensate, mist, Chromosorb 103 GC resin, NaOH-coated annular
denuders, NaOH impregnated quartz filters, K?C0, and NapCO^ impregnated cellulose filters, and Nylasorb
membranes. Atmospheric aerosol was collected on Teflon ana Nuclepore filters using both hi-vol and lo-vol
systems to measure particulate phase concentrations. Samples were collected during 31 discrete day and
night intervals of 0.5-2 hour duration over a 4-day period. Performance of the mist chamber and K-C0, im-
pregnated filter techniques were also evaluated using zero air and ambient air spiked with HC00H ,
CH C00H , and formaldehyde (CH 0 ) from permeation sources. Results of this intercomparison show sig-
nificant systematic and episodic artifacts among many currently deployed measurement systems for HC00H
and CH-C00H . The spiking experiments revealed no significant interferences for the mist chamber tech-
nique and results generated by the mist chamber and denuder techniques were statistically
indistinguishable. The condensate technique showed general agreement with the mist chamber and denuder
methods, but episodic bias between these systems was inferred from large and significant differences ob-
served during the first day of sampling. Nylasorb membranes are unacceptable for collecting carboxylic
acid vapors as they did not retain HC00H and CH COOH quantitatively. Strong base impregnated filter and
GC resin sampling techniques are prone to large positive interferences apparently resulting, in part, from
reactions involving CH 0 to generate HC00H and CH.COOH subsequent to collection. Significant bias
presumably associated with differences in postcollection handling was observed for particulate phase
measurements by participating groups. Analytical bias did not contribute significantly to differences in
vapor and particulate phase measurements.

AL-045

KELLY, K.K., E.V. Browell , K.R. Chan, D.W. FAHEY, G.V. Ferry, G.L. Gregory, L.E. Heidt, R.L. Jones,
M. Loewenstein, M.P. McCormick, D.M. MURPHY, J.R. Podolske, M.H. Proffitt, S.E. Strahan, and J.F.
Vedder . Dehydration in the lower Antarctic stratosphere during late winter and early spring, 1987.
Journal of Geophysical Research 94:11,317-11,357 (1989).

Measurements of total water were made with Lyman a resonance fluorescence hygrometers mounted on the ER-
2 and DC-8 aircraft. Direct evidence was obtained for dehydration of the lower stratosphere over
Antarctica; minimum values were about 1.5 parts per million by volume (ppmv), compared with values of 3.0
1.5 ppmv immediately outside the region high potential vorticity gradient in the potential temperature
range 120 < 6 < 160 K. On one flight, ice crystals large enough to have appreciable sedimentation
velocities were observed. The DC-8 data at 300 < 6 < 320 K frequently showed extensive belts of dry,
ozone-rich air between 60°and 75°S latitude, with the equatorward "edge" in water well correlated with
that observed by the ER-2 some 8-9 km higher. Data from near Punta Arenas and from the ferry flights are
used to argue that the effects of dehydration over Antarctica were visible at mid-latitudes.

AL-046

Langford, A.O., P.D. GOLDAN, and F. C. FEHSENFELD. A molybdenum oxide annular denuder system for gas
phase ambient ammonia measurements. Journal of Atmospheric Chemistry 8:359-376 (1989).

An automated molybdenum oxide annular denuder system (MOADS) has been developed for gas phase ambient
ammonia measurements. This system combines high sensitivity (detection limit <50 pptv) with continuous
sampling, moderate collection times (30 min) and automated operation. The present denuder design confers
two important advantages over the tungsten oxide coated quartz denuder tubes used previously for nitric
acid and ammonia measurements. First, the present denuders use oxidized metal substrates and are easier
to fabricate and more durable than denuders made from metal oxide coated glass or quartz tubes. Second,
molybdenum (VI) oxide surfaces are used which oxidize a reproducible fraction of the adsorbed NH_ directly
to NO upon desorption eliminating the need for a secondary catalytic converter. Laboratory tests of the
collection/recovery characteristics of annular denuders made from both the (IV) and (VI) oxides of
tungsten and molybdenum are described and preliminary results from field tests are presented.

AL-047

Lin, X., M. Trainer, and S.C. LIU. On the nonlinearity of the tropospheric ozone production. Journal
of Geophysical Research 93:15,879-15,888 (1988).

The relationship of photochemical ozone production versus photochemical loss of ozone precursor, that
is, either NO or nonmethane hydrocarbons (NMHCs), is studied by using a box model with particular em-
phasis on the nonlinearity problem of the relationship with respect to the concentration of the precursor.
Model calculations indicate that the composition of NMHCs, the ratio of NMHCs to NO , and the background
concentrations of natural hydrocarbons, CO, and CH. all play important roles in determining the non-
linearity of 0 production with respect to the loss of NO loss processes are also investigated.
Mechanisms that contribute to the nonlinearity are discussed. The nonlinear property of 0, production
versus loss of hydrocarbons and CO is different from that of NO . When the sum of CO and all hydrocar-
bons, including CH^, natural NMHCs, and anthropogenic NMHCs, is used as the reference 0. precursor, the
nonlinearity is much less pronounced for ambient conditions usually found in rural air.

AL-018

LIU, S.C, R.A. Cox, P.J. Crutzen, D.H. Ehhalt, R. Guicherit, A. Hofzumahaus, D. Kley, S.A. Penkett,
L.F. Phillips, D. Poppe, F.S. Rowland. Oxidizing capacity of the atmosphere. In The Changing
Atmosphere, F.S. Rowland and I. S.A. Isaksen (eds.). John Wiley & Sons Ltd. 219-232 (1988).

No abstract.

AL-049

MCAFEE, J.R., B.B. BALSLEY, and K.S. GAGE. Momentum flux measurements over mountains: problems as-
sociated with the symmetrical two-beam radar technique. Journal of Atmospheric and Oceanic Technology
6:500-508 (1989).

An experiment to measure the vertical transport of horizontal momentum was carried out using the Poker
Flat, Alaska, MST radar operating in a symmetrical two-beam mode. We show that the difficulties inherent
in this measurement are magnified by problems associated with the effects of orographic flow over the lo-
cal mountainous terrain. These difficulties show up most clearly when comparing the average vertical
velocities measured using antenna beam position in two orthogonal vertical planes. The measured fluxes

10

are dominated by large values of the long-period (>6h) fluctuations. Although this observation is consis-
tent with previous measurements at other locations, we show that the accuracy of the symmetric two- beam
method under these geographic conditions is questionable.

AL-050

McKellar, A.R.W., J.B. Burkholder, J.J. Orlando, and C.J. HOWARD. Fourier transform infrared spectrum
of the v, band of HCO. Journal of Molecular Spectroscopy 130:445-453 (1988).

The v fundamental band of the formyl radical, HCO, in the 5.3-um region has been observed at high
resolution (0.0025 cm , unapodized) using a Fourier transform spectrometer. The HCO radicals were formed
by the reaction of F atoms with H CO in a fast-flow multiple-traversal absorption cell. A total of 298
lines were measured with an accuracy of about 0.0004 cm and assigned to transitions with values of the
rotational quantum numbers N and K up to 20 and 5, respectively. These data greatly improve the
knowledge of the HCO v line positions and (v.v„v_) = (001) vibrational state molecular parameters as com-
pared to earlier laser magnetic resonance studies of this band, especially for higher values of N. The v
fundamental band of HCO was also observed and an analysis of these data agrees well with the recent study
of Dane et al. [Journal of Chemical Physics 88:2121-2128 (1988)].

AL-051

MOUNT, G.H., S. SOLOMON, R.W. SANDERS, R.O. JAK0UBEK, A. L. SCHMELTEK0PF. Observations of stratospheric
NO and 0 at Thule, Greenland. Science 242:555-559 (1988).

Scattered sunlight and direct light from the moon was used in two wavelength ranges to measure the total
column abundances of stratospheric ozone (0 ) and nitrogen dioxide (N0_) at Thule, Greenland (76.5°N),
during the period from 29 January to 16 February 1988. The observed 0 column varied between about 325
and 400 Dobson units, and the lower values were observed when the center of the Arctic polar vortex was
closer to Thule. This gradient probably indicates that 0, levels decrease due to dynamical processes near
the center of the Arctic vortex and should be considered in attempts to derive trends in 0 levels. The
observed NO. levels were also lowest in the center of the Arctic vortex and were sometimes as low as 5 x
10 molecules per square centimeter, which is even less than comparable values measured during Antarctic
spring, suggesting that significant heterogenous photochemistry takes place during the Arctic winter as it
does in the Antarctic.

AL-052

MURPHY, D.M. Wall collisions, angular flux and pumping requirements in molecular flow through tubes
and microchannel arrays. Journal of Vacuum Science and Technology A. 7:3075-3091 (1989).

MicroChannel arrays can be used to produce intense molecular beams with free molecular flow. Arrays can
attain much higher intensities than a single orifice small enough to be in free molecular flow. Pumping
requirements are greatly reduced compared to supersonic jets producing similar beam intensities.
Theoretical descriptions of the angular flux and wall collisions in single tubes and microchannel arrays
are developed. These results are extended to the situation of a finite mean free path and the considera-
tion of wall collisions which occur before transmission through a tube. Despite the large average number
of wall collisions experienced by molecules passing through a long tube, molecules along the axis of the
beam experience zero or few wall collisions. The near absence of wall collisions on the beam axis allows
reactive species to be sampled with microchannel arrays. Tubes with a length to radius ratio of up to
about 40 are useful for reactive species. Most wall collisions for molecules transmitted along the beam
axis through microchannel arrays are collisions in which a molecule enters the array, collides with the
wall, goes back to the source region, and then is transmitted through the array. The nearly effusive beam
allows the selection of species based on their thermal velocities. A long single tube used as a skimmer
will provide a greater pressure drop than an orifice.

AL-053

MURPHY, D.M., K.R. Chan, K.K. KELLY, M. Loewenstein, J.R. Podolske, M. H. Proffitt, S.E. Strahan, and
A.F. TUCK. Indicators of transport and vertical motion from correlations between in situ measurements
in the airborne Antarctic ozone experiment. Journal of Geophysical Research 94 :1 1 ,669-1 1 ,685 ( 1989) .

Analysis of small-scale structure in the in situ measurements made from the ER-2 during the Airborne
Antarctic Ozone Experiment shows the existence of a region at the boundary of the chemically perturbed
region where the mixing ratios and small-scale structure of trace gases are influenced by transport across
the boundary. This transition region is characterized by horizontal interchange and vertical layering cf
air parcels from within and outside of the chemically perturbed region and negative small-scale correla-
tions between CIO and ozone. The horizontal transport in this region creates large surface areas

11

between dissimilar air masses, providing the potential for substantial mixing. This paper does not at-
tempt to quantify the amount of mixing. Correlations between CIO and 0- show that the transition region
extends to 2°-4° of latitude to either side of the boundary of the chemically perturbed region. A +4-wide
transition region would contain nearly as much air as the chemically perturbed region proper. Analysis of
water vapor and nitrous oxide data suggests that diabatic descent is associated with dehydration. This
could be caused by strong radiative cooling of those polar stratospheric clouds in which enough water con-
denses for the particles to fall and dehydrate the air.

AL-054

Nastrom, CD., J.L. GREEN, T.E. VANZANDT, K.S. GAGE, and W.L. CLARK. Measurement of large-scale verti-
cal velocity using clear-air Doppler radar. Conference Proceedings, 4th MST Radar Workshop, Kyoto,
Japan, November 29-December 2, 1988. Handbook for MAP 28:367~376 (1989).

No abstract.

AL-055

Nastrom, G.D., M.R. Peterson, J.L. GREEN, K.S. GAGE, and T.E. VANZANDT. Sources of gravity waves as
seen in vertical velocities measured by the Flatland VHF radar. Preprints, 24th Conference on Radar
Meteorology, Tallahassee, FL, March 27-31, 1989. American Meteorological Society, Boston, MA, 713-716
(1989).

No abstract .

AL-056

PARRISH, D.D., and F.C. FEHSENFELD. Rural ozone production: Field study measuring many of the
photochemically important trace species. Preprints, 198th Meeting of the American Chemical Society,
Miami Beach, FL, September 10-15, 1989. Division of Environmental Chemistry, American Chemistry
Society, 472-476 (1989) .

Extended abstract.

AL-057

Proffitt, M.H., J.G. Anderson, and W.H. Brune. Ozone destruction by chlorine radicals within the
Antarctic vortex: The spatial and temporal evolution of C10-0, anticorrelation based on in situ ER-2
data. Journal of Geophysical Research 94:11,465-11,479 (19897.

In situ 0^ and CIO data obtained from the ER-2 aircraft are used to define the chemical evolution of the
Antarctic vortex region from August 23 to September 22, 1987. Initial conditions are characterized at
aircraft flight altitude (18 km) by highly amplified CIO mixing ratios (800 parts per trillion by volume
(pptv) within a well-defined "chemically perturbed region" (CPR) poleward of the circumpolar jet, within
which ozone exhibits limited erosion (~15/S) in middle to late August. Within this CPR, ozone decays con-
sistently throughout the course of a 10-flight series, such that by late September, 75% of the 0, has
disappeared within the region of highly amplified C10 concentrations (which reached 500 times normal
levels at ER-2 cruise altitude). As this ozone depletion develops, 0 and C10 exhibit dramatic negative
correlation on isentropic surfaces, obtained as the aircraft passed through the edge of the CPR. Taken in
conjunction with an analysis of the mechanisms defining the rate of catalytic 0 destruction, it is con-
cluded that C10 is an essential constituent in the catalytic destruction of ozone with the vortex.
Therefore it is concluded that the observed disappearance of ozone with the Antarctic vortex would not
have occurred in the absence of global chlorof luorocarbon release.

AL-058

Proffitt, M.H., K.R. Chan, D.W. FAHEY, B.L. Gary, K.K. KELLY, A.J. Krueger, M. Loewenstein, J.J.
Margitan, J.R. Podolske, J. A. Powell, M.R. Schoeberl , and A.F. TUCK. A chemical definition of the
boundary of the Antarctic ozone hole. Journal of Geophysical Research 94 : 1 1 , 437-1 1 , 488 ( 1 989) .

A campaign utilizing an ER-2 high-altitude and a DC-8 aircraft, both fitted with state-of-the-art in-
strumentation to study the Antarctic ozone hole, was conducted out of Punta Arenas, Chile, from August 17
through September 22, 1987. Data indicated a chemically perturbed region roughly coincident with the
Antarctic polar vortex and with the region of large temporal decrease of ozone that is usually referred to
as the Antarctic ozone hole. A rapid rise in C10 was observed as the ER-2 proceeded into the ozone hole
at about 18 km altitude, and it is this feature that is used to define the boundary of the chemically per-
turbed region as that latitude along the flight track where C10 reaches 130 parts per trillion by

12

volume (pptv). In situ data taken simultaneously aboard the ER-2 as well as Total Ozone Mapping
Spectrometer (TOMS) satellite ozone data along the flight tracks, are analyzed at fixed positions rela-
tive to this boundary and are presented as averages over the duration of the mission. These analyses
indicate a narrow transition zone for the chemical species N?0 and H?0 and for the meteorological
parameters of temperature, wind speed, and potential vorticity is also seen, indicating the dynamical
character of the chemically defined boundary. TOMS column values of about 260 Dobson units (DU) generally
persisted at the boundary during this period. One-month temporal trends of the in situ data both inside
and outside this boundary are also presented. Interpretations of these analyses are offered that are con-
sistent with ongoing diabatic cooling, accompanying advective poleward transport across the boundary.
These data strongly implicate man's release of chlorine into the atmosphere as a necessary ingredient in
the formation of the Antarctic ozone hole.

AL-059

REID, G.C., K.S. GAGE, and J.R. MCAFEE. The response of the tropical tropospheric and lower strato-
sphere to variations in pacific sea-surface temperature. Proc . of the 13th Annual Climate Diagnostics
Workshop, Cambridge, MA, 61-65 (1988).

No abstract.

AL-060

Riddle, A.C., K.S. GAGE, and B.B. BALSLEY, Preparation of an archival data base for the Poker Flat,

Alaska, MST radar. Conference Proceedings, 1th MST Radar Workshop, Kyoto, Japan, November 29-

December 2, 1988. Handbook for MAP 28:669-671 (1989).

No abstract.

AL-061

SANDERS, R.W., S. SOLOMON, M.A. CARROLL, and A.L. SCHMELTEKOPF. Visible and near-ultraviolet spectros-
copy at McMurdo Station, Antarctica 4. Overview and daily measurements of N0_, 0 , and 0C10 during 1987.
Journal of Geophysical Research 94:11,381-11,391 (1989).

Neai — ultraviolet absorption spectroscopy in the wavelength range from 330 to 370 nm was used to measure
0 , NO , and BrO at McMurdo Station (78°S) during 1987. Visible absorption measurements of 0 , NO , and
0C10 were also obtained using the wavelength range from about 403 to 453 nm. These data are described and
compared to observations obtained in 1986. It is shown that comparisons of observations in the two
wavelength ranges provide a sensitive measure of the altitude where the bulk of atmospheric absorption
takes place. The measurements indicate that the bulk of the NO column abundance is located near 30 km,
while those of 0C10 and 0- are near 20 km. The measurements of N0? display a systematic increase during
the month of September, probably reflecting the release of odd nitrogen from reservoirs formed earlier in
the winter season. The m s r m ts ~f 0C10 display a strong diurnal variation, with considerably higher
values being obtained in the evening than those measured in the morning. The evening twilight 0C10 column
abundances obtained in 1987 were notably larger than those in 1986, perhaps because stratospheric tempera-
tures were colder, and associated heterogeneous chemistry may have been more intense. This in turn
implies a faster rate of ozone destruction in 1987 than in 1986 by halogen chemistry. These observations
provide important constraints on the coupled nitrogen-halogen chemistry of Antarctic spring and its in-
fluence on the springtime Antarctica ozone depletion.

AL-062

Sengupta, N. , J.M. WARN0CK, E.E. Gossard, and R.G. Strauch. Remote sensing of meteorological parameters
using a wind-profiling radar. Preprints, First European Wind Profiler Workshop, Trappes, France,
March 6-8, 1989, D9-D20 (1989).

The described experiment tested the f sibility of (a) using a surface-based radar to measure gradients
of temperature and humidity aloft and (b) using standard radiosonde data to calculate height profiles of
the radio refractive index structure parameter, C2. The statistical model developed by NOAA's Aeronomy
Laboratory was used to calculate values of C2 and e for comparison with the radar-measured values. The
radar-calculated and observed quantities were found to be in reasonably good agreement.

AL-063

SOLOMON, S., H.L. Miller, J. P. Smith, R.W. SANDERS, G.H. MOUNT, A.L. SCHMELTEKOPF, and J.F. Noxon.
Atmospheric NO, 1. Measurement technique and the annual cycle at 40°N. Journal of Geophysical Research
94:11 ,041-1 1 ,048 (1989).

13

The nitrate radical abundance is often measured by making use of its strong absorption of visible radia-
tion in a band near 662 nm. We show that this N0_ absorption feature has strong negative correlation with
water vapor, which requires that water vapor absorption be explicitly considered in attempts to measure
NO. from the ground. Concurrent observation of a second, weaker N0_ feature near 623 nm provides an inde-
pendent means of confirming and quantifying the accuracy of the measurement. The considerations are
included in the analysis of a full year of nighttime stratospheric NO., data at 40°N. The observations are
in good general agreement with theoretical predictions and do not support the existence of a stratospheric
scavenger for NO.,.

AL-064

SOLOMON, S., G.H. MOUNT, R.W. SANDERS, R.O. JAKOUBEK, and A.L. SCHMELTEKOPF. Observations of the
nighttime abundance of 0C10 in the winter stratosphere above Thule , Greenland. Reprint Series, Science
242:550-555 (1988).

Observations at Thule, Greenland, that made use of direct light from the moon on 2, 3, 4, 5, and 7
February 1988 revealed nighttime chlorine dioxide (0C10) abundances that were less than those obtained in
Antarctica by about a factor of 5, but that exceeded model predictions based on homogeneous (gas-phase)
photochemistry by about a factor of 10. The observed time scale for the information of 0C10 after sunset
strongly supports the current understanding of the diurnal chemistry of 0C10. These data suggest that
heterogeneous (surface) reactions due to polar stratospheric clouds can occur in the Arctic, providing a
mechanism for possible Arctic ozone depletion.

AL-065

SOLOMON, S., R.W. SANDERS, M.A. CARROLL, and A.L. SCHMELTEKOPF. Visible and near-ultraviolet spectros-
copy at McMurdo Station, Antarctica 5. Observations of the diurnal variations of BrO and 0C10. Journal
of Geophysical Research 94 : 1 1 , 393-1 1 ,403 (1989).

Observations of the diurnal variations of 0C10 and BrO during austral spring, 1987 using long-path
visible and near-ultraviolet absorption spectroscopy are presented and compared to simplified model cal-
culations. It is shown that care must be taken to compare model calculations and measurements along the
line of sight of the instrument. Evening twilight observations of C01 0 are found to be broadly consistent
with current photochemical schemes, assuming C10 and BrO levels near 50 mbar of about 0.5 parts per bil-
lion by volume (ppbv) and 7 parts per trillion by volume (pptv) , respectively, throughout the observing
period from late August to mid-October. Nighttime observations of 0C10 obtained using the Moon as a light
source display evidence for growth after sunset in late August, but not in late September. Further, the
observed morning twilight 0C10 abundances are in agreement with model calculations in late August, but
they generally fall below calculations in late September and October. Observations of BrO in mid-
September show far greater evening than morning twilight abundances. It is shown that the diurnal
variations of BrO and 0C10 in mid-September and October can be explained by formation of the BrONOp, reser-
voir species at night, although other reservoir species with comparably long lifetimes could also explain
the observations. If formation of Br0N0_ is the correct explanation for these data, the observations sug-
gest that N0_ levels in the Antarctic lower stratosphere are of the order of a few pptv or less in late
August, a few tens of pptv in mid-September, and a few hundred pptv in October.

AL-066 '

Strauch, R.G., K.P. Moran, P.T. May, A.J. Bedard, and W.L. ECKLUND. RASS temperature soundings with
wind profiler radars. Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL, March 27-
31, 1989. American Meteorological Society, Boston, MA, 741-745 (1989).

No abstract.

AL-067

Tsuda, T. , T. Inoue, D.C. Fritts, T.E. VANZANDT, S. Kato, T. Sato, and S. Fukao . MST radar observations
of a saturated gravity wave spectrum. Journal of the Atmospheric Sciences 46:2440-2447 (1989).

We present vertical wavenumber spectra of mesoscale wind fluctuations using data observed in the tropo-
sphere, lower stratosphere and mesosphere by the MU radar at 35°N in Japan in October 1986 and
June 1987, as well as lower stratospheric spectra obtained by the Arecibo UHF radar at 18°N in Puerto Rico
in June 1983. These spectra are much more homogeneous than previously available spectra since all of the
data were observed by the same radar technique, the data in the different atmospheric regions were taken
essentially simul' aneously , and all of the spectra were analyzed using very similar methods. In the
large-wavenumbe- ranges of the observed spectra, the asymptotic slopes and amplitudes agree well with the
saturated gravity wave spectral model developed by Dewan and Good (1986) and Smith et al . (1987), which

14

has a slope of -3 and a spectral amplitude proportional to the buoyancy frequency squared. The good
agreement between the model spectrum and the observed spectra from different altitudes, different seasons,
and two different stations located at 35° and 18°N suggests that the model is essentially correct, in
spite of the heuristic nature of some of its assumptions. The spectral densities of the zonal and
meridional components are similar at large wavenumbers, while the meridional spectrum has larger energy
density at small wavenumbers where the spectrum is not saturated. The dominant vertical scales of the
gravity wave field in the mesosphere, lower stratosphere, and troposphere are estimated to be >10 km, 2.2
to 3.3 km, and >3-3 km in October and >4.5 km in June, respectively, consistent with determinations from
previous studies.

AL-068

Tsuda, T. , T.E. VANZANDT, S. Kato, S. Fukao , and T. Sato. Spectral analysis of temperature and Brunt-
Vaisala frequency fluctuations observed by radiosondes. Conference Proceedings, Symposium 6, The Middle
Atmosphere After MAP, COSPAR 88, Espoo, Finland, July 18-23, 1988. Handbook for MAP 27:461-168 (1989).

We have observed temperature profiles over the MU observatory, Japan, by using a radiosonde with 30m
height resolution in summer from 30 June to 4 September 1987, and in winter from 22 December 1986 to
25 February 1987 [Figs. 1 -4 ] . In summer, the tropopause is located at around 16 km. There is a sharp in-
crease in the N2 (N: Brunt-Vaisala frequency) profile, which clearly separates the troposphere and
stratosphere. On the other hand, in winter the increase of N2 is gradual and somewhat irregular, so that
the transition region from the troposphere to the stratosphere is fairly broad, although the tropopause is
usually found at 10-12 km. We present in this paper vertical wavenumber spectra of normalized temperature
perturbation and N2 determined in the 2-8.5 km (troposphere) and 18.5-25 km (lower stratosphere) altitude
ranges [Figs. 5 and 6]. The observed spectra are compared with saturated gravity wave theory, which
predicts a spectrum of normalized temperature as 1 /1 0xN'*/(g2m3 ) and N2 as
1/10xNVm, where g and m are acceleration of gravity and vertical wavenumber, respectively.

AL-069

TUCK, A.F. Synoptic and chemical evolution of the Antarctic vortex in late winter and early spring,
1987. Journal of Geophysical Research 91:11,687-11,737 (1989).

Evidence from the ER-2 and DC-8 aircraft flights is considered, together with analysis of temperature,
winds, potential vorticity and trajectories, satellite data, and ozonesonde observations, to come to a
view of whether the air in the lower stratosphere over Antarctica during winter and early spring of 1987
was a fixed slug of air, or if there was significant mass flow through the system. It is concluded that
synoptic-scale forcing, via "sudden coolings", produced polar stratospheric clouds, which intervened to
alter the homogeneous gas phase chemical balance. As a result, there was a source of the CIO molecule and
sinks for HO, NO (equal to the sum of reactive gas phase nitrogen compounds), and 0 operating within
the region of hign potential vorticity gradients on isentropic surfaces, that is, inside the vortex. It
is further concluded that as a result of horizontal mixing, downward diabatic motion, and, at potential
temperatures below 400 K, advective transfer, that the effects of these polar sinks and chemical reactions
can be transmitted to middle latitudes.

AL-070

TUCK, A.F., J. Austin, E.V. Browell , R.L. Jones, A.J. Krueger , M.P. McCormick, and D.S. McKenna.
Diagnostic studies of the Antarctic vortex during the 1987 airborne Antarctic ozone experiment: Ozone
miniholes. Journal of Geophysical Research 94:11,641-11,668 (1989).

During the Airborne Antarctic Ozone Experiment (AAOE) localized rapid reductions in total ozone, called
"miniholes", were observed by the Total Ozone Mapping Spectrometer (TOMS) within the main ozone hole.
Evolving too rapidly to be the result of chemical destruction, miniholes must be the result of atmospheric
transport. An important question then is "Do miniholes represent large-scale transport of ozone poor air
into the vortex?" In this paper we examine the genesis and evolution of miniholes, and we demonstrate by
the calculation of air parcel trajectories that miniholes are not the result of irreversible transport of
ozone-poor air into the polar vortex. We show instead that minihole genesis can be attributed, in large
part, to synoptic-scale tropospherically forced reversible advection (both horizontal and vertical) of
low-ozone air below the level of the main ozone depletion, resulting from the poleward penetration of an
anticyclone below the main vortex. We then examine the implications of the disturbed flows associated
with minihole formation. Employing differential infrared absorption laser (DIAL) data, Stratospheric
Measurement (SAM) II retrievals, and United Kingdom Meteorological Office (UKM0) global analysis fields
and trajectories, we highlight two aspects of minihole formation, which have important implications for
both theories of photochemical ozone destruction and vortex isolation. We conclude that tropospheric
forcing which reduces the ozone column through advection also forces the formation of Polar Stratospheric
Clouds (PSCs) (type I and II), throughout a substantial depth of atmosphere, resulting in a large portion

15

of the air in the vortex being exposed to heterogeneous chemistry as it passes through individual guasi-
stationary PSC regions. Finally we conclude that synoptic-scale transport associated with these events
can lead to the exchange of vortex air with air from lower latitudes. The lower limit on the mass ex-
change over the period of ozone depletion is estimated to be 4? of the total depleted mass, with large
uncertainties.

AL-071

TUCK, A.F., E.P. Condon, J.J. Margitan, O.B. Toon, and R.T. Watson. The planning and execution of
ER-2 and DC-8 aircraft flights over Antarctica, August and September 1987. Journal of Geophysical
Research 94:11,181-11,222 (1989).

During August and September 1987, instrumented ER-2 and DC-8 aircraft flew 12 to 13 flights over
Antarctica, respectively, to investigate the dramatic loss of ozone that has occurred there in the lower
stratosphere during recent austral springs. The flights, which are documented in some detail, provided a
wealth of data on homogeneous gas phase composition, upon polar stratospheric clouds, and upon tracers for
dynamic motion. An important aspect of the ER-2 data is that periods of high surface winds at Punta
Arenas, Chile, which generally prevented a flight, frequently coincided with equatorward extension of the
vortex toward the flight track region (52° -72°S, 60° -80°W). The ER-2 flights are thus biased toward
days when the vortex was being pushed away from the tip of South America and the Antarctic Peninsula. Any
attempt to use the ER-2 data as a time series must take into account the variable position of the vortex
edge along the flight track. At DC-8 flight levels, numerical weather prediction models had a tendency to
underestimate the wind speeds by up to 50? in situations of strong meridional flow. Since such events had
detectable effects on the lower stratospheric vortex, this too could be an important limitation.

AL-072

Tyndall, G.S., and C.J. HOWARD. Kinetics of the reaction of CH S with 0 at 298 K. The Journal of
Physical Chemistry 93:4707-1710 (1989).

Laser- induced fluorescence was used to detect CH S radicals in the laser flash photolysis of CH..SH-0..-
H^0-He (SF,) mixtures. Evidence_was_f ound for a reaction between CH S and 0,, with a rate coefficient
(5.1 + 2.0? x 10 cm molecule s . The yield of CH S from the reaction OH + CH SH was determined to
be 1.1 ±0.2. Our results suggest that the CH S + 0„ reaction could be the major sink for CH,S in the at-
mosphere.

AL-073

Tyndall, G.S., and A.R. RAVISHANKARA . Kinetics and mechanism of the reactions of CH S with 0 and NO
at 298 K. The Journal of Physical Chemistry 93:2426-2435 (1989).

Rate coefficients for the reactions CH S + 0 „ -> products (1) and CH S + NO ■» products (2) have been
measured at 298 K by laser induced fluorescence detection of CH S which was generated by pulsed 248-nm
laser photolysis of . CH^SSCH^, k was found to be less than 2.5 x 10 cm s . k_ was measured to be
(6.10+0.90) x 10 cm s . The mechanism of reactions 1 and 2 was investigated. The major product in
reaction 2 is NO, with a yield of 0.80 ± 0.20. Secondary production of NO was observed, indicating that
CH SO formed in reaction 2 also reacts with NO , with a rate coefficient of (8 ± 5) x 10
long reaction times laser excited fluorescence was detected from a product, possibly CH.S0.

cm s ' . At

AL-074

Vaghjiani, G.L., and A.R. RAVISHANKARA. Absorption cross sections of CH 00H, HO, and D_0_ vapors be-
tween 210 and 365 nm at 297 K. Journal of Geophysical Research 94(D3) :3487~3492 T1989).

The gas phase absolute UV absorption cross sections at 213i9f.nm for CH 00H, HO, and DO have been
determined to be (22.51 ± 0.78) x 10 , (33.04 ± 2.17) x 10 , and (35.57 ± 4.25) x 10 cm

molecule , respectively, at 297 ± 1 Kz The corresponding values at 253-7 nm for H?0 and DO were (7.37
± 0.31) x 10 and (7.86 ± 1.04) x 10 cm molecule . The UV absorbance of a slowly flowing mixture

of peroxide and helium carrier gas in a Pvrex absorption cell was measured, followed by collection and
titration of the eluting peroxide with Fe or I solutions. The relative cross sections for CH.00H and
H?0 at 298.1, 326.1, 340.4, and 361.1 nm were also determined, using the absolute values at 213.9 nm.
The absorption spectra of these peroxides were recorded in the wavelength region between 210 and 365 nm,
using a diode array spectrometer, and normalized to the above cross sections to obtain absolute values for
the UV absorption cross sections over this entire wavelength region. The obtained results are compared to
those from previous investigations. The atmospheric relevance of our measured cross sections is dis-
cussed.

16

AL-075

Vaghjiani, G.L., and A.R. RAVISHANKARA. Kinetics and mechanism of OH reaction with CH 00H. The Journal
of Physical Chemistry 93:1948-1959 (1989).

The reaction of hydroxyl radical with methyl hydroperoxide, CH^OOH, was investigated in the temperature

rate coefficient for the overall reaction, OH + CH.OOH ■* products (k ) was measured by using ' "OH and OD
in place of OH. The rate coefficient for the CH.O, production channel OH + CH 00H ■» CH 0 + HO (k ) was

1a'
bserved

range 203-423 K by pulsed photolytic generation of OH and detection by laser-induce fluorescence. The
rate coefficient for the overall reaction, OH + CH.OOH * products (k ) was measured by using OH a '
in place of OH. The rate coefficient for the CH 0^ production channel OH + CH 00H ■» CH 0 + HO (k
obtained by using OH. The channel that yields CH 00H, OH + CH 00H ■> CH 00H + H.O (k..), is not obs
when monitoring OH since CH?00H rapidly falls apart to give back OH (and CH 0) But is observed when study-
ing the OH or OD reaction with CH 00H. By monitoring OH production in OD + CH OOH reaction at 249 K,
the two-channel mechanism was confirmed, and the values for k and k were also determined. Both reac-
tion 1 and channel 1a show negative activation energies, with k = (2.93 ± 0.30) x 10 exp[(190 ± 1 4) /T]
cm3 molecule" s (average of OH and OD studies) and k, = (1.78 + 0.25) x 10_ exp[(220 ± 21)/T] cnr

2ule_ s (average of OH and OD studies) and k = (1.78 ± 0.25) x 10 exp[(220 ± 21)/T] cm-

molecule s , where the indicated error is 1o, including estimated systematic errors and o = Ao ..
The rate coefficient for the reaction of 0D with CH 00D is at least a factor of 2 smaller than that for
reaction 1a. The thermal decomposition lifetime for CH.OOH to give OH + CH_0 is deducted to be shorter
than 20 ys at 205 K. The mechanism of reaction 1 and the implications of our kinetic and mechanistic
results to Earth's atmospheric chemistry are discussed. The measured value of k and the branching ratio,
k /•<.., at 298 K are compared with previous indirect measurements of Niki et al . [Journal of Physical
Chemistry 87:2190 (1983)].

AL-076

VANZANDT, T. E. Advances in understanding the gravity wave spectrum during MAP. Conference Proceedings,
Symposium 6, The Middle Atmosphere After MAP, C0SPAR 88, Espoo, Finland, July 18-23, 1988. Handbook for
MAP 27:123-131 (1989).

No abstract .

AL-077

VANZANDT, T. E. Progress in existing and planned MST and ST radars. Conference Proceedings, 4th MST
Radar Workshop, Kyoto, Japan, November 29-December 2, 1988. Handbook for MAP 28:450 (1989).

No abstract.

AL-078

VANZANDT, T. E. , and D.C. Fritts. A theory of enhanced saturation of the gravity wave spectrum due to
increases in atmospheric stability. Pure and Applied Geophysics 130:399-420 (1989).

In this paper we consider a vertical wavenumber spectrum of vertically propagating gravity waves imping-
ing on a rapid increase in atmospheric stability. If the high-wavenumber range is saturated below the
increase, as is usually observed, then the compression of vertical scales as the waves enter a region of
higher stability results in that range becoming supersaturated, that is, the spectral amplitude becomes
larger than the saturation limit. The supersaturated wave energy must then dissipate in a vertical dis-
tance of the order of a wavelength, resulting in an enhanced turbulent energy dissipation rate. If the
wave spectrum is azimuthally anisotropic, the dissipation also results in an enhanced vertical divergence
of the vertical flux of horizontal momentum and enhanced wave drag in the same region. Estimates of the
enhanced dissipation rates and radar reflectivities appear to be consistent with the enhancements observed
near the high-latitude summer mesopause. Estimates of the enhanced mean flow acceleration appear to be
consistent with the wave drag that is needed near the tropopause and the high-latitude summer mesopause in
large-scale models of the atmosphere. Thus, this process may play a significant role in determining the
global effects of gravity waves on the large-scale circulation.

AL-079

VANZANDT, T. E. , J.L. GREEN, G.D. Nastrom, K.S. GAGE, W.L. CLARK, and J.M. WARN0CK. Measurement of ver-
tical velocity using clear-air Doppler radars. Conference Proceedings, Symposium 6, The Middle
Atmosphere After MAP, C0SPAR 88, Espoo, Finland, July 18-23, 1988. Handbook for MAP 27:477-481 (1989).

No abstract.

17

AL-080

VANZANDT, T. E. , G.D. Nastrom, J.L. GREEN, and K.S. GAGE. The spectrum of vertical velocity from
Flatland radar observations. Conference Proceedings, 4th MST Radar Workshop, Kyoto, Japan, November 29-
December 2, 1988. Handbook for MAP 28:377-383 (1989). Also Preprints, 24th Conference on Radar
Meteorology, Tallahassee, FL, March 27-31, 1989. American Meteorological Society, Boston, MA, 717-720
(1989).

No abstract .

AL-081

VANZANDT, T. E. , S.A. Smith, T. Tsuda , D.C. Fritts, T. Sato, S. Fukao , and S. Kato. Anisotropy of the

velocity fluctuation field in the lower stratosphere. Conference Proceedings, 4th MST Radar Workshop,

Kyoto, Japan, November 29-December 2, 1988. Handbook for MAP 28:350-352 (1989).

No abstract.

AL-082

Wahner, A., R.O. JAKOUBEK, G.H. MOUNT, A.R. RAVISHANKARA , and A.L. SCHMELTEKOPF. Remote sensing obser-
vations of nighttime 0C10 column during the Airborne Antarctic Ozone Experiment, September 8, 1987.
Journal of Geophysical Research 94:11,405-11,411 (1989).

The daytime and nighttime slant column abundances of 0C10 were measured by near-UV absorption spectros-
copy between 64° and 76°S latitude and 62° and 84°W longitude during the DC-8 flight on days 251 and 252
(UT) 1987 as a part of the Airborne Antarctic Ozone Experiment (AAOE). Daytime and nighttime measurements
used the scattered sunlight and the Moon as the light sources, respectively. The measured 0C10 column
abundance during the nighttime was found to be 10 times larger than that measured during the day.

AL-083

Wahner, A., A.R. RAVISHANKARA, S.P. Sander, and R.R. Friedl. Absorption cross section of BrO between
312 and 385 nm at 298 and 223 K. Chemical Physics Letters 1 52(6 ) :507-51 2 (1988).

2 2

The absolute UV cross section of BrO at 338.1 ± 0.1 nm , the peak of the (7*0) band of the A( n)<-XLn)

transition, was measured at 298 ± 2 and 223 ± 4 K to be (1.71 ± 0.14) x 10 and (221 ± 0.16) x 10~

cm , respectively, using the technique of flash photolysis-ultraviolet absorption. The spectral resolu-
tion for these measurements was 0.18 nm. The absorption spectra of BrO in the wavelength range 312-385 nm
were measured at 298 ± 2 and 223 ± 4 K using a flow tube reactor coupled to a diode array spectrometer.
Using the (7,0) band cross sections, the absorption cross sections in the above wavelength range were cal-
culated.

AL-084

WARN0CK, J.M., R.R. Beland, J.H. Brown, W.L. CLARK, F.D. Eaton, L.D. Favier, K.S. GAGE, J.L. GREEN,
W.H. Hatch, J.R. Hines, E.A. Murphy, G.D. Nastrom, W.A. Peterson, and T. E. VANZANDT. Comparison among
clear-air radar, thermosonde and optical measurements and model estimates of C2 made in very flat ter-
rain over Illinois. Conference Proceedings, 4th MST Radar Workshop, Kyoto, Japan, November 29-December
2, 1988. Handbook for MAP 28:432-438 (1989).

No abstract.

AL-085

WARN0CK, J.M., K.S. GAGE, and J.L. GREEN. Flatland radar measurements of tropopause heights and com-
parison of specular echo strength with model estimates. Conference Proceedings, 4th MST Radar Workshop,
Kyoto, Japan, November 29-December 2, 1988. Handbook for MAP 28:39-42 (1989).

No abstract.

AL-086

WARNOCK, J.M., K.S. GAGE, and J.L. GREEN. Studies of the radar reflectivity of vertical echoes measured

by the Flatland VHF clear-air Doppler radar. Preprints, 24th Conference on Radar Meteorology,

Tallahassee, FL, March 27-31, 1989. American Meteorological Society, Boston, MA, 721-724 (1989).

18

No abstract.

AL-087

WEINSTOCK, J. A theory of turbulent transport. Journal of Fluid Mechanics 202:319-338 (1989).

A calculation is made of the turbulent transport terms (third moments) that occur in the Reynolds stress
equation for buoyant and/or sheared fluids. This calculation is based on neglect of a two-time fourth-
order cumulant - a weaker approximation than neglect of the usual single-time fourth-order cumulant. The
previously used eddy-damping assumption for single point moments is avoided. This assumption is then ex-
amined critically. Comparison is afterward made between the turbulent transport terms derived here and
those derived previously by the eddy-damping method, and between the respective derivations. Also the
dissipation of third moments is calculated. The calculation is formally limited to mean quantities which
very but slowly in space and time, and to small anisotropy.

AL-088

WEINSTOCK, J. Comparison of a pressure-strain rate theory with simulations. Journal of Fluid Mechani cs
205:195-214 (1989).

A theoretical expression for the slow part (the nonlinear fluctuation part) of the pressure-strain rate
is compared with simulations of anisotropic homogeneous flows. The purpose is to determine the quantita-
tive accuracy of the theory and to test its qualitative predictions that the generalized Rotta
coefficient, a non-dimensionalized ratio of slow term to kinetic energy anisotropy, varies with direction
and can be negative (this is counter to isotropy return). Comparisons are made between theoretical and
simulated values of the slow term and of the generalized Rotta coefficients. Also compared to simulations
is an extension of the theory to account for non-stationary turbulence fields. The implication of the
comparison for two-point closure theories and for Reynolds stress modelling is pointed out.

AL-089

WEINSTOCK, J. Superadiabatic excess and gravity wave saturation. Journal of the Atmospheric Sciences
45:22 (1988).

Attention is called to a recent calculation of the superadiabatic excess - the ratio of wave amplitude
at saturation to wave amplitude at convective instability threshold - caused by a saturated gravity wave.
(This excess is also referred to as the degree of supersaturation) . The implications of this excess for
linear saturation by convective instability are pointed out. Errors and misprints in the recent calcula-
tion are also pointed out and corrected.

AL-090

WEINSTOCK, J. Time averaged transport coefficients in photo-chemical modeling: A conjecture. Journal
of Geophysical Research 94 : 1 4, 703-1 4,704 (1988).

It has been pointed out by several authors that constituent dif f usi vi ties associated with breaking
gravity waves vary dramatically with the wave saturation amplitude. This variation introduces an uncer-
tainty for the value to be used for diffusivity. In principle, this particular uncertainty may be avoided
if an appropriate time average is used, and the corresponding wave statistics are known. A simple
hypothesis is put forward regarding what average is appropriate.

AL-091

Wormhoudt , J., K.E. McCurdy, and J.B. Burkholder. Measurements of the strengths of infrared bands of
CF . Chemical Physics Letters 1 58(6 ) :480-485 (1989).

The vp infrared band strength of. the CF radical has been measured using tunable diode laser absorption
by the R (20) line at 1240.50 cm . Experiments were performed in a flow apparatus in which CF was gen-
erated by thermal dissociation of CF HC1 . Simultaneous single pass absorption of UV light from a KrF
excimer laser was used with a literature value of the UV absorption cross. section to quantify CF con-
centrations. The measured line strength at 360 K is (1.4+0^4) x 10 cm (molecule/cm ) . This results
in a band strength of (1.1±0.4) x 10 cm (molecule/cm ) , in good agreement with a measurement using
a different technique. Analysis of FTIR spectra of the v. and v- bands indicates that the v, band
strength is larger by a factor of 2.4.

19

Addendum

AL-092

BALSLEY, B.B. The MST radar technique: Historical background and potential for atmospheric research.
In Future Directions in Electrical Engineering : Atmospheric and Space Sciences , (Proceedings of the
Cornell Electrical Engineering Centennial Symposium, St. Louis, MO, April 17, 1985), S. Linke (ed.).
Promethean Press, Ithaca, NY, 473-^96 (1988).

No abstract.

AL-093

BALSLEY, B.B., W.L. ECKLUND, D.A. CARTER, and A.C. Riddle. A note on reducing the horizontal sidelobes
of near-vertically directed COCO arrays. IEEE Transactions on Antennas and Propagation 36:139-141

(V

I).

A method of modifying quasi -broadside arrays of coaxial collinear (COCO) antennas in order to sig-
nificantly reduce horizontal sidelobe levels is discussed. Tests made prior to and after these
modifications show a sidelobe reduction of more than three orders of magnitude.

AL-094

GAGE, K.S., B.B. BALSLEY, W.L. ECKLUND, D.A. CARTER, A.C. Riddle, and J.R. MCAFEE. Zonal wind observa-
tions at Christmas Island (2°N, 157°W) during the 1986-87 El Nino. Proceedings, Twelfth Annual Climate
Diagnostics Workshop, Salt Lake City, UT, October 12-16, 1987. NOAA/NWS/NMC Climate Analysis Center,
37-49 (1987).

No abstract.

AL-095

GREEN, J.L., G.D. Nastrom, K.S. GAGE, T.E. VANZANDT, W.L. CLARK, and J.M. WARNOCK. Observations of ver-
tical velocity over Illinois by the Flatland radar. Geophysical Research Letters 15:269-272 (1988).

A new VHF clear-air Doppler radar has been constructed in very flat terrain near Urbana, Illinois. This
radar, called the Flatland radar, as presently configured measures a profile of the vertical component of
the wind velocity every 2.5 minutes. It is found that typical time variances of vertical velocity over
this very flat terrain are similar to the small variances observed during "quiet" periods near mountains.
The observed absence of extended periods of large variance supports the hypothesis that the "active"
periods observed near mountains are mainly due to orographic effects. The absence of such effects at
Flatland should facilitate the study of other meteorological processes. For example, in the case study
presented here it is suggested that the vertical motions associated with large-scale baroclinic storms are
measurable by the Flatland radar.

20

AIR RESOURCES LABORATORY

AR-001

ANGELL , J.K. Relation of Antarctic 100 mb temperature and total ozone to equatorial QBO,
Equatorial SST, and sunspot number, 1953-87. Geophysical Research Letters 15(8) : 915-918 (1988).

Year-to-year changes in springtime (September-October-November or SON) values of Antarctic 100 mb
temperature and total ozone have been compared with each other and with year-to-year changes in SON
values of equatorial 50 mb temperature (reflecting the quasi-biennial oscillation or QBO) and
sea-surface temperature (SST) in eastern equatorial Pacific (reflecting El Nifto). During the 30-year
period 1958-87, there has been a significant (at the 5% level) correlation of 0.73 between
year-to-year changes in SON values of Antarctic 100 mb temperature and total ozone, as well as a
significant correlation of -0.64 between year-to-year changes in SON values of Antarctic 100 mb
temperature and equatorial 50 mb temperature. There has been little correlation (-0.18) between
year-to-year changes in Antarctic 100 mb temperature and SST in eastern equatorial Pacific. However,
year-to-year changes in Antarctic total ozone have been almost equally related to year-to-year changes
in equatorial 50 mb temperature and equatorial SST (respective correlations of -0.44 and -0.42), with
a significant correlation of -0.60 if the latter two quantities are considered jointly (multiple
correlation). Unlike the Arctic in winter, there is no evidence of an increase in springtime values
of Antarctic 100 mb temperature (and total ozone) with increase in sunspot number when the equatorial
QBO is in the west-wind phase, but there is provisional evidence of such an increase in the east-wind
phase .

AR-002

ANGELL, J.K. Variations and trends in tropospheric and stratospheric global temperatures, 1958-87.
Journal of Climate 1( 12) : 1296-1313 (1988).

Examined in this paper are the variations and trends in tropospheric and low-stratospheric
temperature for seven climatic zones, hemispheres, and world for intervals 1958-87 and 1973-87, based
on 63 well-distributed radiosonde stations. For the 30-yr interval 1958-87, these data indicate an
increase in year-average global temperature at the surface and in the tropospheric 850-300 mb layer of
0.08°C (10 yr)"1 and 0.09°C (10 yr)"1, respectively, just significant at the 5% level. Nevertheless,
during this interval there is evidence for a slight decrease in year-average temperature at the
surface and in the troposphere of north polar and north temperate zones. The global 300-100 mb
temperature is indicated as having decreased by 0.18°C (10 yr) during this 30-yr interval
(significant at the 1% level), with a temperature decrease in all seven climatic zones, though largest
in the south polar zone (associated with the Antarctic "ozone hole" phenomenon). For the 15-year
interval 1973-87, the global temperature in the low-stratospheric 100-50 mb layer is indicated as
having decreased by a significant 0.62°C (10 yr) , the decrease again largest in the south polar zone
2.04°C (10 yr) but observed in all zones except the north temperate zone. During 1958-87, there is
evidence for an increase in the meridional temperature gradient between equatorial zone and north
polar zone both at the surface and in the troposphere, but in the Southern Hemisphere there has been a
decrease in this gradient at the surface and essentially no change in the troposphere. In the
hemispheric and global average, warming has been greater (though not significantly so) in MAM
(March-April-May) and JJA than in DJF and SON, both at the surface and in the troposphere, though in
both polar zones the surface warming has been greatest in winter. The close relation between
sea-surface temperature in eastern equatorial Pacific and tropospheric temperature in the tropics is
discussed in some detail. Finally, temperature variations and trends in the western hemisphere
tropics are examined up to heights of 55 km using high-level radiosonde data and rocketsonde data.

AR-003

ARTZ, R.S., and G.D. ROLPH . Evaluation of precipitation chemistry siting criteria using paired
stations from northern Maine and southeastern Texas. Atmospheric Environment 23 ( 5) : 1033-1050
(1989).

Two-year precipitation chemistry data records from each of two paired stations are compared to
determine whether the precipitation chemistry is different. In each pair, one of the stations
(Caribou, Maine, and Victoria, Texas) violates National Atmospheric Deposition Program (NADP) siting
requirements, while the other station (Presque Isle, Maine, and Beeville, Texas) is in compliance.
Methods employed to carry out this study include the calculation of precipitation weighted statistics,
the study of logarithmic distributions, the study of regression line residuals, the study of relative
sample differences, and the use of the non-parametric Wilcoxon test for two matched samples. Results
indicate no clear differences occurred between paired stations over a seasonal or longer period of
time; however, considerable variation was observed on a weekly basis. Maine stations were in

21

excellent agreement for all ions; Texas stations showed small differences between ions typically
associated with soil dust and between ions typically associated with anthropogenic activity.

AR-004

ARTZ, R.S., G.D. ROLPH, and J. HARRIS. Meteorological summary of four WATOX 1985 research
intensives. Atmospheric Environment 22( 11) : 2361-2369 (1988).

A detailed review of four intensive events in the Western Atlantic Ocean Experiment (WATOX) in 1985
is given. Three air parcel trajectory models are used to assess the general flow characteristics
associated with these events, and results show that all three models produce trajectories with similar
source regions. Not surprisingly, isentropic trajectories tended to show faster transport because of
vertical movement from higher altitudes. The goal of sampling during periods of strong northwesterly
flow was generally met.

AR-005

BALDOCCHI , D.D. Canopy-atmosphere water vapour exchange: Can we scale from a left to a canopy?
Estimation of Areal Evapotranspiration (Proceedings of a Workshop held at Vancouver, B.C., Canada,
August 1987). IAHS Publ. No. 177, 21-41 (1989).

A goal of canopy micrometeorology is to understand mass and energy exchanges at the leaf and canopy
levels and to scale these exchanges from one level to another. This paper discusses the processes
governing evaporation that are amenable to scaling and the environmental and physiological conditions
under which such scaling may be applicable. Factors affecting the scaling of evaporation from a leaf
to a canopy include: the degree of canopy development, the relationship between the aerodynamic and
surface resistance, the degree of coupling between the leaf, plant and canopy and their environment,
and whether or not certain processes are operational or significant at one scale, but are not on
another scale.

AR-006

BALDOCCHI, D.D. Turbulent transfer in a deciduous forest. Tree Physiology 5:357-377 (1989).

Carbon dioxide, water vapor and other passive scalars are physically transferred between a plant
canopy and the atmosphere by turbulence. Intense and intermittent sweep and ejection events transfer
most of the mass. Although the capacity for turbulence to transfer material is high, mass transfer is
coupled to the diffusive source or sink strength of the foliage and soil and is ultimately limited to
a minimum level set up the supply of material, or the demand for it. The diffusive source/sink
strength of material leaving or entering leaves and the soil is a function of many physical,
biological and chemical attributes and processes. These attributes and processes include the amount
and distribution of foliage, the leaf boundary layer and surface resistances, the turbulence and
radiative regimes in the canopy, biochemical and photochemical reactions and the scalar concentrati
field within and above the canopy and inside leaves and the soil. Here we discuss how these factors
contribute to turbulent transfer in a deciduous forest.

AR-007

BALDOCCHI, D.D. Turbulence transfer of sensible heat and momentum in an almond orchard. Preprint
Volume, 19th Conference on Agriculture and Forest Meteorology and the Ninth Conference on
Biometeorology and Aerobiology, Charleston, SC, March 7-10, 1989. American Meteorology Society,
Boston, 186-187 (1989).

No abstract.

AR-008

BALDOCCHI, D.D. Turbulent transfer in a broadleaf forest. Proceedings, Fourth Australasian
Conference on Heat and Mass Transfer, Christchurch, New Zealand, May 9-12, 1989. University of
Canterbury, Christchurch, New Zealand, 9-23 (1989).

Turbulent transfer in a plant canopy is regulated by many structural, physical, physiological and
chemical processes. The processes that contribute to turbulence transfer in a canopy are best
described using a multi-layer framework since turbulence, radiation, thermal and structural properties
vary appreciably with depth inside the canopy. The theory that describes turbulent transfer in a
deciduous forest canopy is discussed and is examined in light of models and measurements.

on

22

AR-009

BALDOCCHI , D.D., B.B. HICKS, and T.P. MEYERS. Measuring biosphere-atmosphere exchanges of
biologically related gases with micrometeorological methods. Ecology 69( 5) : 1331-1340 (1988).

Ecologists are expected to play an important role in future studies of the biosphere/atmosphere
exchange of materials associated with the major biogeochemical cycles and climate. Most studies of
material exchange reported in the ecological literature have relied on chamber techniques.
Micrometeorological techniques provide an alternative means of measuring these exchange rates and are
expected to be used more often in future ecological studies, since they have many advantages over the
chamber techniques. In this article we will provide an overview of micrometeorological theory and the
different micrometeorological techniques available to make flux measurements.

AR-010

BALDOCCHI, D.D., and T.P. MEYERS. A spectral and lag-correlation analysis of turbulence in a
deciduous forest canopy. Boundary -Layer Meteorology 45:32-58 (1988).

The processes influencing turbulence in a deciduous forest and the relevant length and time scales
are investigated with spectral and cross-correlation analysis. Wind velocity power spectra were
computed from three-dimensional wind velocity measurements made at six levels inside the plant canopy
and at one level above the canopy. Velocity spectra measured within the plant canopy differ from
those measured in the surface boundary layer. Noted features associated with the within-canopy
turbulence spectra are: (a) power spectra measured in the canopy crown peak at higher wavenumbers
than do those measured in the sub-canopy trunkspace and above the canopy; (b) peak spectral values
collapse to a relatively universal value when scaled according to a non-dimensional frequency
comprised of the product of the natural frequency and the Eulerian time scale for vertical velocity;
(c) at wavenumbers exceeding the spectral peak, the slopes of the power spectra are more negative than
those observed in the surface boundary layer; (d) Eulerian length scales decrease with depth into the
canopy crown, then increase with further depth into the canopy; (e) turbulent events below crown
closure are more correlated with turbulent events above the canopy than are those occurring in the
canopy crown; and (f) Taylor's frozen eddy hypothesis is not valid in a plant canopy. Interactions
between plant elements and the mean wind and turbulence alter the processes that produce, transport
and remove turbulent kinetic energy and account for the noted observations.

AR-011

BALDOCCHI, D.D., and T.P. MEYERS. Turbulence spectra in a deciduous forest. Preprint Volume, 19th
Conference on Agriculture and Forest Meteorology and the Ninth Conference on Biometeorology and
Aerobiology, Charleston, SC, March 7-10, 1989. American Meteorological Society, Boston, 89-90
(1989) .

No abstract.

AR-012

BATES, J.J., and C. Gautier. Interaction between net shortwave flux and sea surface temperature.
Journal of Applied Meteorology 28:43-51 (1989).

Ocean surface shortwave irradiance estimate, from GOES satellite data computed using the model of
Gautier and Frouin (1985), are compared to in situ measurements from research vessels and buoys during
the frontal air-sea interaction experiment (FASINEX). They reveal that the satellite method
overestimates percentage cloudiness during fractional cloud cover and large satellite viewing angles.
An empirical relationship, based on physical constraints, is developed to correct for the
overestimation of percentage cloud cover under these conditions. Subsequent comparison of the
corrected satellite estimates with in situ measurements show a root-mean-square difference of 10% of

_ o

the daily mean values, with a mean difference between satellite and in situ data of 1-10 W m . From
fields of corrected satellite estimates a cloudiness parameter, called the equivalent cloud amount is
used to examine the influences and feedbacks between the clouds and the sea surface temperatures
(SST's). Correlations between cloud and SST fields show a high day-to-day variability attributed to
the passage of several large-scale frontal cloud bands. The monthly mean correlation, however, shows
large, positive values. This indicates that in the mean there are more clouds and/or clouds with
higher liquid water content over the colder northern waters versus the warmer southern waters. Thus,
the longer-term mean cloudiness field may act in a positive feedback sense, keeping the cold water
from gaining as much heat as the already warmer water.

23

AR-013

BOATMAN, J.F. The role of atmospheric aerosols in modifying the earth's climate. In Environmental
Quality and Ecosystem Stability: Vol VI-A, Environmental Quality, M. Luria, Y. Steinberger, and E.
Spanier (eds.). ISEEQS, Jerusalem, Israel, 331-334 (1989).

The Earth is a planet in radiative equilibrium. Of course, the temperature at which radiative
balance is achieved on Earth may change in response to a change in the sun's energy, the planetary
albedo, the atmospheric transmissivity , or the atmospheric absorption. The concentration of so-called
"greenhouse" gases (CO2, CO, CH^ , N2O, chlorof luorocarbons , and others) is increasing. In the absence
of other changes, this must inevitably lead to a rise in the Earth's radiative equilibrium
temperature. This paper discusses the role of atmospheric aerosols in modifying the Earth's climate.
It describes possible climatic feedback mechanisms between clouds, aerosols, and the sea. A
conceptual mode, based on these feedback mechanisms, is developed. Model predictions of possible
changes in the Earth's climate are discussed with an eye toward new confirmatory research.

AR-014

BOATMAN, J.F. , M. Luria, C.C. VAN VALIN, and D.L. WELLMAN . Continuous atmospheric sulfur gas

measurements aboard an aircraft: A comparison between the flame photometric and fluorescence

methods. Atmospheric Environment 22( 9) : 1949-1955 (1988).

Analyzers that use the flame photometric and pulsed fluorescence techniques measured trace
concentrations of S gas aboard an instrumented aircraft. Concentrations in the range of 1-20 ppbv
were found at various locations over the U.S. East Coast and near Bermuda at altitudes up to 4000 m
(650 mb). The response of both instruments changes significantly with ambient air pressure. In the
case of the fluorescence method, a simple correction is applied to both the zero and span values. For
the flame photometric instrument, the correction is more complicated, less accurate and valid only for
ambient air pressures above 750 mb . A comparison between the two methods, based on several thousand
1-min averages, shows that the flame photometer produced consistently larger concentrations (27%) than
the fluorescence device. Additional comparisons between the continuous monitors aboard the OAA King
Air and similar instruments aboard other aircraft sampling in parallel produced reasonable agreement.
The use of two different techniques for measuring S gas establishes a range in the S gas
concentration. This range is meaningful, since it delineates the contributions of the various
interferences .

AR-015

BOATMAN, J.F., C. VAN VALIN, and L. GUNTER. The relationship between sulfur dioxide and hydrogen
peroxide in the northeastern United States during summer: 3 case studies. Preprints, Sixth Joint
Conference on Applications of Air Pollution Meteorology, Anaheim, CA, January 30 - February 3,
1989. American Meteorological Society, Boston, 48-51 (1989).

Extended abstract.

AR-016

BOATMAN, J.F., D.L. WELLMAN, C.C. VAN VALIN, R.L. GUNTER, J.D. Ray, H. Sievering, Y. Kim, S.W.
WILKISON, and M. Luria. Airborne sampling of selected trace chemicals above the central United
States. Journal of Geophysical Research 94 (D4 ): 5081-5093 (1989).

Field observations during a series of 24 atmospheric sampling flights in winter, spring, summer.

and fall of 1987 provided a preliminary climatology of selected trace chemicals above the central

United States. Flights were along the 91.5°W meridian between 29° and 41°N latitude. The data set

includes continuous measurements of trace gases (O3, SO9 , H9O0 , and NO/NO ) , aerosol number and size

distributions, meteorological variables, and position. Filter samples produced SOf , NOo , and SO9 ,

and trace metal data. Flask air samples yielded methane, hydrocarbon (C^-Cc), and CO concentrations.

Mean concentrations of the measured species at 2450 + 150 m and 1450 + 150 m represent each season.

These data are discussed as functions of season, location, and air mass origin. Solar energy (821-991

- 2 00 — 1

w rn ), temperature (18 -11.6 C) and water vapor mixing ratio (13.5-10.1 g kg ) peaked during summer

at low and high altitude. Carbon monoxide levels 88-160 parts per billion by volume (ppbv) peaked in

spring and were characteristic of the planetary boundary layer during both spring and summer. Methane

concentrations were maximized during spring (1770-1744 ppbv) and fall (1774-1733 ppbv) and minimized

during winter (1747-1730 ppbv) and summer (1736-1705 ppbv) at low and high altitude. Spring had the

highest (21.3-21.4 ppbv) and summer the lowest (7.1-5.3 ppbv) hydrocarbon concentrations at low and

high altitude. Sulfur dioxide concentrations were highest in summer (1.0-23 ppbv) and winter (0.9-1.6

ppbv) at low altitude. S09 concentrations at high altitude had no seasonal trend and averaged less

- 3
than 0.9 ppbv. Sulfate concentrations were highest in summer (3.2-1.7 /ig m ) at low and high

altitude. The average hydrogen peroxide concentration varied by a factor of 16 (0.3-4.8 ppbv) between

winter and summer. Ozone concentrations were between 49 and 70 ppbv and were highest in spring and

24

summer. The ratio of sulfate to sulfur dioxide increased sightly with altitude during winter, spring
and summer. This is probably due to S0£ oxidation in clouds. The ratio of H2O2 to SO2 is >1 during
spring and summer and <1 during winter. This indicates that the conversion of sulfur dioxide to
sulfate by reaction with hydrogen peroxide is not oxidant-llmited during spring and summer.

AR-017

BODHAINE, B.A., and ROSSON, R.M. (eds.) Geophysical Monitoring for Climatic Change No. 16 Summary
Report 1987. Environmental Research Laboratories, Boulder, CO, 110 pp. (1988).

No abstract .

AR-018

Bowne, N.E., J.E. Howes, Jr , F. POOLER, JR., and J.K.S. CHING. Acid model operational diagnostic
evaluation study surface measurements program. Preprints, Sixth Conference on Applications of Air
Pollution Meteorology, Anaheim, CA, January 29 - February 3, 1989. American Meteorological
Society, Boston, 1-4 (1989).

Extended abstract.

AR-019

BRIGGS, G.A. Field measurements of vertical diffusion in convective conditions. Preprints, Sixth
Joint Conference on Applications of Air Pollution Meteorology, Anaheim, CA, January 30 - February
3, 1989. American Meteorological Society, Boston, 167-170 (1989).

Extended abstract.

AR-020

BRIGGS, G.A. Surface inhomogeneity effects on convective diffusion. Boundary-Layer Meteorology
45:117-135 (1988).

It is suggested that convective scaling, with appropriate extensions, provides the most useful

framework for estimating the effects of urban-scale surface inhomogeneities on diffusion in convective

conditions. Strong contrasts in surface heat flux exist between cropland, forest, urban areas, and

water or marshland surfaces. It is argued that a typical fetch for convective turbulence to readjust

to changed heat (or buoyancy) input from the surface below is 2(U/w*)h, where U is the mean wind speed

in the mixing layer, w* is the convective scaling velocity, and h is the mixing depth. In contrast,

the fetch required for wind speed to readjust to new underlying surface roughness is of the order

o
(U/u*) h/2, where u* is the friction velocity. The ratio w*/U is the best index of diffusion rates in

moderately to very unstable conditions. General urban effects on heat flux, h, and U are discussed

separately, then their combined effects on w*/U are estimated. While this ratio can double over a

large city during light winds, its increase is much less for small cities, or during moderate winds.

Finally, some examples of heat flux inhomogeneities causing stationary convective features are

presented. Steady downdrafts associated with these features are of the order of 0 . Aw* , and could

significantly increase surface concentrations from elevated sources.

AR-021

BRODE, R.W. Screening procedures for estimating the air quality impact of stationary sources.
EPA-450/4-88-010, Office of Air Quality Planning, and Standards, Research Triangle Park, NC , 145
pp. (1988).

No abstract.

AR-022

BRODE, R.W., and T.E. PIERCE. SCREEN: A PC-based regulatory screening model for diffusion
estimates. Preprints, Sixth Joint Conference on Applications of Air Pollution Meteorology,
Anaheim, CA, January 30 - February 3, 1989. American Meteorological Society, Boston, 179-182
(1989) .

Extended abstract.

25

AR-023

Brown, M.J., S.P.S. Arya, and W.H. SNYDER. Vertical dispersion from surface and elevated releases.
Preprints, Sixth Joint Conference on Applications of Air Pollution Meteorology, Anaheim,
California, January 29 - February 3, 1989. American Meteorological Society, Boston, 1:163-166
(1989).

No abstract.

AR-024

Butler, J.H., J.W. ELKINS, CM. Brunson, K.B. Egan, T.M. THOMPSON, T.J. CONWAY, and B.D. Hall.
Trace gases in and over the West Pacific and East Indian Oceans during the El Nino-Southern
Oscillation event of 1987. NOAA DR ERL ARL-16 (PB89-159685) , 104 pp. (1988).

Five trace gases in the surface water and atmosphere of the West Pacific and East Indian Oceans
were measured by automated gas chromatography from May through July 1987. The data included more than
1000 measurements each of N20, Fll and F12 in the surface water and in the atmosphere, and about 2000
measurements each of CH^ and CH9 in the surface water and atmospheric boundary layer of the West
Pacific. In addition, over 600 measurements of dissolved NnO were obtained from hydrocasts made along
the entire 45,000 km cruise track. Data from this cruise are presented here in graphic and tabular
form, along with detailed discussions of the methods used in analyzing the samples and reducing the
data, and a brief summary of the results and their significance. Also included are results from
laboratory tests of a new, automated headspace technique for dissolved N2O and laboratory tests of the
Weiss equilibrator . Data from the equilibrator tests were used to develop a mathematical model of its
performance .

AR-025

Butler, J.H., J.E. Pequegnat, L.I. Gordon, and R.D. Jones. Cycling of methane, carbon monoxide,

nitrous oxide, and hydroxylamine in a meromictic, coastal lagoon. Estuarine . Coastal and Shelf

Science 27:181-203 (1988).

The vertical distributions of methane, carbon monoxide, nitrous oxide, and hydroxylamine were
measured in a seasonally stratified, coastal lagoon in northern California. The production of gases
was estimated from mass-balance calculations where possible, including considerations of diffusion and
microbial oxidation. From late spring through most of the summer the lagoon remained oligotrophic ,
with biological activity concentrated near the pycnocline and the sediments. Methane, attaining high
levels of super-saturation, was produced mainly in the sediments and in the metalimnion. Its
subsequent fate was governed primarily by transport, but also by microbial activity. Carbon monoxide
also reached high concentrations, but, having a turnover time of a few hours, was regulated almost
entirely by micro-organisms. Nitrous oxide production was evident near the halocline throughout most
of the study, but was apparent near the sediments only in the spring. Throughout the summer, N2O in
the hypolimnion was consumed in the sediments, presumably by denitrif ication . Hydroxylamine was
present in the spring when nitrous oxide was produced, but absent during the summer when nitrous oxide
was being consumed. Nitrous oxide distribution, like that of methane, was governed by diffusion and
microbial processes, but hydroxylamine, with estimated turnover times of only a few hours, was
probably regulated by microbes and in situ chemical oxidation.

AR-026

Castro, I. P., W.H. SNYDER, and R.E. LAWSON, Jr. Wind direction effects on dispersion from sources
downwind of steep hills. Atmospheric Environment 22( 10 ): 2229-2238 (1988).

A previous experimental study of the nature of c'ispersion from point sources downwind of
three-dimensional hills of various crosswind aspect ratio (spanwise breadth/height) has been extended
to the case when the approaching wind is not normal to the spanwise axis of the hill. Surface
concentration patterns resulting from sources placed at various heights have been examined, with
attention limited to cases which led to the greatest concentration for the normal wind direction
( 0=0 ). Sufficient data have been obtained to determine the terrain amplification factor (i.e., the
ratio of the maximum ground-level concentration in the presence of the hill to that in its absence)
for various wind directions, hills and source heights, and also to find how the ground-level
concentration at the position of its maximum value for 0=0 varies with wind direction. This allows one
to use wind tunnel data to estimate the effects of long-time-scale wind meander, assuming that
wind-tunnel averages are equivalent to full-scale averages of, say, 15 minutes. It is demonstrated
that in some circumstances the amplification factor (A) for a particular source position actually
increases with small changes in wind direction. In general, however, there is a monotonic decrease in
A as 6 from zero, which is most rapid for hills of small aspect ratio. In the case of wider hills, it
is possible for the amplification factor to be reduced below unity for large 6.

26

AR-027

Chimonas, G. , and C.J. NAPPO. Wave drag in the planetary boundary- layer over complex terrain.
Boundary-Layer Meteorology 47:217-232 (1989).

The concepts of mountain-induced wave drag are applied to the smaller scale problem of the boundary
layer over complex terrain. It is found that the Reynolds stress and surface drag caused by surface-
generated waves can be at least as large as those conventionally associated with turbulence.
Conditions in which wave effects are important are identified.

AR-028

CHING, J.K.S. Simulating vertical transport and transformation of mixed layer pollutants by
non-precipitating convective cumulus clouds. Preprints, Sixth Joint Conference on Applications of
Air Pollution Meteorology, Anaheim, CA, January 30 - February 3, 1989. American Meteorological
Society, Boston, 19-22 (1989).

Extended abstract.

AR-029

CLARK, T.L., R.L. DENNIS, and S.K. Seilkop. Re-examination of interim estimates of annual sulfur
dry deposition across the eastern United States. EPA/600/4-89/026 , Atmospheric Research and
Exposure Assessment Laboratory, Research Triangle Park, NC, 34 pp. (1989).

During the summer of 1987 annual amounts of sulfur dry deposition were first estimates, heretofore
termed interim estimates since they were expected to be superceded in the near future, were derived
from predictions of the Regional Acid Deposition Model (RADM) adjusted using the empirical data from
two monitoring networks. Since that time, additional years of empirical data have become available
and a portion of the previously available empirical data have been superseded. Consequently, the
process of estimating annual amounts of sulfur dry deposition was repeated to determine whether these
interim estimates should be revised, and if so by how much. This study concludes that the interim
estimates appeared to be too low by 13% and recommends that the interim estimates be systematically
increased by the same amount. A comparison of the revised estimates to empirically-derived sulfur dry
deposition amounts suggests that there is one systematic error in the revised estimates. Adjusted
RADM predictions of dry deposition tend to be biased low in the most significant source regions (where
at least 2300 ktonnes SO^/yr are emitted within 80 km of the site). Conversely, in locations farther
removed from significant sources (81-160 km) there is evidence that the estimates are biased high.
However, in general, sulfur dry deposition estimates from adjusted model predictions are within +602
of the empirical data.

AR-030

CLARK, T.L., S. Seilkop, and R.D. Cohn. Protocol for the evaluation of long-range transport and
diffusion models using 1987 ANATEX data. Preprints, Sixth Joint Conference on Applications of Air
Pollution Meteorology, Anaheim, CA, January 30 - February 3, 1989. American Meteorological
Society, Boston, 86-89 (1989).

Extended abstract.

AR-031

CLAWSON, K.L. Irrigation scheduling by remote sensing. Proceedings, 31st Annual Symposium, Idaho
Academy of Science, Idaho Falls, ID, April 13-15, 1989, pp. 27 (1989).

No abstract.

AR-032

CLAWSON, K.L., C.R. DICKSON, and G.E. START. High-tech application of balloons in pollution
meteorology: A transport and diffusion measurement tool. Proceedings, 31st Annual Symposium,
Idaho Academy of Science, Idaho Falls, ID, April 13-15, 1989, pp. 32 (1989).

No abstract.

27

AR-033

CLAWSON, K.L., R.D. Jackson, and P.J. Pinter, Jr. Evaluating plant water stress with canopy
temperature differences. Proceedings, 1988 Annual Meetings, American Society of Agronomy, Crop
Science Society of America, Soil Science Society of America, Anaheim, CA, November 27-December 2,
1988, pp. 15 (1988).

No abstract.

AR-034

DELUISI, J.J., D.U. Longenecker, C.L. Mateer, and D.J. Wuebbles . An analysis of northern
middle-latitude Umkehr measurements corrected for stratospheric aerosols for 1979-1986. Journal of
Geophysical Research 94 (D7 ) : 9837-9846 (1989).

Umkehr observations of ozone profile for five northern middle-latitude Dobson spectrophotometer
stations are objectively corrected for stratospheric aerosol during the period 1979-1986. The
corrections are done by means of theoretical calculations, using observations of stratospheric ozone
and aerosols. Stratospheric ozone and aerosol profile data to correct the Umkehr measurements are
derived from ozonesonde observations and observations provided by five lidar stations in the northern
hemisphere middle latitudes. Optical properties of the stratospheric aerosol existing during and
after the major injection by El Chich6n are derived from surface and aircraft photometric observations
and in situ aircraft observations of aerosol size distribution. The corrected Umkehr data display
some noteworthy ozone reductions in the upper stratosphere. The magnitude of these reductions does
not seem to be extraordinary when considering features seen in long-term Umkehr data. However, the
rates may be extraordinary, for example, in layers 8 and 9, in which decreases in ozone concentration
during 1979-1986 were 9% and 15/E respectively, using corrected data.

AR-035

DENNIS, R.L., J.N. McHenry, and S.K. Seilkop. A sulfur dioxide emissions sensitivity study
conducted with the RADM engineering model. Preprints, Sixth Joint Conference on Applications of
Air Pollution Meteorology, Anaheim, CA, January 30 - February 3, 1989. American Meteorological
Society, Boston, 30-33 (1989).

Extended abstract.

AR-036

DENNIS, R.L., J.N. McHenry, R.E. Stogner, and J.S. Chang. A source-receptor analysis comparing
estimates from the RADM engineering model with estimates from the Lagrangian RELMAP model.
Preprints, Sixth Joint Conference on Applications of Air Pollution Meteorology, Anaheim, CA,
January 30 - February 3, 1989. American Meteorological Society, Boston, 36-39 (1989).

Extended abstract.

AR-037

DIAZ, H.F., J.T. Andrews, and S.K. Short. Climate variations in northern North America (6000 BP to
present) reconstructed from pollen and tree-ring data. Arctic and Alpine Research 21(l):45-59
(1989).

The characteristic anomaly patterns
tree-ring indices (0-300 yr ) and fossi
data base consists of 245 climate stat
and 39 fossil pollen sites. A few are
generally consistent patterns during a
surface changes are related to the red
the planetary-scale waves and to north
zone where the largest changes occur i
Arctic and Pacific airstreams. Establ
concomitant changes in atmospheric cir
paleoclimatic signals are indeed relat

of modern surface temperature and precipitation are compared to
1 pollen (0-6000 yr) variations in northern North America. The
ions, 55 tree-ring chronologies, 153 modern pollen collections,
as exhibit relatively high climatic sensitivity, displaying
lternate warm and cold periods, regardless of time scales. The
istribution (i.e., changes in the mean position and strength) of
-south shifts in the mean boundary of the Arctic Front. The
s typically located along the mean present-day boundary between
ishing plausible relationships between vegetation responses and
culation patterns increases our confidence that the
ed to large-scale circulation changes.

AR-038

DIAZ, H.F., R.S. Bradley, and J.K. Eischeid. Precipitation fluctuations over global land areas
since the late 1800's. Journal of Geophysical Research 94 (Dl ): 1195-1210 (1989).

28

An analysis of southern hemisphere land precipitation records for the last 100 years indicates an
increase in mean annual precipitation since the 1940's, with positive anomalies, compared to the
1921-1960 reference period, occurring during approximately the last 15 years in all seasons except
southern summer (December-February). There is little or no temporal correlation with corresponding
precipitation indices for the northern hemisphere (Bradley et al., 1987a). Furthermore, while trends
in the northern hemisphere temperate regions were opposite those in the northern tropical areas, in
the southern hemisphere both zones exhibit similar trends. The change toward higher precipitation in
middle latitudes begins about 10 years earlier in the northern than in the southern hemisphere (in the
1940's versus the 1950's, respectively). For the northern hemisphere, the overall linear trend from
1890 to 1986 is not significantly different from zero. However, a decline is evident since the
1950's, primarily due to lower rainfall amounts south of about 30°N. Globally, the trend is toward
higher values in annual and seasonal precipitation, except for the boreal summer season (June-August).
Most of the observed increase, however, took place from about 1940 to the mid- 1950's, after which
time the record has displayed little overall trend, instead exhibiting decade-long fluctuations. The
observations are only broadly consistent with zonally averaged profiles of precipitation changes
derived from general circulation model (GCM) simulations of climate using doubled atmospheric CCU
concentrations, although we note that there is considerable variability in precipitation response from
one model to another. One possible discrepancy occurs in the northern hemisphere tropics, where most
GCMs indicate relatively little change in precipitation in response to CO? doubling (Gutowski et al. ,
1988), whereas in the past couple of decades there has been a major decline in rainfall in this
region. The overall increase in southern hemisphere precipitation is consistent with marine
observations for the tropics and extratropical southern latitudes, which show an increase in sea
surface temperature of about 0.3°C since the mid-1970's and an increase in surface wind speed of
between 0.4 and 0.8 m/s since 1950. The potential increase in evaporation could have contributed to
the observed rainfall trends. We note, however, that precipitation in tropical land areas is strongly
influenced by the phases of the El Nino/Southern Oscillation (ENSO), being generally lower during warm
events and higher during the opposite cold phase. The effects of the strong ENSO warm events of
1982-1983 and around 1940 are clearly evident in the global record, as are precipitation peaks during
cold years, such as 1974-1975 and 1954-1956.

AR-039

Dobosy, R.J., K.S. Rao, J.W. Przybylowicz , R.M. ECKMAN , and R.P. HOSKER. Mass and momentum balance
in the Brush Creek drainage flow determined from single-profile data. Journal of Applied
Meteorology 28(6) : 467-476 (1989).

Fluxes and flux-divergences of mass and momentum in Brush Creek Valley, computed from measurements
taken by Tethersondes and Doppler sodars in the 1984 ASCOT experiment, are presented. Estimates of
mass influx from open sidewalls in Brush Creek, derived from concurrent tower measurements, are also
given. Mass and momentum fluxes calculated from single-profile data were within a factor of 1.5 of
those obtained by integrating Doppler lidar data. Flux-divergences for budget calculations should be
derived from a Doppler lidar or equivalent remote sensor data, because single-profile measurements
were found to have sampling errors which are too large for reliable flux divergence estimates. The
mass influx from the sidewalls was insufficient to account for the mass flux-divergence in the main
valley. This imbalance in the drainage flow mass budget is speculated to be due to inflow from the
small box-canyon tributaries, rather than from subsidence of air above the main valley.

AR-040

DOLL, D.C., T.E. PIERCE, and N.C. POSSIEL. Regional ozone modeling in the northeastern United
States: Selection of meteorological episodes. Preprints, Sixth Joint Conference on Applications
of Air Pollution Meteorology, Anaheim, CA, January 30 - February 3, 1989. American Meteorological
Society, Boston, 40-43 (1989).

Extended abstract.

AR-041

DONNELLY, R.F. The solar electromagnetic radiation flux study (SERFS). STP Newsletter 88-1, World
Data Center A for Solar Terrestrial Physics, Boulder, CO, 34-36 (1988).

No abstract.

AR-042

DONNELLY, R.F. The solar UV Mg II core-to-wing ratio from the N0AA9 satellite during the rise of
solar cycle 22. Advances in Space Research 8(7):77-80 (1988).

29

The Solar Backscatter Ultraviolet (SBUV/2) instrument on the N0AA9 satellite monitors daily the
solar UV spectral irradiance in the Mg II h and k lines. The core-to-wing ratio R(MgIIc/w) is
presented for 27 May 1986 through 31 May 1988. R(MgIIc/w) has a minimum in both 27-day and 81-day
running averages in early Jan. 1987 with a secondary minimum in late Aug. 1986. Strong 27-day
solar-rotational variations peaked in Oct. 1986, April and July 1987, and April 1988. The solar-cycle
22 rise in rotational minima started in Feb. 1987 and increased to a more rapid rise in Nov. 1987
through May 1988. The rotational peak of April 1988 was 4.4% higher than the solar cycle minimum
27-day average, which is a little less than half the decline in R(MgIIc/w) from NIMBUS7 from solar
maximum to minimum during solar cycle 21.

AR-043

DONNELLY, R.F. Solar UV variability. MAP Handbook. Vol 29, Proceedings, IAGA Symposium on Solar
Activity Forcing of the Middle Atmosphere, Czechoslovakia, April 4-7, 1989, J. Lastoricka (ed.).
SCOSTEP Secretariat, University of Illinois, Urbana, 1-8 (1989).

No abstract.

AR-044

DRAXLER, R.R. HYBRID single-particle Lagrangian integrated trajectories (HY-SPLIT): Model
description. NOAA TM ERL ARL-166 (PB89-127591 ) , 23 pp. (1988).

The algorithms and equations used in the development of a long-range transport and dispersion model
are presented. The model calculation methods are a hybrid between Eulerian and Lagrangian approaches.
A single pollutant particle represents the initial source. Advection and diffusion calculations are
made in a Lagrangian framework. However, meteorological input data can either be gridded from
rawinsonde observations or archived from the output of an Eulerian primitive equation forecast model.
As the dimensions of the initial particle diffuse into regions of different wind direction or speed,
the single particle is divided into multiple particles to provide a better representation of the more
complex flow field. Air concentrations are calculated on a fixed three-dimensional grid by
integrating all particle masses over the sampling time.

AR-045

DRAXLER, R.R. Overview and preliminary results from the Across North America Tracer Experiment
(ANATEX). Preprints, Sixth Joint Conference on Applications of Air Pollution Meteorology, Anaheim,
CA, January 30 - February 3, 1989. American Meteorological Society, Boston, 82-85 (1989).

Extended abstract.

AR-046

DRAXLER, R.R., and J.L. HEFFTER (eds.). Across North America Tracer Experiment (ANATEX) Volume I:
Description, ground-level sampling at primary sites, and meteorology. NOAA TM ERL ARL-167 (PB89-
156137), 83 pp. (1989).

ANATEX was conducted during the first 3 months of 1987 with routine emissions of tracers,
regardless of the synoptic conditions, from two sources separated by about 1000 km. Ground-level
tracer measurements were made at "primary" sites up to 3000 km from the sources and at "remote" sites
for hemispheric coverage. Tracer measurements were also made from aircraft flying within about 500 km
of the sources and on towers located along a ground-level sampling arc (Volumes II and III). Three
months of sampling data provide a comprehensive data base for evaluating the accuracy and reliability
of the transport and dispersion aspects of long-range models. Since a different and unique tracer was
released from each source site, the sampling data can be used to demonstrate the ability of models to
separate the effects of local and distant sources. Further, because these data are on the regional
scale, covering the entire eastern United States and Canada, it is possible to characterize the
meteorological influences on regional transport. ANATEX was conducted between January 5, 1987, and
March 29, 1987. Three different tracers totaling about 7500 kg were released during this period.
There were 33 releases of the different tracers from each of two sites: Glasgow, Montana (GGW) and
St. Cloud, Minnesota (STC). Tracer was routinely released every 2.5 days, alternating between
0500-0800 GMT and 1700-2000 GMT. Thus, a unique feature of ANATEX is that it was conducted during a
wide variety of meteorological conditions with both daytime and nighttime tracer releases.
Supplemental rawinsondes were taken at 0600 and 1800 GMT during the entire ANATEX period, near both
tracer sources and at four additional sites within about 500 km. Ground-level air samples of 24-h
duration were taken at 77 sites for 84 days starting January 5. Most of the sites were located near
rawinsonde stations east of 105°W and between 26°N and 55"N and along two arcs at 1000 and 1600 km
from GGW. Additional long-term weekly samples were taken at 12 remote sites between San Diego,
California and Pt . Barrow, Alaska and between Norway and the Canary Islands. Short-term 6-h samples

30

were collected at ground-level and 200 m along an arc of five towers between Tulsa, Oklahoma and Green
Bay, Wisconsin. Aircraft sampling near GGW and STC was used to establish the initial tracer path, as
the ground-level sampling network was non-existent or too widely spaced near the source locations.

AR-047

DUTTON , E.G., R.S. Stone, and J.J. DELUISI . South Pole surface radiation balance measurements
April 1986 to February 1988. NOAA DR ERL ARL-17 (PB89-224018) , 49 pp. (1989).

Measured radiation budget (or balance) components with daily time resolution are presented for the
U.S. South Pole Station. The measurement project and the data reduction and summary procedures are
described. Useful plots and tables are used to present the data in final form. Additionally,
meteorological data, which could be useful in interpretation of the radiation measurements, are
included. It is seen that, during the three peak solar months, there is a radiative gain of about 20
W m by the surface (except for December 1987 where a small loss was recorded) whereas during the
dark months there is an average loss of about 15 to 20 W m . Many transitory events of one to
several days duration are also seen in the record. Radiation budget measurements are continuing at
the site on an ongoing basis in an effort to establish a climatological record.

AR-048

ECKMAN, R.M. The suitability of different wind-field techniques for an emergency-response
dispersion model. Proceedings, ANS Topical Meeting on Emergency Response - Planning, Technologies,
and Implementation, Charleston, SC , September 26-28, 1988. CONF-880913, UC-610, Paper 4-4 (1988).

A dispersion model in an emergency-response system must use some technique to generate an accurate
wind field from limited measurements. Most wind-field techniques fall into four categories:
interpolation, mass-conservative, diagnostic, and dynamic techniques. In this extended summary, the
suitability of these categories for emergency response is discussed. For a dispersion model that must
provide real-time dispersion estimates during an accident, spatial interpolation will be the most
appropriate technique. For more complex models that are used in emergency-response planning and
post-accident assessments, either a mass-conservative or diagnostic technique should be suitable.

AR-049

ECKMAN, R.M., and R.J. Dobosy. The suitability of diffusion and wind-field techniques for an
emergency-response dispersion model. NOAA TM ERL ARL-171, 28 pp. (1989).

Most atmospheric dispersion models have two separate components: a diffusion component that
simulates the dilution of a contaminant by turbulence, and a wind-field component that transports the
contaminant away from the source. Many modeling techniques have been developed for each of these
components. This report examines the suitability of these modeling techniques for a near-field
emergency response model that must simulate the dispersion of a hazardous contaminant out to several
kilometers from a source. For an emergency response model that must provide real-time dispersion
estimates (a Class A model), a puff model is the most appropriate diffusion technique, and simple
interpolation is the most appropriate wind-field technique. For more-complex models that are used for
emergency planning and post-accident assessments (Class B models), a puff model is still suitable, but
the wind-field techniques should be able to remove spurious velocity divergence and channel the wind
flow in complex terrain.

AR-050

EDER, B.K. An examination of SO^ precipitation patterns over the eastern United States: 1981-1986.

Preprints, Sixth Joint Conference on Applications of Air Pollution Meteorology, Anaheim, CA,

January 30 - February 3, 1989. American Meteorology Society, Boston, 25-29 (1989).

Extended abstract.

AR-051

EDER, B.K., L.E. TRUPPI , and P.L. FINKELSTEIN. A climatology of temperature and precipitation

variability in the United States. EPA/600/3-89/025, Atmospheric Research and Exposure Assessment

Laboratory, Research Triangle Park, NC , 43 pp. (1989).

This paper examines the seasonal and annual variance and standardized range from temperature and
the seasonal and annual coefficient for variation and normalized standardized range for precipitation,
on a climatic division level for the contiguous United States for the period 1895 to 1985.
Examination of the temperature variance reveals a continentality phenomenon in which the largest
variances occur in the upper midwest section of the country, while the smallest variances are

31

generally found in coastal regions along the West Coast, the Gulf Coast and southeastern states. The
winter season displays roughly twice the amount of seasonal variance as does spring, and roughly four
times that of summer or autumn. Analysis of the standardized temperature range supports the
continentality phenomenon; however, the transitional seasons, spring and autumn, display the largest
amount of within season variability with winter and summer displaying the least amount. Examination
of the coefficient of variation for precipitation depicts a propensity for the largest seasonal and
annual variation to occur over the southwestern states from Texas to California. Conversely, the
smallest coefficient of variations are found over the northeastern sections of the country from New
England into the mid-Atlantic and Great Lakes states. Analysis of the seasonal and annual
standardized precipitation range reveals that the pattern mimics the coefficient of variation
patterns, but does however, exhibit less of a gradient, resulting in a smoother pattern. Areas of
greater than normal seasonal and annual precipitation ranges include the southwestern states from
Texas to California, while areas of less than normal ranges include the northeastern and Ohio River
Valley states.

AR-052

Eischeid, J.K., S.J.S. Khalsa, and K.M. WEICKMANN. Comparisons between the 30-60 day oscillations
in the tropics and the varying frequency of atmospheric angular momentum oscillations. Preprints,
18th AMS Conference on Hurricanes and Tropical Meteorology, San Diego, CA, May 16-19, 1989.
American Meteorological Society, Boston, 129-130 (1989).

Extended abstract.

AR-053

ELLIOTT, W.P. (ed). The statistical treatment of C02 data records. NOAA TM ERL ARL-173, 131 pp.
(1989) .

This collection of papers is an outgrowth of a meeting concerned with the treatment of carbon
dioxide data held in Hilo, Hawaii, 24-26 March, 1988. A small group of scientists gathered to discuss
various methods of extracting from raw CO, data information on the background concentration in the
atmosphere. The meeting was sponsored by the National Oceanic and Atmospheric Administration (NOAA)
and the World Meteorological Organization (WMO) . While the subject of the meeting was the treatment
of COo data, some of the considerations should be applicable to any trace gas measurement program.
These programs will encounter many of the same problems, as well as others of their own.

AR-054

ESKRIDGE, R.E., B. Lamb, and E. Allwine. Analysis of the wind and plume dispersion in a
residential neighborhood. Preprints, Sixth Conference on Applications of Air Pollution
Meteorology, Anaheim, CA, January 29 - February 3, 1989. American Meteorological Society, Boston,
146-149 (1989).

No abstract.

AR-055

Fryrear, D.W., J.E. Stout, and D.A. GILLETTE. Instrumentation for wind erosion. Proceedings, 1988
Wind Erosion Conference, Lubbock, TX , April 11-13, 1988. Sponsored by Texas Tech University,
Lubbock, 118-132 (1988).

Reliable field measurement of soil losses due to wind erosion have not been possible because of the
lack of satisfactory equipment. Many wind erosion samplers have been developed; but some require
accessory equipment to operate, some are difficult to construct and maintain, and some lack the
capacity or efficiency to be suitable for field use. Within the last five years new equipment has
been designed and extensively tested that will permit the measurement of soil movement across and
above eroding soil surfaces. These new samplers are efficient, will operate under extremely adverse
conditions, and can provide total soil movement information both horizontally and vertically over
eroding surfaces. Another new wind erosion instrument will measure momentum of eroding material at
specified levels as well as at the instant threshold conditions that are exceeded in the field.
Laboratory and portable wind tunnels have been used to study the wind erosion process and to test wind
erosion control practices. Laboratory tunnels permit complete control of many factors, but some
tillage and natural weathering conditions cannot be duplicated under laboratory conditions. Portable
wind tunnels will permit the testing of various practices under natural weathering conditions, but
there is a limit in the height of plant material that can be tested. Scientists must recognize the
limitations of any wind tunnel when trying to duplicate field boundary conditions.

32

AR-056

Galloway, J.N., R.S. ARTZ, U. Dayan, and J.F. BOATMAN. WATOX-85: An aircraft and ground sampling
program to determine the transport of trace gases and aerosols across the western Atlantic Ocean.
Atmospheric Environment 22( 11 ): 2345-2360 (1988).

This paper presents an overview of the design and results of WATOX-85, an intensive measurement
program of a variety of trace chemicals in the atmosphere of the western North Atlantic Ocean. WATOX-
85 is a component of the Western Atlantic Ocean Experiment (WATOX), which is designed to determine the
fate and flux of several types of chemical compounds that are advected eastward from North America to
the Atlantic Ocean atmosphere. WATOX-85 occurred during the period February-April 1985. Measurements
of the composition of gases, aerosols, and precipitation were performed at ground level at Lewes,
Delaware and High Point, Bermuda and in the boundary layer and free troposphere off the east coast of
Virginia and around the island of Bermuda. The above ground measurements were performed with a
Beechcraft King Air aircraft. Atmospheric sampling was focused on times when the flow was westerly,
generally just after cold front passages. In the gas phase SO2 , HNO3 , NO, NOx, HCHO, O3 , CO, C2-C4
HCs and Rn were measured. SO^~, NO3 , NH^, trace metals, HCOOH, CA2+, Mg2 , NA and chlorinated HCs
were analyzed in the precipitation and aerosols samples that were collected.

AR-057

GILLETTE, D.A. Estimation of dust production by wind erosion, for use by the National Acid
Precipitation Assessment Program. Proceedings, 1988 Wind Erosion Conference, Lubbock, TX, April
11-13, 1988. Sponsored by Texas Tech University, Lubbock, 188-197 (1988).

No abstract.

AR-058

GILLETTE, D.A. Threshold friction velocities for dust production for agricultural soils. Journal
of Geophysical Research 93(D10 ): 12, 645-12 , 662 (1988).

Threshold velocities for agricultural soils were measured for a wide variety of conditions in order
to quantify a model of dust emissions for the United States. These measurements supplement threshold
velocities for arid and semiarid soils (Gillette, et al., 1980, Gillette, et al., 1982). The model
will be used in precipitation acid/base balance studies. The soils were organized according to
surface texture, organic matter content, and calcium carbonate composition. They were further
organized by the physical surface states; smooth-loose, cloddy, and crusted. Sandy soils were found
to have the lowest threshold velocities and were the least affected by wetting (precipitation). Loamy
soils were found to have the highest threshold velocities and were the most affected by precipitation
wetting.

AR-059

GILLETTE, D.A., and K.J. HANSON. Spatial and temporal variability of dust production caused by
wind erosion in the United States. Journal of Geophysical Research 94(D2) . '2197-2206 (1989).

Variability of model dust emissions by wind erosion was tested for sensitivity to variations of
wind speed in the United States for a 31-year period (1948-1978) and for a wide range of threshold
velocities that arise from differing precipitation scenarios, from drought to abundant rainfall.
Results showed that dust production increased about an order of magnitude when threshold velocities
were changed from those appropriate for abundant rainfall to those appropriate for drought. About the
same range of variability for dust production was seen in the model results when soil conditions and
land use were held constant and U.S. wind data for 1948-1978 were used. Maximum dust production for
the United States occurs in the spring, and minimum dust production occurs in the summer. Maximum
model dust production for a 1-year period occurred in the early 1950's and early 1970's, when a U.S.
wind record for 1948-1978 was used. The location of maximum dust production is the area including the
panhandles of Texas and Oklahoma and some surrounding areas.

AR-060

GILLETTE, D.A., and R. Passi. Modeling dust emission caused by wind erosion. Journal of
Geophysical Research 93 (DP : 14 . 233-14 . 242 (1988).

A model for the estimation of total dust production for the United States is discussed. Its
primary use will be in the inventory of alkaline elements for use in acid/base balance studies of
atmospheric precipitation by the National Acid Precipitation Assessment Program (NAPAP). The model is
a summation of the expected dust production caused by wind erosion for individual sampling units of
the detailed soil and land use inventory of the National Resources Inventory compiled by the U.S.
Department of Agriculture, the model is based on a dust emission function derived theoretically and

33

verified by experiment. An extremely important parameter is the threshold velocity for dust
production; this parameter is dependent on effects of vegetative residue, roughness of the soil, live
standing plants, soil texture and the effect of atmospheric precipitation. Experimentation has
supplied values of this parameter for the calculation. Wind data used in the model were obtained from
the Wind Energy Resource Information System (WERIS). The model was calibrated with dust emission data
for the area, including the panhandles of Texas and Oklahoma.

AR-061

GODOWITCH, J.M. Evaluation and sensitivity analyses results of the MESOPUFF II model with CAPTEX
measurements. EPA/600/3-89/056, Atmospheric Research and Exposure Assessment Laboratory, Research
Triangle Park, NC , 99 pp. (1989).

The MESOPUFF II regional Lagrangian puff model has been evaluated and tested with the
Cross-Appalachian Tracer Experiment (CAPTEX) data base. The model was applied to the sic full-scale
CAPTEX episodes in order to simulate the tracer plume formed from the 3-hour release of an inert,
non-depositing perf luorocarbon tracer gas from either one of two selected sites. Surface tracer
measurements were made at 3 hour or 6 hour intervals over an extensive sampling network of arcs
downwind to 1100 km in the northeastern U.S. and southeastern Canada. An operational evaluation was
conducted by exercising the model transport and dispersion components with all default features set
according to the user's guide. Transport in the model is simulated by a mixed-layer averaged wind
field and an upper level wind field averaged from the mixing height to 700 mb level. Puff growth
within 100 km downwind is governed by horizontal and vertical dispersion parameters derived from
expressions fitted to the standard PGT curves, while time dependent formulas are applied at greater
distances. Model performance was quantitatively determined from standard statistical measures of
difference and correlation between modeled and observed tracer concentrations paired in time and
location. The model over-predicted peak and mean concentrations, whether paired in time and/or
location. Modeled mean concentrations were within a factor of two of observed mean values in four of
the experiments. The over-predictions are primarily attributed to an underestimation of vertical
dispersion during neutral stability conditions which were specified during the afternoon hours after
releases. Graphical maps and comparative tests between observed and modeled concentration pairs
revealed that spatial displacements between the observed and modeled plumes contributed to the large
scatter and low correlations found in the evaluation statistics. Analysis of plume centroid positions
revealed that the greatest changes in the separation of the observed and modeled plumes occurred
during the nocturnal periods. Revisions are suggested to better treat this source type in the model.
Diagnostic model test results with optional wind fields in the model (e.g. surface, 850 mb single
level wind fields) and various dispersion options are compared to those from the operational model and
the observed data. A surface wind field transported the modeled plume considerable slower and
generally to the left of the observed plume while the single level 850 mb wind field consistently
shifted the modeled plume to the right (clockwise) of the actual plume location. Model results with
the mixed-layer averaged wind field displayed the best overall performance in comparisons of the
position and time of impact of the peak concentration with the observed plume values at the 300 km
arc. The 24-h peak and plume average concentration results from model test runs, which focused on
different options and variations in key parameters of the dry deposition and chemical transformation
modules, are compared to base case values. All model runs were performed with SO„ emissions from a
realistic elevated point source. Peak SO? concentrations showed negligible variations when deposition
or chemical transformation were omitted, however, mean SO£ concentrations were more sensitive than SO2
by variations in the surface resistance and by changes in parameters controlling the chemical
transformation rate.

AR-062

GODOWITCH, J.M. Evaluation and testing of the MESOPUFF II model system with CAPTEX measurements.

Preprints, Sixth Joint Conference on Applications of Air Pollution Meteorology, Anaheim, CA,

January 30 - February 3, 1989. American Meteorological Society, Boston, 56-59 (1989).

Extended abstract.

AR-063

HALTER, B.C., J.M. HARRIS, and T.J. CONWAY. Component signals in the record of atmospheric carbon
dioxide concentration at American Samoa. Journal of Geophysical Research 93 (D12 ) : 15 , 914-15 , 918
(1988) .

Variability in atmospheric CO2 concentration over periods of 1-5 days at Cape Matatula, American
Samoa, was studied. The variability was found to be the result of the alternating influences of three
air mass source regions. Partitioning of Samoa CO2 data according to these air mass source regions
revealed annual cycles in the partitioned data sets corresponding to those of the tropical South
Pacific, the mid-latitude southern hemisphere, and the tropical North Pacific regions.

34

AR-064

Hansen, A.D.A., B. A. BODHAINE, E.G. DUTTON, and R.C. Schnell. Aerosol black carbon measurements
at the South Pole: Initial results, 1986-1987. Geophysical Research Letters 15(11) : 1193-1196
(1988).

In December 1986 an aethelometer was installed at the NOAA/GMCC South Pole Observatory to measure
concentrations of the combustion effluent trace species aerosol black carbon (BC) with a time
resolution of one hour. We present data covering a 1-yr period from December 1986 through November
1987. The hourly data show infrequent events in which the concentrations increased greatly for
periods of a few hours. We attribute these events to local contamination and identified them as such
in the database. The remaining background data then yield daily average BC concentrations generally
ranging from 50 pg m to 5 ng m , with a minimum in the early austral winter. The results imply
long-range transport of this aerosol species, and suggest a minimum value of the order of 10 pg m"3
for its global background concentration.

AR-065

HANSON, K. , G.A. Maul, and T.R. Karl. Are atmospheric "Greenhouse" effects apparent in the
climatic record of the contiguous U.S. (1895-1987)? Geophysical Research Letters 16(l):49-52
(1989).

The temperature and precipitation climate records for the United States have been examined. These
records consist of area-averages across the contiguous United States and northern plains. They are
based on as many as 6,000 stations. Time series of these data were tested for constancy of the mean
using the Spearman rank test and two-phase regression. Test results indicate that overall trends are
near zero. The only evidence for a long-term trend is in Fall precipitation for the contiguous United
States. This trend appears to result from higher fall precipitation during the period 1970-1987
compared to the remainder of the period (1895-1969).

AR-066

HEFFTER, J.L. ANATEX measured concentration uncertainty considerations in model evaluation.
Preprints, Sixth Joint Conference on Applications of Air Pollution Meteorology, Anaheim, CA,
January 30 - February 3, 1989. American Meteorological Society, Boston, 90-96 (1989).

Extended abstract.

AR-067

HICKS, B.B. Assessment of atmosphere/ocean flux measurement techniques and capabilities. The
Ocean as a Source and Sink for Atmospheric Trace Constituents, Final Report of SCOR Working Group
72, Unesco, pp. 9-20 (1989).

No abstract.

AR-068

HICKS, B.B., C.E. Kolb, and D.H. Lenschow. Chapter 5 - New opportunities for flux measurement.
Global Tropospheric Chemistry - Chemical Fluxes in the Global Atmosphere, D.H. Lenschow and B.B.
Hicks (eds.). Report of Workshop on Measurements of Surface Exchange and Flux Divergence of
Chemical Species in the Global Atmosphere, 83-85 (1989).

No abstract.

MATT, and R.T. McMILLEN. A micrometeorological investigation of surface exchange
A case study. Boundary-Layer Meteorology 47:321-336 (1989).

Data obtained in an intensive field study of the dry deposition of sulfur dioxide, ozone, and
nitrogen dioxide, conducted in 1985 in central Pennsylvania, are used to illustrate the factors that
must be considered to assure that high quality results are derived. In particular, the quality of the
site must be such that flux measurements made above the surface are representative of surface values.
For this purpose, tests involving momentum transfer and the surface energy budget are especially
useful. In addition, conditions must not be changing rapidly, and the statistical uncertainty
associated with flux measurement must be low. For the set of data presented here, conservative
quality-assurance guidelines are used to reject potentially erroneous flux data. For ozone, most of
the measured fluxes are of use in deriving surface resistances. For S02 , far fewer data points are
available. For N02 , fluxes appear to lack the order of the 03 and S02 fluxes, and do not enable

AR-069

HICKS,

B.B. , D.R.

of 03,

S02 and N02

35

surface resistances to be computed. The highest-quality SO^ and O3 data yield surface resistances in
fair average agreement with model predictions for S02 , but substantially higher than predictions for

AR-070

HICKS, B.B., D.R. MATT, and R.T. McMILLEN. A micrometeorological investigation of surface exchange
of trace gases: A case study. NOAA TM ERL ARL-172, 71 pp. (1989).

Data obtained in an intensive field study of the dry deposition of sulfur dioxide, ozone, and
nitrogen dioxide, conducted in 1985 in central Pennsylvania, are used to illustrate the factors that
must be considered to assure that high quality results are derived. In particular, the quality of the
site must be such that flux measurements made above the surface are representative of surface values.
For this purpose, tests involving momentum transfer and the surface energy budget are especially
useful. In addition, conditions must not be changing rapidly, and the statistical uncertainty
associated with flux measurement must be low. For the set of data presented here, conservative
quality-assurance guidelines are used to reject potentially erroneous flux data. For ozone, most of
the measured fluxes are of use in deriving surface resistances. For SO2, far fewer data points are
available. For NC^, fluxes appear to lack the order of the O3 and SO2 fluxes, and do not enable
surface resistances to be computed. The highest-quality SO2 and O3 data yield surface resistances in
fair average agreement with model predictions for SO2, but substantially higher than predictions for

AR-071

HICKS, B.B., and T.P. MEYERS. Measuring and modelling dry deposition in mountainous areas. In
Acid Deposition at High Elevation Sites . M.H. Unsworth and D. Fowler (eds.). Kluwer Academic
Publishers, 5*1-552 (1988).

A trial programme has been initiated to test methods for estimating dry deposition rates from
measurements of air concentration, using selected surface and atmospheric data to specify the
appropriate deposition velocities. Results obtained in the testing programme are used here to compare
a site on the slopes of Whiteface Mountain, New York, and a similarly forested site distant from
mountains. Data are presented on atmospheric resistances to turbulent exchange, and on the surface
resistance associated with the dry deposition of sulphur dioxide. All considerations involving the
concept of a deposition velocity combining surface and vertical-diffusion components are limited in
generality, because of the overriding assumption that the aerodynamic transfer is dominated by
vertical diffusion, therefore neglecting advective effects such as blowthrough. For the case of
sulphur dioxide, the increase in computed dry deposition resulting when such advective effects are
taken into account is found to be small. This results from the fact that SO2 exchange is largely
controlled by surface rather than atmospheric resistance; hence a similar result is expected for other
trace gases most strongly influenced by surface resistance, such as ozone, and could be expected to
extend to particle deposition in some size ranges. However, for nitric acid vapour (and presumably
for all other trace gases having surface resistance small in comparison to atmospheric resistance) the
consequences of surface heterogeneity and topographic complexity on deposition velocities could be
very large.

AR-072

HICKS, B.B., T.P. MEYERS, C.W. Fairall, V.A. Mohnen, and D.A. Dolske. Ratios of dry and wet
deposition of sulfur as derived from preliminary field data. Global BioKeochemical Cycles
3(2):155-162 (1989).

Preliminary data obtained in the operation of a nested-network dry deposition measurement program
in the eastern United States are used in conjunction with wet deposition data obtained at (or near)
the same sites to investigate the variability of ratios of dry to wet deposition of sulfur (as sulfur
dioxide and submicron sulfate for dry deposition, and as sulfate for wet deposition). On a monthly
basis, the ratio is extremely variable at every location; however, a more coherent picture arises when
the average annual cycle is considered. The sites studied here (Oak Ridge, Tennessee; State College,
Pennsylvania; Whiteface Mountain, New York; and Bondville, Illinois) yield dry/wet ratios for sulfur
deposition that minimize in the summer, with values of about 0.3. At other times of the year, values
sometimes exceeding 2.0 are obtained. A summer peak at Oak Ridge is tentatively attributed to the
effects of a local drought. The variability is such that use of dry/wet ratios to estimate dry
deposition rates when only wet deposition data are available cannot be recommended.

36

AR-073

HICKS, B.B., K.S. Rao, R.J. Dobosy, R.P. HOSKER, JR., J. A. Herwehe, and W.R. PENDERGRASS. TRIAD:
a puff-trajectory model for reactive gas dispersion with application to UF = released into the
atmosphere. NOAA TM ERL ARL-168 (PB89-182703) , 136 pp. (1989).

Chemical reactions between released pollutants and atmospheric constituents can influence
atmospheric dispersion if the heats of reaction are such that buoyancy can be affected or mechanical
turbulence damped. If the reaction is sufficiently exothermic, plume rise can be increased; if
sufficiently endothermic, then plume rise can be suppressed. The model described here focuses on
uranium hexaf luoride, a common chemical in the nuclear industry, which reacts exothermically with
atmospheric water vapor. The reaction can generate heat at a sufficient rate that turbulent mixing is
enhanced considerably. The model is constructed to take the consequences of such chemical reactions
into account by modifying the initial puff specification. A puff dispersion code is operated in
conjunction with a wind field routine that accepts data from an array of towers (or a single tower, if
that is all that is available), and interpolates wind field information as required. The puff module
is based on the INPUFF-2 model developed by the Environmental Protection Agency. The three components
(initial puff specification, wind field, and puff dispersion) of the model have been combined into a
single code named TRIAD. This report outlines the theoretical basis for the chemical
parameterizations , summarizes the results of tests conducted using a more sophisticated air chemistry
model, discusses the capabilities and limitations of the TRIAD, and includes a detailed User's Guide
to the current version of the TRIAD model.

AR-074

HUBER, A.H. Video images of smoke dispersion in the near wake of a model building. Part I.
Temporal and spatial scales of vortex shedding. Journal of Wind Engineering and Industrial
Aerodynamics 31:189-224 (1988).

No abstract.

AR-075

HUBER, A.H., and W.B. PETERSEN. Simulating concentration fluctuations in the wake of a building
using a Gaussian integrated puff model. Preprints, Sixth Conference on Applications of Air
Pollution Meteorology, Anaheim, CA, January 29 - February 3, 1989. American Meteorological
Society, Boston, 154-157 (1989).

No abstract.

AR--076

Hutchison, B.A., and D.D. BALDOCCHI . Forest meteorology. Chapter 3, Analysis of Biogeochemical
Cycling Processes in Walker Branch Watershed. D.W. Johnson and R.I. Van Hook (eds.).
Springer-Verlag, 21-95 (1989).

No abstract.

AR-077

Kahl, J.D. Confidence limits on source-receptor relationships determined by ensemble trajectory
analysis. Preprints, Sixth Joint Conference on Applications of Air Pollution Meteorology, Anaheim,
CA, January 30 - February 3, 1989. American Meteorological Society, Boston, 93-96 (1989).

No abstract.

AR-078

Kahl, J.D., and A.D.A. Hansen. Determination of regional sources of aerosol black carbon in the
Arctic. Geophysical Research Letters 16(4 ): 327-330 (1989).

Black carbon aerosol (BC), a strong absorber of visible light, constitutes a small but significant
fraction of the effluent arising from carbonaceous fuel combustion processes. Estimates of the source
strengths and geographical distribution of BC emissions, needed to model their effects on radiative
transfer, are currently unavailable. In this letter we present a methodology for estimating regional
emissions of BC in Arctic latitudes based on the synthesis of three independent pieces of information:
time-resolved measurements of BC and C02 at Pt. Barrow, Alaska; long-range atmospheric trajectory
analyses; and tabulated values of regional fuel consumption. From a limited data base we obtain an
example result indicating annual BC emissions in the Novaya Zemlya/Taymyr Peninsula regions of the
northern U.S.S.R. on the order of 108 g yr"1.

37

AR-079

Karl, T.R., H.F. DIAZ, and G. Kukla. Urbanization: Its detection and effect in the United States
climate record. Journal of Climate 1( 11 ): 1099-1123 (1988).

Several equations were developed that related the effect of urban growth, measured by increasing
population, to the mean seasonal and annual temperature: the diurnal maximum, minimum, average and
range. These equations were derived from a network of 1219 stations across the United States, which
were analyzed for the years 1901-84. The results indicate that urban effects on temperature are
detectable even for small towns with populations under 10,000. Stations with populations near 10,000
are shown to average 0.1°C warmer for the mean annual temperature than nearby stations located in
rural areas with populations less than 2000. Urbanization decreases the daily maxima in all seasons
except winter and the temperature range in all seasons. It increases the diurnal minima and the daily
means in all seasons. The equations indicate that, for the annual mean temperature, urbanization
during the twentieth century accounts for a warm bias of about 0.06°C in the U.S. Historical
Climatology Network (HCN). Due to the large number of stations located in sparsely populated areas
[(over 85% (70%) of all stations had a 1980 population of less than 25,000 (10,000)], the impact of
urbanization is not large in relation to decadal changes of temperature in the United States. The
average heat island impact during the period 1901-84 for the HCN is largest for the daily minima
(0.13°C) and the temperature range (-0.14°C), while the impact on the daily maxima (-0.01*0 is an
order of magnitude smaller.

AR-080

Khalsa, S.J.S., and K.M. WEICKMANN. A composite study of intraseasonal oscillations in atmospheric
angular momentum and outgoing long-wave radiation during Northern Hemisphere winter. Proceedings,
Thirteenth Annual Climate Diagnostics Workshop, Cambridge, MA, October 31-November 4, 1988, 66-72
(1988).

No abstract.

AR-081

Kiladis, F.N., and H.F. DIAZ. Global climatic anomalies associated with extremes in the Southern
Oscillation. Journal of Climate 2:1069-1090 (1989).

Composite temperature and precipitation anomalies during various stages of an event in the Southern
Oscillation (SO) have been computed for several hundred stations across the globe. Large regions of
coherent, significant signals are shown to exist for both extremes of the SO, with warm event signals
generally opposite to those during cold events. In addition, during the year preceding the
development of an event in the SO (year -1), climatic anomalies tend to be opposite to those during
the following year (year 0). This confirms that the biennial tendency of the SO over the
Pacific/Indian ocean sectors is also present in more remote regions with climatic signals related to
the SO. Many of the signals are consistent enough from event to event to be useful for extended range
forecasting purposes.

AR-082

Kim, Y.J., H. Sievering, and J.F. BOATMAN. Airborne measurement of atmospheric aerosol particles
in the lower troposphere over the central United States. Journal of Geophysical Research
93(D10):12, 631-12, 644 (1988).

A series of airborne measurements of atmospheric aerosols were made in four seasonal field periods
over the central United States as part of Central U.S. RADM Test and Assessment Intensives (CURTAIN).
The primary objective of the CURTAIN aerosol measurements was to provide a data base for evaluation of
the Regional Acid Deposition Model (RADM) . Aerosol size distributions were measured at two altitudes
of about 1450 and 2450 m above sea level (asl) over the size range 0.1-16 urn, using two Particle
Measuring Systems, Inc., probes, an active scattering aerosol spectrometer probe and a forward
scattering spectrometer probe, mounted on the National Oceanic and Atmospheric Administration King Air
research aircraft. Aerosol samples were also collected by a 2.5-cm filter pack system for subsequent
elemental analysis by X ray fluorescence (XRF). The average aerosol number concentration reached a
maximum in summer at both low and high altitudes. The average aerosol number concentration was
minimized during fall at low altitude and during winter at high altitude. The coarse particle mode of
the aerosol volume distributions displayed a drastic seasonal change, with a winter volume geometric
median diameter (VGMD) of 4.34 iim and a summer VGMD of 9.21 urn. The summer peak in the coarse-mode
VGMD and volume concentration is attributed to increased windblown dust particles and the presence of
liquid water as part of the aerosol volume under high relative humidity conditions. No significant
latitudinal dependence was found in the CURTAIN aerosol data at low and high altitude, during the day
or night, or from season to season. The CURTAIN aerosol data are influenced differently by the mixed
layer from season to season. In winter, high-altitude aerosol data were collected above the top of

38

the mixed layer. Therefore the vertical profile of aerosol concentration shows a general decrease
above the base of the mixed layer temperature inversion. In summer, high-altitude aerosol data were
collected within the mixed layer. The vertical distribution of aerosol number concentration was
rather constant during summer. XRF elemental analysis performed on the collected aerosol samples
shows that fine-fraction Fe and K are fairly strongly correlated with accumulation mode mass during
summer. This indicates that soil and agricultural fertilizer aerosol sources are important
contributors. Correlations for fine and coarse masses with various atmospheric parameters are
calculated. Positive correlations with temperature and relative humidity are found. Low wind speed
and east winds are correlated with higher fine mass.

AR-083

KOMHYR, W.D., R.D. GRASS, and R.K. Leonard. Dobson spectrophotometer 83: A standard for total
ozone measurements, 1962-1987. Journal of Geophysical Research 94 (D7 ) : 9847-9861 (1989).

Dobson spectrophotometer 83 was established in 1962 as a standard for total ozone measurements in
the United States. In 1980 the instrument was designated by the World Meteorological Organization
(WMO) as the primary standard Dobson spectrophotometer for the world. Since the early 1960s,
virtually all (~90) Dobson instruments in the global Dobson instrument network have been calibrated
several times, either directly or indirectly, relative to instrument 83. Calibrations of instrument
83 by the Langley method were performed in 1962 at Sterling, Virginia, and during 1972-1987 at Mauna
Loa Observatory (MLO) , Hawaii. A detailed analysis of these calibration data, as well as calibration
data based on standard lamp measurements made since 1962, indicates that the long-term (25-year) ozone
measurement precision for the instrument is known to within an uncertainty of +0.5%. On an absolute
scale, the ozone measurements made at MLO with instrument 83 are estimated to be too low by about
2.4%, as a result of errors in the A and D wavelength ozone absorption coefficients used with the
instrument and their temperature dependence. Cumulative other biases most likely do not exceed +1%.
This documentation of the calibration history of instrument 83 lends credence to the accuracy with
which other Dobson instruments have been calibrated in the past and to dobson and satellite instrument
ozone measurement comparisons, thereby increasing confidence in ozone trends determined by these ozone
measurement systems in recent years.

AR-084

KOMHYR, W.D., R.D. GRASS, P.J. REITELBACH, S.E. KUESTER, P.R. Franchois, and M.L. FANNING. Total
ozone, ozone vertical distributions, and stratospheric temperature at South Pole, Antarctica in
1986 and 1987. Journal of Geophysical Research 94 (D9) : 11 , 429-11 , 436 (1989).

Ozone and temperatures measured in 1986 and 1987 at South Pole, Antarctica, are compared, with
emphasis on observations made at the time of formation of the Antarctica ozone hole. In early October
1987, total ozone decreased at South Pole to a record low of 127 Dobson units (DU), compared with the
early October 1986 value of 158 DU . Electrochemical concentration cell (ECC) ozonesonde soundings
made during both years showed the ozone depletion at 11-23 km in 1987 to be greater in vertical extent
and magnitude and to proceed more rapidly. As in 1986, two exponential ozone decrease rates occurred
in 1987 at 17 + 1 km, with half-lives of 19.5 and 4.5 days (compared with half-lives of 35 and 12 days
observed in 1986). By early October 1987, nearly all ozone was depleted from a 4-km-thick atmospheric
layer centered at 17 km. At the time of ozone hole formation, stratospheric temperatures were colder,
but tropospheric temperatures were warmer, in 1987 compared to 1986. Because polar vortex breakdown
occurred 3 weeks later in 1987 than it did in 1986, stratospheric temperatures in the heart of the
ozone depletion region were 10°-40°C colder in mid-to-late November 1987.

AR-085

KOMHYR, W.D., T.B. HARRIS, L.S. WATERMAN, J.F.S. CHIN, and K.W. Thoning. Atmospheric carbon
dioxide at Mauna Loa Observatory 1. NOAA global monitoring for climatic change measurements with a
nondispersive infrared analyzer, 1974-1985. Journal of Geophysical Research 94 (D6 ): 8533-8547
(1989) .

Atmospheric CO£ measurements made with a nondispersive infrared analyzer during 1974-1985 at Mauna
Loa Observatory, Hawaii, are described, with emphasis on the measurement methodology, calibrations,
and data accuracy. Monthly mean CO£ data, representative of global background conditions, are
presented for the period of record. The monthly means were derived from an all-data base of CO?
hourly averages archived at the National Oceanic and Atmospheric Administration (NOAA) Geophysical
Monitoring for Climatic Change (GMCC) facility in Boulder, Colorado; at the Carbon Dioxide Information
Analysis Center (CDIAC) in Oak Ridge, Tennessee; and in the microfiche version of this paper. Flags
in the all-data base identify CO? hourly averages that have been deemed unreliable because of sampling
and analysis problems or that are unrepresentative of clean background air because of influences of
the local environment, for example, CO2 uptake by nearby vegetation or contamination and pollution
effects. The select NOAA GMCC monthly mean data are compared with similar data obtained independently

39

at Mauna Loa Observatory by the Scripps Institution of Oceanography. The average difference of
corresponding monthly mean CO2 values for the two data sets is 0.15 + 0.18 ppm, where the indicated
variability is the standard deviation. Careful scrutiny of the NOAA GMCC measurement, calibration,
and data processing procedures that might have caused the small bias in the data has revealed no
unusual errors .

AR-086

KOMHYR, W.D., J. A. LATHROP, V.N. Arbuzova, V.U. Khattatov, P.G. Nureyev, V.V. Radokov, and I.V.
Zamyshlayev. ECC ozonesonde observations at Mirny, Antarctica, during 1988. NOAA DR ERL ARL-19,
125 pp. (1989).

Atmospheric ozone vertical distributions, air temperatures, and wind speed and direction data are
presented for 40 balloon electrochemical concentration cell (ECC) ozone soundings made at Mirny,
Antarctica, in 1988.

AR-087

KOMHYR, W.D., J. A. LATHROP, R.W. POSTON, and T.O. MULLEN. ECC ozonesondes at South Pole,
Antarctica, during 1988. NOAA DR ERL ARL-18, 277 pp. (1989).

Atmospheric ozone vertical distributions, air temperatures, and wind speed and wind direction data
are presented for 67 balloon electrochemical concentration cell (ECC) ozonesonde soundings made at
South Pole, Antarctica, in 1988.

AR-088

LAMB, R.G. Simulated effects of hydrocarbon emissions controls on seasonal ozone levels in the
Northeastern United States: A preliminary study. EPA/600/3-88/017, Atmospheric Sciences Research
Laboratory, Research Triangle Park, NC , 86 pp. (1988).

The second generation Regional Oxidant Model (ROM2) is used to simulate ozone concentrations in the
Northeastern United States over two week periods in each of three months: April, July and August
1980. In each period three separate model simulations are performed. The first of these, referred to
as the base case, used the 1980 NAPAP 5.3 emissions inventory to specify anthropogenic hydrocarbon and
NO„ emissions. The second simulation, referred to as Control Strategy #1, assumed reductions of 5% to
SOX in hydrocarbon emissions depending on the county in which sources are located. The third
simulation, Control Strategy #2, used the same emissions as Control Strategy #1 but with hydrocarbon
emission rates reduced an additional 22% across the board. In all three simulations the NO emissions
are the same and the hydrocarbon emissions from natural sources are identical. The predicted ozone
changes that result from the emissions changes are extrapolated from the three, 2-week periods to the
"ozone season", which begins on 1 April and runs through 31 October. The extrapolation is performed
using a technique developed in this paper. Three general conclusions are drawn: (1) reducing
hydrocarbon emission rates generally reduces ozone levels; (2) the emissions changes proposed in
control strategies 1 and 2 reduce peak O3 concentrations most -- they have virtually no effect on
concentrations below about the 95-percentile level; (3) the impact of controls on ozone levels is
sensitive to meteorological conditions. These and other results of the model simulations are
discussed .

AR-089

LAWSON, R.E., JR., W.H. SNYDER, and R.S. Thompson. Estimation of maximum surface concentrations
from sources near complex terrain in neutral flow. Atmospheric Environment 23 (2 ): 321-331 (1989).

A wind tunnel study was conducted to determine maximum ground-level concentrations for a variety of
source positions (locations and heights) both upstream and downstream of two model hills, an
axisymmetric hill (maximum slope 24°) and a two-dimensional ridge (maximum slope 16°), immersed in a
simulated neutral atmospheric boundary layer. Terrain amplification factors derived from these
measurements were used to construct contour plots showing regions or "windows" of enhanced
ground-level concentration. These windows of enhanced ground-level concentration are shown to be a
useful guide for estimating the effects of complex terrain on pollutant dispersion or, conversely, for
determining source locations near complex terrain which minimize the enhancement of ground-level
concentration .

AR-090

Lean, J. Chapter 7, Solar EUV irradiances and indices. Advances in Space Research 8(5):263-292
(1988).

40

Information about the solar EUV spectrum and its temporal variability is essential for studies of
the earth's upper atmosphere. Despite a data base which spans two solar cycles, neither the EUV
irradiance variations associated with the eleven-year solar activity cycle, nor the EUV spectral
irradiance of the inactive ("quiet") sun have yet been accurately determined. Because ground-based
solar observations have been made more frequently, and with a long-term accuracy superior to that of
EUV irradiance measurements, they have assumed an important role as indicators of solar activity in
studies of the earth's thermosphere . In this paper, the solar EUV irradiance data base acquired over
the past 25 years is briefly described. The extent to which emissions at different EUV wavelengths
and ground-based solar indices are similar, is examined statistically over time scales of the 27-day
solar rotation, and less rigorously over the eleven-year solar cycle. It is shown that the detailed
temporal structure of the EUV irradiance variations is a complicated function of wavelength and cannot
be exactly reproduced by any of the traditional ground-based indices over either short- or long-time
scales .

AR-091

Lean, J.L., H.J. Kostkowski, R.D. Saunders, and L.R. Hughey. Comparison of the NIST SURF and argon
miniarc irradiance standards at 214 nm. Applied Optics 28( 15) : 3246-3253 (1989).

Comparison of NIST's SURF-II primary irradiance standard and argon miniarc irradiance standard at
214 nm with an uncertainty of -3% shows that at this wavelength these irradiance standards agree to
within the uncertainties of 1.3 and 7%, respectively, assigned to them by NIST.

AR-092

Lee, R.N., K.M. Busness, and B. STUNDER. Aircraft operations and airborne measurement of
perf luorotrimethylcyclohexane (PTCH) during ANATEX . Preprints, Sixth Joint Conference on
Applications of Air Pollution Meteorology, Anaheim, CA, January 30 - February 3, 1989. American
Meteorological Society, Boston, 113-116 (1989).

Extended abstract.

AR-093

Luria, M. , C.C. VAN VALIN, and J.F. BOATMAN. Sulfur budget for the south-central United States.
Man and His Ecosystem, Proceedings, 8th World Clean Air Congress 1989, The Hague, The Netherlands,
September 11-15, 1989, L.J. Brasser and W.C. Mulder (eds). Elsevier Science, Amsterdam, 355-362
(1989).

The concentrations of sulfur dioxide (SO2), particulate sulfate SO£ and other trace gases, as well
as meteorological and position parameters were measured from an instrumented aircraft over the
south-central United States. Research flights were performed from Little Rock, Arkansas, along a
north-south track near the 91.5°W meridian between 29° and 41°N latitude, at constant altitudes of
1700 and 2600 m above sea level. The measurements were carried out during 1987 and totaled about 24 h
of air-sampling flight time during each of the four seasons. The average concentrations of SO, ranged
from 1.6 to 6.8 /ig m at the lower elevation and from 0.5 to 2. A jxg m at the higher elevation.
Particulate sulfate ranged from 1.3 to 3.2 fig m"3 at the lower elevation and 0.5 to 1.7 fig m~3 at the
higher elevation. Both SO2 and particulate SO^~ concentrations peaked during the summer measurements.
However, the increase of SO^ from winter to summer was the more notable, probably as a result of
enhanced photochemical activity. Sulfur fluxes were calculated using the concentrations and wind data
observed during this study and following a procedure previously suggested by the authors. The
calculations revealed that the net sulfur fluxes during the winter and summer are directed westward.
Spring and fall fluxes are directed eastward.

AR-094

Luria, M., C.C. VAN VALIN, J.N. Galloway, W.C. Keene, D.L. WELLMAN, H. Sievering, and J.F. BOATMAN.
The relationship between dimethyl sulfide and particulate sulfate in the mid-Atlantic Ocean
atmosphere. Atmospheric Environment 23(1)139-147 (1989).

Dimethyl sulfide (DMS) and atmospheric aerosols were sampled simultaneously over the Atlantic Ocean

in the vicinity of Bermuda using the NOAA King Air research aircraft. Total and fine (50% cut off at

2 fim diameter) aerosol fractions were sampled using two independent systems. The average non-sea-salt

(nss) SO^~ concentrations were 1.9 and 1.0 /ig m (as SO^ ) for the total and the fine fractions in

the boundary layer (BL) and 0.53 and 0.27 ng, m in the free troposphere (FT). Non-sea-salt SO^ in

the two aerosol fractions were highly correlated (r = 0.90), however a smaller percentage (55%) was

found in the fine aerosol near Bermuda relative to that (90%) near the North American continent. The

9 _
BL SO£ concentrations measured in this study were higher than those measured by others at remote

marine locations despite the fact that the 7-day air mass back trajectories indicated little or no

41

continental contact at altitudes of 700 mb and below; trajectories were over subtropical oceanic areas
that are expected to be rich in DMS . DMS concentrations were higher near the ocean surface and
decreased with increasing altitude within the BL; the average DMS concentration was 0.13 /ig m

Trace levels of DMS were also measured in the FT (0.01 /ig in ° ) . Computer_simulation of the oxidation
and removal of DMS in t
to the natural S cycle.

o _

and removal of DMS in the marine atmosphere suggests that <50% of the S0£ observed could be related

AR-095

Luria, M. , C.C. VAN VALIN, W.C. Keene, D.L. WELLMAN , J.N. Galloway, and J.F. BOATMAN. Eastward
sulfur flux from the northeastern United States. Atmospheric Environment 22( 9) : 1847-1854 (1988).

During January and February 1986 the concentrations of sulfur dioxide (SO2) and particulate sulfate

(SO^~) were measured from an instrumented aircraft 80-120 km east of the New England coast. The

average concentration of SO2 in the boundary layer (BL) was 10 jig m", the maximum 30-min average was

26 /ig m~3 , The average and maximum values in the free troposphere (FT) were 3.9 and 31 /ig m ,

respectively. The concentrations of non-sea-salt SO?" averaged 2.0 and 0 . 7 tig, m in the BL and FT,

and the maximum concentrations were 7.7 and 3.2 jig m • Continuous wind speed records from the

o _
aircraft LORAN system were used to estimate altitude profiles of the offshore fluxes of S02 and S0£

for the duration of the study. The estimated advection flux is (3.5 + 0.4) x 10"3 Tg(S)day_1 from the

coastal segment between 41 and 43°N latitudes. Most (89%) of the S flux was found to be in the form

of SO,; the remainder corresponded to particulate So|~ . The ratio of aerosol to gas-phase S in the BL

was found to be similar to that in the FT, despite the fact that removal of SO2 from the BL is

expected to be much faster than that from the FT.

AR-096

Malanchuk, J.L., C.N. Herrick, and R.L. DENNIS. Comparative evaluations of NAPAP's illustrative
future scenarios. Proceedings, 82nd Annual Meeting of the Air and Waste Management Association,
Anaheim, CA, June 25-30, 1989. Air and Waste Management Association, Pittsburgh, Paper 89-113.10
(1989).

The objective of the NAPAP Integrated Assessment is to provide users with objective, broadly
reviewed data and analyses for several realistic examples of control scenarios. These results are
compared to a reference case that projects estimates of future conditions without the assumption of
additional initiatives directed at acidic deposition control. The comparative evaluations will help
to distinguish strategies over a broad range of policy questions that are more effective than others,
and perhaps just as important, will help identify situations in which different strategies produce
similar results. This paper will discuss issues of model adequacy and model linkage, suggest methods
to approach these issues, and provide an illustrative comparison of two control strategies.

AR-097

MEYERS, T.P., and D.D. BALDOCCHI . A comparison of models for deriving dry deposition fluxes of O3
and S02 to a forest canopy. Tellus 40B:270-284 (1988).

Four canopy models, representing the various classes of models that are currently used to estimate
gaseous deposition to plant canopies are presented. The predictive capabilities of the models are
evaluated with direct eddy correlation measurements of SO? and 03 fluxes to a deciduous forest for
both well-watered and water-stressed conditions. By increasing the degree of detail of the
exchange-governing physical processes from the more simple single layer model to the more detailed
multi-layer models, the predictions of the deposition rates improved by 40-50% as determined from the
root mean square error (rmse). We also found by including the effect of water stress in the stomatal
resistance formulations, the rmse of the predictions were decreased by generally 50% for the models
that were examined.

AR-098

NAPPO, C.J., K.S. Rao, and J. A. Herwehe. Pollutant transport and diffusion in katabatic flows.
Journal of Applied Meteorology 28( 7 ): 618-625 (1989).

The characteristics of pollutant transport and diffusion of a passive contaminant in a two-
dimensional katabatic flow over a simple slope are examined using a primitive equation hydrodynamic
model. It is shown that pollutants released above the drainage layer can be entrained into the layer
and diffused to the ground surface. For elevated releases within the drainage layer, subsidence in
the flow leads to relatively high surface concentrations of pollutants close to the stack. Pollutants
released at ground level can spread through the entire depth of the drainage layer. This vertical
diffusion is more effective for a shallow slope, resulting in higher concentrations at all heights,
than for a stepper slope. These dispersion characteristics are quite different from those for stable

42

flows over flat terrain. The differences result from increases of boundary-layer depth, wind speed,
and turbulence as the katabatic flow develops downslope. The katabatic flow and dispersion model is
tested by simulating the perf luorocarbon and heavy methane tracer releases for Night 4 of the 1980
ASCOT field study in Anderson Creek Valley, California. These tests show that the observed
concentrations and the depth of the drainage layer in the lower region of the slope are underpredicted
because the model could not simulate the convergence of drainage air (pooling) in the valley basin.
The nightly average values of the observer* concentrations, however, are predicted well. It is
concluded that the model is applicable to nearly two-dimensional open slopes.

AR-099

NOVAK, J. Verification procedures applied to the U.S. EPA Regional Oxidant Model. In Air
Pollution Modeling and Its Application VI, H. van Dop (ed.). Plenum Publishing Corp., New York,
345-356 (1988).

Regional air quality simulation models have been developed as research tools to gain a greater
understanding of long range transport and transformation of air pollutants and to evaluate regional
control strategy alternatives. To ensure credibility of these complex model predictions, the
performance of model codes must be verified for their adherence to theoretical formulations, accuracy
of numerical algorithms, ability to reproduce observed data and sensitivity to uncertainties in input
data. This paper describes the procedures used for verification of the U.S. EPA Regional Oxidant
Model. Comparisons with observed data are presented together with a brief summary of the results from
two ozone control strategy applications. The sensitivity of the model to known uncertainties in input
data is discussed in relation to its effect on air pollution control strategy evaluation.

AR-100

NOVAK, J.N., and T. Birth. Development of a Geographic Information System for assessment of air
pollution problems. Proceedings, 82nd Annual Meeting of the Air and Waste Management Association,
Anaheim, CA, June 25-30, 1989. Air and Waste Management Association, Pittsburgh, AWMA 89-105P.2
(1989).

Geographic Information Systems (GIS) are powerful tools for the spatial analysis of related
information. Recognizing common needs and the requirement to share data, several EPA offices in the
Research Triangle Park, North Carolina, cooperated in the design and implementation of a pilot GIS
system for analysis of Regional Oxidant Model (ROM) pollutant concentration predictions in conjunction
with other associated data sets of interest, such as emissions, air quality, and population, etc. The
primary goal of the pilot project is to provide to analysts and researchers 1) a graphical analysis
tool they can use directly with little GIS experience, and 2) direct access to a variety of large data
sets required for assessment of air pollution issues. One of the main advantages of the GIS is the
ability to overlay multiple data sets and highlight relationships of interest. The demonstration
illustrates the typical use of GIS for analysis of the effectiveness of a particular VOC and NOx
emissions control strategy for reducing ozone concentrations in the Northeastern U.S.

AR-101

PARUNGO, P., C. NAGAMOTO, and B. KOPCEWICZ. Front range acidic clouds and precipitation.
Preprints, 82nd Annual Meeting and Exhibition, Anaheim, CA, June 25-30, 1989. Air and Waste
Management Association, Pittsburgh, 89-112.4 (1989).

No abstract.

AR-102

Patrinos, A.A.N. , M.J. Leach, R.M. Brown, R.L. Tanner, and F.S. BINKOWSKI. An acid rain study in
the Washington, D.C. area. Journal of Applied Meteorology 28:948-968 (1989).

A field study in the Washington, D.C. area explored the impact of urban emissions and mesoscale
meteorology on precipitation chemistry. The study was a follow-up to an earlier, considerably more
industrialized, study in the Philadelphia area; emissions along the Delaware Valley were found to
affect the deposition of nitrate and sulfate on the urban mesoscale. The Washington studies were
designed to complement and enhance the earlier study with an expanded sampling domain, sequential
precipitation sampling and airborne measurements. Four storms were sampled successfully between
October 1986 and April 1987. Results appear to confirm the conclusions of the Philadelphia study,
although the upwind-downwind contrast in nitrate and sulfate deposition is not as pronounced. This
difference is attributed to the area's widely distributed emission patterns and to the prevailing
theories regarding the production of nitric acid and sulfuric acid on the relevant time and space
scales. The importance of mesoscale meteorology and hydrogen peroxide availability is highlighted in
at least two of the sampled storms.

43

AR-103

PERRY, S.G., D.J. Burns, L.H. Adams, R.J. Paine, M.G. Dennis, M.T. Mills, D.G. Strimaitis, R.J.
Yamartino, and E.M. Insley. User's guide to the Complex Terrain Dispersion Model Plus Algorithms
for Unstable Situations (CTDMPLUS). Volume I: Model description and user instructions.
EPA/600/8-89/041, Atmospheric Research and Exposure Assessment Laboratory, Research Triangle Park,
NC, 206 pp. (1989) .

The Complex Terrain Dispersion Model Plus Algorithms for Unstable Situations (CTDMPLUS) is a
refined air quality model for use in all stability conditions for complex terrain applications. It
contains the technology of the original Complex Terrain Dispersion Model (CTDM) for stable and neutral
conditions, but also models daytime, unstable conditions. The model makes use of considerable detail
in the terrain and meteorological data (as compared to current EPA regulatory models) and requires the
parameterization of individual terrain features, thus considering the three-dimensional nature of the
interaction of the plume and terrain. This user's manual describes, in detail, the technical basis of
the model and instructions for its use.

AR-104

PERRY, S.G., and W.H. SNYDER. Laboratory simulations of daytime mixed layer heights in complex
terrain. Preprints, Sixth Conference on Applications of Air Pollution Meteorology, Anaheim, CA,
January 29 - February 3, 1989. American Meteorological Society, Boston, 256-259 (1989).

No abstract.

AR-105

PETERSEN, W.B., W.H. SNYDER, J.Y. Ku, and S.T. Rao. Dispersion of dense gas releases in a wind
tunnel. Preprints, 17th International Technical Meeting of NATO-CCMS on Air Pollution Modeling and
its Application, Volume II, September 19-22, 1988, Cambridge, England. NATO/CCMS, Brussels,
Belgium, II. 5 (1988).

In view of numerous accidental releases of toxic gases into the atmosphere in recent years, there
is increasing concern regarding the atmospheric dispersion of toxic and hazardous materials. Given
that exposures to the toxic substances could be life threatening or severely incapacitating, there is
an urgent need to develop and validate modeling approaches relevant to the atmospheric dispersion of
airborne toxic material. The main point of this work is to illustrate the transport and dispersion of
dense gas plumes using data collected in a wind tunnel, and to test the performance of two available
dispersion models with the CO and SF concentration data from the wind tunnel experiments. It is not
the intent to provide an exhaustive evaluation of atmospheric dispersion models appropriate to
heavier-than-air releases. Rather we choose to compare one state-of-the-art dense gas model with a
Gaussian puff model which is appropriate for neutrally buoyant releases. Although the simple Gaussian
models do not incorporate the relevant physics for dense gas spread and diffusion, they may be useful
in estimating ground level centerline concentrations.

AR-106

PIERCE, T.E. An air pollution climatology around an isolated point source using convective scaling
parameters. Atmospheric Environment 22:2463-2475 (1988).

An air pollution climatology, which incorporated convective scaling parameters, is used to
investigate the conditions associated with hour SO2 concentrations from a coal-fired power plant. One
year of data from the Paradise power plant in central Kentucky (U.S.A.) were analyzed. Variables
which were examined included emission rate, plume rise, wind speed, wind direction, stability class,
convective scaling velocity and similarity categories. The results show the meteorological conditions
leading to high surface concentrations are the daytime hours having neutral/unstable atmospheric
stability, light winds and effective plume height to mixing height ratios typically >0.85. In more
than half of the 30 h of highest observed concentrations, the atmospheric conditions satisfy the
criteria for mixed-layer scaling.

AR-107

PIERCE, T.E. An evaluation of a convective scaling parameterization for estimating the diffusion

of a buoyant plume. In Air Pollution Modeling and Its Application VI, H. van Dop (ed.). Plenum

Publishing Corp., New York, 203-215 (1988).

During limited-mixed convective conditions, high concentrations of air pollutants have been
observed at ground-level from buoyant plumes. Routinely-applied Gaussian plume dispersion models have
difficulty simulating diffusion for these conditions. However, advances in convective scaling offer
some hope for improved model formulations. This paper evaluates the usefulness of a diffusion formula

44

proposed by Briggs. Thirty-nine hours of extensive meteorological, source, and tracer data were
analyzed from the Kincaid field study. The evaluation of the Briggs formula compared to a Gaussian
plume dispersion model showed better model performance. Because of the sensitivity of the Briggs
formula to values of w* (convective scaling velocity), additional research is recommended to improve
estimates of the sensible heat flux. Also, further study of the horizontal diffusion of buoyant
plumes in the convective boundary layer is recommended.

AR-108

PIOTROWICZ, S.R., R.A. Rasmussen, K.J. HANSON, and C.J. FISCHER. Ozone in the boundary layer of
the equatorial Atlantic Ocean. Tellus 41B:314-322 (1989).

Shipboard (~7 m) ozone and carbon monoxide measurements made in the equatorial Atlantic Ocean,
south of the intertropical convergence zone, between 5°N and 10°S and 10°-30°W in August and September
of 1986 exhibited variability in excess of a factor of 2. Ozone mixing ratios ranged from <25 to over
50 ppbv while carbon monoxide mixing ratios ranged from <50 to over 120 ppbv along the western edge of
the equatorial Atlantic in spite of the fact that the prevailing, surface winds were from the east to
southeast at between 5 and 15 m/s. Ozone and carbon monoxide mixing ratios were generally lower and
exhibited less variability in the eastern tropical Atlantic where a lighter, south to southeasterly
wind regime predominated. Isobaric trajectory analyses indicated that the high ozone and carbon
monoxide mixing ratios appear to be related to long-range transport off of the African continent.
Time-series analysis of the ozone data indicated a diel cycle in ozone mixing ratios with a morning
maximum and afternoon minimum.

AR-109

POSSIEL, N.C., J. A. Tikvart, J.H. NOVAK, K.L. SCHERE , and E.L. Meyer. Evaluation of ozone control
strategies in the northeastern region of the United States. In Atmospheric Ozone Research and its
Policy Implications . T. Schneider et al. (eds.). Elsevier Science Publishers B.V., Amsterdam,
623-632 (1989).

The transport of ozone and precursor pollutants over hundreds of kilometers has an important impact
on air quality in the Northeastern U.S. Of particular concern is the relatively close proximity of
several major urban areas, joined with the influence of large rural fuel combustion sources. This
paper reviews initial applications of a regional scale model to assess the effect of selected control
strategies for reducing ozone concentrations in the Northeast region, and especially in the urban
corridor. Generally it is found that reducing emissions of volatile organic compounds is an effective
control measure. The need for further joint controls of volatile organic compounds and nitrogen
oxides is addressed.

AR-110

Rao, K.S., R.M. ECKMAN, and R.P. HOSKER, JR. Simulation of tracer concentration data in the Brush
Creek drainage flow using an integrated puff model. Journal of Applied Meteorology 28( 7 ): 609-616
(1989) .

During the 1984 ASCOT field study in Brush Creek Valley, two perf luorocarbon tracers were released
into the nocturnal drainage flow at two different heights. The resulting surface concentrations were
sampled at 90 sites, and vertical concentration profiles at 11 sites. These detailed tracer
measurements provide a valuable dataset for developing and testing models of pollutant transport and
dispersion in valleys. In this paper, we present the results of Gaussian puff model simulations of
the tracer releases in Brush Creek Valley. The model was modified to account for the restricted
lateral dispersion in the valley, and for the gross elevation differences between the release site and
the receptors. The variable wind fields needed to transport the puffs were obtained by interpolation
between wind profiles measured using tethered balloons at five along-valley sites. Direct turbulence
measurements were used to estimate diffusion. Subsidence in the valley flow was included for elevated
releases. Two test simulations -- covering different nights, tracers, and release heights -- were
performed. The predicted hourly concentrations were compared with observations at 51 ground-level
locations. At most sites, the predicted and observed concentrations agree within a factor of 2 to 6.
For the elevated release simulation, the observed mean concentration is 40 pL/L, the predicted mean is
21 pL/L, the correlation coefficient between the observed and predicted concentrations is 0.24, and
the index of agreement is 0.46. For the surface release simulation, the observed mean is 85 pL/L, and
the predicted mean is 73 pL/L. The correlation coefficient is 0.23, and the index of agreement if
0.42. The results suggest that this modified puff model can be used as a practical tool for
simulating pollutant transport and dispersion in deep valleys.

45

AR-111

Rao, K.S., J.-Y Ku, and S.T. Rao. A comparison study of three urban air pollution models.
Atmospheric Environment 23:793-801 (1989).

The predictions of three urban air pollution models with varying degrees of mathematical and
computational complexities are compared against the hourly SOo ground-level concentrations observed on
10 winter nights of the RAPS experiment in St. Louis. The emphasis in this study is on the prediction
of urban area source concentrations. Statistics for the paired comparison of predictions of each
model with the observations are presented. The RAM and the ATDL model with stable diffusion
coefficients overestimated the observed night-time concentrations. The results show that the
performance of the ATDL model with near-neutral diffusion coefficients is comparable to the more
sophisticated 3-D grid numerical model.

AR-112

Rao, S.T., G. Sistla, J.-Y. Ku, K.L. SCHERE, R.D. Scheffe, and J.M. GODOWITCH. Nested grid
modeling approach for assessing urban ozone air quality. Proceedings, 82nd Annual Meeting of the
Air and Waste Management Association, Anaheim, CA, June 25-30, 1989. Air and Waste Management
Association, Pittsburgh, AWMA 89-42A.2 (1989).

This paper describes an effort to interface the modeled concentrations and other outputs of the
Regional Oxidant Model (ROM) as an alternative set of input files to apply in Urban Airshed Model
(UAM) simulations. Five different days exhibiting high ozone concentrations during the 1980 ozone
season were simulated by the UAM for the New York metropolitan area for a base scenario and for
different sets of initial and boundary conditions and winds from the ROM. The methodology of
integrating the ROM results into the UAM processor system is discussed. The modeled UAM ozone
concentrations are compared with measured values for the various model input data scenarios in
assessing the performance of the nested grid modeling approach. The results indicate relatively good
agreement over the New Jersey/New York portion of the UAM domain, and an underprediction of ozone
levels over Connecticut.

AR-113

Roberts, P.J.W., W.H. SNYDER, and D.J. Baumgartner. Ocean outfalls I: Submerged wastefield
formation. Journal of Hydraulic Engineering 115(l):l-25 (1989).

Experiments to study the dilution and formation of wastefields resulting from discharge into a
linearly density-stratified steady current of arbitrary speed and direction are reported in three
papers. The experiments were conducted using a model multi-port diffuser for a range of parameters
typical of ocean wastewater outfalls. In this paper, results are given from which the established
wastefield characteristics for the "line plume" source conditions can be predicted. In general, the
wastefield rise height and thickness decrease as the current speed increases. Dilution increases with
current speed for all current directions, with diffusers perpendicular to the current resulting in
higher dilutions than when parallel. Concentration profiles for perpendicular currents show little
horizontal structure as the individual plumes rapidly merge. The results for dilution show no
dependency on port spacing or source momentum flux over the parameter range tested, and the dominant
source parameter is the buoyancy flux per unit length. The results confirm the value of the "line
plume" approximation for predicting dilutions for deepwater ocean outfalls over a fairly wide
parameter range.

AR-11A

Roberts, P.J.W., W.H. SNYDER, and D.J. Baumgartner. Ocean outfalls II: Spatial evolution of
submerged wastefields. Journal of Hydraulic Engineering 115(1) :26-A8 (1989).

Some of the basic features of submerged wastefield formation in stratified currents are reported in
this paper. Dilution increased with distance from the diffuser in the initial mixing region until it
attained a maximum value, which is the initial dilution, after which it remained constant. By
assuming a model of buoyancy-induced turbulence collapse, expressions for the observed dependency on
current speed in the forced entrainment regime of initial dilution, rise height, and mixing region
length were obtained. An expression for lateral spreading in parallel currents was derived which was
found to be of the same form as for unstratified currents, except that the rate of spreading in
stratified currents is much slower. An expression for the rate of spreading in perpendicular currents
was derived by applying results from mixed-region collapse. An applications example shows that the
mixing region can extend for several hundred meters downstream from the discharge. Because of the
gravitational spreading a line diffuser will produce a wastefield width comparable to the diffuser
length for most oceanic conditions, suggesting that Y or similarly complex diffuser configurations are
not necessary to produce a widely dispersed wastefield.

46

AR-115

Roberts, P.J.W., W.H. SNYDER, and D.J. Baumgartner. Ocean outfalls III: Effect of defuser design
on submerged wastefield. Journal of Hydraulic Engineering 115(1) :49-70 (1989).

The effects of port spacing and jet momentum flux on the characteristics of submerged wastefields
produced by multi-port ocean outfalls in linearly stratified currents were investigated
experimentally. Within the parameter range studied the primary effect of these variables is on the
rise height and thickness of the wastefield, and dilution is closely approximated by line plume
results. Increased momentum flux causes a reduction in rise height at low current speeds while
leaving the total entrainment path length of the jets, and hence dilution, fairly constant. The
effects of increased momentum flux decrease as the current speed increases. Increased port spacing
still resulted in merging of individual plumes even when fairly widely spaced, particularly in flowing
currents, so point plume results were of limited applicability in predicting wastefield properties.
Results are presented in graphical and tabular form from which rise heights and thicknesses can be
estimated for discharges which do not approximate line plumes. An example of the procedure is given,
and some implications for diffuser design are discussed.

AR-116

ROBINSON, E. Book Review. Tropospheric Ozone, Regional and Global Scale Interactions. (NATO ASI
Series, Kluwer Academic Publishers, D. Reidel Publishing Co., Dordrecht, Holland, 1988, 425 pp.)
Water. Air and Soil Pollution 44:415-417 (1989).

No abstract.

AR-117

ROBINSON, E., and T.E. DE FOOR. Stratospheric aerosol conditions over Mauna Loa during recent
quiescent volcanic periods. In Aerosols and Climate . P.V. Hobbs and M.P. McCormick (eds.).
Deepak, Hampton, Virginia, 325-334 (1988).

Lidar observations of stratospheric aerosol conditions have been made at the Mauna Loa Observatory
for more than 10 years. Plumes from large-scale volcanic eruptions, the usual causes of enhanced
aerosol backscattering in the stratosphere, and the impacts of major volcanic events such as Fuego in
1974 and El Chich6n in 1982 are readily evident in the lidar record. However, in the intervals
between major eruptions over the past 10 years the apparent residual or "background" stratospheric
aerosol optical depth, as calculated from the Mauna Loa ruby lidar at 694 nm, has gradually increased
at an annual rate of about 4.5 x 10" , or about 10% per year. The most likely explanation for this
long-term increase in residual aerosol backscattering is the gradual accumulation of volcanic eruption
materials in the stratosphere both from the large, well-publicized eruptions and from the more
numerous, less intense events. These features of the residual stratospheric aerosol conditions and
the impact of the more frequent moderate-scale eruptions are examined in this discussion with
particular reference to recent Mauna Loa lidar observations.

AR-118

ROLPH, G.D., and B.J.B. STUNDER. Meteorological support: Descriptions of application programs for
accessing and displaying data. NOAA TM ERL ARL-169 (PB89-194625) , 68 pp. (1989).

Programs for accessing and displaying meteorological data are described. Surface and upper-air
observations and model-generated forecast data may be accessed. Step-by-step procedures and examples
are provided for each application program. Brief descriptions of air-parcel trajectory models are
also included. Most of the programs require access to the NAS 9000 computer in Suitland, MD .
Meteorological data for these programs are provided by NOAA's National Meteorological Center in Camp
Springs, MD .

AR-119

Rosen, J.M., S.J. OLTMANS, and W.F. Evans. Balloon borne observations of PSCS, frost point, ozone
and nitric acid in the north polar vortex. Geophysical Research Letters 16( 8) : 791-794 (1989).

A new balloon borne instrument called a backscattersonde has been used to study Polar Stratospheric
Clouds (PSCs) at Alert, NWT (82°N, 61.5°W) during January and February of 1989. These measurements
were supplemented with frost point, ozone and nitric acid vapor soundings. Type I PSCs were observed
at temperatures and pressures generally consistent with present vapor pressure models of HNO3/H2O
condensate, but some noticeable inconsistencies exist. It is suggested that these apparent problems,
as well as some characteristic peculiarities in the PSC profiles, could be explained by the presence
of two phases of the HNO3/H2O condensate.

47

AR-120

Rosinski, J., P.L. Haagenson, C.T. NAGAMOTO, B. QUINTANA, F. PARUNGO, and S.D. Hoyt . Ice-forming
nuclei in air masses over the Gulf of Mexico. Journal of Aerosol Science 19( 5) : 539-551 (1988).

Aerosol particles collected over the Gulf of Mexico during the period from 20 July to 30 August

1986 were examined for their ability to nucleate ice by condensation-followed-by freezing.

Ice-forming nuclei (IFN) in the 0.1-0. A jim-diameter size range nucleated ice at a temperature of -4°C;

their concentrations were between 2 and 10 m . Fractions of aerosol particles in that size range

— 8 -7
nucleating ice at the initial (the highest) temperatures were between 10 ° and 10 . Peaks in the

concentration of dimethyl sulfide (DMS) (0800 h) preceded peaks in ice-nucleating temperatures (1300

h) by 5 h; this is sufficient time for DMS molecules to be oxidized to sulfates and to produce mixed

aerosol particles through coagulation of different-sized aerosol particle and absorption of

sulfur-bearing gas molecules. Fractions of aerosol particles larger than 0.2 (xm in diameter

containing So|~ ions were larger than 0.90; most of the time they were 0.99-1.00. All IFN displayed

characteristic features of mixed IFN, that is of marine origin (part of IFN concentration independent

of temperature) and of continental origin (part of IFN concentration dependent on temperature).

AR-121

SCHERE, K.L., and R.A. Wayland. Development and evaluation of the regional oxidant model for the
northeastern United States. In Atmospheric Ozone Research and its Policy Implications . T.
Schneider et al. (eds.). Elsevier Science Publishers B.V., Amsterdam, 613-622 (1989).

The second generation U.S. EPA Regional Oxidant Model (R0M2) has been developed over the last 10
years and is not operational. The 3-D grid model has been applied to the Northeast U.S. for a 50-day
period in 1980. Model evaluation results show the ROM2 is performing well with respect to predicting
the frequency distributions and spatial pattern of observed O3 concentrations.

AR-122

SCHERE, K.L., and R.A. Wayland. EPA Regional Oxidant Model (ROM2.0): Evaluation on 1980 NEROS
data bases. EPA/600/3-89/057, Atmospheric Research and Exposure Assessment Laboratory, Research
Triangle Park, NC , 351 pp. (1989).

The second generation U.S. EPA Regional Oxidant Model (ROM2.0) has been evaluated for the
northeastern United States using the 1980 NEROS data bases. The theoretical basis of the model and
its structure and organization are described. The data bases available from the summer 1980 period
include the routine monitoring data of meteorological and air quality parameters from the National
Weather Service and the SAROAD network. In addition, several extensive field measurement projects
were sponsored during the summer of 1980 in the northeastern U.S. on regional and urban scales.
Supplementary meteorological and air quality measurements were made at the surface as part of these
field projects. In addition, an extensive measurement campaign was conducted aloft using several
aircraft also on regional and urban scales. Also, a complete emissions inventory was assembled for
the 1980 base year for use in air quality modeling. The emissions inventory was composed of
anthropogenic and biogenic components. The ROM2 . 0 evaluation was conducted using quasi-deterministic
and diagnostic techniques. Strict temporal and spatial pairing between observations and predictions
was not used in the analysis. Model simulation was conducted during the period of July 12 to August
31, 1980. The simulation was begun under relatively clean tropospheric conditions to circumvent the
difficult problem of initialization. Model performance over the simulation period showed an overall
2% overprediction of the daily surface maximum O3 concentrations. ROM-predicted concentrations,
however, had a narrower range for ambient O3 with underestimation of highest values and overestimation
of lowest values. The ROM underpredicted daily maximum O3 values at the 75th percentile for group 1
sites by 30-50 ppb during major episodes. Ratios of observed to predicted NOx and NMHC concentrations
during the 06-09 h, LDT period were 2.5 and -5, respectively, for surface observations. The spatial
extent and concentrations of urban O3 plumes were generally simulated well, although a bias in the
transport direction along the East Coast caused frequent misalignment of the plumes. Model
performance analyses using aircraft data showed the model to underpredict the regional Oo tropospheric
burden under episodic conditions, although individual plumes were modeled well.

AR-123

SCHIERMEIER, F.A. Sources and evaluation of uncertainty in long-range transport models. In Air
Pollution Modeling and Its Application VI, H. van Dop (ed.). Plenum Press Corp., 11:357-366
(1988).

The American Meteorological Society, under joint sponsorship from the U.S. Environmental Protection
Agency, the Atmospheric Environment Service, Canada and the Ontario Ministry of the Environment,
Canada, convened a workshop in September 1984 to address an aspect of long-range transport modeling
that has become a topic of considerable concern, that is, the quantification of uncertainty in

48

long-range transport model predictions and the implications of these uncertainties on formulations of
control policy. A series of draft chapters provided a focus for discussion by 38 invited national and
international experts in the areas of policy perspectives, methods for sensitivity and uncertainty
analysis, and sources of errors and uncertainty in Eulerian, Lagrangian, and stochastic long-range
transport models. Composite uncertainty in model outputs consists of the meteorological, chemical,
and emissions input data uncertainty combined with model formulation uncertainty, the latter due to
representation of the physical-chemical processes and partly attributable to the mathematical
integrations. Therefore, insight into a model's response to arbitrary varying inputs for a particular
formulation is required in order to evaluate quantitative estimates of the expected change in air
quality or deposition as a result of specific changes in emissions. This insight can then be put to
use in determining the most effective strategies to mitigate air-pollutant-related environmental
problems .

AR-124

Sievering, H. , J. BOATMAN, M. Luria, and C.C. VAN VALIN. Sulfur dry deposition over the western
North Atlantic: The role of coarse aerosol particles. Tellus 4KB ) : 338-343 (1989).

A number of investigators have observed substantial amounts of coarse fraction (D> 1 nm) non-sea-
salt or excess sulfate (XSO^) to prevail in marine boundary layer (MBL) aerosol. Its dry deposition
velocity may be 1 cm s~* or more with low uncertainty relative to the dry deposition velocity of fine-
fraction XSO^ . Estimates of total sulfur dry deposition using MBL ambient air data over the western
North Atlantic Ocean are presented. It is shown, at distances of hundreds to 1000 km downwind from
sulfur source regions, that sulfur dry removal from the western North Atlantic MBL is dominated by the
dry deposition of XSO^ rather than that of SO2 .

AR-125

SNYDER, W.H. Fluid Modeling applied to atmospheric diffusion in complex terrain. Abstracts,
Second International Conference on Atmospheric Sciences and Applications to Air Quality, Tokyo,
Japan, October 3-7, 1988. Science Council of Japan, pp. 53 (1988).

Wind-tunnel and towing-tank studies conducted over the past 10 years at the U.S. Environmental
Protection Agency's Fluid Modeling Facility (FMF) of flow and diffusion in complex terrain are
reviewed. A primary impetus for this work was EPA's Complex Terrain Model Development Program
(CTMDP) -- designed to develop reliable atmospheric dispersion models applicable to large pollutant
sources in complex terrain, with primary emphasis on plume impaction during nighttime stable
conditions. The FMF interacted closely with the model developers participating in the CTMDP and
provided support in various ways through the conduct of a wide range of laboratory studies. Work at
the FMF prior to the inception of the program provided the basic framework for the model -- the
dividing-streamline concept -- and the focal point around which the field program was designed. At
the beginning of the program, the FMF provided direct support as an aid to planning the details and
strategies of the field experiments and testing the limits of applicability of the dividing-streamline
concept. Later work included exercises of "filling in the gaps" in the field data, furthering the
understanding of the physical mechanisms important to plume impaction in complex terrain and in stably
stratified flows in general, testing various modeling assumptions, providing data for "calibration" of
various modeling parameters, and testing the ability of the laboratory models to simulate full-scale
conditions. Simultaneously, the FMF responded to the needs of the regulatory arm of EPA, the Office
of Air Quality Planning and Standards (OAQPS), by providing guidance concerning expected terrain
effects and by conducting demonstration studies. These latter studies were concerned primarily with
simulation of diffusion in the neutral atmospheric boundary layer. Finally, several supplemental
studies were conducted, broadening and expanding upon the specific requests of the model developers
and the OAQPS. The highlights of the FMF complex-terrain research work are described herein.

AR-126

Spicer, C.W., C.L. Lindsey, W. Seiler, G. Schufmann, J. BOATMAN, G. Isaac, R. Leaitch, and J.K.S.
CHING. Aircraft measurements for diagnostic evaluation of acid deposition models. Preprints,
Sixth Joint Conference on Applications of Air Pollution Meteorology, Anaheim, CA, January 30 -
February 3, 1989. American Meteorological Society, Boston, 1-6 (1989).

Extended abstract.

AR-127

START, G.E., C.R. DICKSON, J.F. SAGENDORF , G.R. ACKERMANN, K.L. CLAWSON, R.C. JOHNSON, and N.R.
HUKARI . Atmospheric diffusion for airflows in the vicinity of the James Forrestal Campus,
Princeton, University, Special Report to the U.S. Department of Energy, Princeton Area Office,
Princeton, N J , Vols. I and II, 469 pp. (1989)

49

During July, August, and September of 1988, a field measurement program was conducted l,o directly
evaluate atmospheric diffusion conditions in the vicinity of the Princeton Plasma Physics Laboratory.
Three conservative gaseous tracers were released simultaneously during 14 separate test windows. Each
test was of six hours duration and 12 samples of 30 minutes length were collected at each of 98
sampling sites within 1000 m of the TFTR facility. The results of those direct tracer measurements
were evaluated and compared with model estimates of expected atmospheric diffusion. The findings of
those comparisons revealed greater dilutions of airborne effluents within the first kilometer downwind
than estimated by the regulatory models. There were substantial differences between the site specific
diffusion climatology and estimates from the generic diffusion (e.g., Pasquill-Gif f ord) family of
diffusion curves. The CIT calculations performed using the generic diffusion curves provided
overestimates of C/Q values expected in the PPPL setting. Use of the PPPL diffusion climatology
permits reduction of the amount of overestimation in C/Q values and leads to well-founded
calculations .

AR-128

Stewart, R.W., A.M. Thompson, M.A. Owens, and J. A. Herwehe. Comparison of parameterized nitric
acid rainout rates using a coupled stochastic-photochemical tropospheric model. Journal of
Geophysical Research 94:5219-5226 (1989).

A major tropospheric loss of soluble species such as nitric acid (HNO3) results from scavenging by
water droplets. Several theoretical formulations have been advanced which relate an effective time
independent loss rate for soluble species to statistical properties of precipitation such as the wet
fraction and length of a precipitation cycle. There is not enough data available on trace species
concentrations to test the computational results of alternative loss rate models against observations.
Therefore in this paper, various "effective" loss rates that have been proposed are compared with the
results of detailed time dependent model calculations carried out over a seasonal time scale. The
model which we have developed for this purpose is a stochastic precipitation model coupled to a
tropospheric photochemical model. The results of numerous time dependent seasonal model runs are used
to derive numerical values for the nitric acid residence time for several assumed sets of
precipitation statistics. These values are then compared with the results obtained by utilizing
theoretical "effective" loss rates in time independent models.

AR-129

STUNDER, B.J.B. Initial transport and diffusion based on ANATEX aircraft tracer measurements.
Preprints, Sixth Joint Conference on Applications of Air Pollution Meteorology, Anaheim, CA,
January 30 - February 3, 1989. American Meteorological Society, Boston, 97-100 (1989).

Extended abstract.

AR-130

Tans, P.P., T.J. CONWAY, and T. Nakazawa. Latitudinal distribution of the sources and sinks of
atmospheric carbon dioxide derived from surface observations and an atmospheric transport model.
Journal of Geophysical Research 94 (D4 ): 5151-5172 (1989).

Determination of the present global budget of atmospheric carbon dioxide (CO5) from the small and
persistent concentration gradients that exist in the atmosphere is discussed. The CO, concentration
at any site results from a combination of two factors: local sources or sinks and long-range
transport. To separate these two effects, an atmospheric transport model is needed. The extensive
sets of global C0£ measurements of the National Oceanic and Atmospheric Administration's (NOAA)
Geophysical Monitoring for Climatic Change (GMCC) division and of the Upper Atmosphere and Space
Research Laboratory of Tohoku University are combined with a two-dimensional transport model to
derive, in an "inverse" calculation, the latitudinal and seasonal distributions of sources and sinks
of CO2 necessary to reproduce the observed concentrations. The model transport parameters were
previously derived from a three-dimensional general circulation model. It is found that the southern
oceans are a sink of carbon of 0.8-1.5 Gt yr (1 Gt equals 10 g) and that the equatorial areas are a
source to the atmosphere of 1.4-2.8 Gt yr . Tropical deforestation as a major source of CO, must be
smaller than that because the oceans account for a significant part of the equatorial flux. There
seems to be significant seasonality in the sources and sinks of CO2 , both in the tropics and in the
southern oceans. The seasonal net ecosystem production north of 25°N is found to be 6.2-8.2 Gt of
carbon, but these estimates are probably somewhat too low. The source deduction problem is difficult
to solve, especially for the middle and high latitudes in the northern hemisphere. This is due to a
lack of observations over the continents, which occupy more than half of the global area at these
latitudes and are the regions where the sources and sinks are most intense. Evidence is found in the
results obtained for the GMCC and Tohoku data that the longitudinal variability of the data is large
enough, even in equatorial and southern latitudes, to prevent a two-dimensional model from calculating

50

a fully credible source/sink field. The longitudinal variations in the observations have to be
accounted for with a three-dimensional transport model.

AR-131

Taylor, G.E., Jr., P.J. Hanson, and D.D. BALDOCCHI . Pollutant deposition to individual leaves and
plant canopies: Sites of regulation and relationship to injury. Chapter 10, Assessment of Crop
Loss From Air Pollutants. W.W. Heck, O.C. Taylor, and D.T. Tingey (eds.). Elsevier, New York,
227-257 (1988).

No abstract.

AR-132

Thompson, A.M., R.W. Stewart, M.A. Owens, and J. A. Herwehe. Sensitivity of tropospheric oxidants
to global chemical and climate change. Atmospheric Environment 23:519-532 (1989).

A photochemical model has been used to quantify the sensitivity of the tropospheric oxidants O3 and
OH to changes in CHi , CO and NO emissions and to perturbations in climate and stratospheric chemistry.
Coefficients of the form 31n [O3] /31n[X] and 31n[OH] /31n[X] , where [X]=flux of CHA , CO, NO;
stratospheric O3 and HoO have been calculated for a number of "chemically coherent" regions (e.g.
nonpolluted continental, nonpolluted marine, urban) at low and middle latitudes. Sensitivities in O3
and OH vary with regional emissions patterns and are nonlinear within a given region as [X] changes.
In most cases increasing CH^ and CO emissions will suppress OH (negative coefficients) and increase O3
(positive coefficients) except in areas where NO and O3 influenced by pollution are sufficient to
increase OH. Stratospheric O3 depletion will tend to decrease O3 (except in high NO areas) and
increase OH through enhanced u.v. photolysis. Increased levels of water vapor (one possible outcome
of a global warming) will also decrease O3 and increase OH. We conclude that in most regions, NO, CO
and CH^ emission increases will suppress OH and increase O3 , but these trends may be opposed by
stratospheric O3 depletion and climate change. A regional survey of OH and O3 levels suggests that
the tropics have a pivotal role in determining the earth's future oxidizing capacity.

AR-133

Thoning, K.W., P.P. Tans, and W.D. KOMHYR. Atmospheric carbon dioxide at Mauna Loa Observatory 2.
Analysis of the NOAA GMCC data, 1974-1985. Journal of Geophysical Research 94 (D6) : 8549-8565
(1989).

The first 12 years (1974-1985) of continuous atmospheric CO2 measurements from the NOAA GMCC
program at the Mauna Loa Observatory in Hawaii are analyzed. Hourly and daily variations in the
concentration of CO2 due to local sources and sinks are described, with subsequent selection of data
representing background concentrations. A digital filtering technique using the fast Fourier
transform and low-pass filters was used to smooth the selected data and to separate the seasonal cycle
from the long-term increase in CO2 . The amplitude of the seasonal cycle was found to be increasing at
a rate of 0.05 + 0.02 ppm yr . The average growth rate of C02 was 1.42 + 0.02 ppm yr"1, and the
fraction of CO2 remaining in the atmosphere from fossil fuel combustion was 59%. A comparison between
the Mauna Loa continuous CO2 data and the CO2 flask sample data from the sea level site at Cape
Kumukahi, Hawaii, showed that the amplitude of the seasonal cycle at Cape Kumukahi was 23% larger than
at Mauna Loa, with the phase of the cycle at Mauna Loa lagging the cycle at Cape Kumukahi by about 1-2
weeks .

AR-134

Tikvart, J. A., J.L. DICKE, and J.S. TOUMA. Recent air quality modeling: Review of new techniques.
Proceedings, 1989 TAPPI Environmental Conference, Charleston, SC , April 1989. Technical
Association of the Pulp and Paper Industry, Atlanta, GA, Paper 14.1 (1989).

New and improved air quality modeling techniques regularly become available. Thus, it is necessary
to periodically update and expand EPA's, guidance on such technique for regulatory applications to
insure that the most accurate air quality impact assessments are always available. Since, the last
revisions to this guidance were made in 1988, new techniques have been released for complex terrain,
valley stagnation, and other, applications. Through a public hearing process, EPA has sought comment
on the validity, accuracy, merits, limitations, and potential for regulatory, use of these techniques.
Based on an analysis of the comments, EPA will make a formal proposal at a later time on the
techniques considered to have, merit.

51

AR-135

Tobiska, W.K. , and S.D. Bouwer. Intermediate-term variations of chromospheric and coronal solar
flux during high solar cycle 21 activity. Geophysical Research Letters 16(8) : 779-782 (1989).

The solar Lyman-a emission, the Mgll core-to-wing ratio, R(MgIIc/w), the 10.7-cm radio flux, F^g y,
and the 1-8 A X rays are compared during high solar cycle 21 activity from 1981-83. Daily variations
of the Mg II and Lyman-a ultraviolet (UV) lines are highly correlated. There is moderate linear
correlation between these lines and Fig j and poor linear correlation with 1-8 A X rays. Power
spectral analysis indicates that all four fluxes have 27-day periodicities due to solar rotation while
the R(MgIIc,w) and Lyman-a have noticeable 13-day periods in the datasets . F^g 7 moderately
represents the 27-day solar UV variations and represents to a lesser degree variations shorter than or
longer than rotation variations. X rays are not represented by F^g -j on intermediate-term or shorter
time-scales .

AR-136

TOUMA, J.S., C.F. Cole, K.D. Winges, and J.L. DICKE. Pit retention of particulate matter at
surface coal mines. Proceedings, 82nd Annual Meeting of the Air and Waste Management Association,
Anaheim, CA, June 25-30, 1989. Air and Waste Management Association, Pittsburgh, AWMA 89-114.5
(1989).

Five alternative analytical techniques were developed to predict the mass of particulate matter
that escapes from surface coal mine pits. The escape fraction techniques were evaluated by comparing
values of escape fraction computed from the analytical techniques to values of escape fraction,
inferred from smoke release studies performed at western surface coal mines. The simplest of the
predictive techniques appears to perform best, although none of the techniques predicts escape
fraction reliably over the range of wind speeds or stability classes measured at the surface coal
mines .

AR-137

TOUMA, J.S., D.B. Joseph, J.L. DICKE, and R.G. Ireson. Improved techniques for assessing plume
visual impact. Proceedings, 62nd Annual Meeting of the Air and Waste Management Association,
Anaheim, CA, June 25-30, 1989. Air and Waste Management Association, Pittsburgh, AWMA 89-14B.2
(1989).

No abstract.

AR-138

TOUMA, J.S., D.J. McNaughton, and P.M. Bodner. Development of a workbook for assessing impacts of
toxic air pollutants. Proceedings, 82nd Annual Meeting of the Air and Waste Management
Association, Anaheim, CA, June 25-30, 1989. Air and Waste Management Association, Pittsburgh, AWMA
89-30.1 (1989).

No abstract.

AR-139

TOUMA, J.S., G.J. Schewe, and S.M. Templeman. Development of a shoreline dispersion model.
Proceedings, 82nd Annual Meeting of the Air and Waste Management Association, Anaheim, CA, June 25-
30, 1989. Air and Waste Management Association, Pittsburgh, AWMA 89-43.3 (1989).

No abstract.

AR-140

TURNER, D.B., L.W. Bender, T.E. PIERCE, andW.B.
Environmental Software 4:52-61 (1989).

PETERSEN. Air Quality Simulation Models from EPA.

Air Quality Simulation Models have been made available using the UNAMAP system. UNAMAP consists of
FORTRAN source codes, test data and resulting print files on 9-track magnetic tape plus user's guides
from NTIS. It is also available on EPA's IBM 3090 as executable codes and source codes. An
assessment has been made of UNAMAP with recommendations to bring the system up-to-date regarding the
state-of-the-art of technology transfer. An electronic Bulletin Board Service has been supporting
UNAMAP since July 1987. FORTRAN mainframe source codes will soon be available on floppy diskettes
from NTIS.

52

AR-141

VAN VALIN, C.C., and M. Luria. O3 , CO, hydrocarbons and dimethyl sulfide over the western Atlantic
Ocean. Atmospheric Environment 22(11 ): 2401-2409 (1988).

The concentrations of O3 CO, dimethyl sulfide (DMS) and light hydrocarbons (C2_C^) were measured
from an instrumented aircraft during February-April 1985, near the U.S. East Coast and in the vicinity
of Bermuda as part of the Western Atlantic Ocean Experiment (WATOX). Sampling flights were performed
within the boundary layer (BL) and in the free troposphere (FT) at both locations. Photochemical
generation of 03 in polluted air parcels transported from the continent within the BL was identified
as the probable source of excess O3 (up to 50 ppbv above background). Convective lifting of boundary
layer air carried pollutants into the free troposphere. The concentrations of HC compounds in air
sampled near Bermuda had a significant inverse relation to air mass transport time from the continent.
The BL concentrations of the more reactive HCs (ethylene, propane, propylene, normal, and isobutane)
declined faster than the less reactive HCs (acetylene and ethane), and were found to be proportional
to air mass transport time over the ocean. DMS was detected, with few exceptions, only with the BL at
both sampling locations. The average concentrations in the BL samples collected near the U.S. East
Coast and in the vicinity of Bermuda were 27 and 54 pptv. In all samples taken in the BL the DMS
concentration decreased sharply as a function of altitude.

AR-142

Vet, R.J., A. Sirois, D. Lamb, and R. ARTZ. Intercomparison of precipitation chemistry data
obtained using CAPMoN and NADP/NTN protocols. NOAA TM ERL ARL-174, 39 pages + appendix (1989).

Results of a comparison of precipitation chemistry data, acquired under the CAPMoN and NADP/NTN
protocols at the two colocated sites, are presented. For this intercomparison study precipitation was
collected daily (CAPMoN) and weekly (NADP/NTN) for slightly more than one year. The data were
analyzed qualitatively through scattergrams and statistically by testing the difference data against a
simple constant-bias model. Although measurable and statistically significant biases exist in some
variables (ammonium, nitrate, free acidity, and precipitation depth), the data from each network track
each other and can be considered representative of the precipitation at the respective sampling sites,
at least on a weekly time scale. It should be possible to combine the data from the NADP/NTN and
CAPMoN networks in a meaningful way to analyze the spatial distribution of wet deposition across North
America, as long as due concern is given to the comparability of the measurements.

AR-143

VIEBROCK, H.J., and E.M. Poole-Kober. Fiscal year 1987 summary report of NOAA Meteorology Division
support to the Environmental Protection Agency. NOAA TM ERL ARL-170 (PB89-194294 ) , 50 pp. (1989).

The Meteorology Division provided meteorological research and operational support to the U.S.
Environmental Protection Agency. Basic meteorological operational support consisted of the
application of dispersion models, and the conduct of dispersion studies and model evaluations. The
primary research effort was the development and evaluation of air quality simulation models using
numerical and physical techniques supported by field studies. Modeling emphasis was on the dispersion
of photochemical oxidants and particulate matter on urban and regional scales, dispersion in complex
terrain, and the transport, transformation and deposition of acidic materials. Highlights during
FY-1989 included completion of the Complex Terrain Dispersion Model (CTDM), establishment of an
electronic bulletin board for use under the User's Network for Applied Modeling of Air Pollution
(UNAMAP), application of the Regional Oxidant Model (ROM) to assess the impact of proposed N0X control
strategies on ozone concentrations in the northeastern United States, completion of a sulfur-only
version of the Regional Acid Deposition Model (RADM), and initiation of a major field study to
evaluate the RADM and other regional dispersion models.

AR-144

Voldner, E.C., M.P. Olson, T.L. CLARK, R.L. DENNIS, M. Alvo , and S. Seilkop. International Sulfur
Deposition Model Evaluation (ISDME): A Summary. In Air Pollution Modeling and Its Application VI,
H. van Dop (ed.). Plenum Publishing Corp., New York, 305-320 (1988).

Eleven linear-chemistry atmospheric models of sulfur deposition were evaluated for each season of
1980. The evaluation data set consisted of sulfur wet deposition amounts calculated from screened
precipitation chemistry measurements at 46 sites across eastern North America. The focus of this
study differed substantially from those of preceding model evaluation studies in that the ISDME
emphasized the ability of the models to replicate, within the uncertainties of the observations, the
spatial patterns of observed seasonal amounts. Patterns of the predictions and observations were
constructed via an interpolation technique known as simple kriging, which minimizes interpolation
errors and estimates uncertainties resulting from the interpolation errors as well as measurement
errors. The evaluation results indicated that for all seasons but spring, the models generally did

53

not mimic the observed location of the seasonal maximum amounts of sulfur wet deposition within the
uncertainty limits. However, the interpolated predictions of eight models were within the uncertainly
limits of the interpolated observations across at least 80% of the evaluation regional for at least
three seasons.

AR-145

Vukovich, F.M., and J.K.S. CHING. Table look-up model to estimate cloud vertical transport for
acid deposition models. Preprints, Sixth Joint Conference on Applications of Air Pollution
Meteorology, Anaheim, CA, January 30 - February 3, 1989. American Meteorological Society, Boston,
43-47 (1989).

Extended abstract.

AR-146

Wakamatsu, S., I. Uno, and K.L. SCHERE . Application of a three-dimensional photochemical smog
formation model to the Tokyo Metropolitan Area. In Air Pollution Modeling and Its Application VI,
H. van Dop, (ed.). Plenum Press, New York, 259-270 (1988).

No abstract.

AR-147

Wang, H., and D.D. BALDOCCHI . A numerical model for simulating the radiation regime within a
deciduous forest canopy. Agricultural and Forest Meteorology 46:313-337 (1989).

A numerical model that simulates the radiation regime inside a fully leafed and leafless deciduous
forest canopy is discussed and tested. The model incorporates features which account for the vertical
variation on leaf inclination angles and penumbral effects; these features have been experimentally
shown to significantly influence the radiation regime in a deciduous forest. This version of the
model mimics measured values quite well and improves upon estimates of the canopy radiation regime
that are based upon the general assumption that the leaf inclination angle distribution is spherical
and that the Poisson probability distribution describes the probability of beam penetration. On the
other hand, the numerical model assumes first-order scattering, which is inferior to multiple
scattering routines.

AR-148

WEICKMANN, K.M. Convection and circulation anomalies over the oceanic warm pool during 1981-82.
Proceedings, Western Pacific International Meeting and Workshop on TOGA-COARE , J. Picaut, R. Lukas
and T. Delcroix, (eds.). Centre ORSTOM de Noumea, 214-224 (1989).

An important issue in understanding the low frequency evolution of the atmospheric circulation and
the ocean-atmosphere system is the role of transients during individual events. We examine this
question from an observational point-of-view for two different time scales and speculate on the
importance of transients from these two different perspectives. Our analysis period covers September
1981-April 1982 which includes the development phase of the 1982-83 El Nino Southern Oscillation
(ENSO) as well as six Madden-Julian (30-60 day) Oscillations (MJO). The latter include a strong event
during December 1981 that is studied in detail. The self-similarity of these two time scales
(Webster, 1989) is also highlighted.

AR-149

WEICKMANN, K.M. , and S.J. Khalsa. Observations of coupling between oscillations in northern
hemispheric angular momentum and the 30-60 day oscillation in the tropics. Preprints, 18th AMS
Conference on Hurricanes and Tropical Meteorology, San Diego, CA, May 16-19, 1989. American
Meteorological Society, Boston, 161-162 (1989).

Extended abstract.

AR-150

WELLMAN, D.L., M. Luria, C.C. VAN VALIN, and J.F. BOATMAN. The use of an airborne air sampling
platform for regional air quality studies. NOAA TR ERL 437-ARL 10, 15 pp. (1989).

A Beechcraft King Air, owned and operated by the Office of Aircraft Operations, National Oceanic
and Atmospheric Administration (NOAA), was converted from a passenger airplane into an atmospheric air
quality sampling platform. It has been used in several regional air quality studies including the

54

Gulf Coast Experiment, the Western Atlantic Ocean Experiment (WATOX), and the Processing of Emissions
by Clouds and Precipitation (PRECP) experiment. The aircraft is equipped to measure atmospheric trace
gases (S02, 03 , and N0X ) , aerosols, and meteorological parameters (temperature, humidity, wind speed,
wind direction, atmospheric pressure, and solar radiation). It has grab sampling equipment (for
aerosol chemistry and organic compounds) and instruments for continuously recording position and
heading. Most of the scientific equipment aboard was provided by the Air Quality Group, Air Resources
Laboratory, NOAA, with additional support from several universities and other institutions. The WATOX
project is used as an example to demonstrate the capabilities of the aircraft as a regional air
quality sampling platform. During this experiment, air samples were taken in the winter and spring
seasons of 1985 and 1986 at two locations off the U.S. East Coast (Newport News, VA, and Boston, MA)
and in the vicinity of Bermuda. These locations were selected to provide samples representative of
contaminated air masses exiting from the continent and being transported over the Atlantic Ocean.
Flight tracks were designed to assess the flux of atmospheric pollutants above and within the
planetary boundary layer. Through the successful use of the aircraft, it was revealed that most of
the pollutant transport within this region was being accomplished inside the boundary layer.
Additionally, in several cases, contaminated air masses were observed in the free troposphere.

AR-151

Young, J.O., M. Aissa, T.L. Boehm, C.J. Coats, Jr., J.R. Eichinger, D.J. Grimes, S.W. Hallyburton,
W.E. Heilman, D.T. Olerud, Jr., S.J. Roselle, A.R. Van Meter, R.A. Wayland, and T.E. PIERCE.
Development of the Regional Oxidant Model Version 2.1. EPA/600/3-89/044 , Atmospheric Research and
Exposure Assessment Laboratory, Research Triangle Park, NC , 55 pp. (1989).

This report describes improvements that were made to version 2.0 of the Regional Oxidant Model
(ROM) in order to create version 2.1. The ROM is an Eulerian grid model that calculates hourly
concentrations of ozone and other chemical species for episodes up to about a month long. The ROM's
modeling domain, composed of grid cells that are approximately 19 km on a side, encompasses an area on
the order of 1000 km by 1000 km. The physical processes that the ROM simulates include
photochemistry, nocturnal jets and temperature inversion, spatially- and temporally-varying wind
fields, terrain effects, dry deposition, and emissions of biogenic and anthropogenic ozone precursors.
Major technical improvements include upgrading the Carbon Bond Mechanism to version 4.2, improving the
biogenic emissions processing system (which now includes a canopy model), updating the wind fields
processor, and expanding the use of buoy data for determining meteorological data fields over water.
Also, ROM 2.1 can be adapted more easily than version 2.0 to various modeling domains in eastern North
America. In addition, the computer software has been redesigned to facilitate ROM's eventual
application by outside users.

Addendum

AR-152

DIAZ, H.F. , C.S. RAMAGE, S.D. WOODRUFF, and T.S. Parker. Climatic Summaries of Ocean Weather
Stations . NOAA - Environmental Research Laboratories, Boulder, CO, 48 pp. + summary (1987).

Surface and upper air climatological summaries for 16 Ocean Weather Stations (OWS) are presented.
Periods of record for surface data vary from 7 years for OWS X to more than 30 years for OWS C, M, and
P. OWS T operated primarily during the summer typhoon season (May to November). Valid upper air
records are generally of equal or lesser duration than those taken at the surface. The interval of
time covered extends from 1945 for the earliest starting OWS to 1982 for a few OWS, some of which are
still operating. The purpose of this special report is to make available to the scientific community
high-quality climatological data over generally fixed ocean areas for comparison with data from
traveling merchant ships and for comparison with profiles derived from satellite observations. The
basic data used for preparation of the summaries are available through either the National Center for
Atmospheric Research in Boulder, Colorado or the National Climatic Data Center in Asheville, North
Carolina .

AR-153

Gillani, N,, V., W.H. White, and J.S. CHING. A semi-empirical mass balance approach for estimating
primary emissions of reactive species from an urban-industrial complex. Proceedings, 80th Annual
Meeting of the Aj.r Pollution Control Association, New York, NY, June 21-26, 1987. Air Pollution
Control Association, Pittsburgh, 087-58.5 (1987).

No abstract.

55

AR-154

LAMB, R.G. Design and applications of the Regional Oxidant Model (ROM). Proceedings, North
American Oxidant Symposium, Quebec, Canada, February 25-27, 1987. Ministere de 1' environment,
Quebec, Canada, 154-189 (1987).

The basic design of the EPA's Regional Oxidant Model (ROM) is described and preliminary results are
presented of a study of the impact of biogenic hydrocarbon emissions on ozone concentrations in the
Northeastern United States. It is shown that the predicted maximum ozone levels during a six day
period in July 1980 agree better with observed concentrations when the biogenic component is included
in the hydrocarbon emissions then when it is omitted. The largest effects of the biogenic
hydrocarbons occur in the Appalachians, downwind of large N0X sources in the Ohio River, Where peak
1-hour averaged concentrations over the six-day period drop by as much as 50 ppb when the biogenic
emissions are shut off.

AR-155

OLTMANS, S.J., W.D. KOMHYR, and R.D. GRASS. Atmospheric ozone at the South Pole during 1986.
Antarctic Journal of the United States . 1987 Review, XXII ( 5) : 257-259 (1987).

No abstract.

AR-156

Tikvart, J. A., J.L. DICKE, and J.S. TOUMA. Including new modeling techniques in regulatory
programs. Proceedings, 80th Annual Meeting of the Air Pollution Control Association, New York, NY,
June 21-26, 1987. Air Pollution Control Association, Pittsburgh, Paper 87-73.1 (1987).

No abstract.

AR-157

VAN VALIN, C.C., M. Luria, D.L. WELLMAN, R.L. GUNTER, and R.F. Pueschel. Natural sulfur flux from
the Gulf of Mexico: Dimethyl sulfide, carbonyl sulfide, and sulfur dioxide. NOAA TR ERL 432-ARL 9
(PB88-137484), U pp. (1987).

Atmospheric measurements of natural sulfur compounds were performed over the northern Gulf of
Mexico during the late summer months of 1984. Air samples were collected with an instrumented
aircraft at elevations of 30-3500 m, during both day and night. Most air samples were representative
of the clean maritime atmosphere, although some were from continental contaminated air during periods
of offshore flow at the coastline. In all samples, carbonyl sulfide concentrations were within the
range of 400-500 pptv. Conversely, the dimethyl sulfide concentrations showed significant
variability: during clean atmospheric conditions the average of all measurements was 27 pptv, whereas
under polluted conditions the average was 7 pptv. Measurable quantities of dimethyl sulfide (>5 pptv)
were not observed above the boundary layer. The average sulfur dioxide concentration measured in the
marine (clean) atmosphere was 215 pptv, which is consistent with the oxidation of dimethyl sulfide
being its major source.

56

ATLANTIC OCEANOGRAPHIC AND METEOROLOGICAL LABORATORY

AO-001

Barnes, CM., E.J. Zipser, and B. Ryan. Rainband structure in developing Tropical Cyclone Irma (1987).
Research supported by NOAA Grant 45-WCNR-5-00388 . Extended Abstracts, 18th Conference on Hurricanes and
Tropical Meteorology, San Diego, CA, May 16-19, 1989. American Meteorological Society, Boston, 151-152
(1989) .

Extended abstract.

AO-002

BITTERMAN, D.S., and D.V. HANSEN. Direct measurements of current shear in the tropical Pacific Ocean and its
effect on drift buoy performance. Journal of Atmospheric and Oceanic Technology 6(2) :274-279 (1989) .

Measurements of ocean surface currents derived from drift buoy trajectories are subject to errors caused by
slippage of the buoy relative to the surrounding water. This slippage error is caused by a number of forces
acting on the buoy and drogue element, one of which is the current shear in the water. Idealized model calcu-
lations are used to exemplify some effects of vertical current shear on drogues, and on the performance of
drogued buoy systems in current shear. It is shown that shear enhances the performance of drogues, and that
long drogues should perform better than short drogues in shear, but shear also can induce slippage by adding
drag force to the buoy hull. To establish environmental design parameters, average and rms current shear
values between 9.7 m and 22.5 m depth were computed from Doppler acoustic current profiler measurements from
the tropical Pacific Ocean. Largest values of shear (~0.25 s_1 rms) were found near the equator in the eastern
Pacific as expected. Elsewhere the shear was generally less than 0.02 s_1, mostly less than 0.01 s_1. Average
values of shear were generally less than 0.007 s_1 .

AO-003

BLACK, M.L. Signal loss of WSR-57 radars as a function of range in tropical cyclones. Preprints, 24th Con-
ference on Radar Meteorology, Tallahassee, FL, March 27-31, 1989. American Meteorological Society, Boston,
514-517 (1989) .

No abstract.

AO-004

BLACK, M.L., and F.D. MARKS, JR. Concentric eyewalls in Hurricane Gilbert (1988). Extended Abstracts, 18th
Conference on Hurricanes and Tropical Meteorology, San Diego, CA, May 16-19, 1989. American Meteorological
Society, Boston, 224-225 (1989).

Extended abstract.

AO-005

BLACK, P.G. , R.L. Elsberry, L.K. Shay, R.M. Partridge, and J.D. Hawkins. Atmospheric boundary-layer and
oceanic mixed-layer observations in Hurricane Josephine obtained from air-deployed drifting buoys and
research aircraft. Journal Qf Atmospheric and Oceanic Technology 5(6) :683-698 (1988) .

Three drifting buoys were successfully air-dropped ahead of Hurricane Josephine. This deployment resulted in
detailed simultaneous measurements of surface wind speed, surface pressure and subsurface ocean temperature
during and subsequent to storm passage. This represents the first time that such a self-consistent data set of
surface conditions within a tropical cyclone has been collected. Subsequent NOAA research aircraft overflights
of the buoys, as part of a hurricane planetary boundary-layer experiment, showed that aircraft wind speeds,
extrapolated to the 20 m level, agreed to within ± 2 m s-1, pressures agreed to within ± 1 mb, and sea-surface
temperatures agreed to within ± 0.8°C of the buoy values. Ratios of buoy peak 1 rain wind (sustained wind) to
1/2 h mean wind > 1.3 were found to coincide with eyewall and principal rainband features. Buoy trajectories
and subsurface temperature measurements revealed the existence of a series of mesoscale eddies in the subtropi-
cal front. Buoy data revealed storm-generated, inertia-gravity-wave motions superposed upon mean current
fields, which reached a maximum surface speed > 1.2 m s-1 immediately following storm passage. A maximum
mixed-layer temperature decrease of 1.8°C was observed to the right of the storm path. A temperature increase
of 3.5°C at 100 m and subsequent decrease of 4.8°C following storm passage indicated a combination of turbulent
mixing, upwelling and horizontal advection processes.

AO-006

BLACK, P.G. , L.K. Shay, R.L. Elsberry, and J.D. Hawkins. Response of the Gulf of Mexico to Hurricane
Gilbert. Extended Abstracts, 18th Conference on Hurricanes and Tropical Meteorology, San Diego, CA, May
16-19, 1989. American Meteorological Society, Boston, 226-227 (1989).

Extended abstract.

AO-007

BURPEE, R.W. A summer day without significant rainfall in south Florida. Monthly Weather Review 117(3):
680-687 (1989) .

Precipitating cumulus clouds occur regularly in the afternoon over the south Florida peninsula during summer
months. A day without significant rainfall or radar echoes is rare. This paper discusses one such day, 23
July 1987, during which a dry, stable airmass covered the Florida peninsula. Nonprecipitating shallow cumulus
formed in a few areas, but there were not any deep, precipitating cumulus clouds over land. The thermodynamic
characteristics of the airmass are described and the synoptic-scale patterns that produced the airmass are
presented.

A0-008

BURPEE, R.W., and M.L. BLACK. Temporal and spatial variations near the centers of two tropical cyclones.
Monthly Weather Review 117(101:2204-2218 (1989).

The Hurricane Research Division collected radar reflectivity data with a portable recorder that was attached
to the WSR-57 radar at National Weather Service offices as Hurricane Alicia of 1983 and Elena of 1985
approached the U.S. coastline. The reflectivity data were used to compute rain rates for the eyewall region,
including the rain-free eye and the rainbands in the annular area outside the eyewall, but within 75 km of the
center of the eye. Area- and time-averaged rain rates (R) in the eyewall region were 5.2 and 6 . 0 mm h_1 ,
respectively, for Alicia and Elena. The corresponding averages in the rainband region were 2.8 and 3.4 mm Ir1 .
The rain rates include reflectivity corrections that were based upon the variation of average returned power
with range in four hurricanes. Precipitation was convective in the eyewall region and largely stratiform in
the rainband region. Comparison with published results from other tropical cyclones suggests that the cor-
rected R's in the eyewall region are underestimated, but are within a factor of 1.6 of the actual amount. The
R's in the rainband region, however, are similar to those from other studies. Alicia's eyewall region repre-
sented ~15% of the computational area and contributed ~25% of the total rain rate within 75 km of the center
of the eye. Elena's eyewall region comprised ~22% of the area and contributed — 33% of the area-averaged rain
rate. The area-averaged rain rate (R) in the eyewall region of both hurricanes varied by up to 4 mm in 1-2 h.
In Alicia, the variations of R were caused by the growth and decay of mesoscale convective areas with reflec-
tivity > 38 dBZ that achieved maximum areas of 500-800 km2. In Elena, life cycles of individual convective
cells with maximum reflectivities > 48 dBZ also accounted for large changes in the eyewall R. In both hurri-
canes, the time series of R in the rainband regions were less variable than the eyewall R because the rainband
regions included larger areas than the eyewall and had a smaller percentage of area with convective activity.
For several hours, the maximum rain rates in the eyewall and rainband regions of Alicia occurred in the left-
front quadrant relative to the storm motion. Then the maximum rain rate in the eyewall region shifted to the
right-front quadrant and the maximum in the rainband region moved to the right of the storm track. In Elena,
the maximum rain rates in the eyewall and rainband regions were in the right-front quadrant throughout the com-
putational period. About 55% of the precipitation in Elena's eyewall region occurred in the right-front quad-
rant. In both hurricanes, the maximum rain rate in the rainband region was generally oriented to the right of
that in the eyewall region.

AO-009

BURPEE, R.W. , M.L. BLACK, and F.D. MARKS, JR. Vertical motions measured by airborne Doppler radar in the
core of Hurricane Elena. Extended Abstracts, 18th Conference on Hurricanes and Tropical Meteorology, San
Diego, CA, May 16-19, 1989. American Meteorological Society, Boston, 69-70 (1989).

Extended abstract.

AO-010

Carbone, R.E., and F.D. MARKS, JR. Velocity track display (VTD) : A real-time application for airborne
Doppler radar data in hurricanes. Extended Abstracts, 18th Conference on Hurricanes and Tropical Meteo-
rology, San Diego, CA, May 16-19, 1989. American Meteorological Society, Boston, 11-12 (1989).

Extended abstract.

A0-011

Carder, K.L., R.G. Steward, G.R. HARVEY, and P.B. 0RTNER. Marine humic and fulvic acids: Their effects on
remote sensing of ocean chlorophyll. Limnology and Oceanography 34(1):68-81 (1989).

Marine humic and fulvic acids were concentrated from about 1,400 liters of seawater from the Gulf of Mexico,
and specific absorption coefficients were measured for each from 240 to 675 nmi . Spectral absorption coeffi-
cients were then calculated for Gulf of Mexico stations where earlier data on humic and fulvic acid concentra-
tions were available. Marine humic and fulvic acid values have low molecular weights consistent with extrapo-
lations from soil-derived curves of their specific absorption coefficients vs. molecular weight. Marine fulvic
and humic acids appear to account for most, if not all, water color or Gelbstoff in the offshore regions of the
Gulf of Mexico. Based on a remote-sensing reflectance model, it appears that the increase in the Gelbstoff:
chlorophyll ratio for waters adjacent to and downstream from regions of high primary productivity accounts for
much of the deviation found for such waters from the global chlorophyll algorithm of the Coastal Zone Color
Scanner .

58

AO-012

CLARKE, T.L., J.R. PRONI , and L.C. Huff. Joint CGS-AOML acoustical bottom echo-formation research II: Field

experiment results and recommendations for echo-sounder design. NOAA TM ERL AOML-67 (NTIS number not yet

available) , 71 pp. (1989) .

Field experiments were conducted to test and verify a mathematical model that has been developed to assess
the effects of bottom roughness and material properties on bottom echo shape. The physical basis of the model
is reviewed and model output is presented. The experiments were conducted in lower Chesapeake Bay and involved
taking high resolution acoustic data at a number of frequencies and taking supporting sediment samples. A
unique, high-resolution bottom profiler was used to measure bottom roughness profiles for input to the model.
While model predictions were in general agreement with the data, fine structure was observed in the echoes that
could not be explained by the existing model. An extension to the model has been developed that is able to
account for this structure. The essential ingredient of this extension is to consider bottom surface scat-
tering as arising from a number of statistically independent patches within the transducer beam. This revised
model should lead to improved predictions of bottom echo waveforms for echo-sounder design. The algorithm
developed for removing ship motion from the observations suggests a design for a new type of echo-sounder
detector circuit based on an energy threshold. This circuit could be easily implemented with modern digital
signal processing (DSP) circuits, and it might be suitable for retro-fitting to existing echo-sounders.

AO-013

DEMARIA, M. A nested spectral model for hurricane track forecasting. Extended Abstracts, 18th Conference on
Hurricanes and Tropical Meteorology, San Diego, CA, May 16-19, 1989. American Meteorological Society, Boston,
206-207 (1989) .

Extended abstract.

A0-014

DEMARIA, M. , J.M. Davis, and D.M. Wojtak. Observations of mesoscale wave disturbances during the Genesis of
Atlantic Lows Experiment. Monthly Weather Review 117 (4) : 826-842 (1989).

The Portable Automated Mesonet (PAM) data obtained during the Genesis of Atlantic Lows Experiment (GALE) are
used to document mesoscale wave activity during the three-day period from 4-6 February 1986. From the surface
pressure analyses, four cases of wave activity are identified with wavelengths of 200-400 km, phase speeds of
20-40 m s_1 , and trough-to-crest pressure amplitudes of 0.5-3.5 mb. Precipitation was associated with the
waves in two of the four cases. Detailed analyses of the horizontal structure show that the waves do not have
the pressure-wind relationship expected from linear gravity wave theory. The wind vectors are oriented from
high to low pressure, with a maximum amplitude between the high- and low-pressure areas. Low-level inversions
were present in three of the four cases. In the case without a low-level inversion, the amplitude rapidly
decreased as the wave moved towards the east. In the case that lasted for the longest time period (at least
8 h) and had the largest pressure amplitude, the sounding had a critical level (where the wind speed equaled
the wave speed) and a level where the Richardson number was < 0.25. Vertical velocities as large as 30 cm s_1
were observed and there was some evidence that the wave was vertically tilted towards its direction of motion.
Complex principal component analysis (CPCA) is applied to the surface pressure data to determine the applica-
bility of this technique to the study of mesoscale waves. It is shown that CPCA could be used to generalize
the results of this study to the entire 60-day period of GALE.

A0-015

DODGE, P.P. The precipitation structure of Hurricane Elena. Preprints, 24th Conference on Radar Meteo-
rology, Tallahassee, FL, March 27-31, 1989. American Meteorological Society, Boston, 522-524 (1989).

No abstract.

AO-016

Eberhart, G.L., P. A. R0NA, and J. Honnorez. Geologic controls of hydrothermal activity in the Mid-Atlantic
Ridge rift valley: Tectonics and volcanics. Marine Geophysical Research 10:233-259 (1988).

The rift valley at three widely separated sites along the Mid-Atlantic Ridge is characterized using geologi-
cal and geophysical data. An analysis of bottom photographs and fine-scale bathymetry indicates that each
study area has a unique detailed geology and structure. Spreading rates are apparently asymmetric at each
site. Relationships between tectonic and volcanic structure and hydrothermal activity show that various stages
in the evolution of the rift valley are most favorable for seafloor expression of hydrothermal activity. In a
stage found at 26°08'N, site 1 (TAG), the rift valley is narrow, consisting of both a narrow volcanically
active valley floor and inner walls with small overall slopes. High-temperature hydrothermal venting occurs
along the faster spreading eastern inner wall of this U-shaped rift valley. Site 2 (16°46'N) has a narrow
valley floor and wide block faulted walls and is at a stage where the rift valley is characterized by a
V-shape. No neovolcanic zone is observed within the marginally faulted, predominantly sedimented floor and
hydrothermal activity is not observed. The rift valley at site 3 (14°54'N), with postulated extrusive volcanic
activity and a stage in valley evolution tending toward a U-shape, shows evidence of hydrothermal activity

59

within the slightly faster spreading eastern inner wall. Evidence for tectonic activity (inward- and outward-
facing faults and pervasive fissuring) exists throughout the wide inner wall. Hydrothermal activity appears to
be favored within a U-shaped rift valley characterized by a narrow neovolcanic zone and secondarily faulted
inner walls.

AO-017

ENFIELD, D.B. El Nino, past and present. Reviews of Geophysics 27(11:159-187 (1989).

El Nino events - anomalous warmings of the tropical Pacific with associated climatic and economic impacts
around the globe - have occurred at several-year intervals since before written records began with the logs of
Francisco Pizarro in 1525. In this review, the history of El Nino research is traced from its beginnings
through the key innovations of Bjerknes and Wyrtki to the unusual 1982-1983 event. Recent research is then
reviewed, with detailed discussions of the key processes: instability growth and vacillation between climate
states. Throughout the paper there are adjunct discussions of extraregional teleconnections , ecological
impacts, and research on El Nino in the ancient record. The final section discusses the present paradigm for
vacillations between El Nino and non-El Nino states and speculates on the possible chaotic nature of El Nino.
El Nino and its atmospheric counterpart, the Southern Oscillation, appear to occur as an internal cycle of pos-
itive and negative feedbacks within the coupled ocean-atmosphere climate system of the tropical Pacific,
although hypotheses based on external forcing also exist. All events are preceded by westerly wind anomalies
on the equator near the date line. Baroclinic equatorial Kelvin waves are generated, propagating eastward
toward South America where they depress the thermocline and raise sea level, while the deep, upper ocean reser-
voir of warm water in the western Pacific is depleted. Sea surface temperature (SST) anomalies in the cool
eastern Pacific occur primarily because the normal source of cold water is depressed below the reach of mixing
and upwelling processes. In the central equatorial Pacific, eastward advection by anomalous zonal flows is the
principal mechanism. Nonlinear heat transfer to the lower atmosphere creates a positive ocean-atmosphere feed-
back resulting in the unstable growth of anomalies along the equator. Much of the present research aims at
determining how the ocean-atmosphere system vacillates between the El Nino and non-El Nino states. Coupled
models suggest that a longer time scale, negative-feedback process produces the transitions: at the apex of an
El Nino development an anomalous atmospheric convection above the areas of reduced upper layer thickness in the
off-equatorial ocean, which slowly propagate westward to the western boundary as Rossby waves and back to the
central equatorial Pacific as upwelling Kelvin waves, re-establishing the normal cooling process. A similar
negative feedback of opposite sign completes the second half of an oscillation, returning again to the El Nino
state. However, the notion that El Nino/Southern Oscillation variability results only from an internal feed-
back process is still highly contentious and a number of external forcing mechanisms have been proposed.

AO-018

ENFIELD, D.B. Is El Nino becoming more common? Oceanography l(2):23-27 (1988).

No abstract.

AO-019

FRANKLIN, J.L. Objective analyses of Omega dropwindsonde data from Hurricane Josephine (1984). Extended
Abstracts, 18th Conference on Hurricanes and Tropical Meteorology, San Diego, CA, May 16-19, 1989. American
Meteorology Society, Boston, 204-205 (1989).

Extended abstract.

A0-020

FRANKLIN, J.L., C.S. Velden, CM. Hayden , and J. KAPLAN. A comparison of VAS and ODW data around a subtropi-
cal cold low. Extended Abstracts, 4th Conference on Satellite Meteorology, San Diego, CA, May 16-19, 1989.
American Meteorological Society, Boston, 141-144 (1989).

Extended abstract.

AO-021

GAMACHE, J.F. Retrieval of thermodynamic and microphysical variables from airborne Doppler observations in
Hurricane Norbert (1984). Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL , March 27-31,
1989. American Meteorological Society, Boston, 525-528 (1989).

No abstract.

AO-022

GAMACHE, J.F. The eyewall water budget of Hurricane Norbert (1984) as determined from airborne Doppler
radar. Extended Abstracts, 18th Conference on Hurricanes and Tropical Meteorology, San Diego, CA, May 16-19,
1989. American Meteorological Society, Boston, 73-74 (1989).

Extended abstract.

60

AO-023

Georges, T.M., D.R. PALMER, R.M. Jones, and J. P. Riley. A survey of acoustic techniques for monitoring El
Nino. Journal of the Acoustical Society pJL America 84:S91 (1988).

The challenge of understanding the El Niflo-Southern Oscillation (ENSO) cycle in the equatorial Pacific Ocean
is a test of one's abilities to observe, model, and forecast the processes of global climate change. Moni-
toring the structure, dynamics, and energetics of the ocean interior on the space-time scales of the ENSO
signal appears to be a task for acoustic remote sensing. Therefore, the following acoustic strategies for
monitoring ENSO-induced changes in the upper ocean are examined: (1) ocean acoustic tomography; (2) a long-
range acoustic thermometer; (3) passive monitoring of ambient acoustic noise level; (4) an occultation tech-
nique that depends on bottom absorption; and (5) space-time scintillation analysis. Models of the ocean's
acoustic properties are formulated from measurements made during the 1982-1983 ENSO event and we simulate
acoustic amplitude and travel-time measurements to find out how sensitive they are to the temperature changes
that accompany a strong El Nino.

AO-024

HANSEN, D.V. Physical aspects of the El Nino event of 1982-1983. In Global Ecological Consequences of the
1982-83 El Nino-Southern Oscillation. P.W. Glynn (ed.). Elsevier Oceanography Series (preprint) (1989).

El Nino events are marked by the appearance of anomalously warm ocean waters and unusual rainfall in normally
arid coastal regions of Ecuador and Peru. During the past century such events have occurred at about four-year
intervals on average, and nine of the events have been described as strong or very strong. In the spring of
1982 the heavy rainfall that normally characterizes the Indo-Pacific archipelago began to shift eastward toward
the central Pacific. During the following year the region of anomalous rainfall traversed the ocean to the
coast of South America, in phase with anomalous winds, currents, and sea surface temperatures. At the peak of
the event in the eastern tropical Pacific, Peru and Ecuador experienced record-setting rainfall leading to
flooding and avalanches, near surface ocean currents reversed from their normal direction, sea surface tempera-
ture rose to 5°C or more above normal, the thermocline plunged to 100 m or more below normal, and sea level
rose to nearly half a meter above normal. Upon reaching the coast, many of the oceanic perturbations propa-
gated poleward along the continental margins in both hemispheres, carrying the signs and effects of El Nino to
middle and high latitudes in the Pacific. The magnitude of this event made it the "event of the century" in
most variables, and the event of several centuries in some. The magnitude of perturbation of the atmosphere in
the tropical Pacific sector certainly carried anomalies also in distant regions of the atmosphere, and thereby
secondarily in other parts of the ocean. At greater distance, however, it becomes increasingly difficult to
distinguish between anomalies resulting from El Nino and those arising from other kinds of variations of the
atmospheric circulation.

AO-025

HANSEN, D.V., and A. HERMAN. A seasonal isotherm depth climatology for the eastern tropical Pacific. NOAA
TR ERL 434 AOML-33 (Revised) (NTIS number not yet available), 35 pp. (1989).

A seasonal climatology of the depths of the 10°C, 15°C, and 20°C isotherms in the eastern tropical Pacific is
presented. The analyses used Kriging, which is a method for optimal interpolation of data fields. The data
set consisted of 10,505 expendable bathythermograph (XBT) and conductivity-temperature-depth (CTD) stations
collected during non-El Nino years. Results are presented on shaded contour maps with values overprinted at 2°
intervals. The method of analysis also yields an estimate of the uncertainty of each interpolated point.

AO-026

HANSEN, D.V., and A. HERMAN. Temporal sampling requirements for surface drifting buoys in the tropical
Pacific. Journal of Atmospheric and Oceanic Technology 6(4) : 599-607 (1989) .

Drifting buoy data from the eastern tropical Pacific Ocean are used to evaluate the degradation of sea sur-
face temperature and current information incurred by reducing the number of transmissions from drifting buoys
using the ARG0S system for position finding. Buoy locations are interpolated at uniform time intervals using
an optimum interpolation method known as Kriging, which provides also an estimate of the rms position error.
It is found that the published standard for surface current measurement for the TOGA Program (5 cm s^1) can be
met with transmissions on one day of three in the Southern Hemisphere. Due to stronger mesoscale variability
in the Northern Hemisphere the standard would be jeopardized by reducing transmissions even to one day of two.
The standard for observation of sea surface temperature (0.1°C) can be met in either hemisphere with transmis-
sions on one day of four. The Lagrangian decorrelat ion times for the Northern Hemisphere region of the eastern
tropical Pacific are estimated as four days in the meridional direction, and 14 days in the zonal direction.
It is recommended that transmissions be made on one day of three, and the time scale for the TOGA standard be
revised accordingly.

AO-027

HANSON, K. , and G.A. MAUL. Analysis of the historical meteorological record at Key West, Florida (1851-1986)
for evidence of trace-gas induced climate change. In Chapter 2.1. Implications of Climatic Changes in the
Wider Caribbean Region. United Nations Environment Programme, UNEP (0CAJ/CAR WG.1/INF.3, 27-35 (1989).

61

Meteorological data for Key West, Florida have been examined for evidence of changes during recent decades
that may be attributed to increasing trace gases in the atmosphere. The 136-year temperature record (1851-
1986) gives evidence that a warming has occurred. However, there are questions of the reality of the warming,
because of the mix of temperature observing conditions over the period of record. The 101-year precipitation
record (1886-1986) gives evidence that no significant change in precipitation has occurred during the period of
record. Future work on the reality of the apparent warming at Key West is suggested.

AO-028

HANSON, K. , G.A. MAUL, and T.R. Karl. Are atmospheric "greenhouse" effects apparent in the climatic record
for the contiguous U.S. (1895-1987)? Geophysical Research Letters 16(l):49-52 (1989).

The temperature and precipitation climate records for the United States have been examined. These records
consist of area-averages across the contiguous United States and northern plains. They are based on as many as
6,000 stations. Time series of these data were tested for constancy of the mean using the Spearman rank test
and two-phase regression. Test results indicate that overall trends are near zero. The only evidence for a
long-term trend is in fall precipitation for the contiguous United States. This trend appears to result from
higher fall precipitation during the period 1970-1987 compared to the remainder of the period (1895-1969).

AO-029

HARVEY, G.R., and M.S. YOUNG. Ozone in seawater and lake water: A reversible reservoir. Geophysical
Research Letters 15(111:1199-1201 (1988).

Observations made at sea and examination of global ozone monitoring data from oceanic sites indicate that
ozone mixing ratios often increase with increasing wind speed. However, the slope of the increase approaches
zero at wind speeds above about 6 m/sec (13 kts). Subsequent laboratory experiments confirmed that ozone can
be purged from any seawater sample whether freshly collected, stored, or from depths of 3,500 m. Samples of
Lake Michigan water are purged of ozone in less time than seawater and its capacity is less than that of sea-
water. The rate of evolution of ozone is increased by altering the pH, changing the ionic strength by the
addition of salts or by evaporation. These results suggest that a significant portion of tropospheric boundary
layer ozone mixing ratios could be maintained by a reversible equilibrium with the ocean and lake surfaces.

AO-030

HIRSH, M.A., and H.A. FRIEDMAN. Creating an awareness of the hurricane problem in at-risk coastal communi-
ties of south Florida. Proceedings, 2nd Conference on School and Popular Meteorological Education, Crystal
City, VA, July 12-16, 1989. American Meteorological Society, Boston, 160-162 (1989).

Extended abstract.

AO-031

Houze , R.A., Jr. Observed structure of mesoscale convective systems and implications for large-scale
heating. Research partially supported by NOAA Grant 40-WCNR-6-02428 . Quarterly Journal of the Royal
Meteorological Society 115(487 1:425-461 (1989).

Mesoscale convective cloud systems that produce large amounts of rain in midlatitudes and most of the rain in
the tropics consist of convective and stratiform clouds. The convective regions contain numerous deep cells
that are often, but not always, arranged in lines. The stratiform region is an outgrowth of the convective
ensemble; it lies adjacent to the convective region and is seeded by ice particles detrained from convective
towers. Sometimes it lies to the rear of a propagating convective line, while on other occasions it surrounds
the convection. The heating of the large-scale environment by a mesoscale convective system is affected by
both the convective and stratiform regions. Although processes such as melting and radiation are important,
the net heating system is dominated by condensation and evaporation associated with vertical air motions. This
paper reviews recent observational evidence regarding the mean vertical motion profiles in the convective and
stratiform regions of mesoscale convective systems and the implications of these mean motions for the vertical
distribution of heating of the large-scale environment. In both the convective and the stratiform regions,
vertical motions have been determined by various techniques, including composites of rawinsonde and aircraft
wind data, single- and dual-Doppler precipitation radar analyses, and wind-profiler observations. In strati-
form regions, these data consistently show vertical velocity that is upward in the upper troposphere and down-
ward in the lower troposphere. The level separating upward from downward motion is located from 0 to 2 km
above the 0°C level, depending on location within the stratiform region. Diagnostic calculations show that
these vertical motion profiles imply heating of the upper troposphere and cooling of lower levels by strati-
form-region processes. Data on vertical motions in the convective regions are less consistent from case to
case. These data sometimes indicate that the mean vertical velocity in convective regions is maximum in the
lower troposphere. In other cases, the data indicate a maximum in the high troposphere. Diagnostic calcula-
tions show that heating profiles diagnosed from these two types of profile are quite different, the first
having a maximum of heating in the lower troposphere, while the second has a maximum in the middle troposphere.
Although it is difficult to determine whether or not the differences in estimates arise from different types of
observations, analysis methods or sampling strategies, it seems likely that they stem from differences in the

62

large-scale environment of the different mesoscale systems. The ubiquitous occurrence of stratiform regions in
mesoscale convective systems and hurricanes, together with their consistent heating profiles which systemati-
cally concentrate heating in upper levels while cooling lower levels, are a major consideration in evaluating
the interaction of mesoscale systems with the large-scale environment. However, the consistency of the strati-
form profiles from case to case lies primarily in the variation of the convective-region profiles from one case
to another. It is suggested that future work should focus on the convective-region vertical profiles of verti-
cal motion and heating and on the large-scale environmental factors that may control the variation of these
profiles from case to case.

AO-032

JOHNS, E. , D.R. Watts, and H,T. Rossby. A test of geostrophy in the Gulf Stream. Journal q£ Geophysical
Research 94 (C3 ): 3211-3222 (1989).

In July 1982 two detailed sections of density and absolute velocity were taken across the Gulf Stream north-
east of Cape Hatteras to conduct an accurate test of geostrophy in a strong current. The sections, which were
taken about four days apart, were each completed within 48 hours, using one ship to make closely spaced (12 km)
conductivity-temperature-depth measurements to 2,000 m, and a second ship to simultaneously take Pegasus abso-
lute velocity profiles to the ocean bottom. The Gulf Stream path and curvature were also surveyed. The dynam-
ically inferred velocity profiles were made absolute by matching their velocities to the Pegasus profiles at
2,000 m. The geostrophic method (properly referenced) underestimated the observed velocities by 10-25 cm s_1
in the core of the current above 500 m where speeds exceeded 150 cm s^1 . The difference is a factor of 2
larger than the sampling and measurement errors in corresponding parts of the current, estimated to be
5-10 cm s_1 in the strong current and 2-5 cm s_1 elsewhere. We can account for the supergeostrophic currents
quite effectively by including the centripetal acceleration (from the path curvature) in the momentum equation.
In this case the differences in the current core decrease to less than 5-10 cm s_1, well within the uncertain-
ties of the method. The transport above 2,000 m is less sensitive to curvature effects; it agrees to within
3 Sv before and 1 Sv after correcting for curvature, or approximately 2% of the total 93 Sv transport. The
deep velocity field below 1,000 m had significant changes (10-20 cm s^1) in structure, and even reversals, in
the four days between the sections, with cross-stream scales of 50-100 km. This deep variability, attributed
to topographic Rossby waves, introduces more than 10 Sv uncertainty in defining the total volume transport of
the Gulf Stream.

AO-033

Landsea, C.W., H.E. WILL0UGHBY, and J.M. Masters. Analysis of Hurricane Gilbert at its maximum intensity.
Extended Abstracts, 18th Conference on Hurricanes and Tropical Meteorology, San Diego, CA, May 16-19, 1989.
American Meteorological Society, Boston, 222-223 (1989).

Extended abstract.

AO-034

Leaman, K.D., E. JOHNS, and T. Rossby. The average distribution of volume transport and potential vorticity
with temperature at three sections across the Gulf Stream. Journal of Physical Oceanography 19(1):36-51
(1989) .

Average cross sections of downstream velocity and temperature, obtained using PEGASUS current profilers at
three locations along the Gulf Stream, have been portioned into 2.5°C temperature intervals to examine the dis-
tribution of transport increase versus temperature between the two southern sections (27° and 29°N) and off
Cape Hatteras (73°W) . Between 27°N and 29°N the total transport of the Florida Current over the sections
increased only by about 3 x 106 m3 s_1 (3 Sv) but the current broadens by about 50%. By Cape Hatteras, the
transport has increased nearly three-fold to 93.7 Sv , of which two-thirds of the increase is contained in the
19.5°-17.0°C ("18°") layer and in water colder than the 7°C "sill" temperature found at 27°N. Cross-stream
distributions of layer transport, potential vorticity, and thickness are estimated. At each section, the
10 x 10-7 nr1 S"1 contour tends to be a boundary (independent of temperature) between the region of relatively
uniform layer potential vorticity on the anticyclonic (offshore) side of the current and an area with high lat-
eral potential vorticity gradients on the cyclonic (onshore) side. In the colder (< 7°C) waters off Cape
Hatteras, layer potential vorticity also tends to be uniform at ~5 x 10 7 m"1 s-1. Layer potential vorticity in
the 18° layer is quite uniform with minimum values ~3 . 5 x 10^7 nr1 s^1 at 27° and 29°N and somewhat less off
Cape Hatteras, which is close to where 18°C water is formed in the wintertime. At Cape Hatteras this same
layer shows a peak in transport/unit width at the point where the layer begins to thin as one moves into the
Gulf Stream core from the southeast. A simple model based on conservation of layer potential vorticity is pro-
posed to describe this transport structure.

AO-035

Liao, Q. , and M.C. PAZOS. Drifting buoy data from western tropical Pacific for the period February 1, 1986
through February 28, 1989. N0AA DR ERL A0ML-14 (NTIS number not yet available), 125 pp. (1989).

No abstract.

63

AO-036

LONG, R.B., and W.C. THACKER. Data assimilation into a numerical equatorial ocean model. Part I: The model
and the assimilation algorithm. Dynamics of Atmospheres and Oceans 13:379-412 (1989).

Numerical modeling provides a powerful tool for the study of the dynamics of oceans and atmospheres. How-
ever, the relevance of modeling results can only be established by reference to observations of the system
being modeled. Typical oceanic observation sets are sparse, asynoptic, of mixed type and limited reliability,
generally inadequate in some respects, and redundant and inconsistent in others. An optimal procedure for
interfacing such data sets with a numerical model is the so-called adjoint method. This procedure effectively
assimilates the observations into a run of the numerical model by finding that solution to the model equations
that best fits all observations made within some specified space-time interval. The method requires the con-
struction of the adjoint of the numerical model, a process made practical for models of realistic complexity by
the work of Thacker and Long (1988). In the present paper, the first of two parts, we illustrate the applica-
tion of Thacker and Long's approach by constructing a data-assimilating version of an equatorial ocean model
incorporating the adjoint method. The model is subsequently run for five years to near-steady state, and
exhibits many of the features known to be characteristic of equatorial oceanic flows. Using the last 54 days
of the run as a control, a set of simulated sea level and subsurface density observations are collected, then
successfully assimilated to demonstrate that the procedure can recover the control run, given a generous amount
of data. In part II (Long and Thacker, 1989), we conduct a sequence of numerical experiments to explore the
ability of more limited sets of observations to fix the state of the modeled ocean; in the process, we examine
the potential value of sea level data obtained via satellite altimetry.

AO-037

LONG, R.B., and W.C. THACKER. Data assimilation into a numerical equatorial ocean model. Part II: Assimi-
lation experiments. Dynamics of Atmospheres and Oceans 13:413-439 (1989).

A sequence of numerical experiments is conducted using a linear, semi-spectral equatorial ocean model and an
advanced data assimilation scheme. The numerical model is based on decomposition of the oceanic fields into
Kelvin and Rossby waves belonging to the baroclinic modes of a stratified equatorial ocean. The assimilation
procedure finds that solution to the model equations that best fits, in the generalized least-squares sense,
all observations made within some specified space-time interval. All experiments are of the "identical twin"
type; synthetic data are generated by sampling the observable fields produced by a control run of the model,
then the data are assimilated using the same model. The sequence of numerical experiments serves two purposes:
to demonstrate the performance of the assimilation procedure in the context of a fully three-dimensional, time-
varying equatorial ocean model; and to examine the utility of specified data sets, and in particular, observa-
tions of sea level, in estimating the state of the equatorial ocean. The results indicate that the assimila-
tion procedure works very well when sufficient data are provided. However, sea level data alone are not
sufficient and must be supplemented with subsurface observations if more than a few baroclinic modes are
allowed in the model ocean. The required amount of supplementary subsurface data (in the form of density pro-
files in these experiments) can be reduced by imposing smoothness constraints on the recovered model solution.

AO-038

LORD, S.J. Vorticity advection from nested analyses of the hurricane environment. Extended Abstracts, 18th
Conference on Hurricanes and Tropical Meteorology, San Diego, CA, May 16-19, 1989. American Meteorological
Society, Boston, 202-203 (1989).

Extended abstract.

AO-039

Lyons, W.A., M.G. Venne , P.G. BLACK, and R.C. Gentry. Hurricane lightning: A new diagnostic tool for tropi-
cal storm forecasting? Extended Abstracts, 18th Conference on Hurricanes and Tropical Meteorology, San
Diego, CA, May 16-19, 1989. American Meteorological Society, Boston, 113-114 (1989).

Extended abstract.

AO-040

MARKS, F.D., JR. Kinematic structure of the inner core of hurricanes as viewed by airborne Doppler radar.
Proceedings, 3rd Interagency Airborne Geosciences Workshop, La Jolla, CA, February 21-24, 1989. American
Meteorological Society, Boston, IV-79-IV-81 (1989).

Extended abstract.

AO-041

MARKS, F.D., JR. Radar observations of tropical weather systems. In Radar in Meteorology. D. Atlas (ed.).
American Meteorological Society, Boston, 1024 pp. (1989).

No abstract.

64

AO-042

MARKS, F.D. , JR. Three-dimensional structure of the eyewall of Hurricane Emily (1987) as determined from an
airborne Doppler radar. Extended Abstracts, 18th Conference on Hurricanes and Tropical Meteorology, San
Diego, CA, May 16-19, 1989. American Meteorological Society, Boston, 71-72 (1989).

Extended abstract.

AO-043

MARKS, F.D. , JR., and S.J. LORD. Kinematic structure of Hurricane Gloria as viewed by airborne Doppler radar
and Omega dropwindsondes . Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL , March 27-31,
1989. American Meteorological Society, Boston, 529-532 (1989).

No abstract.

AO-044

MAUL, G.A. Climate change and sea level rise in the Caribbean region. The Siren 39:15-17 (1989).

No abstract.

AO-045

MAUL, G.A., Editor, Implications of climatic changes in the wider Caribbean region. Draft Report, United
Nations Environment Programme, UNEP(OCA)/CAR WG. 1/INF. 3 , 183 pp. (1989).

No abstract.

AO-046

MAUL, G.A. Implications of climatic changes in the wider Caribbean region: An overview. In Coping with
Climate Change. J.C. Topping (ed.). Climate Institute, Washington, D.C., 432-458 (1989).

No abstract.

AO-047

MAUL, G.A. , and N.J. BRAVO. Fate of satellite-tracked buoys and drift cards off southeastern Atlantic coast
of the United States. Florida Scientist 52(3) : 154-170 (1989).

Twelve satellite-tracked drifting buoys were released, one each month between April 1984 and March 1985, at
the 75 m isobath, 70 km southeast of Cape Canaveral, Florida. Starting in May 1984, 500 drift cards were also
released at each buoy deployment from the same site (28°N, 80°W) . In addition, satellite-tracked buoys from
May 1979, September 1983, and February 1985, which drifted into or through the area, were studied for infor-
mation about surface currents and particle trajectories. All 12 buoys from the 28°N/80°W launch site drifted
north past Cape Canaveral (28.5°N); only the May 1984 buoy drifted into the coastal zone off Mayport, FL
(30.4°N), although several others showed a tendency to do so in that area. Every buoy deployed within 5 km of
the western edge of the Gulf Stream was entrained into the current, and some as far as 25 km were also
entrained. The September 1983 buoy, which was deployed slightly west of 286N/80°W, and the February 1985 buoy,
which was deployed in the Gulf of Mexico, both came ashore near St. Lucie Inlet, FL (27.2°N), 140 km south of
Cape Canaveral. Drift cards from May, September, October, and November 1984, and February 1985 were recovered
west and north of 28°N/80°W. Forty percent of the cards recovered were from south of Cape Canaveral; Cocoa
Beach, FL (28.3°N), and Pontevedra Beach, FL (30.2°N), reported most of the returns. For those months when
drift cards were returned, buoy trajectories showed little correlation with drift card vectors. Drift cards
established the possibility of materials coming ashore along the Florida Atlantic coast, both north and south
of Cape Canaveral, particularly in the autumn.

AO-048

MAUL, G.A. , and K. HANSON. Sea level variability in the IntraAmerican Sea with concentration on Key West as
a regional example. In Chapter 2JL, Implications o_f_ Climatic Changes in ihe. Caribbean Region. United
Nations Environment Programme, UNEP (OCA)/CAR WG. 1/INF. 3 , 89-101 (1989).

No abstract.

AO-049

MAUL, G.A. , and N.M. KAVANAGH. English-Spanish bibliography in physical oceanography and climate for the
Caribbean Sea and adjacent regions. Intergovernmental Oceanographic Commission of UNESCO, IOC/INF-783, 49
pp. (1989).

No abstract.

65

AO-050

MAUL, G.A. , D.A. MAYER, M. BUSHNELL, and K. HANSON. Volume transport fluctuations in the Gulf Stream system
modeled from Florida sea level records, 1931-1988. Proceedings, Chapman Conference on the Physics of the
Gulf of Mexico. American Geophysical Union, 12 (1989).

No abstract.

AO-051

McCreary, J. P., Jr., H.S. Lee, and D.B. ENFIELD. The response of the coastal ocean to strong offshore winds:
With application to circulation in the Gulfs of Tehuantepec and Papagayo. Journal of Marine Research
47:81-109 (1989) .

Two ocean models are used to investigate the response of the coastal ocean to strong offshore winds: a
linear 1 1/2-layer model, and a non-linear 1 1/2-layer model that allows entrainment of cool water into the
surface layer. The models are forced by wind stress fields similar in structure to the intense winter-time,
mountain-pass jets (~20 dyne/cm2) that appear in the Gulfs of Tehuantepec and Papagayo for periods of three to
ten days. Solutions are arranged in a hierarchy of increasing dynamical complexity, in order to illustrate the
important physical processes. They compare favorably with observations in several ways. Some properties of
solutions are the following. While the wind strengthens there is an ageostrophic current (not Ekman drift)
that is directed offshore. This offshore drift forces coastal upwelling, thereby lowering the local sea level
and sea surface temperature (SST). Although the drop in sea level at the coast can be large and rapid (of the
order of 20 cm at the peak of a wind event), none of this signal propagates poleward as a coastally-trapped
wave. While the wind weakens the ageostrophic current is directed onshore, and consequently the coastal ocean
readjusts toward its initial state. Throughout the wind event, cyclonic and anticyclonic gyres spin up off-
shore on either side of the jet axis due to Ekman pumping. Entrainment cools SST offshore on and to the right
(looking onshore) of the jet axis, and virtually eliminates the cyclonic gyre. The advection terms intensify
the anticyclonic gyre and give it a more circular shape. After a wind event, the anticyclonic gyre propagates
westward due to (3. Its propagation speed is enhanced over that of a linear Rossby wave due to the non-linear
terms associated with the increased layer thickness at the center of the gyre and with the divergence of momen-
tum flux.

A0-052

Metz, S., J.H. Trefry, and T.A. NELSEN . History and geochemistry of a metalliferous sediment core from the
Mid-Atlantic Ridge at 26°N. Geochimica et Cosmochimica Acta 52:2369-2378 (1988).

Fourteen thousand years of hydrothermal deposition are recorded in a metalliferous sediment core recovered
from the Trans-Atlantic Geotraverse (TAG) Hydrothermal Field on the Mid-Atlantic Ridge at 26CN. An estimated
26 to > 96% of the sediment at this core site is hydrothermally derived as determined from the CaC03i Al and Fe
data. Layers of essentially pure vent precipitates contain < 3% CaC03 and < 0.5% Al, with high concentrations
of Fe (43%), Cu (4.1%), Zn (1.2%), Mn (1.1%), V (480 ppm) , Pb (175 ppm) , Cd (32 ppm) and Hg (3.8 ppm) . Sedi-
ment accumulation rates vary from ~1 to > 30 g/cm2/l,000 y throughout the core, a function of the intensity of
hydrothermal inputs. Distinct hydrothermal events are recorded at 6,000 and 8,500 y B.P. in layers containing
> 90% vent-derived material. Vertical metal profiles and interelement relationships in the core result from
variable deposition of oxides and sulfides, oxidation and dissolution of sulfide phases and scavenging of
metals from seawater.

AO-053

Molinari, J., and D. Vollaro. External influences on hurricane intensity. Part I: Outflow layer eddy
angular momentum fluxes. Research supported by NOAA Grants 50-WCNR-6-06096 and 50-WCNR-8-06055 . Journal of
the Atmospheric Sciences 46(81:1093-1105 (1989).

Outflow layer winds were objectively analyzed every 12 h for six days during the life cycle of Hurricane
Elena (1985). A high correlation was found between angular momentum fluxes by azimuthal eddies at large radii
and central pressure changes in the storm 27-33 h later. Momentum flux by eddies exceeded that by the azi-
muthal mean outside the 800 km radius, while vortex spin-up by the eddies reached instantaneous magnitudes as
large as 25 m s_1/day. Outflow maxima and minima repeatedly appeared > 1,000 km from the hurricane center and
tracked inward with time. The results provide evidence of significant environmental control on the behavior of
the storm. After reaching hurricane strength, Elena experienced a major secondary intensification associated
with a large inward cyclonic eddy momentum flux produced by the passage of a middle latitude trough north of
the hurricane. An outflow maximum appeared radially inside of the eddy momentum source, consistent with bal-
anced vortex theory, and tracked inward with the eddy momentum source during the following 24 h. When the out-
flow maximum reached the storm core, an extended period of rapid pressure falls followed. It is speculated
that these pressure falls represented a response to midlevel spin-up forced by the outflow layer momentum
sources. Although environmental forcing dominated the later stages of Elena, the rapid initial intensification
of the storm as it moved from land to water appeared to be a precursor to subsequent environmental interac-
tions. The enhanced anticyclonic outflow from this initial deepening reduced the outflow-layer inertial
stability, allowing a more radially extended region for external forcing. The secondary intensification of
Elena is thus viewed as a cooperative interaction between mesoscale events at the hurricane core and synoptic-
scale features in the upper tropospheric environment.

66

AO-054

Molinari, J., and D. Vollaro. Interaction of a hurricane with a baroclinic wave. Research supported by NOAA
Grant 50-WCNR-8-06055 . Extended Abstracts, 18th Conference on Hurricanes and Tropical Meteorology, San
Diego, CA, May 16-19, 1989. American Meteorological Society, Boston, 50-51 (1989).

Extended abstract.

AO-055

MOLINARI, R.L., and J. Morrison. The separation of the Yucatan Current from the Campeche Bank and the intru-
sion of the Loop Current into the Gulf of Mexico. Journal o_i Geophysical Research 93 (C9) : 10 , 645-10 , 654
(1988) .

Data collected in the eastern Gulf of Mexico during 1974, 1975, and 1976 show that the penetration of the
Loop Current into the Gulf is strongly correlated with the location of the Yucatan Current on the Campeche
Bank. The Loop does not penetrate far into the Gulf when the Yucatan Current separates from the bank in the
vicinity of the Catoche Tongue (i.e., the eastern Campeche Bank). Deep Loop penetrations are correlated with
separations farther west on the bank. The angle of the Yucatan Current at separation is also correlated with
the location of separation (i.e., smaller angles relative to due east are correlated with separations from far-
ther east on the bank). Thus, small angles at separation are correlated with shallow intrusions of the Loop.
Historical temperature data collected in the eastern Gulf are reviewed and support these correlations. Simple
conservation of potential vorticity considerations can explain the correlation between the angle at separation
and the penetration of the Loop.

AO-056

ORTNER, P.B., L.C. HILL, and S.R. CUMMINGS. Zooplankton community structure and copepod species composition
in the northern Gulf of Mexico. Continental Shelf Research 9(4):387-402 (1989).

Zooplankton community structure and copepod species composition are analyzed in samples obtained during
spring and winter from three areas of the northern Gulf of Mexico: near the Mississippi River outflow, off
Cape San Bias, and in the central Gulf of Mexico. Samples from different regions were distinguishable in
correspondence analysis of dominant species and/or functional groups. The near-surface communities of the
Mississippi and central Gulf were particularly distinct while Cape San Bias was intermediate in both structure
and specific character. Saltier waters directly beneath the Mississippi Plume yielded samples similar to those
from near-surface waters well offshore. At the same time near-surface waters off the Mississippi and off Cape
San Bias to the west were distinguishable even during spring when the outflow from the Mississippi was at its
annual peak. These differences are consistent with the discharge and flow patterns of the Mississippi River
plume and the northern Gulf and with systematic differences in such parameters as temperature, salinity and
chlorophyll concentration. The implications of these observations upon the feeding environments of the larvae
of commercially significant fish species are addressed since both zooplankton prey and larval predators appear
to be particularly abundant in the Mississippi River plume environs.

AO-057

OOYAMA, K.V. Thermodynamics in the primitive form for modeling the moist atmosphere. Extended Abstracts,
18th Conference on Hurricanes and Tropical Meteorology, San Diego, CA, May 16-19, 1989. American Meteorolog-
ical Society, Boston, 157-158 (1989).

Extended abstract,

AO-058

PALMER, D.R., T.M. Georges, and R.M. Jones. New techniques for investigating the properties of chaotic ray
paths. Journal of UlS. Acoustical Society of America 84:S91 (1988) .

It has been established that acoustic ray paths in a range-dependent ocean environment can exhibit chaotic
behavior [Palmer £i al. , Geophys. Res. Lett. 15, 569-572 (1988)]. The usual techniques for identifying chaotic
rays are the examination of Poincare sections and power spectra of path depth, as well as the observation of
exponential sensitivity to initial conditions. These techniques are not always useful, however, and are not
directly related to observable signal characteristics. Travel times, ray elevation angle at axis crossings,
and upper and lower turning point depths have practical relevance and provide new insights into the character
of chaotic rays. Since this effort involved the numerical calculation of ray paths for both the Helmholtz and
parabolic equations, procedures were developed for comparing results obtained for the two equations.

AO-059

PALMER, D.R., M.G. Brown, F.D. Tappert , and H.F. BEZDEK. Classical chaos in nonseparable wave propagation
problems. Geophysical Research Letters 15(61:569-572 (1988).

Numerical calculations show that acoustic ray paths in a weakly range-dependent, deterministic ocean model
exhibit chaotic behavior, that is, have an exponentially sensitive dependence on initial conditions. Since the

67

ray equations define a nonautonomous Hamiltonian system with one degree of freedom, these results may be under-
stood in terms of recent advances in classical chaos. The Hamiltonian structure of ray equations in general
suggests that chaotic ray trajectories will be present in all types of linear wave motion in geophysics when
variables do not separate, as in laterally inhomogeneous media.

AO-060

PIOTROWICZ, S.R., R.A. Rasmussen, K.J. HANSON, and C.J. FISCHER. Ozone in the boundary layer of the equato-
rial Atlantic Ocean. Tellus 41B: 314-322 (1989).

Shipboard (~7) ozone and carbon monoxide measurements made in the equatorial Atlantic Ocean south of the
inter-tropical convergence zone between 5°N and 10°S and 10°-30°W in August and September of 1986 exhibited
variability in excess of a factor of 2. Ozone mixing ratios ranged from < 25 to over 50 ppbv while carbon mon-
oxide mixing ratios ranged from < 50 to over 120 ppbv along the western edge of the equatorial Atlantic in
spite of the fact that the prevailing surface winds were from the east to southeast at between 5 and 15 m/sec.
Ozone and carbon monoxide mixing ratios were generally lower and exhibited less variability in the eastern
tropical Atlantic where a lighter, south to southeasterly wind regime predominated. Isobaric trajectory
analyses indicated that the high ozone and carbon monoxide mixing ratios appear to be related to long-range
transport off of the African continent. Time series analysis of the ozone data indicates a diel cycle in ozone
mixing ratios with a morning maximum and afternoon minimum.

AO-061

POWELL, M.D. Boundary-layer kinematic structure in outer hurricane rainbands. Extended Abstracts, 18th Con-
ference on Hurricanes and Tropical Meteorology, San Diego, CA, May 16-19, 1989. American Meteorology Society,
Boston, 67-68 (1989).

Extended abstract.

AO-062

POWELL, M.D. Boundary-layer structure and dynamics in outer hurricane rainbands. Preprints, 24th Conference
on Radar Meteorology, Tallahassee, FL, March 27-31, 1989. American Meteorological Society, Boston, 533-536
(1989) .

No abstract.

AO-063

PRONI, J.R., and W.P. DAMMANN. Observations of acoustic backscatter from oceanic wastewater outfalls.
Journal q£ the Acoustical Society of. America 85 : S42 (1989) .

Narrow beam echo sounders were used to characterize the spatial distribution of wastewater plume material
from six ocean outfalls in the south Florida area. Volume scattering strengths were computed and plotted as a
function of depth and horizontal distance for 200 kHz echoes. Reduction in peak scattering strength with
increased range from the outfall locations correlated well with reduction in concentration of Rhodamine-WT dye
introduced into the undiluted wastewater at a concentration of 1 ppm. Sound power reflection coefficients
ranging from 10-5 to 10~9 were observed for these wastewater plumes. The data presented demonstrates the degree
to which the sound power reflection coefficient for a distribution of scatterers is dependent upon the concen-
tration of those scatterers, and shows the utility of the acoustical method in watermass characterization.

AO-064

PSZENNY, A. A. P., A.J. Castelle, and J.N. Galloway. A Study of the sulfur cycle in the Antarctic marine
boundary layer. Journal of Geophysical Research 94 (D7) : 9818-9830 (1989).

Atmospheric sampling was conducted aboard R/V POLAR DUKE from March 21 to April 27, 1986, in the southern
Drake Passage and in the coastal waters west of the Antarctic Peninsula. Average atmospheric concentrations
(n=6) of sulfur dioxide (SO2) vapor, aerosol methane-sulfonate (CH3SO3-) and aerosol non-sea-salt sulfate
(nss-S04=) were 0.36, 0.22, and 0.34 nmol nr3, respectively. Cascade impactor data indicated that more than 85%
of the masses of both CH3SO3- and nss-S04= were on particles of < 0.25-n.m mean aerodynamic radius. Average
concentrations (n=8) of CH3SO3- and nss-S04= in precipitation were 0.09 and 0.57 (iM, respectively. Box model
calculations based of this limited data suggest a total sulfur removal rate from the local marine boundary
layer of 0.3-7.2 |a.mol m-2 day"1. This removal approximately balances the oceanic source of dimethylsulf ide
(DMS) sulfur of 1.2-4.4 |imol nr2 day-1 (± 100%) estimated by Berresheim (1987) from data obtained during the
same cruise. The box model calculations also suggest that heterogeneous S02 oxidation may be the major pathway
for DMS to sulfate conversion (~75%) and/or that other sources of sulfate may not be negligible. Observed
mineral aerosol and 222Rn concentrations were low but slightly elevated above "pure" remote marine background
levels, suggesting a weak but discernible continental character in sampled air. Uncertainties are large owing
to the limited sampling time, study area, and numbers of samples obtained, but overall, the sulfur cycle in the
coastal Antarctic marine boundary layer appears not to differ remarkably from that in other remote marine
regions.

68

AO-065

RAMOS, P. A. , and D.R. PALMER. Comments on the Deep Six Sound Channel. Journal o_f the Acoustical Society of
America 85:1767 (1989).

Some features of the Deep Six Sound Channel [J. C. Miller, J. Acoust. Soc . Am., H, 859-862 (1982)], which
may be important to those who wish to use the model in various applications, are noted and discussed.

AO-066

Rao, R.R., R.L. MOLINARI, and J.F. FESTA . Evolution of the climatological near-surface structure of the
tropical Indian Ocean. Part I: Description of mean monthly mixed layer depth and sea-surface temperature,
surface current, and surface meteorological fields. Journal of Geophysical Research 94 (C8) : 10, 801-10, 815
(1989) .

Mean monthly mixed layer depth (MLD) , sea-surface temperature (SST) , and surface current climatologies are
generated for the tropical Indian Ocean. In addition, surface meteorological climatologies are produced for
those variables which could influence the evolution of the MLD and SST fields. Only the MLD climatology is
described in detail as climatologies for the other variables have appeared previously in the literature. The
sum of the annual and semi-annual harmonics account for greater than 75% of the energy in the MLD time series
over most of the basin. The amplitude of the annual signal is greater than 20 m between 10°S and 25°S, with
deepest MLD's observed during the southern hemisphere winter. The south-central Arabian Sea, between the equa-
tor and 10°N, and the northern Arabian Sea are also regions of larger annual harmonic amplitude (> 15 m) . The
amplitude of the semi-annual harmonic is largest in the central Arabian Sea (> 25 m) . Deepest MLD's are
observed there during the height of the two monsoon seasons. Correlation coefficients are computed between MLD
and SST and several other oceanographic and meteorological variables to explore possible causal relationships.
Net energy flux through the sea surface can account for 75% of the variance in the SST and MLD time series over
most of the region south of the equator. Large coefficients are also observed in the northwestern Arabian Sea.
Correlations between SST and MLD and surface currents are, in general, small throughout the region with maxima
observed in the central Arabian Sea, in the vicinity of the South Equatorial Current and in the extreme eastern
equatorial Indian Ocean. These correlations are examined in more detail in Part II of this study in which
simple models of mixed layer dynamics are employed.

A0-067

Rappaport, E.N., and P.G. BLACK. The utility of special sensor microwave/imager data in the operational
analysis of tropical cyclones. Extended Abstracts, 18th Conference on Hurricanes and Tropical Meteorology,
San Diego, CA, May 16-19, 1989. American Meteorological Society, Boston, J21-J24 (1989).

Extended abstract.

AO-068

RONA, P. A. Hydrothermal mineralization at oceanic ridges. Canadian Mineralogist 26:431-465 (1988).

A compilation of over 100 mineral occurrences at oceanic ridges and rifts comprising the global seafloor
spreading center system has been made in terms of host-rock lithology (volcanic- or sediment-hosted) and of
stage (early, advanced) and rate (slow-, intermediate- to fast-spreading) of opening of an ocean basin. At
this early phase of exploration when less than 1 percent of the ~55,000 km global length of spreading centers
has been systematically explored, examples of almost all major varieties of volcanic- and sediment-hosted
hydrothermal deposits associated with basaltic rocks in the geologic record have been found at present
spreading centers. Review of this global data base indicates that a range of hydrothermal mineral deposit
sizes from small to large (> 1 x 106 tonnes) occurs at all seafloor spreading rates. However, larger deposits
but fewer per unit length of spreading axis appear to form at slow- than at intermediate- to fast-spreading
centers based on available data. Larger deposits are more common in sediment-hosted than in volcanic-hosted
settings regardless of spreading rate. A spectrum of hydrothermal deposit varieties (stratiform, stockwork and
disseminated sulfides; various forms of sulfate, carbonate, silicate, oxide and hydroxide deposits) occurs in
almost all of the tectonic settings. High-intensity, ore-forming, subseafloor hydrothermal convection systems
that conserve heat and mass and concentrate hydrothermal precipitates are extremely localized by anomalous
physical and chemical conditions relative to nearly ubiquitous low-intensity hydrothermal activity at and
flanking seafloor spreading axes at all spreading rates. Two distinct shapes of volcanic-hosted hydrothermal
deposits at seafloor spreading centers and in the geologic record may be explained by differences in fluid
dynamic behavior controlled by temperature-salinity properties of solutions. Massive sulfide deposits that are
mound-shaped in profile are constructed by hydrothermal solutions that discharge as buoyant plumes; examples
are the TAG massive sulfide mound forming on the Mid-Atlantic Ridge and the Archean Noranda-area deposits.
Massive sulfide deposits that are saucer- or bowl-shaped in profile are formed by ponded solutions denser than
surrounding seawater; examples are the Atlantis II Deep deposits of the Red Sea and Cretaceous Troodos deposits
of Cyprus. Review of an existing data set on 508 massive sulfide deposits in the geologic record indicates that
fewer volcanic- and sediment-hosted massive sulfide deposits are associated with basaltic rocks than with rhyo-
litic rocks (< 26% versus 56%, respectively) . This observation suggests that seafloor spreading centers have
been significant as tectonic settings for massive sulfide formation through geologic time, although subsidiary
to continental rifts and volcanic island arcs.

69

AO-069

Rosenfeld, L.K., R.L. MOLINARI , and K.D. Learaan. Observed and modeled annual cycle of transport in the
Straits of Florida and east of Abaco Island, the Bahamas (26.5°N). Journal of Geophysical Research
94(C4) :4867-4878 (1989) .

Direct velocity observations were collected with a free-fall acoustic velocity profiler along an east-west
section extending 65 km offshore of Abaco Island, the Bahamas (26.5°N). The section, which includes five
stations, was occupied 14 times between September 1984 and September 1987. The two inshore stations were
located on the continental slope, and the three offshore stations were located over the abyssal plain (at
depths approaching 4,700 m) . The average total section transport between the surface and 2,500 m (the portion
of the water column best sampled) was 10 Sv (1 Sv = 106 m3/s) to the south. The range of transports is 40 Sv
with maximum northward transport observed during April 1985 (5.3 Sv) and maximum southward transport observed
during April 1986 (34.8 Sv). The average flow above 800-900 m is to the north at the four westernmost stations
and is to the south below 800-900 m and over most of the easternmost station. The southward flow includes the
Deep Western Boundary Current. Strong vertical shears extend to 1,100 m. An approximation for the upper layer
(above 1,100 m) baroclinic transport has a mean of 12.2 Sv to the north and a range of 15 Sv . Results from a
two-layer and a one-and-a-half-layer wind-driven model are compared with the annual cycles of total and upper
layer transport, as determined from the observations. The barotropic transport from the two-layer model has a
range of the order of ± 10 Sv, with a winter maximum and fall minimum. The range of the baroclinic transport
from the one-and-a-half-layer model is an order of magnitude smaller and of opposite sign. Although there are
similarities between the observations and the results of both models, the small signal-to-noise ratio precludes
definitive confirmation of the annual cycle. The situation east of the Bahamas, where the two models give very
different predictions, is compared with the Straits of Florida, where both models predict an annual cycle simi-
lar to that observed for the total transport. The roles played by topography and local and remote wind forcing
in producing these results are discussed.

AO-070

SHAPIRO, L.J. The relationship of the quasi-biennial oscillation to Atlantic tropical storm activity.
Monthly Weather Review 117(7 1:1545-1552 (1989).

Monthly averaged 30 and 50 mb zonal winds at Balboa are used to determine objectively the relationship of the
quasi-biennial oscillation (QBO) to seasonal (August through October) Atlantic tropical storm activity during
the years 1952-1986. The largest correlations between storm activity and the 30 mb wind are found in June,
which is three months before the center of the season. Extrapolation and direct calculation confirm a near
in-phase relationship between tropical storm activity and the zonal wind at about 50 mb . Zonal winds filtered
to remove periods of about < 1 year are used to establish correlations between the QBO and tropical storm
activity for 1955-1983 that are essentially independent of the month considered. A correlation at 30 mb is
established with a conservative estimate of true skill, from both in-phase and out-of-phase information, that
explains 30% of the variance in storm activity. The skill is much greater than that estimated from seasonal
classification of the QBO. The statistics are resilient to removal of the effects of the El Nino cycle. When
El Nino years are explicitly excluded, the true skill explains an estimated 32% of the variance. Low-latitude
storms are even more strongly related to the QBO. Physical mechanisms possibly responsible for the observed
associations are discussed in light of these results. A mechanism for the observed correlations is suggested
that emphasizes the difference between lower tropospheric steering and the lower stratospheric zonal wind. The
relationships of the results, and suggested physical mechanism, to those of Gray are considered.

A0-071

SHAPIRO, L.J. Vortex evolution on a beta plane. Extended Abstracts, 18th Conference on Hurricanes and
Tropical Meteorology, San Diego, CA, May 16-19, 1989. American Meteorological Society, Boston, 98-99 (1989).

Extended abstract.

AO-072

Shay, L.K., R.L. Elsberry, and P.G. BLACK. Vertical structure of the ocean current response to a hurricane.
Journal of Physical Oceanography 19 ( 5 ): 649-669 (1989).

During the passage of Hurricane Norbert in 1984, the Hurricane Research Division of N0AA conducted a plane-
tary boundary-layer experiment that included the deployment of airborne expendable current profilers (AXCP) . A
total of 16 AXCP's provided, for the first time, high-resolution vertical profiles of currents and temperatures
in hurricane wind conditions. This study focuses on the vertical structure of the near-inertial baroclinic
currents excited by the passage of this hurricane. The transient, hurricane-induced currents are isolated from
the AXCP profiles in Norbert by subtracting a spatially-averaged current. Near the center of Hurricane
Norbert, the WKBJ-scaled vertical wavenumber spectra are a decade greater than the Garrett-Munk spectra (GM75).
The first ten linear, baroclinic-free modes are calculated from the spatially-averaged, Brunt-Vaisala fre-
quency. To allow a more direct comparison with the AXCP observations in the high-wind regime, the near-
inertial response for the three-dimensional velocities is simulated by superposing a hurricane-like wind stress
field onto the first ten baroclinic modes. About 70% of the current variance in Hurricane Norbert can be
explained by a sum of only the first four near-inertial modes. Most of the ocean current variability can be

70

accounted for by the wind stress curl, although the direct effect of the wind stress and the stress divergence
do contribute to the observed current variance within 30-60 km from the storm. However, these last two effects
rapidly diminish after one inertial period. Although the energy input by the hurricane forcing is spread over
all of the vertical wavelengths, most of the energy is contained in the gravest four vertical modes which then
govern the dynamics in the wake region.

AO-073

Speer, K. , and P. A. RONA. A model of an Atlantic and Pacific hydrothermal plume. Journal of Geophysical
Research 94 (C5 ): 6213-6220 (1989).

A turbulent entrainment model of a hydrothermal plume was modified to include the effects of vertical struc-
ture in the background temperature and salinity fields. Owing to the stably-stratified salinity field in the
Pacific, relatively warm, salty water spreads at an equilibrium level, where the plume density equals the
ambient density. In contrast, the unstable salinity profile in the Atlantic gives the plume added buoyancy,
and it continues to rise to an equilibrium level where it is relatively cool and fresh. These attributes
result from the mixing between the plume and the surrounding seawater at each level below the spreading layer.
The equilibrium temperature anomaly is not directly proportional to the source strength but depends on the
mixing and background salinity gradient. The net entrainment of surrounding seawater is greater in the
Atlantic plume model than in the Pacific plume model for the same buoyancy flux. Recent data from the TAG
hydrothermal field at 26°N on the Mid-Atlantic Ridge and data from a vent field on the Endeavor segment of the
Juan de Fuca Ridge are compared to model results. The model predicts the penetration height and 9-S character-
istics of the Atlantic plume, and explains some of the differences between the observed Atlantic and Pacific
hydrothermal plumes.

AO-074

Stossmeister , G.J., and G.M. Barnes. Low-level structure of a nondeveloping tropical storm: Isabel (1985).
Research supported by NOAA Grant 45-WCNR-5-00388 . Extended Abstracts, 18th Conference on Hurricanes and
Tropical Meteorology, San Diego, CA, May 16-19, 1989. American Meteorological Society, Boston, 83-84 (1989).

Extended abstract.

AO-075

THACKER , W.C. Fitting models to inadequate data by enforcing spatial and temporal smoothness. Journal of
Geophysical Research 93 (C9) : 10 . 655-10 . 665 (1989).

When observations are too sparse to determine the state of a dynamical model, it is necessary to make use of
prior knowledge or prejudice. The approach discussed here is to require that the model state be the best
smooth fit to the sparse data. The requirement of smoothness is enforced by introducing bogus data, which cor-
respond to hypothetical observations that properties such as slope, curvature, or temporal tendency of model
fields have zero values within some specified accuracy. The bogus data serve to increase the effective ratio
of data to model degrees of freedom. The concept of bogus data allows a bias toward smoothness to be incorpo-
rated easily into the adjoint method for fitting time-dependent models to asynoptic data. Computational exam-
ples using a simple three-wave model show that reasonable fits can be obtained even when the number of real
data is considerably less than the number of model degrees of freedom.

AO-076

THACKER, W.C. The role of the Hessian matrix in fitting models to measurements. Journal of Geophysical
Research 94 (C5 ): 6177-6196 (1989).

A numerical model can be fit to data by minimizing a positive quadratic function of the differences between
the data and their model counterparts. The rate at which algorithms for computing the best fit to data con-
verge depends on the size of the condition number and the distribution of eigenvalues of the Hessian matrix,
which contains the second derivative of this quadratic function. The inverse of the Hessian can be identified
as the covariance matrix that establishes the accuracy to which the model state is determined by the data; the
reciprocals of the Hessian's eigenvalues represent the variances of linear combinations of variables determined
by its eigenvectors. The aspects of the model state that are most difficult to compute are those about which
the data provide the least information. A unified formalism is presented in which the model may be treated as
providing either strong or weak constraints, and methods for computing and inverting the Hessian matrix are
discussed. Examples are given of the uncertainties resulting from fitting an oceanographic model to several
different sets of hypothetical data.

AO-077

Thompson, G., S.E. Humphris, B. Schroeder , M. Sulanowska, and P. A. RONA. Active vents and massive sulfides
at 26°N (TAG) and 23°N (Snakepit) on the Mid-Atlantic Ridge. Canadian Mineralogist 26:697-711 (1988).

Two active hydrothermal vent sites on the Mid-Atlantic Ridge at 26°N (TAG) and 23°N (Snakepit) have recently
been discovered at depths of 3,700 and 3,500 m, respectively. Although black smokers are present at both

71

sites, their geological settings differ. The TAG area is located on older sedimented crust a few kilometers
from the spreading axis, at the junction of the rift-valley floor and the east wall; the Snakepit site is atop
a large volcanic ridge (40 km long, up to 600 m high) in the axial zone of the rift valley. The TAG site is
the larger of the two and is probably older. Hydrothermal discharge from vents at both sites ranges from shim-
mering water, through white smokers (226°C) to black smokers (335°C and 350°C). Hydrothermal solutions are
similar in major-element composition to those from the East Pacific Rise. Mineralization is similar to that
occurring on faster-spreading ridges, e.g., the dominant polymetallic sulfides are pyrite, pyrrhotite, chalco-
pyrite and sphalerite; anhydrite is the main sulfate phase. The deposits differ from some of those on the East
Pacific and Juan de Fuca ridges in having little or no barite, very little amorphous silica, and in having
abundant aragonite as a late-stage precipitate. Diagenesis and weathering, particularly at the TAG site, have
produced abundant amorphous iron oxides and hydroxyoxides , goethite, hematite, atacamite, jarosite and sulfur.
At the Snakepit site the black smokers consist mainly of pyrrhotite, but this sulfide phase is absent from the
active chimneys at TAG. Zinc sulfide occurs as the predominant phase in the lower-temperature white smokers at
both sites.

AO-078

Venne, M.G., W.A. Lyons, C.S. Keen, P.G. BLACK, and R.C. Gentry. Explosive supercell growth: A possible

indicator of tropical storm intensification? Preprints, 24th Conference on Radar Meteorology, Tallahassee,

FL, March 27-31, 1989. American Meteorological Society, Boston, 545-548 (1989).

No abstract.

A0-079

WILBURN, A.M., E. JOHNS, and M. BUSHNELL. Current velocity and hydrographic observations in the southwestern
North Atlantic Ocean: Subtropical Atlantic Climate Studies (STACS) , 1988. NOAA DR ERL A0ML-13 (NTIS number
not yet available), 83 pp. (1989).

No abstract.

AO-080

WILLIS, P.T., and A.J. Heymsfield. Hurricane microphysical trajectories. Extended Abstracts, 18th Confer-
ence on Hurricanes and Tropical Meteorology, San Diego, CA, May 16-19, 1989. American Meteorology Society,
Boston, 75-76 (1989) .

Extended abstract.

AO-081

WILLIS, P.T., and A.J. Heymsfield. Structure of the melting layer in mesoscale convective system stratiform
precipitation. Journal of the Atmospheric Sciences 46(13) : 2008-2025 (1989) .

This study examines the aircraft observations and theoretical evolution of particles above, through, and
below the melting layer in the stratiform region associated with a mesoscale convective system (MCS) . The air-
craft data were obtained from an advecting spiral descent where the descent rate approximately corresponded to
the typical hydrometeor fall speeds. The microphysical and thermodynamic measurements not only allowed us to
characterize the particle evolution, but also enabled us to compare them with the theoretical evolution of the
particles in the melting layer and to quantify the associated heating and cooling rates. Even though complete
melting requires a fairly deep layer, most of the mass melts, and thus most of the cooling occurs, in a thin
layer above the location of the radar bright band. Based upon the magnitude of vertical velocity fluctuations,
the layers below the melting layer appear to be decoupled from those above. The ice water content above the
melting layer is 2-3 times the liquid water content below the melting layer. The production of a few, very
large, aggregates is dramatic after the onset of melting, due in part to a melting-induced increase in the ter-
minal velocity difference between similar-sized hydrometeors . The radar reflectivity maximum (bright band) is
due to these relatively few, very large, aggregates that survive to warmer temperatures. The reflectivity max-
imum is depressed well below the isothermal layer and the level where most of the ice mass is melted. Above
the melting layer, small crystals are replenished by a fragmentation or breakup process.

AO-082

WILLIS, P.T., and P. Tattleman. Drop-size distributions associated with intense rainfall. Journal of
Applied Meteorology 28(11:3-15 (1989).

The probability of occurrence of extreme rainfall rates is reviewed. The drop-size distributions associated
with a range of high rainfall rates are examined using data from tropical storms and hurricanes. Mean drop-
size distributions are presented for a range of high rainfall rates, as well as a [""-distribution fit to the
entire set of normalized drop-size distributions. This fit forms the basis for a model drop-size distribution
for intense rain. The goodness of fit of the model is examined by comparing it with independent drop-camera
measurements of high-rain-rate distributions from several geographic locations. The slope of exponential fits
to the distributions are examined for constancy with rainfall rate and are generally found to decrease with
increasing rainfall rate.

72

AO-083

WILLOUGHBY, H.E., W.P. BARRY, and M.E. RAHN . Real-time monitoring of Hurricane Gilbert. Extended Abstracts,
18th Conference on Hurricanes and Tropical Meteorology, San Diego, CA, May 16-19, 1989. American Meteoro-
logical Society, Boston, 220-221 (1989).

Extended abstract.

AO-084

WILSON, D. , and A. Leetmaa. Acoustic Doppler current profiling in the equatorial Pacific in 1984. Journal
of Geophysical Research 93 (Cll ): 13 . 947-13 . 966 (1989).

Hydrographic data and acoustic Doppler current profiles collected from 150°W to 85°W in the equatorial
Pacific during 1984 showed significant seasonal changes in the temperature and velocity fields. On the equa-
tor, the surface current was eastward in April up to 80 cm s_1 , reversing to westward at 100 cm s_1 by November.
Over the same period, the Equatorial Undercurrent (EUC) transport decreased, the equatorial zonal pressure
gradient (ZPG) increased, and the depth of the mixed layer and EUC core deepened. Off the equator at 150°W,
the North Equatorial Countercurrent (NECC) was absent in April/May but pronounced in October/November. Super-
imposed on this seasonal variability were smaller-scale (roughly 1,000 km wavelength) correlated fluctuations
in the upper ocean temperature and velocity fields. We identify these structures with the 20- to 30-day insta-
bility waves [Legeckis, 1977], The coincident high-resolution velocity and temperature data allowed the calcu-
lation of Reynolds' stresses due to the waves and resultant heat and momentum flux estimates as well as details
of the vertical phase structure. Barotropic instability at the northern edge of the EUC is a likely source of
energy for these waves. Estimated EUC transport decreased from 50 in April to 25 x 106 m3 s_1 in November while
the westward wind stress doubled and the 0-/400-dbar ZPG quadrupled. The data were used to estimate terms in
the momentum balance in the upper 150 m, and it was found that nonlinear terms were often at least as important
as the integrated ZPG in balancing the surface wind stress. East of 120°W, the eastward advection of eastward
momentum, UUX, was particularly important. These momentum equation terms were used to estimate a profile of
the coefficient of vertical eddy viscosity; it was similar to profiles estimated by bulk methods and by parame-
terization by Richardson number.

AO-085

Wood, V.T., and F.D. MARKS, JR. Hurricane Gloria: Simulated land-based Doppler velocities reconstructed from
airborne Doppler radar measurements. Extended Abstracts, 18th Conference on Hurricanes and Tropical Meteo-
rology, San Diego, CA, May 16-19, 1989. American Meteorological Society, Boston, 115-116 (1989).

Extended abstract.

Addendum

AO-086

Houze, R.A., Jr., S.J. Bograd , and B. Mapes. An atlas of horizontal patterns of radar reflectivity observed
during EMEX aircraft missions. Research supported by NOAA Grant 40-WCNR-6-02428 . Department of Atmospheric
Science, University of Washington, Seattle (1988).

No abstract.

AO-087

WILLOUGHBY, H.E. The dynamics of the tropical cyclone core. Australian Meteorological Magazine 36(3):
183-191 (1988) .

The core of a tropical cyclone occupies the inner 100-200 km of the vortex. It is dominated by a cyclonic
primary circulation in balance with a nearly axisymmetric , warm core low-pressure anomaly. Superimposed on the
primary circulation are weaker asymmetric motions and an axisymmetric secondary circulation. The asymmetries,
which may be either internal gravity waves or Rossby waves, modulate precipitation and cloud into trailing
spirals. The axisymmetric secondary circulation, driven by latent heat release and surface friction, comprises
the following parts: surface inflow that extracts latent heat from the sea and replaces the frictional loss of
angular momentum (M) to the sea; diabatically forced deep inflow that supplies an excess of M above frictional
loss; the eyewall, an outward sloping locus of convective ascent; diabatically forced descent inside the eye;
and upper tropospheric outflow. The eyewall usually moves inward as a result of differential adiabatic heating
across the wind maximum. Eyewall succession occurs in intense cyclones when two concentric eyewalls are
present and the outer replaces the inner. Because of their semibalanced dynamics, the primary and secondary
circulations are relatively simple and well understood. These dynamics are not valid in the upper troposphere
where the outflow is comparable to the swirling flow, nor do they apply to the asymmetric motions. Since the
synoptic-scale environment appears to interact with the vortex core in the upper troposphere by means of the
asymmetric motions, future research should emphasize this aspect of the tropical-cyclone dynamics.

73

FORECAST SYSTEMS LABORATORY

FS-001

Albers, S.C. Two-dimensional velocity de-aliasing in highly sheared environments. Preprints, 24th
Conference on Radar Meteorology, Tallahassee, FL, March 27-31, 1989. American Meteorological Society,
Boston, 411-414 (1989).

No abstract.

FS-002

AUGUSTINE, J. A., E.I. TOLLERUD, and B.D. JAMISON. Distributions and Other General Characteristics of
Mesoscale Convective Systems During 1986 as Determined from GOES Infrared Imagery. Preprints, 12th
Conference on Weather Analysis and Forecasting, Monterey, California, October 2-6, 1989. American
Meteorological Society, Boston, 437-442, (1989).

No abstract.

FS-003

BARNES, S.L., and B.R. COLMAN. Quasi-Geostrophic Diagnosis of Tropopause Folding Associated with
Extratropical Cyclone Development. Preprints, 12th Conference on Weather Analysis and Forecasting,
Monterey, California, October 2-6, 1989. American Meteorological Society, Boston, 247-252, (1989).

No abstract.

FS-004

Benjamin, S.G. An operational isentropic mesoscale data assimilation system. Abstracts Volume One,
IAMAP 89, 5th Scientific Assembly, Reading, England, July 31-August 12, 1989. Commission Symposium on
Mesoscale Phenomena: Analysis and Forecasting, August 2-4, 1989, MF33 (1989).

A Mesoscale Analysis and Prediction System (MAPS) has been developed to provide short-range guidance and
detailed analyses over the U.S. at 3-h frequency. The asynoptic data sources for MAPS are commercial
aircraft, notably those producing automated reports, satellites, wind profilers and surface stations.
*A11 components of MAPS, including observation quality control, objective analysis, and primitive equation
model, are configured in isentropic coordinates, providing extra resolution near fronts. The assimilation
cycle is self-contained (three-hour MAPS forecasts serve as the background for subsequent analyses) except
for specification of model lateral boundary conditions from the U.S. Nested Grid Model (NGM) .

The 3-h isentropic cycle has been run in real-time since August 1988. Twelve-hour forecasts from MAPS
compare favorably with those of the NGM model, especially at upper levels. Aircraft data clearly improve
short-range forecasts not just of upper-level winds (observed most frequently), but also of wind and mass
fields at most tropospheric levels. This result is due in part to model adjustment processes, and in part
to analysis procedures, in particular, those concerning the 3-dimensional influence of single-level
observations in isentropic coordinates.

FS-005

Benjamin, S.G. An isentropic meso-alpha scale analysis system and its sensitivity to aircraft and
surface observations. Monthly Weather Review 117:1586-1603 (1989).

An objective analysis scheme for meteorological variables on constant potential temperature surfaces is
presented. The analysis uses a form of multivariate statistical interpolation and is designed to retain
mesoscale detail in disparate observations including rawinsonde, surface, aircraft, satellite, and wind
profiler data while combing them with a forecast background (first guess) field. The wind and mass field
analyses are interdependent. The horizontal correlation of forecast error on isentropic surfaces is
modeled with an analytical function from statistics collected for this study; the vertical correlation of
forecast error is modeled as a function of potential temperature separation. These correlations determine
the weights applied to observed-minus-forecast increments in the analysis. The analysis is two
dimensional except with respect to single-level data where it is three-dimensional. Comparisons of
isentropic and isobaric analyses are shown, and examples of the effects of single-level (aircraft and
surface) observations on isentropic analyses are presented. Although variable in space and time, these
datasets are often of higher density than the rawinsonde network, and they support increased resolution of

74

mesoscale features in the analysis. More importantly, the examples reveal that three-dimensional analysis
increment structures, especially in the vicinity of fronts, appear to be more physically reasonable in an
isentropic analysis than in an isobaric analysis.

FS-006

Benjamin, S.G., K.A. Brewster, R. Brumm&r, B.F. Jewett, T.W. SCHLATTER, T.L. Smith, and P. A. Stamus. A

3-hour mesoscale assimilation system using ACARS aircraft data combined with other observations.

Preprints, 3rd International Conference on the Aviation Weather System, Anaheim, CA, January 30-February

3, 1989. American Meteorological Society, Boston, 117-122, (1989).

No abstract.

FS-007

BERAN, D.B., and J.T. Hastings. The SWORD Project: pointing new direction in environmental science data
management. Proceedings of "Earth Observations and Global Change Decision Making: A National
Partnership," September 18-19, 1989, Washington, DC, ERIM (Environmental Research Institute of
Michigan), Ann Arbor, MI (1989).

The NOAA/Environmental Research Laboratories have an on-going program to "develop, deploy, operate, and
assess" a demonstration network of atmospheric wind profilers during the period 1985-1992. As part of
this program, wind profiler and related data will be made available to researchers across the country
through a subsidiary project known as SWORD, for Synoptic-Scale Weather On-line Research Database. This
document presents a summary of the technological concepts and implementation progress of SWORD, and
suggests directions for future research and development in support of environmental science data
management generally.

FS-008

BERAN, D.W. , and L.M. Kaimal. Test range weather support. Preprints, Third International Conference on
the Aviation Weather System, 30 January-3 February 1989, Anaheim, CA, American Meteorological Society,
Boston, 87-88 (1989).

No abstract.

FS-009

Birkenheuer, D. Use of GOES data for local forecasting. Preprints, GOES I-M Operational Satellite
Conference, Arlington, VA, April 3-6, 1989. American Meteorological Society, Boston, 70-75 (1989).

No abstract.

FS-010

Brady, R.H., and E.J. Szoke. A case study of nonmesocyclone tornado development in Northeast Colorado:
similarities to waterspout formation. Monthly Weather Review, 1 17 (4) : 843-856 (1989).

The evolution of the 26 July 1985 Erie, Colorado, tornado is described using data from NCAR's CP-2
Doppler radar. This tornado develops within 20 km of the radar site under weakly forced synoptic
conditions and weak tropospheric flow, and is not accompanied by a mesocyclone. The initial circulation
forms near the surface at the intersection of two mesoscale boundaries and develops vertically,
intensifying into an Fl tornado when it becomes collocated with the intense updrafts of a rapidly
developing cumulonimbus. This tornado appears to be the land equivalent of a waterspout, and comparisons
between the two vortices are made. It is speculated that Florida and portions of the western High Plains
may be prone to nonmesocyclone tornado development, and that vortex-intensification processes associated
with nonmesocyclone tornadoes may be important in mesocyclone tornadogenesis . Suggestions on how to
better forecast these tornadoes are also presented.

FS-011

Brewster, K.A., S.G. Benjamin, and R. Crawford. Quality control of ACARS meteorological observations —
a preliminary survey. Preprints, 3rd International Conference on the Aviation Weather System, Anaheim,
CA, January 30-February 3, 1989. American Meteorological Society, Boston, 124-129 (1989).

No abstract.

75

FS-012

CHAPPELL, C.F., and D.M. RODGERS. Meteorological Aspects of the Cheyenne, Wyoming, Flash Flood and
Hailstorm of August 1, 1985. NOAA Technical Report ERL 435-FSL 1, 51 pp. (1988).

Analysis of a devastating storm that struck. Cheyenne, Wyoming, on 1 August 1985 shows that the storm
began as an east-west multicellular system just south of the city near the summit of the Cheyenne Ridge.
This system developed in a conditionally unstable air mass that formed over southeast Wyoming as a
southeasterly flow of very moist air at low levels became juxtaposed with an area of steepening lapse
rates to the west. Early cells drifted slowly northward in agreement with the pressure-weighted vector
mean wind of the environment. New onvective growth on the southwest flank of this multicellular system
eventually produced a wave-shaped convective system, which rapidly developed supercell structure. As the
supercell began to rotate, the storm became stationary over the city for nearly 2 hours. This lack of
motion is believed to have been due to helicity, which promoted the transverse propagation of the
supercell's updraft at a rate that counteracted the effects of the vector mean wind of the environment.
The storm began to move southeastward with the arrival of a short-wave trough and soon dissipated as it
encountered increasingly stable conditions. The results of the study suggest that the eastern foothills
of the Rocky Mountains and the adjacent high plains may be particularly vulnerable to this type of storm.
Deep convection frequently occurs over this area when moist air arrives from the Great Plains, driven by a
low-level easterly jet. The combination of strong low-level easterly flow topped by weak middle-level
southerly flow can apparently produce sufficient wind shear for supercell formation, while producing a
vector mean wind for the environment that gives little or no eastward motion relative to the ground.

FS-013

Chen, S.J., L.S. Bai, and S.L. BARNES. Omega Diagnosis of a Cold Vortex with Severe Convection, Weather
and Forecasting 3(4) : 296-304, (December 1988).

A real-time quasi-geostrophic omega diagnostic scheme, based on Hoskins' Q-vector analysis and developed
by Barnes, was applied to a cold mesoscale vortex with severe convection over northeast China in summer.
The limited area model used at the Beijing Weather Center did not predict this event because the
baroclinic forcing was rather weak, but the Q-vector analysis clearly indicated the forcing 12 h before.
In addition to Barnes' diagnostics, we estimate divergence tendency in low levels through computation of
the rotational component of the Q-vector. Combined with the diagnosed stability tendency, moisture
analysis, and low-level wind convergence zone, the convective area can be identified. This microcomputer
diagnostic-graphics scheme, when coupled with intelligent use of conventional data, has potential as an
aid for local short-range weather forecasting.

FS-014

COLMAN, B.R. Mesoscale Analysis of an Upslope Snowstorm in Colorado. Preprints, 12th Conference on
Weather Analysis and Forecasting, Monterey, California, October 2-6, 1989. American Meteorological
Society, Boston, 372-377 (1989).

No abstract.

FS-015

COLQUHOUN, J.R., and D.J. Shepherd. An Objective Basis for Forecasting Tornado Intensity. Weather and
Forecasting 4(l):35-50 (March 1989).

Although violent tornadoes comprise only 2.3 percent of tornado occurrences in the United States they
cause 68 percent of the fatalities attributed to tornadoes and severe thunderstorms. Despite these
statistics, no attempt is made to forecast or warn of tornado intensity. A basis for this is provided in
a study of more than two hundred tornado events. Tornado intensity is best related to the magnitude of
the vertical wind "shear" in the layer between the ground and 600 hPa. The result for this and other
shear parameters are statistically highly significant when the data are grouped into two or three
intensity classifications. Stability, as indicated by the "lifted index" and mid-tropospheric relative
humidity, correlated poorly with tornado intensity. The relationships established have application to
tornado forecasting and nowcasting.

FS-016

Dunn, L.B. Vertical motion evaluation of a Colorado snowstorm from a synoptician' s perspective. Weather
and Forecasting, 3(4) : 261-272 (December 1988).

76

The causes of vertical motions associated with a September snowstorm which resulted in a heavy snowband
in northeastern Colorado have been examined from a synoptician' s perspective. The aim of the examination
is to look at the various causes of vertical motion as a forecaster might in a real-time situation. The
three ways in which the vertical motions were estimated were by 1) a "conventional" approach, including
500 mb positive vorticity advection (PVA) and pattern recognition techniques; 2) a strictly quasi-
geostropic approach, including advection of vorticity by the thermal wind a Q-vector analysis; and 3) a
look at possible ageostrophic forcing in excess of, or operating on smaller scales than those expected
from a purely quasi-geostrophic (QC) framework. Additionally, an examination of the atmosphere's
potential response to forcing was attempted via a conditional symmetric instability analysis. The results
show a failure of both the conventional approach and the purely QG forcing analysis in explaining the
heavy snowband, although Q-vectors did much better than 500 mb PVA on the general area and timing of
precipitation. Ageostrophic forcings operating on smaller scales than those resolved by QG analyses seem
a likely reason for the vertical motions associated with the heavy snowband. The atmosphere was
conditionally symmetrically unstable and thus likely to produce banded precipitation in response to
forcing.

FS-017

GREENHUT, G.K., G. Mastrantonio. Turbulence Kinetic Energy Budget Profiles Derived from Doppler Sodar
Measurements. Journal of Applied Meteorology 28(2): 99-106 (1989).

Doppler sodar wind measurements made in light wind conditions in September 1979 near a power plant in
Turbigo, Italy, are used to derive terms in the turbulence kinetic energy (TKE) budget. Measurements on
five days are grouped into two classes: fair-weather conditions and boundary layer interaction with
subsiding air. Profiles of 0^,/z are used to obtain the surface heat flux and the vertical velocity
scaling parameter, as well as the buoyancy production term in the TKE budget. The vertical transport of
TKE is derived from the profiles of (W')3. The horizontal components are approximated using a
parameterization based on the data of Lenschow et al. Dissipation in the TKE budget is obtained from a
spectral analysis of the Doppler sodar data in the inertial subrange. The resulting TKE budget profiles
for the two classes are compared with budgets obtained previously, using a number of different methods.

FS-018

GRIFFITH, C.G. Skill Scores of Satellite-Estimated Summertime Rainfall. Preprints, 11th Conference on
Probability and Statistics, Monterey, California, October 1-5, 1989. American Meteorological Society,
Boston, 144-149 (1989).

No abstract.

FS-019

Heideman, K.F., D.C. WALKER, and J. A. Flueck. DAR3E-1 Evaluation: An Overview. NOAA Technical Report
ERL 436-FSL 2, 29 pp. (1989).

The unique DAR^E-I (Denver AWIPS-90 Risk Reduction and Requirements Evaluation, Part I) system combines
an advanced, interactive workstation with special meteorological data sets and provides the capability to
demonstrate and test many of the concepts central to the AWIPS-90 (Advanced Weather Interactive Processing
System for the 1990's) component of the planned modernization of the National Weather Service (NWS). This
overview of six evaluation reports focuses on the following areas: (1) forecaster assessment of the
system, (2) forecaster product usage, and (3) forecaster performance as measured by forecasts and
warnings. Forecasters agreed that the integration of standard data sets with new (primarily mesoscale)
data sets into a single workstation, and the capability to manipulate the data in ways not previously
possible, make DAR-^E-I a substantial improvement over the current AF0S (Automation of Field Operations and
Services) system. Forecasters also identified some problem areas and they are being addressed in DARE-^E-
II. Product usage analysis shows that DAR^E-I provides sufficient flexibility in the daily product
inventory to allow forecasters to focus on the contrasting forecasting problems presented on the synoptic
and subsynoptic scales in both the cool and warm seasons. Doppler radar imagery is a key component of the
mesoscale product set available on the DAR^E-I system. On the basis of the data available, assessment of
tornado warnings revealed a number of substantial improvements following installation of DAR-^E-I,
including increased lead time, and decreased size of area warned and false alarm ratio (FAR). Similar,
though smaller, improvements were observed with regard to severe thunderstorm warnings. In contrast, the
probability-of-detection (POD) scores declined for both types of warnings over the same period. There is
a suggestion of improvement in cool and warm season 0-12 hour temperature forecasts whereas precipitation
forecasts after the installation of DARE-^E-I do not show any notable changes in skill or reliability.

77

FS-020

Hinkelman, J.W. An overview of the national program to improve aircraft icing forecasts. Preprints,
"°tional Conference on the Aviation Weather System, Anaheim, CA, January 30-February 3, 1989.
teorological Society, Boston, 443-445 (1989).

3rd International
American Me

No abstract.

FS-021

JESUROGA, R.T. Detailed snowstorm observations during the 15 November 1987 Continental aircraft
accident at Stapleton International Airport. Preprints, 3rd International Conference on the Aviation
Weather System, Anaheim, CA, January 30-February 3, 1989. American Meteorological Society, Boston, 135-
139 (1989).

No abstract.

FS-022

Kelsch, M. An evaluation of the NEXRAD hydrology sequence for different types of convective storms in
northeastern Colorado. Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL, March 27-31,
1989. American Meteorological Society, Boston, 207-210 (1989).

No abstract.

FS-023

Khalsa, S.J.S. and G.K. Greenhut. Atmospheric Turbulence Structure in the Vicinity of an Oceanic Front.
Journal of Geophysical Research 94 (CA) : 4913-4922 (1989).

Fast response data taken aboard the National Oceanic and Atmospheric Administration WP-3D aircraft are
used to determine the structure of atmospheric boundary layer turbulence on either side of a well-
developed sea surface temperature front southwest of Bermuda. The data were taken on February 17, 1986,
as part of the Frontal Air-Sea Interaction Experiment (FASINEX) . A broad region of low-humidity air
extending from 15 km to 35 km south of the front is probably due to the presence of a frontally induced
secondary circulation. Evidence for a secondary flow is found in both the time series of atmospheric
variables and the statistics obtained from conditionally sampled updrafts and downdrafts in the transect
across the SST front. Larger sea-air temperature and humidity differences on the warm (south) side of the
front give rise to surface layer sensible and latent heat and buoyancy fluxes that are larger than those
on the cold side. Turbulence structure appears to be influenced as much by the presence of strong wind
shear at the top of the boundary layer as by differing conditions at the surface on either side of the
front. A larger rate of entrainment on the warm side of the front is indicated by the greater influence
of low-momentum air from the overlying shear layer on updrafts in the upper part of the mixed layer, as
well as the more frequent overturning of cool/moist updrafts and warm/dry downdrafts. It is conjectured
that the larger entrainment rate is due to the interactions between the inversion layer and more energetic
updrafts produced by greater surface forcing on the warm side of the front.

FS-024

Lipschutz, R.C., E.N. Rasmussen, J.K. Smith, J.F. PRATTE, and C.R. Windsor. PROFS' 1988 real-time
Doppler products subsystem. Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL, March 27-
31, 1989. American Meteorological Society, Boston, 211-215 (1989).

No abstract.

FS-025

MARROQUIN, A., and J.M. BROWN. Diagnosis of NGM Performance for Spring Storms Over the Western United
States. Preprints, Conference on Weather Analysis and Forecasting, Monterey, California, October 2-6,
1989. American Meteorological Society, Boston, 617-622 (1989).

No abstract.

78

FS-026

McGEHAN, B.J. What's next in weather forecasting? Preprints, 2nd International Conference on School
and Popular Meteorological and Oceanographic Education, Crystal City, VA, July 12-16, 1989. American
Meteorological Society, Boston, 163-165 (1989).

No abstract.

FS-027

McGINLEY, J. A. and S.G. Benjamin. Mesoscale data assimilation for national, regional and local scales.
Preprints, Department of Defense Environmental Technical Exchange Conference on Mesoscale Phenomena,
Washington, D.C., January 23-27, 1989. Department of Defense, 287-298 (1989).

No abstract.

FS-028

MILLER, P. A., and M.J. Falls. A pilot study of methods to decrease measurement errors of tropospheric
inversions by ground-based microwave radiometry. Journal of Atmospheric and Oceanic Technology
6(2):225-234 (1989).

Results of radiometer temperature profile simulations are analyzed in order to examine the hypothesis
that knowledge of temperature inversion parameters obtained from other instruments would substantially
improve the accuracy of radiometric temperature profiles. Five variations of a statistical retrieval
method are used to produce radiometric temperature profiles. These profiles are then compared with
radiosonde data under both inversion and non-inversion conditions. The best algorithm yields consistently
better results than the traditional (pure radiometric) technique, but still fails to correctly reproduce
the radiosonde inversions.

FS-029

MILLER, P. A., and M.J. Falls. The incorporation of inversion characteristics into ground-based
microwave temperature soundings: A simulation study. Microwave Remote Sensing of the Earth System, A.
Chedin (ed.). Hampton, Virginia, 51-73 (1989).

No abstract.

FS-030

MONINGER, W.R. Artificial Intelligence for Data Management. AT Applications in Natural Resource
Management 3:47-48 (1989).

No abstract.

FS-031

MONINGER, W.R. Artificial Intelligence and Environmental Data. Proceedings, Conference on Earth
Observations and Global Change. September 18-19, 1989, Washington D.C. (1989)

Artificial intelligence techniques can be used to increase the productivity of environmental researchers
in at least three ways. (1) AI can be used to develop computer systems that encourage the recording of,
and manage, critical ancillary information (metadata) necessary to the proper understanding of
environmental data. (2) AI systems can serve as automated curators, also called intelligent front ends,
to environmental databases. (3) Intelligent database rovers can be developed that search unattended
through large environmental databases to identify possible flaws and possible important trends. We
discuss current efforts by the AI community that address these needs, and suggest that environmental
researchers take advantage of what AI has to offer.

FS-032

MONINGER, W.R. (Ed.). Meeting Report: Third Workshop on Artificial Intelligence Research in
Environmental Science (AIRIES) . AI Applications in Natural Resource Management 3:56-63 (1989).

No abstract.

79

FS-033

MONINGER, W.R., A. Ignatowski. METALOG: An interactive system to manage knowledge about data. Preprint
Volume, Fifth International Conference on Interactive Information and Processing Systems for
Meteorology, Oceanography, and Hydrology, Anaheim, CA, February, 1989. American Meteorological Society,
Boston, 321-326 (1989).

No Abstract.

FS-034

MONINGER, W.R., C. BULLOCK, T. Breyfogle, D. Furtney. FIDES: An expert system to provide
methodological forecast guidance. Preprints, Fifth International Conference on Interactive Information
and Processing Systems for Meteorology, Oceanography, and Hydrology, Anaheim, CA, February 1989.
American Meteorological Society, Boston, 397-401 (1989).

No abstract.

FS-035

MONINGER, W.R., J. A. Flueck, C. Lusk, W.F. Roberts. SHOOTOUT-89: A Comparative Evaluation of Knowledge-
based Systems that Forecast Severe Weather. Preprint Volume, Uncertainty and AI Workshop 1989. Windsor,
Canada, 265-271. Windsor Canada (Invited presentation. Substantially the same as Roberts, et al. (1989)

During the summer of 1989, the Forecast Systems Laboratory of the National Oceanic and Atmospheric
Administration sponsored an evaluation of AI systems that forecast severe convective storms. The
evaluation experiment, called SHOOTOUT-89, took place in Boulder, CO, and focussed on storms over the
northeastern Colorado plains. Several systems participated in SHOOTOUT-89. These systems include
traditional expert systems, an analogy-based system, and a system developed using methods from the
cognitive science/judgment analysis tradition. Each day of the exercise, the systems forecasted for each
of four specified forecast regions in northeastern Colorado, the probabilities of occurrence of: nonsig-
nificant weather, significant weather, and severe weather. A verification coordinator working at the
Denver Weather Service Forecast Office gathered ground-truth data from a network of observers. Systems
were evaluated on forecast skill, and also on other metrics such as timeliness , ease of learning, ease of
use, degree of portability to other locations. We report here initial results of the SHOOTOUT-89
experiment .

FS-036

NICKERSON, E.C., C. Ramis, E. Richard, P. Mascart, and J. P. Pinty. On the numerical simulation of
downslope windstorms. Programme on Short- and Medium-Range Weather Prediction Research (PSMP) Report
Series No. 31 , 3rd Session of the Steering Group on Mediterranean Cyclones Study Project, Barcelona,
Spain, 107-112 (1989).

No abstract.

FS-037

Rasmussen, E.N., J.K. Smith, J.F. PRATTE, and R.C. Lipschutz. Real time precipitation accumulation
estimation using the NCAR CP-2 Doppler Radar. Preprints, 24th Conference on Radar Meteorology, March
27-31, 1989, Tallahassee, FL. American Meteorological Society, Boston, 236-239 (1989).

No abstract.

FS-038

Richard, E. , P. Mascart, and E.C. NICKERSON. The role of surface friction in downslope windstorms.
Journal of Applied Meteorology, 28:241-251 (1989).

Numerical simulations of the 11 January 1972 windstorm in Boulder, Colorado, were carried out using a
hydrostatic model with a turbulent kinetic energy parameterization to investigate the role of frictional
effects in the development of nonlinear mountain waves. Sensitivity tests to the roughness length
specification and to the turbulent mixing and dissipation length formulations show that surface friction
delays the onset of the strong surface winds and also prevents the downstream propagation of the zone of
maximum windspeed. Shear production within convectively stable regions is the dominant mechanism for the

80

production of the turbulent kinetic energy. Moreover, these results are consistent with the hypothesis
that a hydrostatic amplification mechanism is capable of accounting for the development of strong
downslope winds.

FS-039

Richard, E. , P. Mascart, and E.C. NICKERSON. Surface friction effects in downslope windstorm.
Abstracts Volume One, IAMAP 89, 5th Scientific Assembly, Reading, England, July 31-August 12, 1989.
Commission Symposium on Mesoscale Phenomena: Analysis and Forecasting, August 2-4, 1989, MF31.

Numerical simulations of the 11 January 1972 windstorm in Boulder, Colorado, were carried out using a
hydrostatic model with a turbulent kinetic energy parameterization to investigate the role of frictional
effects in the development of nonlinear mountain waves. Sensitivity tests to the roughness length
specification and to the turbulent mixing and dissipation length formulations show that surface friction
delays the onset of the strong surface winds and also prevents the downstream propagation of the zone of
maximum wind speed. Shear production within convectively stable regions is the dominant mechanism for the
production of the turbulent kinetic energy. Moreover, these results are consistent with the hypothesis
that a hydrostatic amplification mechanism is capable of accounting for the development of strong
downslope winds.

FS-040

Roberts, W.F., W.R. MONINGER, B. deLorenzis, E. Ellison, J. Flueck, J.C. Mcleod, C. Lusk, P.D. Lampru,
R. Shaw, T.R. Stewart, J. Weaver, K.C. Young, S. Zubrick. A field test of artificial intelligence
systems applied to the problem of severe weather forecasting: SHOOTOUT-89. Preprints, 11th Conference
on Probability and Statistics, and 12th Conference on Weather Analysis and Forecasting, American
Meteorological Society, Boston, and Preprints, 12th Conference on Weather Analysis and Forecasting,
Monterey, CA, October 1989. American Meteorological Society, Boston, J59-J64 (1989).

No abstract.

FS-041

RODGERS, D.M., and C.G. GRIFFITH. Interpretation of GOES Water Vapor Imagery and Its Application to
Forecasting Thunderstorms. Preprints, 3rd International Conference on the Aviation Weather System,
Anaheim, California, January 23 - February 3, 1989. American Meteorological Society, Boston, 351-355
(1989).

No abstract.

FS-042

SCHLATTER, T.W. An integrated approach to the display of Doppler radar and other meteorological data.
Proceedings, International Seminar on Weather Radar Networking, Brussels, Belgium, 5-8 September, 1989.
Commission of the European Communities, Cooperation in Science and Technology (COST 73) Project, 317-330
(1989).

No abstract.

FS-043

SCHLATTER, T.W. Real-time analysis of mesoscale data. Abstracts Volume One, IAMAP 89, 5th Scientific
Assembly, Reading, England, July 31-August 12, 1989. Commission Symposium on Mesoscale Phenomena:
Analysis and Forecasting, August 2-4, 1989, MF17-21.

No abstract.

FS-044

SCHULTZ, P. Relationships of several stability indices to convective weather events in Northeast
Colorado. Weather and Forecasting 4:73-80 (1989).

Seven familiar stability indices were computed from sounding data for each 83 days of a convection
forecasting experiment conducted during the summer 1985 in Northeast Colorado. Observations of
convectively driven weather events were collected; the values of the indices were compared against this
dataset to examine their performance as predictors of severe weather (large hail, tornadoes, high wind)

and significant weather (nonsevere but important from an economic or public safety standpoint). The
results of the analysis are: (1) Benchmark values of the indices that give their typical magnitudes on
active days versus quiescent days. These values, compared with those computed in other regions,
illustrate the potential fallacy of interpreting the indices in the absence of analogous region-specific
reference statistics. (2) Rankings that determine which indices worked best in this experiment. The
highest ranked indices were the SWEAT index for severe weather and buoyancy for significant weather.
Interestingly, SWEAT was the worst of those tested for significant weather. (3) Quantitative convection
forecasting guidance. The observed relative frequencies of severe and significant convection as functions
of the seven indices are presented in graphical form. When used in a forecasting context, these observed
relative frequencies can be interpreted as probabilities of severe and/or significant weather. Some of
the graphs are clearly bimodal; no explanation for this behavior is offered. (4) Some of the benefits
that would be realized by collecting more data, in this and other regions, are suggested. For example,
there is a good possibility that some indices show particular skill for certain types of events (e.g.,
hail vs high wind, etc.), but the present dataset is too small to clearly establish any such connections.

FS-045

SCHWARTZ, B.E. Rawinsonde Data: Operational and Archival Concerns. Preprints, 12th Conference on
Weather Analysis and Forecasting, Monterey, California, October 2-6, 1989. American Meteorological
Society, Boston, 52-57 (1989).

No abstract.

FS-046

SMART, J. The profiler-observed wind structure of a continental type polar cyclone. Transactions,
American Geophysical Union 1988 Fall Meeting, San Francisco, CA, December 5-9, 1988, 69 (44): 1074
(1988).

No abstract.

FS-047

Stewart, T.R., W.R. MONINGER, J. Grassia, R.H. Brady, F.H. MERREM. Analysis of Expert Judgment in a
Hail Forecasting Experiment. Weather and Forecasting 4:24-34 (1989).

This study compared meteorologists, an expert system, and simple weighted sum models in a limited-
information hail forecasting experiment. It was found that forecasts made by meteorologists were closely
approximated by an additive model, and that the model captured most of their forecasting skill.
Furthermore, the additive model approximated the meteorologists' forecasts better than the expert system
did. Results of this study are consistent with the results of extensive psychological research on
judgment and decision making processes. Potential implications are discussed.

FS-048

TOLLERUD, E. I., X.P. Zhong, and B.G. Brown. Evaluating a Composite Climatology of Mesoscale Rainfall.
Preprints, 4th International Meeting on Statistical Climatology, Rotorua, New Zealand, March 27-31,
1989, 216-221.

No Abstract

FS-049

TOLLERUD, E.I., J.M. BROWN, and D.L. Bartels. Structure of an MCS Induced Mesoscale Vortex as Revealed
by the VHF Profiler, Doppler Radar and Satellite Observations. Preprints, 12th Conference on Weather
Analysis and Forecasting, Monterey, California, October 2-6, 1989. American Meteorological Society,
Boston, 81-86 (1989).

No abstract.

FS-050

Wade, C.G., and S.L. BARNES. Geopotential Height Errors in NWS Rawinsonde Date at Denver. Bulletin of
the American Meteorological Society 69 (12) : 1455-1459 (1989).

82

A recent examination of Denver National Weather Service radiosonde data has revealed an error in the

procedure used to establish the surface baseline pressure for Denver soundings obtained between 14 April
1983 and 2 March 1988. As a result of this error the baroswitch was improperly set on each sounding,
resulting in geopotential heights that average from 16 to

30 m too low. This article alerts users of the Denver data to the existence and nature of this problem

and shows the effect that such subtle bias errors in radiosonde height data can have on derived quantities
such as geostrophic vorticity.

FS-051

Wilczak, J.M., D.E. Wolfe and S.C. ALbers. The 2 July 1987 tornado observed during CINDE: implications
for NEXRAD. Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL, March 27-31, 1989.
American Meteorology Society, Boston, 251-254 (1989).

No abstract.

FS-052

Winston, H.A., and E.N. Rasmussen. A study of various implementations of the NEXRAD VIL algorithm.
Preprints, 24th Conference on Radar Meteorology, March 27-31, 1989, Tallahassee, FL. American
Meteorological Society, Boston, 236-239 (1989).

No abstract.

FS-053

Zhong, X.P., and E.I. TOLLERUD. Rainfall in Mesoscale Convective Complexes: Spatial Distribution and

Seasonal Variation. Preprints, 12th Conference on Weather Analysis and Forecasting, Monterey,

California, October 2-6, 1989. American Meteorological Society, Boston, 111-116 (1989).

No abstract.

FS-054

Zupanski, M. and J. McGINLEY. Numerical analysis of the influence of jets, fronts, and mountains on
alpine lee cyclogenesis. Monthly Weather Review 117:154-176 (1989).

Recent diagnostic and numerical studies have shown that lee cyclogenesis events in the lee of the Alps
occur when: (1) an upper level trough is upstream; (2) a low level frontal system impinges on the Alps
and, (3) an upper level jet streak on the west side of the trough moves into the northern Mediterranean.
Three case studies focusing on the rapid development state of Alpine lee cyclogenesis are investigated by
performing a set of numerical experiments, with emphasis on the above mentioned factors. In order to
create slightly different initial fields, we have used a two layer smoothing technique, alternatively
reducing low-level available potential energy [testing (2)], or reducing an upper level wind maxima
[testing (3)]. Once this is done we readjust the mass and momentum fields using a variational
initialization scheme with weak geostrophic constraints. Based on the results of these cases of lee
cyclogenesis, the weaker lee developments were significantly reduced by decreasing the low-level frontal
intensity (2), which implied a greater influence of the low level dynamical processes (frontal
impingement) relative to jet streak processes (geostrophic adjustment). In the case of relatively strong
cyclogenesis, dynamical processes associated with the upper-level jet streak become a more important
factor than low level forcing. An overall inhibitory effect of the Alps was obvious in all three cases,
particularly in the case of strong cyclogenesis. However, these experiments did show localization of
development as manifested by a high-low dipole structure of the mountain induced pressure perturbations.

Addendum

FS-055

VAN DE KAMP, D.W. Profiler Training Manual No. 1: Principles of Wind Profiler Operation. National
Weather Service Office of Meteorology, Washington, DC, 49 pp. (1988).

No abstract.

83

GEOPHYSICAL FLUID DYNAMICS LABORATORY

GF-001

Brasseur, G.P., J. C. Farman, I.S.A. Isaksen, B.C. Kruger, K. Labitzke, J.D. MAHLMAN , M.P. McCormick,

P. Solomon, R.S. Stolarski, A. Turco, R.T. Watson. Changes in Antarctic ozone. In The Changing

Atmosphere, F.S. Rowland and I.S.A. Isaksen (eds). Wiley-Interscience , New York, 235-256 (1988).

No abstract.

GF-002

Carissimo, B.C., R.T. PIERREHUMBERT, and H.L. Pham. An estimate of mountain drag during ALPEX for
comparison with numerical models. Journal of the Atmospheric Sciences 45( 13) : 1949-1960 (1988).

The pressure drag vector for a limited domain including the Alps is estimated for the ALPEX period of
March and April 1982. All of the reported, three hourly, surface pressure data in the domain are used and
maps of analyzed deviation surface pressure are obtained for the mountainous area. The very important
drag values previously reported are confirmed and shown to occur when tight pressure gradients are
localized above the steep orography. The peak values are found to be sensitive to the resolution of the
analysis. A composite of the large drag variations occurring in relation to frontal passage and cyclo-
genesis is constructed. The diurnal cycle observed during periods of quiet synoptic activity is
discussed. The observed drag compares favorably with the drag in the simulation of a case of cyclogenesis
using a numerical model with comparable horizontal resolution.

GF-UU3

Cnang, p., and S.G.H. PHILANDER. Rossby wave packets in baroclinic mean currents. Deep-Sea Research
36(1 ) : 17-37 (1989).

A WKB description of the propagation of Rossby wave packets in a shallow water model of the tropical
oceans indicates that the presence of the baroclinic mean currents can modify the characteristics of wave
propagation significantly. For currents with weak latitudinal shear the effect of the current itself is
less important than the effect of the associated variations in the depth of the thermocline, except near
critical layers where waves are absorbed. For example, a westward current, and the associated shoaling of
the thermocline towards the equator, can cause the speed of the long Rossby waves to decrease with
decreasing latitude. (The speed increases towards the equator in the absence of mean currents.) Westward
currents inhibit meridional propagation, but eastward currents enhance it. The amplification and decay of
a wave packet as it propagates through a mean current are described in terms of the conservation of wave
action. Implications of these results for the propagation of Rossby waves in the real ocean are
discussed .

GF-004

COOK, K.H., and I.M. HELD. Stationary waves of the ice age climate. Journal of Climate. 1(8): 807-81 9
(1988).

A linearized, steady state, primitive equation model is used to simulate the climatological zonal
asymmetries (stationary eddies) in the wind and temperature fields of the 18000 YBP climate during winter.
We compare these results with the eddies simulated in the ice age experiments of Broccoli and Manabe , who
used CLIMAP boundary conditions and reduced atmospheric CO2 in an atmospheric general circulation model
(GCM) coupled with a static mixed layer ocean model. The agreement between the models is good, indicating
that the linear model can be used to evaluate the relative influences of orography, diabatic heating, and
transient eddy heat and momentum transports in generating stationary waves. We find that orographic
forcing dominates in the ice age climate. The mechanical influence of the continental ice sheets on the
atmosphere is responsible for most of the changes between the present day and ice age stationary eddies.
This concept or the ice age climate is complicated by the sensitivity of the stationary eddies to the
large increase in the magnitude of the zonal mean meridional temperature gradient simulated in the ice age
GCM.

GF-005

DELWORTH, T.L., and S. MANABE. The influence of potential evaporation on the variabilities of simulated
soil wetness and climate. Journal of Climate 1(5): 523-547 (1988).

84

An atmospheric general circulation model with prescribed sea surface temperature and cloudiness was
integrated for 50 years in order to study atmosphere-land surface interactions. The temporal variability
of model soil moisture and precipitation have been studied in an effort to understand the interactions of
these variables with other components of the climate system. Temporal variability analysis has shown that
the spectra of monthly mean precipitation over land are close to white at all latitudes, with total
variance decreasing poleward. In contrast, the spectra of soil moisture are red, and become more red
with increasing latitude. As a measure of this redness, half of the total variance of a composite
tropical soil moisture spectrum occurs at periods longer than nine months, while at high latitudes, half
of the total variance of a composite soil moisture spectrum occurs at periods longer than ?2 months. The
spectra of soil moisture also exhibit marked longitudinal variations. These spectral results may be
viewed in the light of stochastic theory. The formulation of the GFDL soil moisture parameterization is
mathematically similar to a stochastic process. According to this model, forcing of a system by an input
white noise variable (precipitation) will yield an output variable (soil moisture) with a red spectrum,
the redness of which is controlled by a damping term (potential evaporation). Thus, the increasingly red
nature of the soil moisture spectra at higher latitudes is a result of declining potential evaporation
values at higher latitudes. Physically, soil moisture excesses are dissipated more slowly at high
latitudes where the energy available for evaporation is small. Some of the longitudinal variations in
soil moisture spectra result from longitudinal variations in potential evaporation, while others are
explicable in terms of the value of the ratio of potential evaporation to precipitation. Regions where
this value is less than one are characterized by frequent runoff and short time scales of soil moisture
variability. By preventing excessive positive anomalies of soil moisture, the runoff process hastens the
return of soil moisture values to their mean state, thereby shortening soil moisture time scales. Through
the use of a second GCM integration with prescribed soil moisture, it was shown that interactive soil
moisture may substantially increase summer surface air temperature variability. Soil moisture interacts
with the atmosphere primarily through the surface energy balance. The degree of soil saturation strongly
influences the partitioning of outgoing energy from the surface between the latent and sensible heat
fluxes. Interactive soil moisture allows larger variations of these fluxes, thereby increasing the
variance of surface air temperature. Because the flux of latent heat is directly proportional to potential
evaporation under conditions of sufficient moisture, the influence of soil moisture on the atmosphere is
greatest when the potential evaporation value is large. This occurs most frequently in the tropics and
summer hemisphere extratropics .

GF-006

Hamilton, K., and J.D. MAHLMAN. General circulation model simulation of the semiannual oscillation of
the tropical middle atmosphere. Journal of the Atmospheric Sciences 45 (21 ): 3212-3235 (1988).

A study has been made of the evolution of the zonal-mean zonal wind and temperature in a multiyear
integration of the 40-level, 3° X 3.6° resolution "SKYHI" general circulation model (GCM) that has been
developed at GFDL. In the tropical upper stratosphere the mean wind variation is dominated by a strong
semiannual oscillation (SAO). The peak SAO amplitude in the model is almost 25 m s~* and occurs near the
1 mb level. The phase of the SAO near the stratosphere is such that maximum westerlies occur shortly
after the equinoxes. These features are in good agreement with the available observations. In addition
the meridional width of the stratopause SAO in the GCM compares well with observations. A diagnostic
analysis of the zonal-mean momentum balance near the tropical stratopause was performed using the detailed
fields archived during the GCM integration. It appears that the easterly accelerations in the model SAO
are provided by a combination of (i) divergence of the meridional component of the Eliassen-Palm flux
associated with quasi-stationary planetary waves and (ii) mean angular momentum advection by the residual
meridional circulation. The effects of the residual circulation dominate in the summer hemisphere, while
the eddy contributions are more important in the winter hemisphere. The westerly accelerations in the
model SAO result from the convergence of the vertical momentum transport associated with gravity waves
that have a broad distribution of space and time scales. Thus, in contrast to some simple theoretical
models, large-scale equatorial Kelvin waves appear to play only a very minor role in the dynamics of the
SAO in the SKYHI GCM. A second equatorial SAO amplitude maximum was found in the tropical upper meso-
sphere of the GCM. This apparently corresponds to the mesopause SAO that has been identified in earlier
observational studies. While the observed phase of this oscillation is reproduced in the model, the
simulated amplitude is unrealistically small. The model integration included the computation of the
concentration of N2O. The results show a fairly realistic simulation of the semiannual variation of
tropical stratospheric N2O mixing ratio seen in satellite observations.

GF-007

HAMILTON, K. Interhemispheric asymmetry and annual synchronization of the ozone quasi-biennial
oscillation. Journal of the Atmospheric Sciences 46( 7) : 1019-1025 (1989).

85

The quasi-biennial oscillation (QBO) in total column ozone has been examined at several tropical
stations. The ozone QBO at Mauna Loa (19.5°N) was found to have a remarkable annual synchronization.
Both positive and negative extremes in the deseasonalized ozone time series almost always occur between
December and March. The annual cycle-QBO phase locking is much more pronounced in this ozone record than
it is for the familiar QBO in the prevailing tropical stratospheric winds. This result is taken as
evidence that the dynamical QBO acts to modulate a strong seasonal ozone transport from midlatitudes to
the tropics. Ir this transport is connected with quasi-stationary planetary waves, then this interpre-
tation offers an obvious explanation for the interhemispheric asymmetry in the ozone QBO that has been
noted in many earlier studies.

GF-008

HAYASHI, Y., and D.G. GOLDER. Tropical intraseasonal oscillations appearing in a GFDL general
circulation model and FGGE data, Part II: Structure. Journal of the Atmospheric Sciences 45(21):3017-
3033(1988).

Space-time spectral and filter analyses are made of the structure of the tropical intraseasonal oscil-
lations appearing in a GFDL 30-wavenumber spectral general circulation model and the FGGE IITb data set.
The model's tropical zonal velocity exhibits spectral peaks with periods of 40-50 and 25-30 days at
wavenumber 1 for six individual years, although the 40-50 day peak is not as pronounced as that found in
the FGGE dataset. Both the eastward moving 40-50 and 25-30 day oscillations take the form of a Kelvin-
Rossby wave pattern in the upper troposphere and a Rossby mode in the lower troposphere. They also take
the form of a latitudinally tilted Walker cell which is modified by a meridional convergence in the
boundary layer.

GF-O09

HAYASHI, Y., D.G. GOLDER, J.D. MAHLMAN , and S. Miyahara. The effect of horizontal resolution on
gravity waves simulated by the GFDL "SKYHI" General Circulation Model. Pageoph 130( 2/3) :421-443 (1989).

To examine the effects of horizontal resolution on internal gravity waves simulated by the 40-level
GFDL "SKYHI" general circulation model, a comparison is made between the 3° and 1° resolution models
during late December. The stratospheric and mesospheric zonal flows in the winter and summer extra-
tropical regions of the 1° model are much weaker and more realistic than the corresponding zonal flows of
the 3° model. The weaker flows are consistent with the stronger Eliassen-Palm flux divergence (EPFD).
The increase in the magnitude of the EPFD in the winter and summer extratropical mesospheres is due mostly
to the increase in the gravity wave vertical momentum flux convergence (VMFC) . In the summer extra-
tropical mesosphere, the increase in the resolvable horizontal wavenumbers accounts for most of the
increase in the gravity wave VMFC. In the winter extratropical mesosphere, the increase of VMFC
associated with large-scale eastward moving components also accounts for part of the increase in the
gravity wave VMFC. The gravity waves in the summer and winter mesosphere of the 1° model are associated
with a broader frequency-spectral distribution, resulting in a more sporadic time-distribution of their
VMFC. This broadening is due not only to the increase in resolvable horizontal wavenumbers but also
occurs in the large-scale components owing to wave-wave interactions. It was found that the phase
velocity ana frequency of resolvable small-scale gravity waves are severely underestimated by finite
difference approximations.

GF-U10

HELD, I.M., S.W. Lyons, and S. Nigam. Transients and the extratropical response to El Nino. Journal of
Atmospheric Sciences 46( 1 ): 163-174 (1989).

A Daroclinic stationary wave model linearized about a zonally symmetric flow is used to interpret the
extratropical atmospheric response to El Nino produced by a general circulation model. When forced by
the anomalous diaDatic heating and tendency due to transients, the linear model provides a useful
simulation of this response. The direct response to anomalous diabatic heating is found to be small in
the extratropics ; the dominant term is the response to the anomalous transients, particularly the
anomalous upper tropospheric transients in the vorticity equation. These results are complementary to
those obtained with a nonlinear barotropic model by Held and Kang , and indicate that the anomalous
subtropical convergence which plays a key role in that study is itself primarily forced by the anomalous
transients. One can distinguish between two distinct parts of the response of the transients to the
tropical heating: the movement of the Pacific storm track associated with the anomalous extratropical
wave train, and changes in the penetration of Rossby waves into the tropics resulting from the modified
tropical winds.

86

GF-011

Kantha, L.H., A. ROSATI , and B. Galperin. Effect of rotation on vertical mixing and associated
turbulence in stratified fluids. Journal of Geophysical Research 94:4843-4854 (1989).

Combined effects of stratification and rotation on vertical mixing and the characteristics of
associated small-scale turbulence are explored using second-moment closure methodology; the rotational
terms in the equations for Reynolds stresses and turbulent heat fluxes are retained, not ignored as in
earlier works. Semianaly tical results valid for arbitrary values of rotation and stratification are
derived Dy further invoking the local equilibrium limit of closure. Two cases are considered: nonzero
vertical rotation and nonzero meridional rotation; the latter case is of more general interest in geo-
physics because of its potential application to equatorial mixed layers. In both cases the influence of
rotation on mixing coefficients and Monin-Obukhov constant flux layer similarity relations is investigated
for arbitrary values of rotation and stratification. In both cases, turbulent mixing coefficients assume
tensorial properties. However, meridional rotation appears to have a stronger influence on vertical
mixing and turbulence characteristics than does vertical rotation. These results, along with perturbation
expansions for weak rotation, suggest that for geophysical flows, in most cases, the direct effect of
rotation on vertical turbulent mixing itself is but a small correction, a few tens of percent at best. It
is seldom large, although it might not be negligible in some particular cases. Nevertheless, the study of
rotational effects on small-scale turbulence provides a fascinating insight into the direct impact of
rotation on the characteristics of small-scale turbulence and mixing in stratified fluids; the results are
also of interest in other fields such as engineering.

GF-U12

LAU , N.-C. Variability of the observed midlatitude storm tracks in relation to low-frequencv changes in
the circulation pattern. Journal of the Atmospheric Sciences 45 ( 1 ): 2718-2743 (198s).

The principal modes of month-to-month variability of the wintertime storm tracks over the North Pacific
and North Atlantic are identified by empirical orthogonal function analysis of the root-mean-square
statistics of bandpass (2.5-6 day) filtered geopotential height data for 19 yr . One of the two leading
modes depicts fluctuations in the level of synoptic-scale activity without any noticeable spatial dis-
placement of the storm track axes, whereas the other mode is associated with meridional shifts of the
storm tracks from their time-averaged positions. Higher order modes are indicative of diversion or
truncation of cyclone tracks in particular geographical regions. It is demonstrated that the leading
storm track modes are linked to some of the best-known monthly averaged teleconnect ion patterns. The
dipolar western Pacific and western Atlantic patterns for the monthly mean flow are seen to be accompanied
by marked changes in the intensity of the storm tracks over the western oceans, whereas the more wave-like
Pacific/North American and eastern Atlantic teleconnection patterns are coincident with north-south
displacements of the storm track axes over the eastern oceans. The representative synoptic scenarios for
various storm track modes are portrayed using composite charts. These patterns illustrate the strong
modulation of the trajectory of weather systems by the intensity and steering action of the monthlv
averaged flow field, so that the storm tracks are preferentially located at and slightly downstream of the
quasi-stationary troughs. The shape and propagation of the synoptic scale eddies along the changing storm
tracks, as well as the barotropic interactions between these disturbances and the monthly mean flow, are
diagnosed using composite patterns of extended Eliassen-Palm vectors and eddy-induced geopotential
tendencies at 300 mb . It is seen that the synoptic-scale fluctuations are typically crescent-shaped, and
sometimes undergo noticeable deformation when they encounter quasi-stationary ridges. In the upper
troposphere, enhanced eddy activity is accompanied locally by eastward acceleration, as well as by
positive geopotential tendency immediately to the south, and negative geopotential tendency to the north,
and vice versa. The distributions of eddy-induced geopotential tendency for individual storm track modes
indicate a near inphase relationship between the synoptic scale barotropic forcing and the quasi-
stationary flow pattern at 300 mb . The characteristic time scale for this forcing is approximately 7-10
days. The characteristic circulations at sea level associated with various storm track modes are examined
using composite charts of the sea level pressure field. Some of these composites resemble the patterns
associated with the North Pacific and North Atlantic Oscillations.

GF-U13

LAU, N.-C, I.M. HELD, and J.D. Neelin. The Madden-Julian oscillation in an idealized general
circulation model. Journal of the Atmospheric Sciences 45( 24 ): 3810-3832 (1988).

The structure of the intraseasonal oscillations in the tropics of an idealized general circulation model
with a zonally symmetric climate is described. Space-time spectra show a peak in zonal winds and
velocity potential at the equator in zonal wavenumbers 1 and 2, corresponding to eastward-propagating
power at phase speeds of V 18 m s~ . This speed is significantly greater than that of the observed oscil-
lation but comparable to that obtained in similar models by Hayashi and Sumi and Swinbank et al. The

87

corresponding eastward-propagating power in the precipitation spectrum is concentrated in wavenumbers 2-5.
A composite procedure is used to describe the three-dimensional structure of the model's oscillation. The
oscillation is characterized by circulation cells oriented along the equatorial zonal plane, with enhanced
precipitation in the region of rising motion. Zonal wind changes tend to be positively correlated with
geopotent ial height changes at the same level. Positive perturbations in the water vapor mixing ratio,
evaporation, and lower tropospheric horizontal moisture convergence all exhibit distinct eastward
displacements from the center of convection. Two different linear models are used to interpret the GCM
results. Tne response to the GCM's composited diabatic heating field is first computed using a linear
primitive equation model on the sphere. This linear model requires strong damping above the heated
region, as well as near the surface, to produce a pattern in rough agreement with the GCM. A simple
Kelvin wave-CISK model, in which the vertical structure of the heating is taken from the composite, is
then shown to be capable of reproducing the phase speed simulated in the GCM.

GF-014

LEV1TUS, S., Decadal and pentadal distribution of hydrographic stations at 1000m depth for the world
ocean, Progress in Oceanography 20(2):83-101 (1989).

Global distributions of hydrographic stations at 1000m depth in the world ocean are presented by decades
for the period 1900-1949 and pentads for the period 1950-1974. Distributions for individual years
1965-1967 are also presented. The distributions indicate regions that may contain enough data to be
suitable for studies of interpentadal and interdecadal variability.

GF-ul5

LEVITUS, S. Interpentadal variability of temperature and salinity at intermediate depths of the
North Atlantic Ocean, 1970-1974 versus 1955-1959. Journal of Geophysical Research 94(C5) : 6091-6131
(1989).

We have composited historical hydrographic observations for the world ocean for two pentads,
1955-1959 and 1970-1974, and have objectively analyzed these data for the purpose of studying the
temporal variaDility of temperature and salinity in the North Atlantic Ocean. The subtropical gyre
(:>U0-i300 m) of the iMorth Atlantic was colder and fresher during 1970-1974 compared to 1955-1959. The
relatively large changes in temperature and salinity on constant-depth surfaces in the subtropical
gyre were due to upward displacements of isopycnal surfaces. At intermediate depths the eastern portion
of the subarctic gyre was also colder and fresher during the 1970-1974 pentad. In contrast, the western
portion of tne suDarctic gyre exhibited higher temperatures and salinities during 1970-1974 compared to
1955-1959. Characteristic differences in temperature and salinity for both gyres were 0.5°C and
0.u25°/oo, respectively. Analysis of changes in potential vorticity indicates that in the subtropical
gyre potential vorticity increased in all density layers above the 26.5 surface, suggesting that
convection in this region may have been shallower in 1970-1974 compared to 1955-1959. Below the 26.5
surface, potential vorticity decreased through the 27.3 surface, indicating that deeper than normal
convection may have formed the water masses in these layers. At 250 m depth, relatively large changes in
temperature and salinity occurred along the line of maximum climatological mixed layer depth that extends
northeast to southwest across the North Atlantic Ocean.

GF-016

LEVY, H., II. Simulated global deposition of reactive nitrogen emitted by fossil fuel combustion.
Proceedings of the IAHS Third Scientific Assembly, Symposium I, Atmospheric Deposition, Baltimore, MD.
May 1989, 3-9 (1989).

We use the medium resolution (265 km horizontal grid) Geophysical Fluid Dynamics Laboratory (GFDL)
general circulation transport model to simulate the global deposition of reactive nitrogen emitted by
fossil fuel combustion. The nitrogen species are transported as a single tracer, the global parameter for
wet deposition is based on the observed wet deposition of nitrogen over North America, and constant bulk
coefficients for dry deposition over land and sea are pre-calculated from measured concentrations and
deposition velocities. The simulated yearly wet depositions in Europe, as well as nearby and distant
export sites, are in reasonable agreement with observations. The agreement is generally quite good and
almost always within a factor of 2. No more than 1.4 Tg of the 21.3 of nitrogen emitted by fossil fuel
combustion are deposited in the Southern Hemisphere, yet this source accounts for less than 10% of the
apparent background deposition. The 4 Tg of nitrogen exported by the three major source regions
(US/Canada, Europe, and Asia) accounts for most of the deposition over the remote Northern Hemisphere.
The simulated deposition over the North Pacific, which is in good agreement with estimates based on
recent observations, is dominated by emissions from Asia, while US/Canadian emissions dominate deposition
over the North Atlantic.

88

GF-U17

LEVY II, H. , and W.J. MOXIM. Simulated global distribution and deposition of reactive nitrogen emitted
emitted by fossil fuel combustion. Tellus 41B, 256-271 (1989).

We use the medium resolution ( ~ 265 km horizontal grid) GFDL general circulation transport model to
simulate the global spread and deposition of reactive nitrogen emitted by fossil fuel combustion. The
nitrogen species are transported as a single tracer with no explicit chemistry. Chemical reactions are
only present implicitly in the bulk coefficients for dry and wet removal. The observed wet deposition of
nitrogen over North America is used to determine the global parameter for wet deposition, and constant
bulk coefficients for dry deposition over land and sea are pre-calculated from measured concentrations and
deposition velocities. The simulated yearly depositions in Western Europe and at regional export sites,
as well as simulated yearly concentrations and their seasonal variation over the North Pacific, are
compared with available observations. The agreement is generally quite good and almost always within a
factor of 2. This model is then used to identify a number of important source regions and long-range
transport mechanisms: (1) Asian emissions supply two-thirds of the soluble nitrogen compounds over the
North Pacific. In the summer, North American emissions are important over the subtropical North Pacific.
(2) Nitrogen emissions from Europe dominate the nitrogen component of Arctic haze in the lower tropo-
sphere, while North American and Asian emissions are only important locally. The model predicts a large
gradient in the Arctic with average winter mixing ratios ranging from less than 0.1 ppbv over Alaska to
more than 1 ppbv over eastern Russia. (3) Throughout the Southern Hemisphere, the emissions from fossil
fuel combustion account for 10% or less of the observed soluble nitrogen at remote sites, an amount less
than a previously simulated contribution from stratospheric injection. The long-range transport of PAN,
NOx production by lightning and biomass burning, and some, as yet, unknown marine biogenic source may all
supply part of this background soluble nitrogen. However, the similarity between the seasonal cycles
observed at Samoa for soluble nitrogen and for O3 , a species known to be supplied from the stratosphere,
suggests a major role for either stratospheric injection or an upper tropospheric source.

GF-U18

Lin, S.-J., and R.T. PIERREHUMBERT. Does Ekman friction suppress baroclinic instability? Journal of
the Atmospheric Sciences 45( 20) : 2920-2933 (1988).

The effect of Ekman friction on baroclinic instability is reexamined in order to address questions
raised by Farrell concerning the existence of normal mode instability in the atmosphere. As the degree of
meridional confinement is central to the result, a linearized two-dimensional (latitude-height) quasi-
geostrophic model is used to obviate the arbitrariness inherent in choosing a channel width in one-
dimensional (vertical shear only) models. The two-dimensional eigenvalue problem was solved bv
pseudospec tral method using rational Chebyshev expansions in both vertical and meridional directions. It
is concluded that the instability can be eliminated only by the combination of strong Ekman friction with
weak large-scale wind shear. Estimates of Ekman friction based on a realistic boundary-layer model
indicate that such conditions can prevail over land when the boundary layer is neutrally stratified. For
values of EKman friction appropriate to the open ocean, friction can reduce the growth rate of the most
unstable mode by at most a factor of two but cannot eliminate the instability. By reducing the growth
rate and shifting the most unstable mode to lower zonal wavenumbers, viscous effects make the heat and
momentum fluxes of the most unstable mode deeper and less mer idionally confined than in the inviscid case.
Nevertheless, linear theory still underestimates the penetration depth of the momentum fluxes, as compared
to observations and nonlinear numerical models.

GF-U19

LIPPS, F.B., and R.S. HEMLER. Numerical modeling of a line of towering cumulus on day 226 of GATS.
Journal of che Atmospheric Sciences 45( 17 ): 2428-2444 (1988).

A three-dimensional numerical model with warm rain bulk cloud physics is used to investigate the
shallow convection observed on Day 226 of GATE. This convection had cloud tops at 3.0 km, cloud bases at
0.4 km and approximately 0.1 cm of rain at the surface. The simulated convection shows a strong sensi-
tivity to the criterion for the onset of autoconversion of cloud water into rain water. The strongest
convection occurs for the case in which no rain water forms. This case, however, does not conform to the
observed convection, lacking the downdraft below cloud base and the observed strong surface outflow. The
primary simulation produces a "finger" of convection propagating to the northeast, perpendicular to the
northwest-southeast orientation of the larger-scale line of convection. The orientation and propagation
speed of the calculated convection are in excellent agreement with observed radar data. This simulation
also has a well-defined leading edge and strong surface outflow as observed. In poorer agreement, the
cloud Dase was too high and the rainfall at the surface was less than observed.

89

Present calculations indicate that below cloud base the boundary layer air is flowing through the line
from southwest to northeast. The primary moisture source for the cloud is the upper half of the subcloud
layer, with nearly horizontal flow entering the cloud.

GF-U20

MANABE , S., and R.J. STOUFFER. Two stable equilibria of a coupled ocean-atmosphere model. Journal of
Climate 1:841-866 (1988).

Two stable equilibria have been obtained from a global model of the coupled ocean-atmosphere system
developed at the Geophysical Fluid Dynamics Laboratory of NOAA. The model used for this study consists of
general circulation models of the atmosphere and the world oceans and a simple model of land surface.
Starting from two different initial conditions, "asynchronous" time integrations of the coupled model,
under identical boundary conditions, lead to two stable equilibria. In one equilibrium, the North
Atlantic Ocean has a vigorous thermohaline circulation and relatively saline and warm surface water. In
the other equilibrium, there is no thermohaline circulation, and an intense halocline exists in the
surface layer at high latitudes. In both integrations, the air-sea exchange of water is adjusted to
remove a systematic bias of the model that suppresses the thermohaline circulation in the North Atlantic.
Nevertheless, these results raise the intriguing possibility that the coupled system may have at least two
equilibria. They also suggest that the thermohaline overturning in the North Atlantic is mainly respon-
sible for making the surface salinity of the northern North Atlantic higher than that of the northern
North Pacific. Finally, a discussion is made on the paleoc limatic implications of these results for the
large and abrupt transition between the Allerod and Younger Dryas events which occurred about 11,000 vears
ago.

GF-021

MIYAKODA, K., A. ROSATI , R. GUDGEL , and Y. Chao. Study of ENSO with an ocean GCM. Pontificia Academia
Scientiarvm 69:97-119 (1988).

A time series of surface atmospheric data is applied to an ocean GCM as a surface boundary condition.
The GCM has 1° X 1° grid in the global domain except 1° X 1/3° high resolution in the equatorial zone, and
has 12 vertical levels. The turbulence closure scheme is used for the vertical mixing. The atmospheric
forcings are twice daily, based on the NMC analysis. The period simulated is the four years from
1980-1983, which include the 1982/83 El Nino. The simulation of the warm event is satisfactory. A
diagnostic study on the ENSO process is performed. The time evolution of SO pressure patterns and of the
surface wind fields for the 1982/83 case compare fairly well with the canonical case presented by
Rasmusson and Carpenter (1982) and van Loon (1986). Based on this analysis, a hypothetical view is
presented on the significance of the SO pattern and wind stress to the El Nino process.

GF-U22

MIYAKODA, K. , and J. SIRUTIS. A proposal of moist turbulence closure scheme, and the rationalization
of AraKawa-Schubert cumulus parameterization. Meteorology and Atmospheric Physics 40:110-122 (1989).

Subgr id-scale parameterizations related to moist process are discussed. In the first half of the
paper, a turDulence closure scheme, including the effect of condensation, is proposed. In this parameter-
ization, the subgrid-scale transfer is limited within a single vertical layer of a model per each time
step, and the specification of condensation is of yes-or-no type. Therefore, the scheme is suited for a
mesoscale circulation model. In the second half of this paper, the bounded derivative method of Kreiss
(1980* is applied to the formulation of parameterizations. One example is the derivation of various
hierarchial versions of turbulence closure schemes such as Mellor and Yamada (1974). Another example is
an interpretation of the key assumption in Arakawa-Schubert (1974) theory of cumulus convection, i.e., the
equilibrium of "cloud-work function".

GF-023

MIYAKODA, K. Atmospheric forecast model data assimilation and air-sea flux computations. Workshop
Report on Atmospheric Forcing of Ocean Circulation, January 4-7, 1988. Tulane University, New Orleans,
LA. Sponsored by ( INo7~ (W0CET7 and (TOGA), 55-94 (1989).

The estimate of air-sea fluxes in data assimilation is discussed. Air-sea fluxes consist of the
transport of sensible and latent heat, radiation, and momentum at the air-sea interface. In order to gain
a clear perspective on the problem of air-sea exchange, the current state of the seasonal forecast
experiment, using an air-sea coupled model, is overviewed . An important feature of the current coupled
model forecasts is that the estimated sea surface temperature is considerably lower than the observed.
Tae deficient heat flux is as large as 100 W m~* in the Equatorial Pacific and Kuroshio regions. The main

90

cause is the model's systematic error ("climate drift"). In the particular case, the atmospheric model's
insufficient horizontal space resolution is responsible for the deficiency. It is pointed out that the
accuracy of calculated fluxes in the GCM framework is determined not only by the specification of the flux
algorithm in the interface boundary layers, but also by the formulations of other physics as well as the
model's resolution. The second half of the paper is devoted to the discussion of estimating air-sea
fluxes within the atmospheric data assimilation process. Data assimilation schemes in general are divided
into two categories, i.e., the intermittent and the continuous versions. The characteristics of these
versions are described, and some samples of the resultant flux estimates are shown. Finally, an
inter-comparision is presented on the state-of-the-art flux estimates at two operational centers.

GF-024

OORT , A.H. Climate observations and diagnostics. In Physically-Based Modelling and Simulation of
Climate and Climatic Change, Part II. M. E. Schlesinger (ed.). Kluwer Academic Publishers, 813-840
(1988).

An observational-statistical approach to the study of the Earth's climate is described. The approach
is based mainly on in situ atmospheric and oceanic observations which are analyzed using the conservation
equations of total mass, angular momentum, energy and water. Through such analyses one can diagnose the
role of the various components in the climatic system. The different observational networks and some
frequently used methods of objective analysis are also presented. Finally, some examples are given to
show the possibilities of the approach to the case of global and regional budgets of energy and water.

GF-o25

OORT, A.H. The search for unity in the climatic system. Summary of a lecture series presented at the
Uaiversite Catholique de Louvain , Institut D'Astronomie et de Geophysique , Georges Lemaitre, Belgium,
October 1987, 1-28 (1988).

Studies of the earth's climate system clearly show that the atmosphere, oceans, land surfaces,
cryosphere and biosphere are intimately connected with each other. Some of the complexities of the
climate system are due to the very different time scales found in the subsystems and due to the operation
of a variety of interactions and feedback processes between them. The role of the oceans and atmosphere
in storing heat seasonally and in transporting energy poleward to maintain the climatic balance is
discussed in detail.

GF-026

OORT, A.H., S.C. Ascher, S. LEVITUS, and J. P. Peix<5to. New estimates of the available potential energy
in the world ocean. Journal of Geophysical Research 94(C3) : 3187-3200 (1989).

On the basis of extensive global data sets the total amounts of internal, potential, latent, and
kinetic energy in the world oceans and atmosphere are estimated and compared for annual mean and seasonal
conditions. Next, an expression for the available gravitational potential energy in the oceans is
derived. The computed amounts of zonal mean and transient eddy available potential energy and the amount
of kinetic energy present in the oceans are found to be much smaller (at least 1 order of magnitude) than
those in the atmosphere. Because of the sparseness of directly measured subsurface values, the estimates
of the kinetic energy and the transient eddy available potential energy were obtained by extrapolation
from the corresponding values measured at the ocean surface. The fact that relatively large density
variations are found only in the upper few hundred meters of the oceans and the greater stability of the
oceans are the basic reasons for the generally small values of the potential and kinetic energy in the
oceans compared with those in the atmosphere.

GF-U27

PHILANDER, S.G.H., and W.J. HURLIN. The heat budget of the Tropical Pacific Ocean in a simulation of
the 1982-A3 El Niflo. Journal of Physical Oceanography 18(6) : 926-931 (1988).

The heat budget of a model that realistically simulates El Nif!o of 1982-1983 indicates that the
enormous changes in the winds during that event failed to disrupt the usual seasonal variations in
meridional heat transport. Cross-equatorial transport towards the winter hemisphere continued as in a
regular seasonal cycle. The key factor was the continued seasonal migrations of the ITC7 during the
El Niflo. In early 1983 the ITCZ strayed further south than usual and remained near the equator longer
than usual thus causing an increase in the northward heat transport. This, together with an increase in
the evaporative heat loss because of higher sea surface temperatures, resulted in a large loss of heat
from the band of latitudes 12°N-12°S approximately, during the El Niflo.

91

GF-028

Ramaswamy , V., and V. Ramanathan. Solar absorption by cirrus clouds and the maintenance of the tropical
upper troposphere thermal structure. Journal of the Atmospheric Sciences 46( 14) : 2293-2310 (1989).

Radiative transfer calculations employing observed values of the ice crystal size distribution demon-
strate that the absorption of solar radiation by cirrus clouds can make a significant contribution to the
diaDatic heating of the upper troposphere. The effects due to this absorption on the upper tropospheric
(100-300 mb) thermal profile are investigated in a general circulation model (GCM) with interactive
clouds; guided by observations, two experiments are performed assuming vastly different vertical profiles
of the ice water density. Solar heating rates within the extensive cirrus decks associated with monsoon
and other convective clouds reach values of 1.5 K day . Thus, cirrus solar heating can be an important
source for east-west asymmetries in the tropical diabatic heating. Furthermore, because of the latitu-
dinal gradients in the solar insolation, cirrus solar absorption can also influence the meridional heating
gradients within the upper troposphere. In spite of the significant east-west asymmetries in the imposed
cirrus solar heating, the change in the GCM tropical temperatures is nearly zonally uniform. The magnitude
of the zonal mean tropical temperature changes in the GCM (up to 5°K at P = 165 mb) indicate that lack of
cirrus solar heating may be one reason for the cold bias of the GCMs . Furthermore, the shortwave heating
can also account for the observed lapse rate stabilization in the upper troposphere. In addition to the
solar effect, the longwave radiative effects of cirrus can also be important but their sign and magnitude
are very sensitive to the vertical distribution of clouds. Cirrus longwave heating rates can range from
large negative values (cooling) when overlying optically thick clouds (for example, in "deep" extended
systems with base below the upper troposphere) to large positive values (heating) for "anvil" type cirrus
located in the upper troposphere and with no other clouds below. For the overcast portions of the
tropics, if "anvil" type cirri are the only clouds of significance in the upper troposphere, the longwave
heating would be the dominant radiative component and this effect becomes more pronounced with increasing
altitude of cloud location. Hence, for the tropical zone as a whole, the sign and magnitude of the
longwave effect depends on the relative composition of the "deep" and "anvil" clouds. Radiation model
calculations that employ climatological values of the vertical distribution of clouds yield a longwave
heating effect for the cirrus with the magnitude being comparable to the solar effect. Thus, our results
suggest a significant role of the cirrus radiative effects in maintaining the zonal mean thermal structure
of the upper troposphere. This inference should be contrasted with the notion that the steep positive
gradient in the tropical upper-troposphere potential temperatures is maintained by the latent heat
released in penetrating cumulus towers.

GF-029

Sarmiento, J.L., T.D. Herbert, and J.R. Toggweiler. Causes of anoxia in the World Ocean. Global
Biogeochemical Cycles 2(2) : 115-128 (1988).

We examine the hypothesis that global scale episodes of anoxia such as occurred in the Cretaceous are
due to high productivity and/or stagnation of the circulation. Two modes of ocean circulation are
considered: a thermohaline overturning cell, essentially vertical, which involves global scale upwelling
into the surface followed by sinking in deep water formation regions; and an approximately horizontal cell
which connects the abyss directly with deeply convecting waters in deep water formation regions. Modern
analogs for these processes are formation of North Atlantic Deep Water and Antarctic Bottom Water,
respectively. Over most of the oceans the surface new production is nutrient limited and thus directly
proportional to the supply of nutrients by the vertical overturning cell. A reduction in oxygen can only
be brought about by increased vertical overturning associated with increased production. In addition, the
model shows that as the deep ocean becomes lower in oxygen, the sensitivity of the oxygen levels to the
meridional circulation decreases such that it becomes difficult or impossible to achieve complete anoxia.
This relative insensitivity of deep ocean oxygen levels to the magnitude of the vertical overturning cell
and associated surface production may explain why it has been difficult to establish a clear connection
between high surface productivities in low and mid-latitudes and anoxia. In deep water formation regions,
on the other hand, new production is not nutrient limited. A reduction in abyssal oxygen can be brought
about by high productivity in such regions and/or by stagnation of the horizontal circulation cell, in
accordance with the stagnation hypothesis. Furthermore, the sensitivity of the deep ocean oxygen to the
processes occurring in deep water formation regions increases as oxygen levels decrease. We therefore
suggest that processes occurring in deep water formation regions may be the critical ones in determining
deep ocean oxygen.

GF- 030

Sarmiento, J.L., T.D. Herbert, and J.R. Toggweiler. Mediterranean nutrient balance and episodes of
anoxia. Global Biogeochemical Cycles 2(4):427-444 (1988).

92

We examine the causes of anoxia in regions such as the Eastern Mediterranean, which have exchange over
sills with adjacent basins. Box models show that the concentration of the limiting nutrient is the major
determinant of deep oxygen levels. The most effective way of increasing nutrient concentrations to the
point where anoxia occurs is to change the flow pattern across the sills ventilating the basins. With a
sill exchange pattern such as that in the present Strait of Sicily, it is difficult to obtain anoxia in
the Eastern Mediterranean without also driving the Western Mediterranean to low oxygen and high nutrient
levels. Episodes of anoxia in the Eastern Mediterranean are associated with a freshening of surface
waters. A reversal in flow directions, presumably resulting from the observed freshening, will inevitably
lead to anoxia associated with increased sediment burial rates of the limiting nutrient and will leave the
Western Mediterranean largely unaffected, in keeping with the observational evidence.

GF-031

Snieder, R.K., and S.B. FELS . The flywheel effect in the middle atmosphere. Journal of the Atmospheric
Sciences 45( 24) : 3996-4004 (1988).

Because of the requirement of geostrophic balance, mechanical inertia can affect the thermal response
of the atmosphere to transient heating. We examine some very simple linear models of this "flywheel
effect," and discuss their possible reference to the Antarctic ozone hold.

GF-U32

TOGGWEILER, J.R., K. DIXON, and K. BRYAN. Simulations of radiocarbon in a coarse-resolution world
ocean model. 1. Steady state prebomb distributions. Journal of Geophysical Research 94(C6) :8217-8242
(1989).

This paper presents the results of five numerical simulations of the radiocarbon distribution in the
ocean using the Geophysical Fluid Dynamics Laboratory primitive equation world ocean general circulation
model. The model has a 4.5° latitude by 3.75° longitude grid, 12 vertical levels, and realistic conti-
nental boundaries and bottom topography. The model is forced at the surface by observed, annually
averaged temperatures, salinities, and wind stresses. There are no chemical transformations or transport
of C by biological processes in the model. Each simulation in this paper has been run out the
equivalent of several thousand years to simulate the natural, steady state distribution of C in the
ocean. In a companion paper the final state of these simulations is used as the starting point for
simulations of the ocean's transient uptake of bomb-produced C. The model reproduces the mid-depth C
minimum observed in the North Pacific and the strong front near.45°S between old, deep Pacific waters and
younger circumpolar waters. In the Atlantic, the model's deep C distribution is much too strongly
layered with relatively old water from the Antarctic penetrating into the northern reaches of the North
Atlantic basin. Two thirds of the decay of C between 35°S and 35°N is balanced by local C input from
the atmosphere and downward transport by vertical mixing (both diffusion and advective stirring). Only
one third is balanced by transport of C from high latitudes. A moderately small mixing coefficient of
0.3 cm s adequately parameterizes vertical diffusion in the upper kilometer. Spatial variation in gas
exchange rates is found to have a negligible effect on deepwater radiocarbon values. Ventilation of the
circumpolar region is organized in the model as a deep overturning cell which penetrates as much as 3500 m
below the surface. While allowing the circumpolar deep water to be relatively well ventilated, the
overturning cell restricts the ventilation of the deep Pacific and Indian basins to the north. This study
utilizes three different realizations of the ocean circulation. One is generated by a purely prognostic
model, in which only surface temperatures and salinities are restored to observed values. Two are
generated by a semidiagnost ic model, in which interior temperatures and salinities are restored toward
observed values with a 1/50 year time constant. The prognostic version is found to produce a clearly
superior deep circulation in spite of producing interior temperatures and salinities which deviate very
noticeably from observed values. The weak restoring terms in the diagnostic model suppress convection and
other vertical motions, causing major disruptions in the diagnostic model's deep sea ventilation.

GF-U33

TOGGWEILER, J.R., K. DIXON, and K. BRYAN. Simulations of radiocarbon in a coarse-resolution world
ocean model. 2. Distributions of bomb-produced carbon 14. Journal of Geophysical Research
94(C6) =8243-8264 (1989).

Part 1 of this study examined the ability of the Geophysical Fluid Dynamics Laboratory (GFDL) primitive
equation ocean general circulation model to simulate the steady state distribution of naturally produced

C in the ocean prior to the nuclear bomb tests of the 1950's and early 1960's. In Part 2 we begin.with
the steady state distributions of Part 1 and subject the model to the pulse of elevated atmospheric C
concentrations observed since the 1950's. This study focuses on the processes and time scales which
govern the transient distributions of bomb C in the upper kilometer of the ocean. Model projections

93

through 1990 are compared with observations compiled by the Geochemical Ocean Sections Study (GEOSECS) in
1972, 1974, and 1978; the Transient Tracers in the Ocean (TTO) expedition in 1981, and the French INDIGO
expeditions in 1985-1987. In their analysis of the GEOSECS C observations, Broecker et al . (1985) noted
that much of the bomD C which entered the ocean's equatorial belts prior to GEOSECS accumulated in the
adjacent subtropical zones. Broecker et al. argued that this displacement of bomb C inventories was
caused by the wind-driven upwelling and surface divergence in the tropics combined with convergent flow
and downwelling in the subtropics. Similar displacements were invoked to shift bomb C from the
Antarctic circumpolar region into the southern temperate zone. The GFDL model successfully reproduces the
oDserved GEOSECS inventories, but then predicts a significantly different pattern of bomb C uptake in
the decade following GEOSECS. The post-GEOSECS buildup of bomb C inventories is largely confined to the
subthermocline layers of the North Atlantic, the lower thermocline of the southern hemisphere, and down to
2000 m in the circumpolar region. A great deal of attention is devoted to detailed comparisons between
the model and the available radiocarbon data. A number of flaws in the model are highlighted by the
analysis. The Subantarctic Mode Waters forming along the northern edge of the circumpolar current are
identified as a very important process for carrying bomb C into the thermoclines of the southern
hemisphere. The model concentrates its mode water formation in a single sector of the circumpolar region
and consequently fails to form its mode waters with the correct T-S properties. The model also moves bomb
C into the deep North Atlantic and deep circumpolar region much too slowly.

GF-034

TOGGWEILER, J.R. Is the downward dissolved organic matter (DOM) flux important in carbon transport?
Productivity of the Ocean: Present and Past, Dahlem Konferenzen, 1988. John Wiley & Sons, (Publ.)
pp. 65-83, (1989)"

A new method for measuring the concentration of dissolved organic carbon (DOC) and dissolved organic
nitrogen (DON) in seawater has recently been applied to the study of the material balance in the oceanic
water column. These measurements suggest that the downward transport of organic carbon and nitrogen in
the dissolved organic phase is every bit as important as the downward transport in sinking particles. It
appears that DOC and DON are the most important organic substrates supporting the consumption of oxygen
and the remineralization of nitrate below the thermocline. Although still controversial, these findings
are supported by a model study which shows that the vertical transport of organic matter cannot be
attributed solely to the fast-sinking particles caught in sediment traps. A characterization of the
vertical flux as such produces a model nutrient distribution which bears little resemblance to observed
distributions .

GF-U35

WILLIAMS, G.P. The dynamical range of global circulations - II. In Climate Dvnamics 3:45-84, Springer-
Verlag (1988).

The dynamical range of global atmospheric circulations is extended to specialized parameter regions by
models. In Part I, we derived the basic range of circulations by altering Q for moist and dry atmospheres
with regular and modified surfaces. Again we find the circulations to be composed of only a few elemen-
tary forms. In axisymmetric atmospheres, the circulations consist of a single jet in the rotational
midrange (Jl*=i-1) and of double jets in the high range (Ji*=2-4), together with one or two pairs of
Hadley and Ferrel cells; where fKf=fl/flg is the rotation rate normalized by the terrestrial value. These
circulations differ from those predicted by first-order symmetric-Hadley (SHj) theory because the moist
inviscid atmosphere allows a greater nonlinearity and prefers a higher-order meridional mode. The axi-
symmetric circulations do, however, resemble the mean flows of the natural system - but only in low
latitudes, where they underly the quasi-Hadley (QH) element of the MOIST flows. In midlatitudes , the
axisymmetric jets are stronger than the natural jets but can be reduced to them by barotropic and baro-
clinic instabilities. Oblique atmospheres with moderate to high tilts ( 0p=25°-9O°) have the equator-
straddling Hadley cell and the four basic zonal winds predicted by the geometric theory ,for the
sols titial-symmetric-Hadley (SSH) state: an easterly jet and a westerly tradewind in the summer
hemisphere, and a westerly jet and an easterly tradewind in the winter hemisphere. The nonlinear
barocliaic instability of the winter westerly produces a Ferrel cell and the same eddy fluxes as the
quasi-geostrophic QG element, while the instability of the summer easterly jet produces a QG-Hadley (QGH)
element with a unique, vertically-bimodal eddy momentum flux. At high 0p and low Q , the oblique
atmospheres reach a limiting state having global easterlies, a pole-to-pole Hadley cell, and a warm winter
pole. At low tilts ( ©p < 10°), the oblique circulations have a mix of solstitial and equinoctial
features. Diurnal heating variations exert a fundamental influence on the riatural-Hadley (NH)
circulations of slowly-rotating systems, especially in the singular range where the zonal winds approach
extinction. The diurnality just modifies the NH element in the upper singular range (1/45 < Q* < 1/16),
but completely transforms it into a subsolar-antisolar Halley circulation in the lower range (0 <I2* <
1/45). In the modified NH flows, the diurnality acts through the convection to enhance the generation of

94

the momentum-transf erring planetary waves and, thereby, changes the narrow polar jets of the non-diurnal
states into broad, super-rotating currents. Circulation theory for these specialized flows remains
rudimentary. It does not explain fully how the double jets and the multiple cells arise in the
axisymme trie atmospheres, how the QGH element forms in the oblique atmospheres, or how waves propagate in
the slowly rotating diurnal atmospheres. but eventually all theories could, in principle, be compared
against planetary observation: with Mars testing the QGH elements; Jupiter, the high-range elements;
Titan, the equinoctial and solstitial axisymmetric states; and Venus, the diurnally modified NH flows.

95

GREAT LAKES ENVIRONMENTAL RESEARCH LABORATORY

GL-001

ASSEL, R.A. Impact of global warming on Great Lakes ice cycles. The Potential Effects of Global
Climate Change on the United States: Appendix A - Water Resources, EPA DW13932631-01-U. U.S. EPA
Office of Policy, Planning and Evaluation, Washington, DC, 5.1-5.30 (1989).

No Abstract.

GL-002

BOLSENGA, S.J. Certain properties of spectrally integrated and spectral transmittances of freshwater
ice from 400-700 NM. Proceedings, P0AC '89: 10th International Conference on Port and Ocean
Engineering under Arctic Conditions, Lulea, Sweden, June 12-16, 1989. Lulea University of Technology,
188-198 (1989).

Considerable information is available on the transmittance of photosynthetlcally active radiation (PAR:
400-700 nm) through sea ice, whereas relatively little is known about PAR transmittance through
freshwater ice. Transmittances of PAR through some common freshwater ice types (including clear ice,
refrozen slush, and snow ice) are reported from studies using instruments which measure both spectral
(2-10 nm increments) and spectrally integrated transmittances over this range. Snow causes the greatest
attenuation of radiation, often reducing transmittances to 10% or less over the spectrum as a result of
even light covers (2-8 cm). Clear ice showed transmittances of 80-95% for the spectrally integrated data
and from 65 to nearly 95% for the spectral data. Transmittances of other ice types were bounded by the
clear ice/snow-covered-ice transmittance range. Comparisons between the spectral and spectrally
integrated data sets show specific applications for each type of measurement.

GL-003

BOLSENGA, S.J., J.E. Gannon, G. Kennedy, D.C. NORTON, and C.E.
ice. Cold Regions Science and Technology 16:89-93 (1989).

Herdendorf. ROV dives under Great Lakes

No abstract.

GL-004

BOLSENGA, S.J. , H.A. VANDERPLOEG, M.A. QUIGLEY, and G.L. FAHNENSTIEL. Note.
ice ecology program. Journal of Great Lakes Research 14( 3) : 372-376 (1988).

Operations for an under-

A pilot program tested the feasibility of conducting a study on the under-ice ecology of the Great
Lakes. The east arm of Grand Traverse Bay, in the lower peninsula of Michigan, was chosen as the test
area. The project was conducted in three phases; (1) a pre-lce cruise (open water), (2) an under-ice
phase, and (3) a post-ice cruise (open water). Overall, an under-ice ecology program that could produce
sound scientific results was found to be feasible. However, to be successful, detailed planning is
essential and careful attention must be given to operational safety, proper winter clothing, and
scientific coordination.

GL-005

CARRICK, H.J., and R.L. Lowe. Benthic algal response to N and P enrichment along a pH gradient.
Hydrobiologia 179:119-127 (1989).

Nutrient enrichment and its effect on benthic algal growth, community composition, and average cell
size was assessed across two sites of differing pH within a single habitat. Nutrients were added using
in situ substrata, which released either N, P, or no additional nutrients (controls) at each site for 21
days. Upon collection, chlorophyll and biovolume standing stocks of the attached algal microflora were
measured. Chlorophyll concentration was different among all treatments, accumulating greatest on P,
followed by N, and the least on C substrata (P < 0.001) and was highest at site-2 (P < 0.001), while
total algal biovolume was highest on P compared to both N and C substrata (P < 0.05) and did not vary
between sites. Increased growth on P substrata was due to the enhanced biovolume of filamentous green
algae, although the affected taxa varied between sites. Biovolume to cell density ratios (as a measure
of average cell size) were highest on P substrata over both N-enriched and control substrata (P < 0.05)
and this pattern was similar between sites. Progression towards a community composed of larger cells
following P enrichment observed along this pH gradient, seems to be related to the dominance of larger

96

celled filamentous green algae. Thus, nutrients exhibited greater control on benthic algal growth than
did changes in hydrogen ion concentration.

GL-006

CARRICK, H.J., R.L. Lowe, and J.T. Rotenberry. Guilds of benthic algae along nutrient gradients:
relationships to algal community diversity. Journal of North American Benthological Society
7(2) : 117-128 (1988).

We attempt to define groups of functionally related benthic algal species or guilds to assess if the
species richness of such guilds varies across experimentally manipulated nutrient gradients, and to
determine the relative contribution of these guilds to total community diversity. Nutrient gradients
were established using nutrient-releasing substrata; treatments consisted of Si, N+P, Si+N+P, and
controls. Nutrient enrichment significantly altered the biovolume of 27 species (out of a total of 141).
Results from one-way ANOVA tests coupled with multiple means range tests categorized these species into
four major guilds: three guilds of species which achieved their highest abundance on either Si, N+P, or
Si+N+P treatments, and a guild that grew best on controls. This pattern of structuring was corroborated
by cluster analysis and principal components analysis. Total community diversity and the relative
contribution of guilds to total community diversity was less on N+P and Si+N+P substrata compared with
that on Si and the control substrata. This suggests that nutrient enrichment may narrow the conditions
amenable to many algal species (nutrient generalists) , creating a niche occupied by those taxa
sufficiently equipped to benefit under such conditions (nutrient specialists).

GL-007

CAVALETTO, J.F., H.A. VANDERPLOEG, and W.S. GARDNER. Wax esters in two species of freshwater
zooplankton. Limnology and Oceanography 34(4) :785-789 (1989).

Lipid classes were determined in three Lake Michigan hypolimnetic calanoid copepods, Limnocalanua
macrurus , Diaptomus slcllls , and Senecella calanoides. Limnocalanus macrurus and Sjj_ calanoides contained
large stores of wax esters (57-80% of total lipid). Wax esters in this amount have not previously been
reported for freshwater zooplankton. Diaptomus sicills exhibits a typical freshwater lipid profile and
contains triacylglycerols as its lipid reserves. Lipid storage sites are morphologically different in
the copepods. Limnocalanus macrurus and S. calanoides store their wax (inters in a large sac that
surrounds the intestine, whereas p_. sicilis maintains lipid droplet morphology typical of freshwater
"triacylglycerol-storing" zooplankton. Limnocalanus macrurus and S^ calanoides are "glacial relicts"
which may explain the origin of their typically marine wax ester lipid class.

GL-008

CLITES, A.H. Observations of concurrent drifting buoy and current meter measurements in Lake Michigan.
Journal of Great Lakes Research 15(2) : 197-204 (1989).

Data generated by satellite-tracked drifting buoys released in the Great Lakes are being used to study
lake circulation and test trajectory prediction models. Before data from drifters can be used with
confidence, the water-tracking accuracy of the drifters must be known. During the winter of 1983,
drogued drifters were released in Lake Michigan in the vicinity of an array of vector-averaging current
meters. Several times during the next 3 months, the drifters moved within a few kilometers of one of the
current meters and remained in the vicinity for up to 30 hours. The average wind effect that best aligns
the currents measured by the moored current meters and the currents from drifter paths is 0.76% of the
wind speed. This value is the weighted average of the wind effects calculated for seven separate cases,
which ranged from 0.06% to 2.09% of the wind speed. The average value is in good agreement with
theoretical estimates and field test results. The horizontal coherence of the currents within 5 km was
fairly high as revealed by comparisons between drifter trajectories and current meter progressive
vectors. The separation distance between the vectors was generally under 1 km while drifter path length
ranged from 4 to 9 km. Results indicate that during these encounters, about 25% of the variability
between current trajectories estimated by drifting buoys and current meter measurements is explained by a
simple wind correction. The remaining discrepancy is attributed to wave action (Stokes drift) and data
limitations such as a lack of overlake wind conditions.

GL-009

CROLEY, T.E., II. Lumped modeling of Laurentian Great Lakes evaporation, heat storage, and energy
fluxes for forecasting and simulation. N0AA TM ERL GLERL-70 (PB89-185540/XAB) 48 pp. (1989).

97

Lake evaporation for the Laurentian Great Lakes is of the same order of magnitude as precipitation and
runoff to the lakes and its estimation is important for simulations and forecasts of lake levels. Water
or energy balance estimates of Great Lakes evaporation require storage-change data, not available in
simulations or forecasts, and errors in the components of the balances are summed in the residual, giving
large estimation errors for evaporation. Evaporation models, which use the aerodynamic equation with
mass transfer coefficients developed originally in the Lake Hefner studies, were further developed for
Lake Ontario during the International Field Year for the Great Lakes and adapted for other Great Lakes.
Neither these models nor the balance models can be verified since independent estimates of evaporation
are not available with sufficient accuracy. However, surface temperatures are available and can be used
as verification data. The mass transfer coefficient research (where water surface temperatures must be
known) is combined here with lumped model concepts of classical energy conservation and superposition
heat storage to provide continuous simulation capability of both water surface temperatures and lake
evaporation for use in outlooks and forecasts of lake levels. A new function is presented that uses a
simple relation between surface temperature and heat stored in a lake based on current understandings of
the thermal structure of large lakes. Calibration of the resulting model matches the water surface
temperatures for those Great Lakes and small Lake St. Clair with satellite observations of water surface
temperatures over the past 20 years. Evaporation and heat budgets over the annual cycle are presented
for four of the Great Lakes and Lake St. Clair, and comparison with long-term water balances are made.

GL-010

CROLEY, T.E., II. Verifiable evaporation modeling on the Laurentian Great Lakes. Water Resources
Research 25(5) : 781-792 (1989).

Water or energy balance estimates of Great Lakes evaporation require storage change data, not available
in simulations or forecasts, and errors in the components of the balances are summed in the residual,
giving large estimation errors. Neither these balance estimates nor evaporation models, which use the
aerodynamic equation with mass transfer coefficients developed originally in the Lake Hefner studies, can
be verified, since independent estimates of evaporation are not available with sufficient accuracy.
However, water surface temperatures can be used to verify energy budgets. The mass transfer coefficient
research is combined here with lumped concepts of classical energy conservation and a new superposition
heat storage model to provide continuous simulation capability of both water surface temperatures and
lake evaporation for use in outlooks and forecasts of lake levels. Calibration matches remotely sensed
water surface temperatures for those Great Lakes with observations over the past 20 years. Model
sensitivities are analyzed and heat and water budgets are compared.

GL-011

CROLEY, T.E., II, and H.C. HARTMANN. Climate change effects on Great Lakes levels. Reprinted from
Hydraulic Engineering Proceedings '89, National Conference, Hydraulic Division/ American Society of
Civil Engineers, New Orleans, LA, August 14-18, 1989. 653-658 (1989).

The Great Lakes Environmental Research Laboratory has developed conceptual models for simulating
moisture storages in and runoff from the 121 watersheds draining into the Laurentian Great Lakes,
overlake precipitation into each lake, the heat storages in and evaporation from each lake, connecting
channel flows and lake levels, and regulation of flows at control points. We determine net water
supplies and levels for each lake to consider climate change scenarios developed from atmospheric general
circulation models through linkages on air temperature, precipitation, humidity, wind speed, and cloud
cover. Scenarios of a doubling of atmospheric CO2 are considered by abstracting changes in linkages,
making these changes in historical data, observing the impact of the changed data in model outputs, and
comparing it to model results obtained from unchanged data. The implications of the climate change
effects modeled herein suggest that new paradigms in water management will be required.

GL-012

CROLEY, T.E., II, and H.C. HARTMANN. Effects of climate changes on the Laurentian Great Lakes levels.
The Potential Effects of Global Climate Change on the United States: Appendix A - Water Resources, EPA
DW13932631-01-0. U.S. EPA, Office of Policy, Planning and Evaluation, Washington, DC, 4.1-4.34 (1989).

No abstract.

GL-013

Eisenreich, S.J., P.D. Capel , J. A. ROBBINS, and R. Bourbonniere. Accumulation and diagenesls of
chlorinated hydrocarbons in lacustrine sediments. Environmental Science and Technology 23(9) : 1116-1126
(1989).

98

Two sediment cores were taken from the Rochester Basin of eastern Lake Ontario and analyzed for the
radionuclides 210pb ancj 137qs ancj several high molecular weight chlorinated hydrocarbons (CHs). The two
sites are geographically proximate but differ in sedimentation rate, permitting sedimentation-dependent
processes to be factored out. The 210pb chronology showed a mixed depth of 3-5 cm and an intrinsic time
resolution of 11-14 years. Vertically integrated numbers of deposit-feeding oligochaete worms and
burrowing organisms are insufficient to homogenize the sediment on the time scale of CH inputs, which are
non steady state. U.S. production and sales of polychlorinated biphenyls (PCBs), DDT, Mirex, and
hexachlorobenzene (HCB), as determinants of the shape of the input function, adequately predict the
overall shape and, in many cases, details in the sedimentary profile. Sediment focusing factors (FF)
inferred from 13/CIS and 210pD inventories averaged 1.17 and 1.74 for cores E-30 and G-32, respectively.
This permitted CH accumulation rates to be corrected for focusing. Apparent molecular diffusion
coefficients modeled for many of the CHs were about (1-3) x 10~9 cm2/s.

GL-014

FAHNENSTIEL, G.L. , and H.J. CARRICK. Primary production in lakes Huron and Michigan: in vitro and in
situ comparisons. Journal of Plankton Research 10(b) : 1273-1283 (1988).

Oxygen- and carbon-14-based primary production estimates from 9-16 h in. vitro incubations were compared
in lakes Huron and Michigan. For surface mixing layer comparisons, gross O2/ ^C photosynthetic quotients
(gross PQ) averaged 2.2, and net 02/^C photosynthetic quotients (net PQ) averaged 1.4. The mean gross
PQ is consistent with a theoretical PQ based on the CO2 and NO3 assimilation ratio. However, within the
deep chlorophyll layer, gross PQ and net PQ averaged 4.9 and 2.8 respectively. These higher values were
likely due to excess NO3 reduction at the expense of CO2 uptake. Thus, during short experiments under
low light conditions, oxygen evolution and CO2 uptake may not be tightly coupled. In vitro and iri situ
02~based production estimates were compared in four diurnal (dawn to dusk) experiments in Lake Huron. In
situ production estimates were determined by measuring water-mass oxygen changes and oxygen transfer
across the air-water interface. I11 situ production estimates were approximately twice iji vitro
production estimates for both surface mixing layer and deep chlorophyll layer comparisons. The
difference between estimates was attributable to containment effects manifest in 13-16 h bottle
incubations. Short-term (1-2 h) in vitro production was also compared to diurnal in vitro production.
Rates of short-term production were ~1.6 times higher than rates of diurnal production, suggesting that
short-term iji vitro production experiments may provide reasonable estimates of iri situ primary
production.

GL-015

Fox, M.G., and A.M. BEETON. Phosphorus concentration trends in the Saline River watershed, USA.
Verhandlungen-Internationale Vereinigung Fuer Theoretische und Angewandte Limnologie 23:1119-1124
(1988).

No abstract.

GL-016

GARDNER, W.S., J.F. CHANDLER, and G.A. LAIRD. Organic nitrogen mineralization and substrate limitation
of bacteria in Lake Michigan. Limnology and Oceanography 34( 2) :478-485 (1989).

Labile organic nitrogen mineralization and the apparent degree of bacterial substrate limitation were
examined to consider seasonal relationships between substrate availability and bacterial activity in Lake
Michigan. Accumulation rates of ammonium nitrogen in amino acid fortified and unfortified samples of
epilimnetic Lake Michigan water, incubated in the dark, provided reasonable estimates of potential and
actual rates of organic nitrogen mineralization. The labile organic nitrogen demand (LOND), defined as
the difference between these respective rates, provided an index of heterotrophic potential. LOND ranged
from ~l-3 ng-atoms N liter h-* (during May- June and November) to 3-9 ng-atoms N liter h-^ (during July-
October) as compared to actual organic nitrogen mineralization rates of < 1 ng-atom N liter h~* in some
unfortified samples. The high LOND, relative to actual turnover, observed in late summer is consistent
with the hypothesis that growth rates of epilimnetic Lake Michigan bacteria are strongly limited by
organic substrate during late stratification.

GL-017

GARDNER, W.S., B.J. EADIE, J.F. CHANDLER, C.C. PARRISH, and J.M. MALCZYK.. Mass flux and "nutritional
composition" of settling epilimnetic particles in Lake Michigan. Canadian Journal of Fisheries and
Aquatic Sciences 46(7) : 1118-1124 (1989).

99

A series of sediment-trap samples, collected at a 30-m depth in southeastern Lake Michigan, was
analyzed to evaluate the seasonal flux and nutritional value of settling epilimnetic particles as
potential food for benthic organisms. Flux was highest in the spring (due in part to resuspension) ,
lowest in the summer during stratification, and intermediate during autumn months. Organic content of
the particles ranged from 10% ash free dry weight (AFDW) in March through May samples to 17-19% in July-
August samples. During the summer, microbial degradation of organic materials occurred in the trap
bottles without added preservative, as evidenced by less AFDW in nonpreserved trap bottles than in
similar chloroform-preserved bottles. The percentage of AFDW occurring as lipid ranged from 3.5% in
April-May up to 14% during May through August. Dominant lipid classes were hydrocarbons, polar lipids
including phospholipids and chlorophyll a, and free fatty acids. The ratio of n-alkane C-17 (algal
indicator) to n-alkane C-29 (terrestrial or resuspension indicator) and the ratio of biogenic silica to
AFDW in preserved samples both reached a maximum in May, shortly before lipid content peaked in the
benthic amphipod Pontoporeia hoyi. This observation agrees with the hypothesis that P_^ hoyi receives
much of its nutrition from the spring algal bloom.

GL-018

GAUVIN, J.M., W.S. GARDNER, and M.A. QUIGLEY. Effects of food removal on nutrient release rates and
lipid content of Lake Michigan Pontoporeia hoyi . Canadian Journal of Fisheries and Aquatic Sciences
46(7) : 1125-1130 (1989).

Pontoporeia hoyi , the dominant benthic invertebrate in the upper Great Lakes, appears to be well
adapted to environments with seasonal inputs of high-quality food such as those supplied by the spring
diatom bloom. Ammonium and phosphate excretion rates and lipid content were examined in P^ hoyi under
the following conditions: (1) field animals sampled seasonally, (2) food-deprived animals in filtered
lake water, and (3) control animals held in native sediments without new food inputs. Nutrient excretion
rates for P^ hoyi (0.5 to 2 nmole NH4 (milligrams dry weight)-1 -h-1 and 0 to 0.15 nmole PO4 (milligrams
dry weight)-1 «h-1) were low relative to rates previously reported for other benthic and pelagic
invertebrates and varied little among the three treatment groups. In contrast to the animals held in the
laboratory without new food inputs, field-collected £. hoyi accumulated Increased levels of lipids
following the spring diatom bloom. However, after lipid levels in field animals peaked in May, they
decreased during the rest of the season at rates similar to those of starved and control animals. P.
hoyi ' s low nutrient-excretion rates, and its ability to accumulate and store energy as lipids, for
periods when food is not abundant, appear to be important factors allowing this animal to thrive in
temperate lakes with spring diatom blooms.

GL-019

HARTMANN, H.C. Historical basis for limits on Lake Superior water level regulations. Journal of Great
Lakes Research 14(3) :316-324 (1988).

The 1979 International Joint Commission (IJC) Supplementary Orders of Approval for the regulation of
Lake Superior outflows call for maintaining Lake Superior water levels below an elevation of 183.49 m
above the International Great Lakes datum of 1955 (IGLD55). When Lake Superior rose above 183.49 m
(IGLD55) in 1985, the IJC ordered discharges in excess of the operational regulation plan outflows.
Continued pressure to reduce high water levels on the lower Great Lakes by storing water in Lake Superior
calls into question the sanctity of the 183.49 ra (IGLD55) limit. Based on IJC hearings and historical
water level records, the present limit appears to be equivalent to the upper limit specified in the
original 1914 Orders of Approval, when the latter is adjusted for differential isostatic rebound.
However, testimony reveals that the IJC of 1914 expected levels to exceed the limit by about 0.15 m
during water supply conditions similar to those of 1869 and 1876, which were matched in 1985. Although
the expected exceedance of the 1914 limit appears to be based on an inaccurate maximum water level
record, other historical records substantiate that Lake Superior should be expected to rise above 183.49
m (IGLD55) during times of high water supplies, such as 1985.

GL-020

KEILTY, T.J. Note. A new biological marker layer in the sediments of the Great Lakes: Bythotrephes
Cederstroemi (Schodler) Spines. Journal of Great Lakes Research 14(3) :369-371 (1988).

The European cladoceran, Bythotrephes cederstroemi (Schodler), recently invaded the Laurentian Great
Lakes. Based on recent zooplankton records, it most likely appeared first in 1984 in Lakes Ontario,
Erie, and Huron, and in 1985 in Lake Michigan. It has yet to be reported from Lake Superior. This
species is a relatively large-bodied predatory form that possesses a long, caudal, latterally barbed
spine. J$. cederstroemi spines and spine fragments were found in the upper fractions (predominantly 0-4
cm) of 35 sediment cores collected from seven areas of deposition in the eastern basin of Lake Erie. All
remains were well preserved and easy to identify. Very few to 0 spines were found in core depths greater

100

than 4 cm suggesting that the invasion of this species has resulted in a new, readily distinguishable
time horizon marker.

GL-021

KEILTY, T.J., and G.R. STEHLY. Preliminary investigation of protein utilization by an aquatic
earthworm in response to sublethal stress. Bulletin of Environmental Contamination and Toxicology
43:350-354 (1989).

Previous studies have illustrated the potential usefulness of monitoring biomolecule levels (total
protein, DNA, and RNA) in juvenile fish and Invertebrates exposed to sublethal doses of environmental
toxicants. Ninety-six hr exposures of five contaminants (benzophenone , ethyl acetate, hexavalent
chromium, hydrogen cyanide, and p-cresol) to larval fathead minnows yielded measurable alterations in
total protein, DNA, and RNA that closely paralleled results from concomitant 28-32 d growth assays
(Barron and Adelman 1984). Daphnia magna exposed to toxicants in various assays also exhibited changes
in protein, RNA, and DNA levels, with the most sensitive responses usually occurring during the rapid
growth life stage (McK.ee and Knowles 1986a, b; Knowles and McKee 1987). These results suggest that the
use of biomolecule analyses as indicators of reduced growth in chemically stressed aquatic organisms
holds promise.

GL-022

KEILTY, T.J., D.S. White, and P.F. LANDRUM. Sublethal responses to endrin in sediment by Limnodrilus
hof fmeisteri (Tubif icidae) , and in mixed-culture with Stylodrilus heringianus (Lumbriculidae) . Aquatic
Toxicology 13:227-250 (1988).

Sediment reworking by Limnodrilus hof fmeisteri (Tubif icidae) alone, and with Stylodrilus heringianus
(Lumbriculidae) were measured in sediments dosed with endrin by monitoring the burial of a i J/ cesium
marker layer. Endrin concentrations ranged from 16.1 to 81 400 ng/g dry sediment weight. Alterations in
reworking rates were observed at sediment concentrations two to five orders of magnitude below LC50
values. In single species experiments with L^. hof fmeisteri at low endrin concentrations, marker layer
burial rate data did not suggest stimulation of reworking, as had previously been found for S^.
heringianus . At higher concentrations, reworking rates were equal to or slower than control rates early
in experiments, followed by dramatic decreases thereafter. Reworking rates with mixed species (1:1
species ratio) suggested that the presence of S^ heringianus enhanced the reworking response of L^.
hof fmeisteri. Post experimental worm dry weights were inversely related to high sediment concentrations
for both species. Reductions in post-experimental 1,. hof fmeisteri mortalities and increases in h.
hof fmeisteri dry weights in mixed species tests at high endrin concentrations implied that L^.
hof fmeisteri benefits from the presence of S_. heringianus , although the reverse was not observed. High
final sediment endrin concentrations in the upper three cm implied worm mediated upward contaminant
transport. Bioaccumulation factors for _S. heringianus ranged from 9.7 to 43.8 and were consistently
three to four times greater than bioaccumulation factors for L. hof fmeisteri (1.7 to 13.6).

GL-023

KEILTY, T.J., D.S. White, and P.F. LANDRUM. Sublethal responses to endrin in sediment by Stylodrilus
heringianus (Lumbriculidae) as measured by a 137cesium marker layer technique. Aquatic Toxicology
13:251-270 (1988).

Sediment reworking rates of Stylodrilus heringianus (Oligochaeta : Lumbriculidae) were measured in
microcosms containing sediments dosed with the chlorinated pesticide, endrin. Reworking rates were
measured at 10°C by monitoring a 137cesium marker layer burial in contaminated and uncontaminated
microcosms. Endrin concentrations ranged from 3.1 to 42 000 ng/g dry sediment. Alterations in reworking
rates were observed at sediment concentrations five and one half orders of magnitude below the LC50 (1
650 mg/g). For the lower concentrations, marker layer burial rate data suggested possible stimulatory
effects in the first 300 to 600 h, followed by significant rate decreases relative to controls. For
higher concentrations, rates were equal to or slower than control rates in the first 600 h, followed by
dramatic decreases in the last 600 h. High final surficlal sediment endrin concentrations at the end of
experiments implied worm mediated upward transport. Worm mortalities were 9.3 to 28% for the two highest
concentrations (42 000 and 11 500 ng/g) and 0 to 6.7% for all other concentrations including controls.
Post experimental worm dry weights were inversely related to high concentrations. Bioaccumulation
factors ranged from 34 to 67 on a g dry organism to g dry sediment basis.

GL-024

LANDRUM, P.F. Bioavailability and toxicokinetics of polycyclic aromatic hydrocarbons sorbed to
sediments for the amphipod Pontoporeia hoyi. Environmental Science & Technology 23(5) :588-595 (1989).

101

The accumulation kinetics, by the benthic amphipod, Pontoporeia hoyi, were measured for sediment-
associated, selected polycyclic aromatic hydrocarbons (PAHs) and 2,4,5,2' ,4' ,5'-hexachlorobiphenyl (HCB).
The kinetics data suggest that uptake occurs largely via the sediment interstitial water and is
kinetically controlled by desorption from sediment particles and dissolved organic matter. Assimilation
from ingested material may be significant for the more strongly sorbed compounds such as benzo[a]pyrene
and HCB. The desorption rate of contaminants from the sediment matrix appears to determine whether the
major sediment contaminant source is interstitial water or ingested particles. The log of the
contaminant uptake clearance is inversely proportional to the log octanol-water partition coefficient for
PAHs. Bioavailability of sediment-sorbed contaminants declined as the contact time between the sediment
and contaminant increased. Chemical extractability remained high even though bioavailability was
reduced. A conceptual model to describe accumulation of organic contaminants from sediments is
described.

GL-025

LANDRUM, P.F., W.R. FAUST, and B.J. EADIE. Bioavailability and toxicity of a mixture of sediment-
associated chlorinated hydrocarbons to the amphipod Pontoporeia hoyi . In Aquatic Toxicology and Hazard
Assessment: 12th Volume, ASTM STP 1027, U.M. Cowgill, and L.R. Williams (eds.). American Society for
Testing and Materials, Philadelphia, 315-329 (1989).

The toxicity and bioavailability of a mixture of 13 sediment-associated chlorinated hydrocarbons were
determined for the amphipod, Pontoporeia hoyi. The processes were traced with two radiolabeled compounds
l^C-2,2' ,4,4'-tetrachlorobiphenyl (2244TCB) and 3H-benzo(a)pyrene (BaP). The toxicity of the chlorinated
hydrocarbon mixture resulted primarily from the lindane and dieldrin components. The 72 h LC50 was 14.5
nmol g~l as the sum of the added chlorinated hydrocarbons and 4.7 nmol g~l as the sum of the lindane and
dieldrin. At 144 h the LC50S had dropped to 1.51 and 0.53 nmol g-l respectively. At the lowest dose,
2.4 nmol g~l sediment, the time to yield 50% mortality (LT5Q) was 119 h. The toxicokinetics for the
radiolabeled compounds yielded sediment uptake clearance constants of 0.0018 and 0.018 g dry sediment g~l
animal h~l for BaP and 2244TCB in the absence of added chlorinated hydrocarbons. At the lowest
chlorinated hydrocarbons dose, the clearance constants of both BaP and 2244TCB were approximately
doubled. The clearance constants were not proportional to the freely dissolved concentration of the
radiolabeled compounds in the interstitial water but were presumed to be proportional to the compound
desorption rates. For the chlorinated hydrocarbons, the uptake clearances were inversely proportional to
the log of the octanol-water partition coefficient. The bioaccumulation factor (BAF, concentration in
the organism divided by the concentration in the sediment) appeared to peak at about a log octanol-water
partition coefficient of 6. However, the BAF ranged from less than 1 to greater than 30 for compounds
with a log KqW near 6.

GL-026

LAWDRUM, P.F., and R. POORE. Toxicokinetics of selected xenobiotics in Hexagenia limbata. Journal of
Great Lakes Research 14(4) :427-437 (1988).

Understanding the role of benthos in the fate and transport of contaminants requires understanding the
toxicokinetics of those organisms for both waterborne and sediment-associated compounds. This effort
focused on the toxicokinetics of Hexagenia limbata as an important component of the benthic community of
the upper Great Lakes connecting channels. The accumulation and elimination of two polycyclic aromatic
hydrocarbon congeners and a hexachlorobiphenyl isomer were followed over the course of a season in H.
limbata collected from Lake St. Clair. Both the water uptake clearance and elimination rate constants
increased with increasing temperature through the spring and summer. The elimination constants were
relatively large. The uptake constant for sediment-associated compounds was essentially constant the two
times it was measured and was large compared to sediment accumulation by Pontoporeia hoyi. Steady state
model calculations indicate that the amount of compound in H^ limbata should decline as temperature
increases. The BCF values on a lipid content normalized basis remain relatively constant for both PAHs
and show some change with season for hexachlorobiphenyl. Based on the best estimates of environmental
concentration of the contaminants studied in both sediment and water, the model suggests that H. limbata
should obtain greater than 90% of its contaminant body burden from the sediment-associated pollutants.

GL-027

LANG, G.A., J. A. MORTON, and T.D. FONTAINE, III. Total phosphorus budget for Lake St. Clair: 1975-80.
Journal of Great Lakes Research 14(3) :257-266 (1988).

As part of the U.S. -Canadian Upper Great Lakes Connecting Channels Study a total phosphorus budget was
developed for Lake St. Clair. An unbiased ratio estimator technique was used to estimate annual loads
and variances from monitored hydrologic areas. During the 1975-80 period, Lake Huron was the major
source of phosphorus to Lake St. Clair, accounting for approximately 52% of the total annual load.

102

Hydrologic area loads, which include diffuse and indirect point sources, contributed approximately 43% of
the total annual load. The remaining 5% came from the atmosphere, shoreline erosion, and direct point
sources. Of the hydrologic area loads, 85% could be attributed to diffuse sources. The Thames area
contributed 58% of the total hydrologic area load, followed by the Sydenham (17%), the Clinton (9%), the
Ruscora (7%), the Black (6%), the St. Clair (3%), and the Rouge (0.4%). Over the entire 6-year period
examined, the lake's total input and output of phosphorus were nearly equal. It was concluded that there
was no significant net source or sink of phosphorus in Lake St. Clair during the 1975-80 period.

GL-028

Lindner, G., W. Pfeiffer, J. A. ROBBINS, and E. Recknagel. Long-lived Chernobyl radionuclides in Lake
Constance: speciation, sedimentation and biological transfer. Proceedings, XV Conference of the
International Radiation Protection Association, Visby, Sweden, September, 1989. The Radio Ecology of
Natural and Artificial Radionuclides. Progress in Radiation Protection Series, FS-89048T, W. Feld
(ed.). Verlag Tuv Rheinland GMBH, Koln, 295-300 (1989).

No abstract.

GL-029

Lindner, G. , W. Pfeiffer, U. Wahl, J. Kleiner, H.H. Stabel, P. Frenzel, J. A. ROBBINS, F. Giovanoll, A.
Lenhard , and E. Recknagel. Sedimentation of longlived radionuclides in Lake Constance. Proceedings,
Heavy Metals in the Environment, Vol. 1, Geneva, Switzerland, September 14, 1989. CEP Consultants Ltd,
J-P. Vernet (ed.), Edinburgh, UK, 449-452 (1989).

The sedimentation of the longlived radionuclides 137Cs, 106Ru, 125Sb, HOm^g and ^CE from Chernobyl
fallout was followed in Lake Constance by gamma spectroscopic analysis of trapped settling particles and
sediment cores. The vertical transport was controlled by the speciation of the radionuclides in the
water. Scavenging from solution occured both for cationic 13' Cs species and, with higher efficiency, for
anionic 106ru anci 125sb species. Autochthonous calcite precipitation appeared to be the main removal
process. Stokesian sinking was suggested for the removal of *^Ce , which was assumed to be included in
nuclear fuel particles. In the sediments a new, sharp radiotracer marker was established.

GL-030

LIU, P.C. On the slope of equilibrium range in the frequency spectrum of wind waves. Journal of
Geophysical Research 94(C4) :5017-5023 (1989).

An effort to empirically assess the slope of the equilibrium range in a wind wave frequency spectrum
with a large number of data recorded in the Great Lakes did not serve to clarify the uncertainty between
a -4 or a -5 frequency exponent representation. The uncertainty is further compounded by indications
that the slope is not necessarily unique, but tends to vary with wave momentum. For sufficiently well
developed wind waves the exponent appears to cluster between -3 and -4. For practical applications the
f~4 equilibrium range is perhaps an effective approximation. What the correct slope is for the
equilibrium range, or even whether or not a unique slope exists, remains elusive and has yet to be
satisfactorily substantiated.

GL-031

LIU, P.C. What is the slope of equilibrium range in the frequency spectrum of wind waves?
Proceedings, 21st Coastal Engineering Conference CERC/ASCE, Costa del Sol-Malaga, Spain, June 21, 1988.
1045-1057 (1988).

An effort to empirically assess the slope of the equilibrium range in a wind-wave frequency spectrum
with a large number of data recorded in the Great Lakes did not serve to clarify the uncertainty between
a -4 or a -5 frequency exponent representation. The uncertainty is further compounded by indications
that the slope is not necessarily unique, it tends to vary with wave momentum. For sufficiently well-
developed wind waves the exponent appears to cluster between -3 and -4. For practical applications the
f-^ equilibrium range is perhaps an effective approximation. What the correct slope is for the
equilibrium range, or even whether or not a unique slope exists, remains elusive and has yet to be
satisfactorily substantiated.

GL-032

McCORMICK, M.J. Potential climate changes to the Lake Michigan thermal structure. The Potential
Effects of Global Climate Change on the United States: Appendix A - Water Resources, EPA
DW13932957-01-0. U.S. EPA Office of Policy, Planning and Evaluation, Washington, DC, 6.1-6.26 (1989).

103

No abstract.

GL-033

MUZZI, R.W., and G.S. MILLER. Improving satellite tracked drifter buoy resolution by using LORAN-C.
Proceedings, Oceans '89, Seattle, WA, September 18-21, 1989. Marine Technology Society and the Oceanic
Engineering Society of the Institute of Electrical and Electronics Engineers, 856-859 (1989).

Free drifting satellite-tracked drifter buoys have provided a wealth of in situ data to examine global
scale spatial variations in surface circulation over vast ocean areas. But in the Great Lakes, their
position inaccuracies and limited number of positions makes them unsuitable for measuring the lake's
smaller scale processes. To overcome this problem, a low-cost system was designed by adding a LORAN-C
receiver to a satellite-tracked buoy. LORAN gives improved spatial and temporal resolution. A modified
Si-Tex EZ97 LORAN-C receiver, Campbell Scientific SM192 solid-state storage module, and an 80C31 CMOS
microprocessor control interface were added to a Polar Research Lab mini-TOD drifter. The LORAN antenna
was positioned next to the ARGOS antenna on the top of the buoy. The microprocessor controlled cycling
of the LORAN receiver and recording of the data. The ARGOS platform was not modified, and provided
position comparison and near real-time positions for aid in retrieval. LORAN position data was recovered
from the buoy after retrieval. Two prototype tests were fully successful, revealing evidence of smaller
scale processes that could not be determined by satellite position tracking.

GL-034

NALEPA, T.F., and J.M. GAUVIN. Distribution, abundance, and biomass of freshwater mussels
(Bivalvia:Unionidae) in Lake St. Clair. Journal of Great Lakes Research 14(4) :411-419 (1988).

A mussel population survey was conducted in Lake St. Clair with divers using SCUBA to sample 29
stations throughout the lake. Mean abundance was 2 m~2 and mean biomass was 4.4 g dry wt m~2. Of the 18
species collected, Lampsilis radiata siliquoidea was by far the most abundant, accounting for 45% of all
individuals. The age-frequency distribution of L^. r^. siliquoidea was dominated by individuals between 9
and 12 years old. In contrast, the second most abundant species, Leptodea fragilis, showed yearly
variation in recruitment with no apparent trends in year class strength. Annual production of L. r .
siliquoidea was 0.20 g m~2 y~l and the turnover ratio was 0.13. The diversity and composition of mussels
in Lake St. Clair appear little changed since the turn of the century, but there are indications that
population numbers may be declining in the future.

GL-035

QUIGLEY, M.A. , and G.A. LANG. Measurement of amphipod body length using a digitizer. Hydrobiologia
171:255-258 (1989).

A digitizer/camera lucida method was developed to measure total body length and gut contents of an
amphipod Pontoporeia hoyi. The method was more accurate and precise than two conventional methods (the
forceps/ocular micrometer method, and the map wheel/camera lucida method). The digitizer/camera lucida
method also provided rapid and direct transfer of body and gut length values to a computer file for
subsequent analysis.

GL-036

QUINN, F.H. Detroit River flow reversals. Journal of Great Lakes Research 14(4) : 383-387 (1988).

Detroit River flow reversals were investigated using a water surface gradient analysis in conjunction
with Detroit River unsteady flow models. Three cases and five highly probable cases were simulated to
occur between 1900 and 1986; the most recent episode occurred in April 1984. Flow reversals are likely
only during St. Clair River ice jams, when the water supply to Lake St. Clair is severely restricted.
The reversals appear to be of limited duration, less than 12 hours, with maximum flows less than 4,200
m^s-!. Flow reversals were most common during the first 40 years of this century and 46 years separate
the last two occurrences. The decreased frequency probably results from the 7.6 m and 8.2 m navigation
dredging projects on the St. Clair River. The use of the Gibraltar water level gage to represent the
mouth of the river was found to be critical for the analysis.

GL-037

QUINN, F.H. Great Lakes water levels, past, present, and future. Proceedings, The Great Lakes:
Living with North America's Inland Waters, Milwaukee, WI, November 6, 1988. American Water Resources
Association, 83-92 (1988).

104

The Great Lakes are one of our nation's greatest water resources containing 95 percent of the nation's
and 20 percent of the world's fresh surface water. At the present time, all of the Great Lakes except
for Lake Ontario, are receding from record high lake levels for this century. The high lake levels have
had a severe impact upon the riparian interests around the lakes. Storms superimposed on the high lake
levels have resulted in extensive flooding, houses destroyed, extreme erosion and bluff damage, marina
problems, and a loss of habitat for various forms of wildlife. This presentation examines Great Lakes
water level fluctuations, past, present, and future. Special emphasis is given to the conditions
resulting in the recent lake level decline. The types of natural lake level fluctuations and their
causes are examined and compared with anthropogenic lake level changes resulting from diversions,
connecting channel dredging, regulation, and consumptive use. A longer term climatic perspective and
possible future scenarios are discussed.

GL-038

QUINN, F.H., and S.A. Changnon. Climate scenarios for the Great Lakes Basin. Preprints, Sixth
Conference on Applied Climatology, Charleston, SC, March 7-10, 1989. American Meteorological Society,
Boston, 27-30 (1989).

No abstract.

GL-039

ROBBINS, J. A. The role of radiotracers in studies of aquatic contamination. Proceedings, Heavy Metals
in the Environment, Vol. 1, Geneva, Switzerland, September 14, 1989. CEP Consultants Ltd, J-P. Vernet
(ed.), Edinburgh, UK, 449-452 (1989).

Natural and man-made radionuclides, particularly 210pD and l^Cs, have been widely used to chronicle
the history of heavy metal contamination of lakes and reservoirs as recorded in sediments. Although this
application is perhaps best known, these and other tracers have also been used in the Laurentlan Great
Lakes and other systems to calibrate lake contamination response models, determine epilimnetic residence
times, establish sediment mixing scale lengths and rates, tag resuspended sediment components, and
estimate the extent and rate of sediment focusing. Some of these applications are illustrated by the
case of 137cs in Lake Erie.

GL-040

ROBBINS, J. A., T.J. KEILTY, D.S. White, and D.N. Edgington. Relationships between tubificid
abundances, sediment composition, and accumulation rates in Lake Erie. Canadian Journal of Fisheries
and Aquatic Sciences 46(2) :223-231 (1989).

Sediment cores taken at 15 sites within the three main depositional basins of Lake Erie from 1976 to
1982 were sectioned in 1-cm intervals and analyzed for the abundance and vertical distribution of benthic
organisms, 13?Cs, and 210pb (^n 80me cores) and for surficial (upper 2 cm) organic and inorganic carbon.
Zoobenthos populations were dominated (>85%) by tubificids (Limnodrilus hof fmeisteri , Quistadrilus
multisetosus , and Tubifex tubifex) and varied in abundance from 6600 to 55 300 individuals •m-^. The
depth above which 90% of the individuals occurred correlated significantly with their abundance and with
radiometrically determined mixed depths. Rates of sediment reworking by tubificids exceeded
sedimentation rates by 5-80 times, indicating that worms alone can produce the observed zone of constant
tracer activity at the sediment-water interface. Tubificid abundance was not significantly related to
organic carbon but instead correlated strongly with the sediment accumulation rate and organic carbon
flux. In Lake Erie the abundance of tubificids may be limited by the rate of supply of nutrients as
measured roughly in terms of the organic carbon flux.

GL-041

SCAVIA, D. On the role of bacteria in secondary production. Limnology and Oceanography
33(5):1220-1224 (1988).

No abstract

GL-042

Schelske, C.L., J. A. ROBBINS, W.S. GARDNER, D.J. Conley, and R.A. Bourbonniere. Sediment record of
biogeochemical responses to anthropogenic perturbations of nutrient cycles in Lake Ontario. Canadian
Journal of Fisheries and Aquatic Sciences 45:1291-1303 (1989).

105

Two sediment cores collected from the Rochester basin of Lake Ontario were dated with 210pD an<j
stratigraphic correlation and analyzed to determine whether nutrient accumulation with time was
consistent with previous computer-simulated total phosphorus (TP) loadings. Relative increases in TP and
nonapatite inorganic phosphorus (NAIP) accumulation were less than the fivefold increase in TP loading
from 1800 to 1950 predicted independently from Chapra's simulation model. In addition, increases in TP
accumulation occurred mainly after 1940 and the proportion of NAIP relative to TP increased in one core
and decreased in the other. Of the nutrients studied, only increases in organic carbon (0C) paralleled
the increases in modelled TP loadings. The relative increase in inorganic carbon (IC) was greatest, with
accumulation increasing an order of magnitude after 1940 in one core. This large increase in IC,
amounting to 20% calcite in recent sediments, was attributed to biologically induced calcite
precipitation, a secondary consequence of increased planktonic photosynthetic removal of carbon dioxide
that resulted from accelerated eutrophication after 1940 when modelled TP concentrations increased
rapidly. Biogenic silica (BSi) accumulation, an indicator of increased diatom production, peaked between
1850 and 1870 when increases in TP and NAIP fluxes were minimal. Results provide evidence that historic
biogeochemical responses inferred from OC, IC, and BSi accumulation in the sediment record provide
stronger signals of phosphorus enrichment effects than can be inferred directly from changes in
accumulation of different forms of phosphorus in the sediment record.

GL-043

SCHWAB, D.J. A numerical wave prediction model for personal computers. Proceedings, 21st Coastal
Engineering Conference CERC/ASCE, Costa del Sol-Malaga, Spain, June 21, 1988. 2991-2997 (1988).

A two-dimensional wave prediction model suitable for use on personal computers is described. The model
requires the two-dimensional time-dependent wind field as input. Output consists of wave height, wave
period, and wave direction estimates at all grid points on a computational grid representing an enclosed
or semi-closed basin. Model predictions compare favorably with observations from a wave research tower
in Lake Erie. A formula is provided to estimate how long a model simulation would take on a personal
computer given the surface area of the computational domain, the grid size, and the computer clock speed.

GL-044

SCHWAB, D.J. The use of analyzed wind fields from the Great Lakes Marine Observation Network in wave
and storm surge forecast models. Preprints, 2nd International Workshop on Wave Hindcasting and
Forecasting, Vancouver, BC, April 25-29, 1989. Environment Canada, Atmospheric Environment Service,
Downsview, Ontario, 257-266 (1989).

No abstract.

GL-045

SCHWAB, D.J., A.H. CLITES, C.R. Murthy, J.E. SANDALL, L.A. Meadows, and G.A. Meadows. The effect of
wind on transport and circulation in Lake St. Clair. Journal of Geophysical Research 94(C4) :4947-4958
(1989).

A numerical circulation and transport model is used to simulate currents and trajectories in Lake St.
Clair. Results from the model are compared to three different types of measurements, namely, (1) mean
currents from an array of fixed current meters, (2) currents measured from a ship during seven synoptic
surveys of the lake, and (3) trajectories of satellite-tracked drifting buoys during four different
experiments. The model is then used to predict the effects of storms on the residence time of water
entering the lake from eight tributaries and the probable horizontal distribution in the lake of water
from a particular tributary. Results show that although the average residence time of the lake is about
9 days, actual residence times range from less than 2 days to over 30 days depending on wind conditions.
The calculated distribution patterns of water from various tributaries coincide closely with observed
distributions of some water quality parameters and biota.

GL-046

STEHLY, G.R., and W.L. Hayton. Disposition of pentachlorophenol in rainbow trout ( Salmo gai rdne r i ) :
effect of inhibition of metabolism. Aquatic Toxicology 14:131-148 (1989).

The accumulation kinetics of pentachlorophenol (PCP) were investigated in rainbow trout (Salmo
gairdneri) in the absence and presence of 25 mg/1 salicylamide, an inhibitor of PCP metabolism. After
exposure to 5mg/l PCP over 1-96 h, the amount of PCP in the whole fish, its concentration in water and
the total amount of metabolites (water, whole fish and bile) were measured. Equations for these
variables, based on a two compartment pharmacokinetic model, were fitted simultaneously to the data using
the computer program NONLIN, which uses an iterative nonlinear least squares technique. Salicylamide

106

decreased the metabolic clearance of PCP, which resulted in an increase in the bioconcentration factor
(BCF); this increase was partially offset by a salicylamide-induced decrease in the apparent volume of
distribution of PCP. A clearance-volume compartment model permitted partitioning of the BCF in terms of
the underlying physiologic and biochemical processes (uptake clearance, metabolic clearance and apparent
volume of distribution). With this approach the BCF can be categorized as either dependent (e.g., PCP)
or independent of uptake and metabolism (elimination) based on the relative sizes of the clearances for
uptake and metabolism. Inhibition of PCP metabolism resulted in a loss of its dependence on uptake and
metabolism. The BCF estimated as the apparent volume of distribution may be useful for assessment of the
risk associated with exposure and bioaccumulation potential, as elimination is generally quite variable
among aquatic species.

GL-047

STEHLY, G.R., and W.L. Hayton. Metabolism of pentachlorophenol by fish. Xenobiotica 19(1):75-81
(1989).

1. Interspecies variability in the metabolism of pentachlorophenol (PCP) was investigated by exposing
rainbow trout, fathead minnows, sheepshead minnow, firemouth, and goldfish to water-borne l^C-PCP for 64
h.

2. The amounts of metabolites in bile and exposure water were species-dependent; all of the
metabolites excreted into the water were sulphate conjugates while bile was enriched in glucuronide
conjugates.

3. Biliary excretion accounted for less than 30% of the total PCP metabolites.

4. Biliary metabolites alone were a poor indication of the metabolites produced and of the major
routes of elimination.

GL-048

TARAPCHAK, S.J. , and L.R. HERCHE. Orthophosphate concentrations in lake water: analysis of Rigler's
radiobioassay method. Canadian Journal of Fisheries and Aquatic Sciences 45(12) : 2230-2237 (1988).

Rigler's radiobioassay method is frequently used to estimate maximum possible orthophosphate (P)
concentrations in natural waters. An evaluation of the method, based on simulated P uptake by
hypothetical phytoplankton communities, reveals that the Rigler value is not a consistent estimator of
true maximum possible P concentration. Analyses show that all members of that family of curves for which
the difference between true and assumed (or estimated) values of P is below the minimum half-saturation
constant of a component species will pass through the plot's origin. A new upper bound, termed R
(Rigler), which is the sum of the true ambient P concentration and the lowest half-saturation constant of
a component species, is identified as a consistently distinguishable bound on maximum possible P
concentrations in lake water. The R curve cannot be distinguished in a lake water experiment because of
the complex behavior of uptake curves in the unobservable substrate region. A theoretical procedure,
based on comparing uptake parameters for lake water samples and multispecif ic hypothetical communities,
offers potential for calculating upper and lower limits on R in P-limited lake water samples.

GL-049

TARAPCHAK, S.J., and L.R. HERCHE. Phosphate uptake by microbial assemblages: Model requirements and
evaluation of experimental methods. Journal of Environmental Quality 18(l):17-25 (1989).

A "compound" Michaelis-Menten model provides a conceptual framework for analyzing substrate-dependent
phosphate (P) uptake by natural microbial assemblages. Phosphate uptake can be separated into three
substrate domains: a region near ambient P concentrations, an intermediate region, and a high-substrate
region representing substrate saturation of microbial uptake sites. Simulated P uptake for hypothetical
microbial communities, ranging from non-phosphorus-limited to multiple-nutrient-limited communities,
shows that (i) commonly used "high-level" P addition schemes will underestimate community uptake rates
near natural ambient P concentrations in phosphorus-stressed systems by at least an order of magnitude,
and (ii) deviations from the simple Michaelis-Menten model may be widespread in nature, particularly in
highly phosphorus-stressed or multiple-nutrient-limited systems. A P uptake experiment on a natural
microbial assemblage from a phosphorus-limited oligotrophic lake Illustrates application of the compound
model and statistical procedures for analyzing data. An empirical procedure, based on the concept of
substrate-dependent continuity in P uptake, is proposed to determine if P addition schemes are adequate
to estimate uptake constants near ambient lakewater P concentrations.

107

GL-050

VANDERPLOEG, H.A., G-A. Paffenhofer, and J.R. LIEBIG. Diaptomus vs. net phytoplankton: Effects of
algal size and morphology on selectivity of a behaviorally flexible, omnivorous copepod. Bulletin of
Marine Science 43(3) :377-394 (1988).

Effects of algal size, colony form, and morphology on selection by Diaptomus sicilis and D. ashlandi
were determined for certain net diatoms commonly found in the pelagic regions in lakes. Mechanisms of
capture, observed by high-speed microcinematography , were correlated with selectivity results from
traditional feeding experiments with mixtures of algae. The attribute of elongation (up to 365 mm) in
one dimension possessed by Synedra spp. was not useful for avoiding grazing. In fact, at low
concentrations, selectivities for Synedra were much higher than for Chlamydomonas of equal cell volume.
This suggests a perceptual bias for capture of elongated algae. Films showed that D. sicilis could even
bite off sections of 700-mm-long Melosira colonies. However, long fragments of Synedra and Melosira were
often left behind after attacks by Diaptomus. Elongation in two dimensions, an attribute possessed by
the stellate colonies of Asterionella f ormosa was extremely effective for avoiding grazing once more than
six to eight cells per colony was reached. This result may explain the abundance of the eight-cell form
in nature. Selectivity of Diaptomus changed with concentration in mixtures of a 12-mm-diameter spherical
green alga and a 240-mm-long Synedra. In these same experiments, the proportion of attacked Synedra that
were only partially ingested - i.e., the proportion rejected after partial ingestion - increased linearly
with attack rate on Synedra , and was not correlated with attack rate on Chlamydomonas or on the sum of
both algal species. These and other data demonstrate that this concentration-variable selectivity is not
an optimal-foraging strategy. We assert these observations can be properly viewed within the classical
ethological framework of motivation and excitability of different motor patterns used to capture, handle,
and xngest different kinds of algae.

GL-051

VANDERPLOEG, H.A. [among 56 others]. Future marine zooplankton research — A perspective: Marine
Zooplankton Colloquium 1, Lake Arrowhead Conference Center, Lake Arrowhead, California, USA, April
18-22, 1988. Marine Ecology Progress Series 55:197-206 (1989).

Zooplankton research over the past 100 yr has been focused largely on temporal scales of hours to weeks
and spatial scales of decameters to kilometers. Research at both greater and lesser scales has been
limited mainly by technical intractability. Recent advances in technology are expanding the horizons of
enquiry to those scales which have long been difficult to observe. Discussions on future advances in
marine zooplankton research and technology from an open meeting of marine zooplanktologists , held at Lake
Arrowhead, California, USA in April 1988, led to specific recommendations for future research. Principal
issues and areas of future research include: (1) characterization of individual small-scale behaviors
leading to a better understanding of the dynamics of aggregation and dispersal; (2) determination of how
environmental variability, rather than mean conditions, affects physiology and behavior; (3) relation of
birth, death and growth rates to environmental conditions, both concurrent and past; (4) determination of
nutritional requirements; (5) long-term observations of population and community dynamics which would
permit analysis of interannual variability and its causes; (6) a critical need to maintain expertise in
taxonomy; and (7) continued development of mathematical models encompassing biological, chemical, and
physical parameters. Concrete steps that could be taken to facilitate these research goals include: (1)
further development of in situ instrumentation that provides (a) measurements at high frequencies and
resolutions, (b) the capability for long-term unattended measurements, and (c) the ability to monitor
birth, growth, and physiology; (2) establishment of a Center of Marine Plankton Studies with the full
spectrum of facilities required for sophisticated culture, maintenance and experimentation with single or
multiple species; and (3) establishment of an Ocean Observatory from which continuous measurements could
be made at multiple scales. Significant advances in many areas can be accelerated through
multidisciplinary activities.

GL-052

Williamson, C.E., and H.A. VANDERPLOEG. Predatory suspension-feeding in Diaptomus: prey defenses and
the avoidance of cannibalism. Bulletin of Marine Science 43(3) :561-572 (1988).

High-speed (500 frames •s"!) 16-mm film analysis was used to examine the predatory suspension-feeding
behavior of Diaptomus pallldus . Prior high-speed film analysis of Diaptomus feeding on algae revealed a
transition from passive to active captures as cell size increased, where the transition from passive to
active captures was distinguished by the additional use of the swimming legs and maxillipeds to aid in
capture. In the current study we found that when feeding on microzooplankton, Diaptomus may also employ
its first antennae and a more vigorous flap of its swimming legs in an actual attack or orientation
response to facilitate prey capture. Diaptomus responded to different prey species at distances that
varied with prey type. Many of the microzooplankton which are potentially vulnerable to predation by
suspension-feeding diaptomids have rheotactic capabilities which permit them to detect the feeding

108

currents of Diaptomus before body contact and avoid predation through a rapid escape response. The most
effective rheotactic escape response is exhibited by the nauplii of Diaptomus . Some experiments with
CC>2-anesthetized nauplii demonstrate that nauplii are highly palatable to the omnivorous adults and that
the rheotactic capabilities of the nauplii aid in reducing cannibalism.

Addendum

GL-053

BENNETT, J.R., and J.E. CAMPBELL. Accuracy of a finite-difference method for computing lake currents.
Journal of Computational Physics 68(2) : 262-27 1 (1987).

A semi-analytic model is used to assess the accuracy of a finite-difference model for computing lake
currents. Both models solve the vorticity equation for two-dimensional, time-dependent flow to compute
currents in a circular lake with a parabolic depth profile. The semi-analytic solution is obtained by
using separation of variables to remove the azimuthal dependence and reduce the equations in cylindrical
coordinates to a single equation in two variables, time and radius. This equation is then solved by a
finite-difference technique for grid sizes small enough that the solution appears to converge.
Comparison with the rectangular finite-difference solution shows a strong improvement in accuracy with
decreasing grid size. It is found that about 20 grid points across a lake basin are required to
adequately resolve wind-driven flow.

GL-054

CROLEY, T.E., II. Water level fluctuations on the Great Lakes. In The Great Lake Erie, A Reference
Text for Educators and Communicators , R.W. Fortner and V.J. Mayer (eds.). The Ohio State University
Research Foundation, Columbus. 93-102 (1987).

No abstract.

109

NATIONAL SEVERE STORMS LABORATORY

NS-001

Balakrishnan, N. , and D.S. ZRNIC. Correction of propagation effects at attenuating wavelengths in
polarimetric radars. Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL, March 27-31,
1989. American Meteorological Society, Boston, 287-291 (1989).

No abstract.

NS-002

Balakrishnan, N., and D.S. ZRNIC. Suggested use of cross-correlation between orthogonally polarized
echoes to infer hail size. Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL, March
27-31, 1989. American Meteorological Society, Boston, 292-296 (1989).

No abstract.

NS-003

Balakrishnan N., D.S. ZRNIC, J. Goldhirsh, and J. Rowland. Comparison of simulated rain rates from
disdrometer data employing polarimetric radar algorithms. Journal of Atmospheric and Oceanic
Technology 6:476-486 (1989).

Disdrometer data collected during three spring days, with moderate to heavy rain in the Norman,
Oklahoma, region are used with various polarimetric radar algorithms to simulate rain rates. It is
assumed that available measurables are 1) reflectivity at horizontal polarization, ZH , 2) differential
reflectivity, ZDR (ratio of horizontal to vertical reflectivity factors in dB) , and 3) differential
propagation constant, KDP. The accuracies of the simulated rain rates from ZH, ZDR and KDP are evaluated
and compared. A new algorithm that utilizes both reflectivity factor and differential propagation
constant is also examined. In comparing the relative accuracies, the disdrometer-derived rain rates are
assumed to be the "truth" measurements.

NS-004

BARTELS , D.L. Mid- level cyclonic vortices generated by mesoscale convectlve systems. M. S. thesis,
University of Oklahoma, Norman, 131 pp. (1989).

The advent of satellites provided the perspective to view entire lifecycles of convective systems and
to identify the wide variety of modes that exist. Since then, Mesoscale Convective Systems (MCSs
[Maddox, 1980; Menard and Fritsch, 1988]) have been the subject of many studies aiming toward the goal of
developing a conceptual model. Three distinct mesoscale circulations are consistently associated with
mature MCS . A large, cold, divergent anticyclone develops in the vicinity of the tropopause owing to
sustained convection overshooting the equilibrium level (Brown, 1979; Fritsch et al. , 1981; Fritsch and
Brown, 1982); this anticyclone apparently is shallow and short-lived (Menard and Fritsch, 1988). The
boundary layer typically is characterized by a divergent meso-high, generated by downdraft cooling and
significant rainfall under the MCC, which often persists for many hours. The mid-levels of the
troposphere are characterized by latent heating and convergence (Maddox, 1981). The resultant mesoscale
upward circulation helps sustain the characteristic cold cloud shield by perturbing the height of the
tropopause. Warm-core cyclonic vortices (Menard and Fritsch, 1988; Johnson et al . , 1988) have been
associated with this mesoscale updraft. The mid- level vortex has been hypothesized to be the principal
dynamical feature that characterizes an MCC (Zhang and Fritsch, 1987; Cotton et al . , 1988). The first
direct observational evidence of residual, mid- level cyclonic circulations was provided by Johnston
(1981), who identified meso-beta scale circulations in film loops of visible satellite imagery. This
study documents, via satellite data, 24 Mesoscale Convectively- generated Vortices (MCVs) over the central
United States between 1981-1988, and examines environmental conditions within which these circulations
become apparent after the demise of the MCS cold cloud shield. Most MCVs emerge from MCC-type (i.e.,
circular) systems, but of the cases noted, only half originated in systems which met the stringent MCC
size and duration criteria (Maddox, 1980). The majority of MCVs (i. e. 80%) were first observed at
latitudes south of 40°N. Since many convective systems occur at latitudes north of 40°N (Bartels et al . ,
1984), the paucity of MCVs in northern latitudes is not the result of a lack of convective systems.
While it is difficult to assess the impact of satellite viewing angle (and other factors, such as diurnal
cycle) on vortex identification, it is believed that the combination of conditions which lead to
long-lived MCVs may well occur most frequently south of 40°N. Furthermore, since several MCVs evolved
from small and relatively short-lived convective systems, the magnitude of latent heating, in some cases,

110

may not be as important as the background synoptic environment in determining which MCSs will exhibit
visually documentable MCVs . Satellite data were used to identify 4 MCV lifecycle stages: (1) before MCV,
(2) during MCV, (3) long-lived MCV, and (4) after MCV. Standard upper-air data were then used to
diagnose the evolution of the kinematic and thermodynamic setting of MCVs. Features of the large-scale
environment that appear conducive to the formation and longevity of MCVs include weak flow, weak vertical
shear and weak background relative vorticity. Furthermore, the rapid meso-vortex generation observed can
be explained with the quasi-geostrophic vorticity equation, i. e., convergence acting on the Coriolis
parameter. Zhang and Fritsch (1988) have shown how convective activity can result in moistening and,
thus a virtual warming of the environment The virtual warming effect is important in generating a
meso-low because density perturbations caused by moisture are not easily dispersed by inertia-gravity
waves. Thus the geographical distribution of MCVs may be partly explained by physiography since the
virtual warming effect would be most pronounced in a region with initially dry mid-levels such as the
west Central Plains. Special data taken within two MCV events are contrasted. Profiler data obtained in
a quasi steady-state MCV revealed the MCV structure is consistent with a arm-core low in geostrophic
balance. Maximum relative vorticity (and tangential winds) on the vortexcale was three to four times the
Coriolis parameter and is located at the base (between 5-6 km) of the circulation. Shear vectors are
consistent with a warm core above the circulation base and a cold core below. Finally, in-situ aircraft
data obtained in a developing MCV verified that cloud features observed on satellite images are
associated with mid- level, warm-core closed circulations.

NS-005

BRANDES , E.A., and R.M. RABIN. Cold front structure as seen by Doppler radar and tall instrumented
tower. Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL, March 27-31, 1989. American
Meteorological Society, Boston, 459-462 (1989).

No abstract.

NS-006

BROWN, R.A. Initiation and propagation of thunderstorm mesocyclones . Ph.D. dissertation, University
of Oklahoma, Norman, 321 pp. (1989).

Dual Doppler radar measurements were used to investigate the kinematic and radar reflectivity features
of a developing supercell storm that occurred in south-central Oklahoma on 6 June 1979 during Project
SESAME. Although the Agawam storm exhibited reflectivity characteristics typical of a supercell storm
propagating continuously to the right of the mean wind, Doppler velocity measurements revealed discrete
propagation through the formation of a series of right- flank updraf ts . The appearance of continuous
rightward propagation evidently was in response to the temporal and spatial integration of decreasing
precipitation being produced by the dying updraft and increasing precipitation being produced by the new
right- flank updraft. The commencement of rightward propagation was associated with the development of
middle-altitude updraft rotation (organizing stage of mesocyclone) . Customarily, updraft rotation is
thought to arise from the vertical tilting and stretching of streamwise horizontal vorticity. Though
streamwise horizontal vorticity was present at low altitudes within the environment of the Agawam storm,
this study indicates that updraft rotation resulted from an entirely different process- -one that was
initiated by the formation of middle -altitude vorticity couplet on the left and right forward flanks of
the updraft. The couplet apparently developed when a nonrotating updraft became strong enough to act as
an obstacle to the middle -altitude environmental flow. Middle-altitude updraft rotation commenced when
the first new right-flank updraft grew upward through the cyclonic member of the vorticity couplet,
entraining and stretching the ambient vertical vorticity. Each new rotating updraft produced its own
vorticity couplet, which in turn was the source of vertical vorticity for the next updraft.

NS-007

BROWN, R.A. , 1989. On the initiation of updraft rotation within the Agawam, Oklahoma, supercell
storm. Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL, March 27-31, 1989. American
Meteorological Society, Boston, 66-69 (1989).

No abstract.

NS-008

BROWN, R.A. , and V.T. Wood. A guide for interpreting Doppler velocity patterns. Report No. R400-DV-
101, October 1987. The NEXRAD Joint System Program Office, Silver Spring, MD , 51 pp. (printed 1989).

The Next Generation Weather Radar (NEXRAD) System incorporates major technological advances that are
designed to aid forecasters in preparing more accurate and timely warnings and short-term forecasts.
Though computer algorithms are available to objectively interpret Doppler velocity data, there remains a

111

necessity for subjectively interpreting the patterns on Doppler velocity displays. This guide has been
prepared- - through the use of simulated flow fields- -to help forecasters become proficient in pattern
interpretation. The simulated patterns represent flow fields within clear air widespread precipitations
as well as within convective storms.

NS-009

BURGESS, D.W., and J. Marwitz. The observed inflow structure of a thunderstorm with a mesocyclone.
Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL, March 27-31, 1989. American
Meteorological Society, Boston, 70-72 (1989).

No abstract.

NS-010

CARACENA, F. , R.L. HOLLE, and C.A. DOSWELL III. Microbursts: A handbook for visual identification.
NOAA/ERL, National Severe Storms Laboratory, Norman, Oklahoma (Available from U.S. Superintendent of
Documents, Washington D.C. 20402, Req . No. 9.01701), 35 pp. (1989).

Aid is provided for spotters who are visually identifying microbursts and for forecasters who identify
the environments in which microbursts are likely to happen. Following a discussion of physical models of
a microburst environment, on which forecasts are based, two environmental extremes (wet/dry) for
microbursts are described and typified by corresponding soundings, and illustrated through photographs
that portray the type of sky associated with these environments. A vortex ring model of the flow within
a microburst is shown, to aid in identification through its integration of subtle visual clues, which are
liberally illustrated in the color photographs. The model accounts for the following characteristics
that warn of microbursts: (1) precipitation (or dust) curl that is carried by the wind back up toward
cloud base; (2) horizontal bulging near the surface in a precipitation shaft, forming a foot-shaped
prominence; (3) an increase rather than a decrease in wind speed as the microburst expands out over the
ground; and (4) abrupt surface wind gusts followed by a rapid dissipation of some types of microbursts.

NS-011

Christian, H.J., V. MAZUR, B.D. Fisher, L.H. Ruhnke , K. Crouch, and R.P. Perala. The Atlas/Centaur
Lightning Strike Incident. Journal of Geophysical Research 94:D11 13,169-13,177 (1989).

On March 26, 1987, an Atlas/Centaur 67 vehicle carrying a naval communication satellite was launched
at 1622:00.768 EST from pad 36B of the Cape Canaveral Air Force Station, Florida. The meteorological
conditions at the time were typical of wintertime storms with heavy overcast, moderate rain, and
occasional scattered lightning activity. The NASA Investigation Board determined that, at approximately
48 s into the flight, the vehicle was struck by a triggered, cloud- to -ground lightning flash, comprised
of at least four return strokes. The resulting lightning current apparently coupled a transient signal
into the wiring of the Centaur digital computer unit (DCU) , which caused a change in one memory location.
The altered memory was associated with the computation of the Atlas engine yaw commands and caused the
DCU to issue a hardover engine gimbal command. This resulted in an excessive angle of attack, large
dynamic loads, and the breakup of the Atlas/Centaur 67 vehicle. The paper represents a case study of
meteorological conditions at the time of launch and of the lightning flash triggered by the Atlas/Centaur
67 vehicle. This is based on comprehensive analyses of the cause of the incident by the NASA
Investigation Board.

NS-012

DAVIES-JONES , R.P. A generalized Q vector and its interpretation. IAMAP 89 Brief Review Papers and
Abstracts, Vol. 1, Fifth Scientific Assembly of the International Association of Meteorology and
Atmospheric Physics, University of Reading, UK, July 31 - August 12, 1989. 1:MF33 (1989).

No abstract.

NS-013

DOSWELL, C.A. III. On the use of holographs- -vertical wind profile information in severe storms
forecasting. NOAA/NWS/SRH, Scientific Services Division, Fort Worth, Texas, and NOAA/ERL, National
Severe Storms Laboratory, Norman, Oklahoma, 19 pp. (1988).

No abstract.

112

NS-014

DOSWELL, C.A. III. Fundamental concepts of operational mesoscale analysis and forecasting for severe
convective storms (Part I). WMO Programme on Short-and Medium Range Weather Prediction Research, PSMP
Report Series No. 30, 81-99 (1989).

No abstract.

NS-015

DOSWELL, C.A. III. Fundamental concepts of operational mesoscale analysis and forecasting for severe
convective storms (Part II). WMO Programme on Short-and Medium Range Weather Prediction Research,
PSMP Report Series No. 30, 101-117 (1989).
No abstract.

NS-016

DOSWELL, C.A. III. Recent research findings on the role of vertical wind shear: Applications to
forecasting. WMO Programme on Short and Medium Range Weather Prediction Research, PSMP Report Series
No. 30, 141-155 (1989).

No abstract.

NS-017

DOSWELL, C.A. Ill, and J. A. Flueck. Forecasting and verifying in a field research project: DOPLIGHT
'87. Weather and Forecasting 4:97-109 (1989).

Verification of forecasts during research field experiments is discussed and exemplified using the
DOPLIGHT '87 experiment. We stress the importance of forecast verification if forecasting is to be a
serious component of the research. A direct comparison and contrast is done between forecasting for
field research and forecasting in the operational sense, highlighting the differences between them. The
verification of field research program forecasting is also different from that done in operations, as a
result of those forecasting differences. DOPLIGHT '87 was a field project conducted jointly by the
National Severe Storms Laboratory and the Oklahoma City National Weather Service Forecast Office, and is
described in detail. This a priori design of the forecasts to consider proper objective verification is,
we believe, unique among research field programs. The forecast evaluation focuses on the contingency
table and summary statistics derived from it, as treated in a companion paper by Flueck (1989; hereafter
referred to as Flu89) . Results are interpreted in terms of their implications for future field research
experiments and for operational forecasting. For example, it is noted that DOPLIGHT '87 forecasts of
convective potential were nearly constant from the evening before an anticipated operational day to about
local noon on that day. This suggests that convective storm field research operational decisions could
be made as early as the evening before an anticipated operational day with negligible loss of skill.
Summary measure of the forecast verification suggest that the DOPLIGHT '87 forecasters demonstrated skill
roughly comparable to the forecasters at the National Severe Storms Forecast Center in issuing outlooks
of convective potential. The requirement for time to assimilate the most recent data is noted both for
field experiments and for operations, and some discussion of the potential impact of new data acquisition
and processing systems is offered.

NS-018

DOVIAK, R.J., and D.R. Christie. Thunderstorm- generated solitary waves: A wind shear hazard.
Journal of Aircraft 26:423-431 (1989).

Observations of a boundary- layer solitary wave sensed with the National Severe Storms Laboratory's
Doppler weather radar and a 444-m-tall instrumented tower suggest that solitary and other nonlinear waves
are a source of significant wind shear hazard to safe flight and thus should be studied both
experimentally theoretically. Wave transport of the horizontal momentum of the vertically sheared
ambient air contributed much to the observed wind perturbations and horizontal wind shear. Observations
are compared with, and shown to agree fairly closely with, the waveform predicted by steady state, weakly
nonlinear, internal wave theory.

NS-019

DOVIAK, R.J., and K.W. Thomas. The wavefront shape and position of a great solitary wave of
translation. Proceedings of International Geoscience and Remote Sensing Symposium, September 13-16,
1988, Edinburgh, Scotland, 1833-1837 (1988).

113

Doppler radar mapped the evolution of atmospheric solitary gravity waves emanating from a thunderstorm
complex. The 100 km long curved wavefront and position of these few kilometer wide waves is hypothesized
to be a result of an amplitude dependent wave speed.

NS-020

EILTS , M.D. Estimation of microburst asymmetry with a single Doppler radar. Third International
Conference on the Aviation Weather System, Anaheim, CA, January 30-February 3, 1989. American
Meteorological Tociety, Boston, 57-61 (1989).

No abstract.

NS-021

EILTS, M.D., and S.K. Oakland. Convergence aloft as a precursor to microbursts. Preprints, 24th
Conference on Radar Meteorology, Tallahassee, FL, March 27-31, 1989. American Meteorological Society,
Boston, 190-193 (1989).

No abstract.

NS-022

EILTS, M.D., and S.D. Smith. Efficient dealiasing of Doppler velocities using local environment
constraints. Final Report DOT/FAA/SA- 89/1 , Federal Aviation Administration, Washington, DC, 37 pp.
(1989).

A Doppler velocity dealiasing algorithm is described that processes one radial at a time by comparing
that radial with a previous radial. This technique has worked reliable on numerous Doppler radar data
sets for clear air, thunderstorm, and severe thunderstorm situations. It was also tested on four volume
scans from severe weather environments with difficult aliasing problems to determine statistically how
well the algorithm performs in a worst case environment. Of some 1.2 million velocities in these severe
storms, 0.2% were improperly dealiased, and 93% of those were above 13 km height in the storm- top
divergent region where shears were extreme. Every tornado, mesocyclone, gust front, microburst, and
storm- top divergent signature was preserved, and could be identified by automated algorithms. This
algorithm is adaptive and therefore efficient because simple checks are made initially, and progressively
more sophisticated and time-consuming checks are used only if they are needed.

NS-023

EILTS, M.D. , and S.D. Smith. Real-time Doppler velocity dealiasing. Preprints, 24th Conference on
Radar Meteorology, Tallahassee, FL, March 27-31, 1989. American Meteorological Society, Boston, 194-
197 (1989).

No abstract.

NS-024

FORSYTH, D.E., D.W. BURGESS, M.H. JAIN, and L.E. Mooney. DOPLIGHT '87: Application of Doppler radar
technology in a National Weather Service Office. Preprints, 24th Conference on Radar Meteorology,
Tallahassee, FL, March 27-31, 1989. American Meteorological Society, Boston, 198-202 (1989).

No abstract.

NS-025

Goodman, S.J., H.J. Christian, and W.D. RUST. A comparison of the optical pulse characteristics of
intracloud and cloud- to-ground lightning as observed above clouds. Journal of Applied Meteorology
27, (12):1369-1381 (1989).

The time-resolved optical waveforms at 777.4 nm and electric-field changes produced by intracloud and
cloud- to -ground lightning flashes were measured above clouds from a U2 airplane (flying at a height of 20
km) at the same time that ground-based measurements of lightning were obtained from a mobile laboratory
and a regional lightning location network. The U2 optical pulse trains are examined for variability both
within and between flashes. The optical pulse characteristics of cloud- to-ground flashes are further
subdivided into first strokes, subsequent strokes, and intracloud components ( k- changes ) . Descriptive
statistics on these pulse categories have been compiled for 25 visually confirmed cloud- to- ground flashes
(229 optical pulses) and 232 intracloud flashes (3126 optical pulses). The pulse shapes and intensities

114

of intracloud and cloud-to-ground flashes as viewed from above cloud are shown to exhibit remarkably
similar waveshapes, radiances, and radiant energy densities. The median radiance at cloud top is
approximately 7 x 1(T3 W nf2 sr"1, and the median energy density is 3 x 10"6 J m"2 sr"1. A simple physical
model is used to estimate, for comparative purposes, the radiance and energy density of the original
light source within the cloud. First stroke optical pulses are seldom the most radiant or energetic
pulses produced by ground discharges as seen from above the clouds. The intracloud components of cloud-
to-ground flashes typically produce the optical pulses with the largest peak radiance within a cloud-to-
ground flash; however, subsequent strokes are more likely to have the largest energy densities and most
complex pulse shapes. On average, intracloud flashes have almost twice as many optical pulses as ground
discharges. There is often significant pulse structure variation within and between individual flashes.
Because of this variation, multiple stroke cloud- to-ground flashes are difficult to distinguish uniquely
from intracloud flashes solely on the basis of their optical signature above cloud. Single stroke cloud-
to-ground flashes, however, appear to have a unique single pulse optical signature. The relevance and
implications of these pulse characteristics for lightning mapping from satellite-based optical sensors is
addressed.

NS-026

Goodman, S.J., D.E. Buechler, P.D. Wright and W.D. RUST. Lightning and precipitation history of a
microburst-producing storm. Geophysical Research Letter 15:1185-1188 (1988).

Quantitative measurements of the lightning and precipitation life-cycle of a micro-burst producing
storm are described. The storm produced 116 total flashes of which only 6 were discharges to ground.
The initial discharge occurred during a period of vigorous vertical development, approximately 4-6 min
after small hail was first indicated by radar. The peak flash rate of 23 flashes min"1 occurred only 7-8
min later, 4 min prior to microburst onset, in conjunction with the peak in 2 storm mass, vertically
integrated liquid water content, echo volume, and cloud height. An abrupt decrease in the total flash
rates is associated with storm collapse and serves as a precursor to the arrival of the maximum
microburst outflows at the surface. Ice -phase precipitation is shown to be an important factor in both
the formation of the strong downdraft and the electrification of the storm.

NS-027

Goodman, S.J., D.E. Buechler, P.D. Wright, W.D. RUST, and K.E. Nielsen. Polarization radar and
electrical observations of two microburst producing storms, Preprints, 24th Conference on Radar
Meteorology, Tallahassee, FL, 27-31 March, 1989. American Meteorological Society, Boston, 109-116,
(1989).

Quantitative measurements of the lightning and precipitation life-cycle of a microburst-producing
storm are described. The storm produced 109 total flashes of which only 6 were discharges to ground.
The initial discharge occurred as the storm reached its maximum height, approximately 6 min after small
hail was first indicated by radar. The first flash was observed during a period of rapid vertical
development when the cloud grew at a nearly constant rate of 12 m s-1. At this time, the maximum radar
reflectivity in the cloud was 66 dBZ at a height of 4.5 km. The peak flash rate of 22 flashes min-1
occurred only 4 min later.

NS-028

Grice, G.K., K.W. HOWARD, S.L. BARNES, and C.A. DOSWELL (editors). A guide for operational
meteorological research. National Weather Service, Fort Worth, TX, 81 pp. (1988).

No abstract.

NS-029

HANE C.E., and M.A. LeMone . Retrieval of pressure and buoyancy from Doppler-derived winds in a High
Plains hailstorm. Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL, March 27-31,
1989. American Meteorological Society, Boston, 38-41 (1989).

No abstract.

NS-030

Houze, R.A. , S.A. Rutledge, M.I. Biggerstaff, and B.F. SMULL. Interpretation of Doppler weather radar
displays of midlatitude mesoscale convective systems. Bulletin of the American Meteorological Society
70: 608-619 (1989).

115

The utility of color displays of Doppler-radar data in revealing real-time kinematic information has
been demonstrated in past studies, especially for extratropical cyclones and severe thunderstorms. Such
displays can also indicate aspects of the circulation within a certain type of mesoscale convective
system- the squall line with trailing "stratiform" rain. Displays from a single Doppler radar collected
in two squall-line storms observed during the Oklahoma -Kansas PRE-STORM project conducted in May and June
1985 reveal mesoscale- flow patterns in the stratiform rain region of the squall line, such as
front- to-rear storm-relative flow at upper levels, a subsiding storm-relative rear inflow at middle and
low levels, and low-level divergent flow associated with strong mesoscale subsidence. "Dual-Doppler"
analysis further illustrates these mesoscale-f low features and, in addition, shows the structure of the
convective region within the squall line and a mesoscale vortex in the "stratiform" region trailing the
line. A refined conceptual model of this type of mesoscale convective system is presented based on
previous studies and observations reported here. Recognition of "single-Doppler-radar" patterns of the
type described in this paper, together with awareness of the conceptual model, should aid in the
identification and interpretation of this type of mesoscale system at future NEXRAD sites. The
dual-Doppler results presented here further indicate the utility of multiple Doppler observations of
mesoscale convective systems in the STORM program.

NS-031

HOWARD, K.W., and R.A. MADDOX. A satellite -based climatology of warm season thunderstorms over
Mexico. Preprints, III InterAmerican Congress of Meteorology, III Mexican Congress on Meteorology
November 14-18, 1988, Mexico City, 414-417 (1988).

Infrared (IR) geosynchronous operational environmental satellite (GOES) hard copy and digital imagery
is used to document thunderstorm frequency over northern Mexico. Satellite imagery is used to define a
"thunder day" and thus capture thunderstorm activity more accurately than classical climatological
depictions based on surface observation. A pronounced shift in daily thunderstorm activity from eastern
to western states occurs by middle summer as the subtropical, mid-tropospheric ridge intensifies westward
across the Gulf of Mexico. This characteristic is clearly shown in monthly "thunder day" tabulations.
Thunderstorm frequency charts also illustrate that orographic circulations along the Sierras strongly
modulate the development of storms and resultant climatologies.

NS-032

HOWARD, K.W. , and R.A. MADDOX. Mexican mesoscale convective systems--A satellite perspective.
Preprints, III InterAmerican Congress on Meteorology, III Mexican Congress on Meteorology November 14-
18, 1988, Mexico City, 404-408 (1988).

Satellite imagery is used to illustrate the types of organization that typify Mexican Mesoscale
Convective Systems (MCS) and to depict typical life cycles. Perusal of imagery for the months of May
through September, 1980-1987, allows development of an initial climatology of these systems. Favored
geographical regions and characteristics of warm season MCSs over Mexico are illustrated, along with
typical tracks, durations, and life cycles. It is hypothesized that these systems play a substantial
role in determining the local climate of several regions of Mexico and that they are important components
of the summertime circulation over much of North America, i.e., the southwestern U.S. monsoon.

NS-033

JORGENSEN, D.P., and M.A. LeMone . Characteristics of convective vertical velocity events observed by
P-3 aircraft during TAMEX. Proceedings, Workshop on TAMEX Preliminary Scientific Results, Taipei,
Republic of China, June 22-30, 1989. National Science Council, Taipei, and National Science
Foundation, Washington, DC, 203-213 (1989).

No abstract.

NS-034

JORGENSEN, D.P., and M.A. LeMone. Precipitation and kinematic structure of the TAMEX 16 June
mesoscale convective system. Part II: Pressure and buoyancy perturbations derived from airborne
Doppler radar data. Proceedings, Workshop on TAMEX Preliminary Scientific Results, Taipei, Republic
of China, June 22-30, 1989. National Science Council, Taipei, and National Science Foundation,
Washington, DC, 103-109 (1989).

No abstract.

116

NS-035

JORGENSEN, D.P., and M.A. LeMone . Vertical velocity characteristics of oceanic convection. Journal
of the Atmospheric Sciences 46: 621-644 (1989).

Oceanic cumulonimbus updraft and downdraft events observed in the Western Pacific during the TAMEX
program by NOAA P-3 research aircraft are analyzed and discussed. The basic data set consists of
flight- level data from 10 missions in the Taiwan region during May and June 1987. The 1 Hz time series
of vertical velocity is used to define convective updrafts using the criteria that the velocity must be
continuously positive for at least 0.5 km and exceed 0.5 m s"1 for Is. A subset of the strongest
drafts, termed cores, are defined as events that exceed 1 m s_1 for 0.5 km. Downdrafts and downdraft
cores are defined analogously. The statistics are from a total of 12,841 km of flight legs and consist of
359 updrafts and 466 downdrafts at altitudes from 150 m to 6.8 km MSL. The populations of average
vertical velocity, maximum vertical velocity, diameter, and mass transport for both drafts and cores are
approximately log-normally distributed, consistent with the results of previous studies of convective
characteristics in other locations. TAMEX drafts and cores are comparable in size and strength with
those measured in GATE and hurricanes but much weaker than those measured in continental thunderstorms.
The median core updraft was less than 3 m s , implying a time scale for ascent from cloud base to the
freezing level of about 35 minutes. The microphysical implications of the low updraft rates are
illustrated by comparing vertical profiles of radar reflectivity for TAMEX with those in other regions.
The data are consistent with the hypothesis that the oceanic convection that was studied in GATE,
hurricanes, and TAMEX is dominated by warm rain coalescence processes and that a large fractional rainout
occurs below the freezing level. The rapid reduction of cloud water and radar reflectivity above the
freezing level, as well as observations of abundant ice particles in all but the strongest updraft cores
at temperatures just below 0°C, implies a rapid conversion of cloud water and rain to ice and graupel as
the air ascends through the freezing level. The lack of reports of hail and other forms of severe
weather in these oceanic regions is consistent with the aircraft and radar observations. The data from
the "best" organized weather system investigated by the P-3 during TAMEX are used to examine the
relationship of cloud buoyancy and vertical motion. Water loading and entrainment have a significant
role in reducing both the core virtual temperature excess over the environment and the updraft velocity
from what would be expected from the convective available potential energy of the environmental air. The
majority of the strongest downdrafts possesses positive temperature perturbations (probably as a result
of mixing with nearby updraft air) with the negative buoyancy being sustained by large amounts of
rainwater .

NS-036

JORGENSEN, D.P., M.A. LeMone, and B. Jou. Precipitation and kinematic structure of an oceanic
mesoscale convective system. Part I: Airborne Doppler radar analysis. Proceedings, 18th Conference
on Hurricanes and Tropical Meteorology, San Diego, CA, May 16-19, 1989. American Meteorological
Society, Boston, 232-233 (1989).

No abstract.

NS-037

Jou, B., D.P. JORGENSEN, and B.F. SMULL. Precipitation and kinematic structure of the TAMEX 16 June
mesoscale convective system. Part I: Airborne Doppler radar analysis. Proceedings, Workshop on TAMEX
Preliminary Scientific Results, Taipei, Republic of China, June 22-30, 1989. National Science
Council, Taipei, and National Science Foundation, Washington, DC, 77-81 (1989).

No abstract.

NS-038

Klingle-Wilson, D., S.H. Olson, W. Wilson, W.P. Mahoney III, S.D. Smith, A. WITT, andM.D. EILTS .
Gust front detection algorithm for the terminal Doppler weather radar. Part II: Performance
Assessment. Preprints, Third International Conference on the Aviation Weather System, Anaheim, CA,
January 30-February 3, 1989. American Meteorological Society, Boston, 398-402 (1989).

No abstract.

NS-039

Lang, S.L., P.S. Ray, and C.L. ZIEGLER. Retrieval and evolution of microphysical fields in a small
mountain thunderstorm. Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL, March 27-31,
1989. American Meteorological Society, Boston, 93-96 (1989).

No abstract.

117

NS-040

LeMone, M.A., and D.P. JORGENSEN. Precipitation and kinematic structure of an oceanic mesoscale
convective system. Part II: Results from analysis of in-situ data. Proceedings, 18th Conference on
Hurricanes and Tropical Meteorology, San Diego, CA, May 16-19, 1989. American Meteorological Society,
Boston, 234-235 (1989).

No abstract.

NS-041

LeMone, M.A., and D.P. JORGENSEN. Precipitation and kinematic structure of the TAMEX 16 June mesoscale
convective system. Part III: Analysis of in-situ data. Proceedings, Workshop on TAMEX Preliminary
Scientific Results, Taipei, Republic of China, June 22-30, 1989. National Science Council, Taipei,
and National Science Foundation, Washington, DC, 110-117 (1989).

No abstract.

NS-042

LEWIS, J.M. GUFMEX: A study of return flow in the Gulf of Mexico. Bulletin of the American
MeteoroloEical Society 70:24-29 (1989).

During February and March 1988, a limited field experiment was conducted over the Gulf of Mexico to
gather data on two phenomena: air mass modification over the Loop Current, and return flow
characteristics of modified polar air returning to the southern shores of the United States. Six-hourly
radiosondes, special Cross-Chain LORAN (Long-Range Aid to Navigation) Atmospheric Sounding System (CLASS)
soundings, and three P-3 flights including dropwindsondes and Airborne Expendable Bathythermograph (AXBT)
measurements were taken. The experiment objectives and the data are described.

NS-043

LEWIS, J.M., C. Hayden, and J. Derber. A method for combining radiances and wind shear to define the
temperature structure of the atmosphere. Monthly Weather Review 117:1193-1207 (1989).

The retrieval of temperature from satellite-observed radiances has traditionally been addressed as a
one -dimensional or columnar problem which uses a guess profile of temperature. In this study, the
traditional approach is augmented by incorporating observed wind shear as a general thermal wind
constraint in the inversion of radiances to make a three-dimensional temperature analysis. The problem
is case as a classical variational problem that minimizes a weighted sum of squares subject to
constraint. The constraints are the general thermal wind equation and a set of regression equations
expressing the radiances in terms of the temperature profile. The solution is found by the method of
conjugate gradients. Experiments using observed winds with both simulated and observed radiances for the
GOES VISSR Atmospheric Sounder (VAS) are described. In both cases, a first guess from a numerical
forecast is used. Simulated radiances are used to establish the optimal relative weighting of the wind
versus radiance observations and to determine the limits of accuracy on the retrieved temperature under
idealized conditions. These relative weights are used in the real data experiments. Experiments are
included where weights are varied horizontally and vertically to simulate uneven distribution or
confidence in the data. Results indicate that (i) the inclusion of wind shear with simulated radiances
reduces the cumulative error variance in the temperature estimate and reduces guess dependence; (ii)
horizontal and vertical variations in parameter weighting is viable and well-behaved; and (iii) the
algorithm's rate of convergence makes it suitable for small computer applications. Experiments with
observed radiances are not as successful. The measured radiances do not improve the forecast. The
principal deficiency appears to be that the regression model for expressing the radiances is inadequate
to account for the influence of water vapor which affect the VAS measurements or the nonlinearity of
radiance with respect to temperature. Extensions to the model as well as application to microwave
measurements, which do not suffer these deficiencies, are discussed.

NS-044

LEWIS, J.M., and L.C. SHOWELL. GUFMEX: Preprints, III Interamerican Mexican Congress of Meteorology,
III Mexican Congress on Meteorology, November 14-18, 1988, Mexico City, Mexico, 106-109 (1989).

118

During February and March 1988, a limited field experiment was conducted over the Gulf of Mexico to
gather data on two phenomena: air mass modification over the Loop Current, and return flow
characteristics of modified polar air returning to the southern shores of the United States. Six-hourly
radiosondes, special Cross -Chain LORAN Atmospheric Sounding System (CLASS) soundings, and three P-3
flights including dropwindsondes and Airborne Expendable Bathythermograph (AXBT) measurements were
accomplished. The experiment objectives and the data are described.

NS-045

LOPEZ, R.E., D. Atlas, D. Rosenfeld, J.L. Thomas, D.O. BLANCHARD , and R.L. HOLLE. Estimation of areal
rainfall using the radar echo area time integral. Journal of Applied Meteorology 28:1162-1175 (1989).

This work extends the Area Time Integral (ATI) method of Doneaud et al . , developed for the lifetime
rainfall from an individual storm, and the instantaneous areawide rainfall method of Atlas et al . , to the
measurement of the cumulative areawide rainfall for periods up to 12 h. The database is the radar and
raingage network data for the three summers of the Florida Area Cumulus Experiment (FACE) II. For 12-h
accumulations, V, over the area of 3.6 X 104 km2 , we find correlations of 0.92 between radar deduced
rainfall and ATI where the latter is computed at intervals from 5 min up to 1 h. The slope of the
regression line V/(ATI) is 3.4 mm h-1. Using a gage network with density of 1/11 km2 over an area 1.5 X
104 km2 the correlation coefficient drops to 0.84, still sufficiently high to confirm the validity of the
ATI approach. Also, with the gages the V/(ATI) slope decreases to 2.6 mm h-1. The decrease in the
correlation is due largely to anomalous propagation which falsely increases storm areas, and partly to
the poorer sampling by the gages. The decrease in the rain volume from radar to gage-determined values
is probably due to: 1) underestimation of the rain cores by the spaced gages; 2) the use of the wide beam
WSR-57 and low threshold for echo area measurements, which detects weak anvil and other precipitation
debris to increase the effective echo area without a proportional increase in surface rainfall; and 3) an
inappropriate Z-R relation. A comparison of the V/(ATI) ratios using either radar or gage rainfall to
the value expected theoretically on the basis of the probability distribution of rain rate at Miami shows
that one should expect about twice the volume per unit echo area as those observed. This too is believed
to be due to the wide beam and the low threshold which tends to enlarge the echo areas excessively.
Improved correlations and better agreement with theory are expected at higher radar/rain rate thresholds
and with narrower beams.

NS-046

LOPEZ, R.E., R.L. HOLLE, W.D. OTTO, and R. ORTIZ. Cloud- to -ground lightning in Colorado: Flashes of
both polarities related to meteorological conditions, radar echoes, and severe weather. Proceedings,
1989 International Conference on Lightning and Static Electricity, Bath, United Kingdom, September
26-28, 1989. Royal Aerospace Establishment, Farnborough, Hampshire, United Kingdom, 1A.2.1-7 (1989).

Cloud- to ground lightning location data have been collected by a three direction-finder network in
northeastern Colorado, USA. The data have been used to study the relationships of flashes to three types
of meteorological parameters. The number of flashes of both polarities, as well as the relative
occurrence of positives, shows a large seasonal variability. These fluctuations have been compared to
the thermodymanic and dynamic parameters related to convective cloud growth potential based on the
afternoon sounding at Denver, Colorado. The seasonal fluctuation of environmental parameters that favor
deep, vigorous, and long- lasting convection coincides with the seasonal fluctuation of absolute lightning
activity (both positive and negative flashes). For the ratio of positive to all flashes, however, the
opposite is true: high ratios are related to a shallow convective layer and a low water-vapor content in
the atmospheric column. High vertical wind shears are associated with low ratios during the summer, but
in the spring and fall they are related to a high relative occurrence of positives. When composited with
radar information, negative flashes were found slightly outside the echoes or in the region of low values
but of the highest gradients of radar reflectivity. Positives occurred in areas of weak and uniform
radar reflectivity away from the intense convective centers, or in the dissipating stages of the storms.
Clouds with a moderate radar-detected precipitation rate near the ground were found to produce a large

119

number of negative flashes but not many positives. Clouds with a high precipitation rate produced a
small number of negative flashes, but a considerable number of positive flashes. Flashes were also
related to severe weather in the region. In the summer of 1985 the frequency of flashes with one or more
severe storm occurrences is 350% greater than the frequency on days with no severe weather events. When
individual severe weather phenomena were identified, such as tornadoes, heavy rain, flash floods, hail,
or high winds, nearly all categories had more than twice as many flashes on days with a specific type of
severe weather than on days without such a weather type.

NS-047

LOPEZ, R.E., R.L. HOLLE, and A.I. WATSON. Meteorological studies with cloud-to-ground lightning data:
Samples of recent analyses. Proceedings, 4th WMO Technical Conference on Instruments and Methods of
Observation (TECIMO-IV), Brussels, Belgium, September 4-8, 1989. WMO/TD No . 303, Geneva, 275-280
(1989) .

No abstract.

NS-048

LOPEZ, R.E., W.D. OTTO, J.R. DAUGHERTY, and R.L. HOLLE. The relationship between radar and lightning
characteristics of northeastern Colorado storm systems. Preprints, 24th Conference on Radar
Meteorology, Tallahassee, FL, March 27-31, 1989. American Meteorological Society, Boston, 85-88
(1989).

No abstract.

NS-049

MACGORMAN, D.R., D.W. BURGESS, V. MAZUR, W.D. RUST, W.L. Taylor, and B.C. Johnson. Lightning rates
relative to tornadic storm evolution on 22 May 1981. Journal of Atmospheric Sciences 46:221-250
(1989) .

On 22 May 1981, we acquired lightning and Doppler radar data on two tornadic storms in Oklahoma.
Cloud- to -ground lightning flash rates were measured with a magnetic direction-finder system, and total
flash rates in the vicinity of the mesocyclone were measured with an L-band radar. In both storms, there
was no clear relationship between tornado occurrence and ground flash rates of the storm as a whole, but
the stroke rate of each storm was highest after it stopped producing tornadoes. For the second storm, we
examined both intracloud and cloud- to-ground lightning rates relative to mesocyclone evolution, analyzing
the region within 10 km of the mesocyclone core. Our analysis began during initial stages of the
mesocyclone core associated with the fourth and strongest of five tornadoes in the storm and continued
until all mesocyclone cores in the storm dissipated. During this period, intracloud lightning flash
rates reached a peak of almost 14 min-1 approximately 10 min after the peak in cyclonic shear at the 6 km
level and at the same time as the peak in cyclonic shear at the 1 . 5 km level. The peak in intracloud
rates also occurred 5-10 min after the peak in the area within 40 and 45 dBZ contours at the 8 km level
and at about the same time as the peak in the area within 50 dBZ contours at 8 km and within 40 dBZ at 6
km. However, ground flash rates in the mesocyclone region were usually less than 1 min -1 during periods
when intracloud rates were high and were negatively correlated with cyclonic shear at both 1.5 and 6 km.
The ground flash rate was the last parameter to peak, approximately 15 min after intracloud lightning and
a few minutes after the latest reflectivity area (the area having >dBZ at the 1 km level) . We suggest
that intracloud rates were governed in part by particle interactions during the growth in reflectivity at
7-9 km and in part by some process associated with the evolution of cyclonic shear at low altitudes.
Earlier studies of tornadic storms indicate that the evolution of updrafts and downdrafts affects the
evolution of both reflectivity and low-altitude cyclonic shear and so, as in previous storm studies,
updraft evolution will affect intracloud rates. We suggest that the peaks in ground flash rates resulted
from increasing the distance between the main positive and negative charge centers, from the
sedimentation of negative charge to lower altitudes, or from the generation or advection of positive
charge below the main negative charge. Although these data are from only a single day, consideration of
sferics data from previous studies suggests that (1) most tornadic storms (80% or more) have an increase
in total flash rates near the time of the tornado, and (2) the increase in total flash rates is often
dominated by intracloud flashes.

NS-050

MACGORMAN, D.R., and W.D. RUST. An evaluation of the LLP and LPATS lightning ground strike mapping
systems. Preprints, 5th International Conference on Interactive Information and Processing Systems
for Meteorology, Oceanography, and Hydrology, Anaheim, CA, January 30-February 3, 1989. American
Meteorological Society, Boston, 249-254 (1989).

No abstract.

120

NS-051

MACGORMAN, D.R. and W.L. Taylor. Positive cloud- to -ground lightning detection by an LLP direction-
finder network. Journal of Geophysical Research 94 : Dll , 13 , 313-13 , 318 (1989).

We have investigated how reliably an automatic direction-finder network manufactured by Lightning
Location and Protection, Inc. (LLP), identifies cloud- to-ground (CG) flashes that effectively lower
positive charge to ground (+CG flashes). To provide independent verification of the occurrence of +CG
flashes, we examined records from an extremely low frequency (ELF) system to determine whether 340 +CG
flashes detected by the LLP system had coincident ELF waveforms characteristic of +CG flashes. The
fraction of +CG flashes that had coincident ELF waveforms increased from 0.67 for flashes with range-
normalized amplitudes of 0-25 LLP units to an average of 0.93 for flashes with range -normalized
amplitudes of at least 75 LLP units. We also analyzed ELF coincidence for -CG flashes recorded by video
systems and by the LLP system. A comparison of the results for +CG flashes and -CG flashes suggests (1)
that false detection is negligible in the LLP system for +CG flashes with range -normalized amplitudes of
at least 50 LLP units and (2) that no more than about 15% of the +CG flashes detected by the LLP system
at smaller amplitudes are false detections. The true percentage of +CG flashes that are false detections
is probably even lower, because at least some of the decrease in ELF coincidence at low amplitudes
appears to have been caused by an increase in the fraction of coincident ELF signals that occurred below
the ELF system's noise level.

NS-052

Mach, D.M., and W.D. RUST. A photoelectric technique for measuring lightning-channel propagation
velocities from a mobile laboratory. Journal of Atmospheric and Oceanic Technology 6 (3):439-445
(1989).

We have developed a device to measure lightning-channel propagation velocities. It consists of eight
solid state silicon detectors mounted behind precision horizontal slits in the focal plane of a 50-mm
lens on a 35 -mm camera body. Each detector has a 0.1° vertical field of view that is separated from
adjacent detector slits by 2.8°. The horizontal fleld-of -view for each detector is 41° and the total
vertical field of view for the device is 21°. The signal from each detector is amplified by a circuit
with a 10-90% rise time of 0.6 ps and an equivalent decay time of 400 /js . The eight photodetector
pulses, IRIG-B time, and slow and fast electric field change waveforms are recorded on a 14 track analog
tape recorder with an upper frequency response of 1.0 MHz and a maximum dynamic interchannel timing error
of 0.6 /js. To provide images of lightning geometry and permit time- to- thunder measurements, color video
and sound are recorded with a standard VHS video cassette recorder. The return stroke velocity (RSV)
device, video camera, and microphone are installed and coaxially aimed in an environmental enclosure on a
remotely controlled pan- tilt unit atop our mobile laboratory permitting the recording of lightning
signals at remote sites and while mobile. To evaluate the performance of the RSV device, we have
analyzed 12 natural return strokes from Alabama, Florida, and Oklahoma and 4 return strokes triggered at
the Kennedy Space Center, Florida. The velocities we determined vary from 1.2 to 2.5 x 109 ms~l, with an
average of 1.7 x 108 ms"1 ± 0.8 x 108 ms"1. From comparisons of our results to those of a streaking
camera, we find no significant differences between the velocities obtained from the same strokes with the
two systems. We also find no differences between the characteristics of the pulses or the velocities
calculated from them while the RSV device is moving or stationary.

NS-053

Mach, D. and W.D. RUST. A solid state lighting propagation speed sensor. Preprints, 27th Aerospace
Sciences Meeting, Reno, NV, January 9-12, 1989. American Institute of Aeronautics and Astronautics
AIAA-89-0785 (1989).

We have developed a device to measure lightning channel propagation speeds. It consists of eight
solid state silicon photodetectors mounted behind precision horizontal slits in the focal plane of a 50
mm lens on a 35 mm camera body. Each detector has a 0.1° vertical field of view that is separated from
adjacent detector slits by 2.8°. With the device, we have analyzed propaeation speeds from 140 strokes
that consist of 98 natural and 43 triggered return strokes. For shorter channel lengths, less than 500m
natural lightning has a statistically higher average return stroke propagation speed of 1.9 ± 0.7 x l8
m s than triggered lightning with an average return stroke propagation speed of 1 . 4 ± 0 4 x 108 m s"1
Return stroke propagation speeds of 1 . 0 and 1 . 7 x 108 m s"1 were determined for two distant single stroke
natural positive cloud-to-ground flashes. Dart leaders are detected for only 18% of the natural
subsequent strokes while over 49% of the triggered strokes have detectable dart leaders The average
natural dart leader propagation speed of 1 . 8 ± 0 . 8 x 107 m s"1 is statistically greater than the average
triggered dart leader propagation speed of 1 . 3 ± 0 . 8 x 107 m s"1 . We find no significant propagation
speed change with height for either natural or triggered dart leaders.

121

NS-054

Mach, D.M., and W.D. RUST. Photoelectric return-stroke velocity and peak current estimates in natural
and triggered lightning. Journal of Geophysical Research 94 : Dll , 13 , 327-13 , 247 (1989).

Using data from a mobile, we present two-dimensional return-stroke velocities from 130 strokes that
consist of 86 negative natural, 41 negative triggered, one positive triggered, and two positive natural
return- strokes . The velocity measurements are divided into two groups: "short -channel" values with
channel segments starting near the ground and less than 500m in length and "long-channel" values that
start near the ground and exceed 500m in length. The average long-channel velocity is 1 . 3±0 . 3 x 108 m s"
1 for natural return- strokes and 1.210.3 x 108 m s"1 for triggered return- strokes . For the short
channels, natural return- strokes have a statistically higher (at the 98% confidence level) average
velocity of 9.1±0.7 x 10e m s"1 than triggered strokes with an average velocity of 1.4+0.4xl08 m s"1. We
compare our results with previous measurements of the return-stroke velocity for comparable channel
segment lengths and find that there is no statistical difference between our results and the previous
ones. A qualitative analysis indicates that the optical waveform from a return-stroke generally
increases in risetime and decreases in amplitude at greater altitudes. Using the transmission line model
(TLM) , the shortest segment one-dimensional return-stroke velocity, and either the maximum or plateau
electric field, we find natural strokes have a peak current distribution that is lognormal with a median
value of 16 kA (maximum E) or 12 kA (plateau E) while triggered lightning has a median peak current value
of 21 kA (maximum E) or 15 kA (plateau E) . We find substantial differences between TLM and the shunt-
measured peak currents and find no significant correlation between shunt peak currents and triggered
return-stroke velocities. We do find correlations between TLM peak currents and velocities for triggered
and natural subsequent return- strokes but not between TLM peak currents and natural first return=stroke
velocities. In both cases where a correlation is found the trend is for greater peak currents to be
associated with lower return- stroke velocities. Our peak current calculations are approximately half as
large as previously reported. This difference is attributed to the greater return-stroke velocity
measured by our photoelectric device and used in the transmission line model. Hence previous estimates
of the return-stroke peak current seem too high. Two natural single-stroke positive cloud- to -ground
flashes had velocities of 1.0 and 1.7 x 108 m s"1 and peak currents of 120-150 kA.

NS-055

MADDOX, R.A., and K.W. HOWARD. Mexican mesoscale convective systems - Two case examples. Preprints,
III InterAmerican Congress on Meteorology, III Mexican Congress on Meteorology November 14-18, 1988,
Mexico City, Mexico, 89-93 (1988).

Two Mexican Mesoscale Convective Systems (MSCs) are examined in a case study mode to explore both the
environmental seetings that lead to these events and the possibility that they effect interactions
between the subtropics and the middle latitude westerlies. A spring event along the east coast and a
summer event over northwestern Mexico are considered. These systems exhibit many similarities with MCSs
that occur frequently over the central United States. It is shown that large-scale forcing for vertical
motion is very weak but that convective instability is surprisingly great. Substantial vertical
displacement of moist boundary layer parcels is required to release the instability, and it is inferred
that mesoscale lifting is essential to initiate and maintain these convective systems.

NS-056

MADDOX, R.A. , and K.W. HOWARD. Mexican mesoscale convective systems- -Large scale environmental
conditions. Preprints, III InterAmerican Congress on Meteorology, III Mexican Congress on Meteorology
November 14-18, 1988, Mexico City, Mexico, 395-399 (1988).

Mean atmospheric conditions associated with th«- occurrence of mesoscale convective systems over both
the eastern and western coasts of Mexico are examined. The typical large-scale environment of these
events appears quite benign with no obvious strong forcing for upward motion. Average soundings,
however, show convective instability of a degree often associated with severe thunderstorms at more
northerly latitudes. Substantial interactions between the large-scale circulation and mesoscale
processes are apparently required to release the available buoyant energy. Candidate mesoscale features
that could lead to the generation of Mexican MCSs include land-sea breezes, mountain-valley winds,
organized mesoscale cold outflows from thunder storms initiated by elevated heating over the mountains
or, in the case of eastcoast MCSs, from storms occurring further to the north over Texas.

NS-057

Marshall, T.C., W.D. RUST, W.P. Winn and K.E. Gilbert. The electrical structure in two thunderstorm
anvil cloud. Journal of Geophysical Research 94:D2, 2717-2181 (1989).

122

Two electric field soundings through thunderstorm anvil clouds show similar charge structures:
negatively charged screening layers on the top and bottom surfaces, a layer of positive charge in the
interior, and one or two layers of zero charge. Both anvil clouds were strongly electrified: the peak
magnitudes of the electric field in the two storms were 70 and 90 kV/m (and so, aircraft penetrating
anvil clouds run the risk of triggering lightning flashes). The non-zero layers had charge densities
comparable to those found in storm cores, ranging in magnitude from 0.4 to 2.7 nC/m3 . The layers ranged
in thickness from 300 to 2000 m. The positive charge probably originated in the main positive charge
region normally found at high altitudes in the core of thunderclouds. The removal of positive charge
from the storm's core to the anvil may influence the ratio of intra-cloud to cloud- to-ground lightning
flashes and the rate of generation of charge in the core. The negatively charged layers probably were
screening layers resulting from the discontinuity in the electrical conductivity at the cloud boundaries.
The lower negative screening layer appeared to be carried toward the storm's core by winds below and at
the lower anvil boundary.

NS-058

MATEJKA, T. Pressure and buoyancy forces and tendencies in a squall line and their relation to its
evolution. Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL, March 27-31, 1989.
American Meteorological Society, Boston, 478-481 (1989).

No abstract.

NS-059

MAZUR, V. A physical model of lightning initiation on aircraft in thunderstorms. Journal of
Geophysical Research, 94:3326-3340 (1989).

A physical model of initiation of lightning flashes by aircraft in thunderstorms, based on the 'bi-
directional, uncharged leader' concept of Kasemir, is verified with airborne data from lightning strikes
to instrumented airplanes (NASA F-106B and FAA CV-580). Characteristics of electromagnetic processes
during lightning attachment to aircraft are identified with those in negative stepped leaders, positive
leaders and continuous current in natural lightning, in flashes triggered by wire trailing rockets, and
in laboratory discharges. It is shown that: (1) a triggered flash starts on aircraft with either
negative corona or positive leader that depends on the ambient electric field vector and the vehicle form
factors, (2) the positive leader with continuous current that increases with time is followed in a few
milliseconds by the negative stepped leader with current pulses of a few kiloamperes, and (3) the two
leaders develop in space simultaneously and bi-directionally from the oppositely charged extremities of
the airplane.

NS-060

MAZUR, V. Triggered lightning strikes to aircraft and natural intracloud discharges, Journal of
Geophysical Research 94:3311-3325 (1989).

A physical model of triggered lightning strikes to aircraft is applied to interpret the initiation of
intracloud flashes depicted with the French UHF-VHF interferometric system. It is shown that both
intracloud discharges and triggered strikes are initiated in a qualitatively similar way: the
simultaneous bi-directional development of the negative stepped leader and the positive leader-continuous
current process. The airborne visual observations and electromagnetic waveform records during the
junction stage of intracloud flashes reveal (1) presence of continuous current during the entire period,
and (2) a "multistroke" feature observed as variations of the low-frequency (continuous) current with
current pulses superimposed and occurred only during periods of rising continuous current. It is shown
that airborne measurements of lightning strikes to aircraft provide an opportunity to recognize recoil
streamers in time domain data and to determine their characteristics (duration and amplitude) , which are
not obtainable with other techniques. Small-scale tortuosity (from tens of centimeters to several meters
long) has been observed in visual images of lightning channels at close range with video cameras aboard
the NASA F-106B airplane. The hypothesis is advanced that high-rate pulse bursts in VHF-and UHF-bands
associated with recoil streamers are radiation pulses attributable to reflection processes at kinks of
the highly tortuous channel traversed by a current pulse.

NS-061

MAZUR, V., B.D. Fisher and P.W. Brown. Cloud- to -ground strikes to the NASA F-106 airplane.
Preprints, 1989 International Conference on Lightning and Static Electricity, University of Bath, UK
26-28 September 1989 8A. 4 . 1-8A. 4 . 3 (1989).

123

Data on cloud- to -ground (CG) strikes to the NASA F-106B instrumented airplane obtained during the
1984-86 seasons in storm penetrations at altitudes below 6 km are summarized. Determination that a
strike to the F-106B was a CG flash was based on the time difference between moment of lightning
attachments to the airplane and the ground as well as the range difference between points of attachments.
In only one CG strike, out of a total of 20, was a first return stroke current flow through the F-106B
indicated, since the time difference between attachment of the lightning channel to the airplane and to
the ground, 10 ms , was within the time accuracy of the CG strike by the locating system (10 ms) . In the
remaining 19 cases, strikes were associated with processes in the flash either preceding or following the
first return stroke. The peak current of CG strikes to the F-106B were less than 26 kA, which is in the
range of average values of negative first return strokes measured at the ground. Also presented is the
analysis of electromagnetic waveform records and video images obtained aboard the F-106B during a
lightning strike which was part of a multistroke CG flash. There is strong indication that the CG flash
began as a triggered strike and later produced nine return strokes, four of which were attached to the
airplane. The analysis illustrates the possibility to investigate dart leaders, recoil streamers, and
continuous current using direct measurements aboard the airplane.

NS-062

MEITIN, J.G., and A.I. WATSON. Comparison of the kinematic structure and precipitation
characteristics of squall and non- squall mesoscale convective systems. Preprints, 24th Conference on
Radar Meteorology, Tallahassee, FL, March 27-31, 1989. American Meteorological Society, Boston,
486-489 (1989).

No abstract.

NS-063

Nielsen, K., and D.R. MacGORMAN. Lightning Ground Flash Rates Relative to Mesocyclone Evolution on
8 May 1986. Preprints, 24th Radar Conference on Radar Meteorology, Tallahassee, FL, 27-31 March,
1989. American Meteorological Society, Boston, 117-120 (1989).

Relationships between lightning ground flashes and other storm parameters are examined for the storm
that produced a damaging tornado in Edmond, Oklahoma on 8 May 1986. Lightning ground strike rates and
location are compared with single-Doppler radar data for a period of approximately 1 hr 20 min, extending
from ten minutes prior to the first tornado until the mesocyclone could no longer be detected in single-
Doppler data. Lightning ground flash rates increased rapidly as cyclonic shear in the mesocyclone
increased, then decreased as the mesocyclone weakened and dissipated. When the mesocyclone was strong
and well-organized, negative cloud- to-ground lightning strikes were most concentrated near the
mesocyclone; there was a substantially higher density within 5 km of the mesocyclone than between 5 and
10 km. Positive CG lightning strikes did not concentrate in any particular area, but tended to avoid
reflectivity cores north of the mesocyclone. The behavior of negative ground flashes in the Edmond storm
is opposite to their behavior in the Binger storm studied by MacGorman et al. (1988). In the Binger
storm, ground strikes were infrequent during the tornado and reached a peak as the mesocyclone
dissipated. The behavior for the Edmond storm is similar, however, to the behavior of intracloud flash
rates and total flash rates in the Binger storm. There were substantial differences in the structure and
evolution of the two storms: During tornadlc activity, the environment of the Edmond storm was uncapped
while it was strongly capped during the Binger tornado; the Edmond storm interacted with and was
overtaken by an approaching thunderstorm complex while the Binger storm was isolated throughout its
lifetime. Also, negative cloud- to-ground lightning flash rates were well-correlated with cyclonic shear
in the mesocyclone of the Edmond storm, but lagged cyclonic shear in the Binger storm, peaking as the
mesocyclone dissipated. Rates and correlation for negative ground flashes in the Edmond storm were
similar to those for intracloud flashes in the Binger storm. The observed differences between the Edmond
and Binger storms suggest that it is not sufficient to treat relationships between lightning and tornadic
activity as being uniform for all tornadoes if the predictive value of these relationships is to be
acceptable. Instead, it is important to include information on storm environment, structure, and
evolution when analyzing lightning or sferics in tornadic storms.

NS-064

Passarelli, R.E., Jr., and D.S. ZRNIC. An expression for phase noise. Preprints, 24th Conference on
Radar Meteorology, Tallahassee, FL, March 27-31, 1989. American Meteorological Society, Boston, 433-
435 (1989).

No abstract.

NS-065

PASSI, R.M. , and R.E. LOPEZ. A parametric estimation of systematic errors in networks of magnetic
direction finders. Journal of Geophysical Re search -Atmospheres 94:13,319-13,328 (1989).

124

We consider the problem of estimating the systematic errors in a network of magnetic direction finders
using bearing data from a historical record containing a large number of lightning flash observations.
It is clear that this problem is linked with the flash location estimation problem and that the two are
statistically confounded in the sense that the effect of the one can not be separated from the other. We
formalize mathematically a connection between the two problems to arrive at a self -consistent system. In
this paper we parameterize the site errors as two-cycle sinusoidal functions and show that the estimation
equations can be described by a model which separates into linear and nonlinear parameters. We take
advantage of this separation to decouple large-dimensional equations into smaller-dimensional equations.
Through these equation we show the link between the site error and flash location estimation problems.
Validation of our modeling procedures is done by heuristic arguments and analysis of residuals. The
latter reveals that not all of the residuals have been explained by sinusoidal site errors but that some
residuals might result from the geometry of the network. This appears to be an important problem and is
presently under study. Also, there is need to test the site error estimation algorithm developed in this
paper against some ground truth.

NS-066

Pitts, F. , B. Fisher, V. MAZUR, and T. Brown. Researching lightning strikes to aircraft. IEEE
Spectrum. 7:34-38 (1988).

No abstract.

NS-067

RABIN, R.M. Diagnosing short-term changes in temperature profiles from single Doppler radar data.
Monthly Weather Review 117:1501-1516 (1989).

A method is outlined to diagnose temperature changes aloft from single Doppler radar data and an
initial radiosonde observation. One aim is to deduce changes in inversion strength and stability between
synoptic soundings, which is particularly important in forecasting thunderstorm initiation. Results of
two test studies are given with recommendations for future work.

NS-068

Reap, R.M. , and D.R. MACGORMAN. Cloud- to-ground lightning: Climatological characteristics and
relationship to model fields, radar observations & severe local storms. Monthly Weather Review. 117:
518-535 (1989).

Data for nearly 2 million lightning flashes recorded during the 1986-86 warm seasons by the National
Severe Storm Laboratory's (NSSL's) lightning strike locating network were evaluated to determine some of
the climatological characteristics of cloud- to-ground lightning. Among the characteristics studied were
the seasonal, diurnal, and spatial variations of positive and negative lightning strike activity,
including flash rates, signal strength, and flash multiplicity. The lightning data were also compared to
manually digitized radar data, reports of tornadoes, large hail, and damaging winds, and to analyzed 0000
UTC fields obtained from operational numerical models. An examination of the diurnal distribution of
lightning revealed that peak rates occurred later than in other sections of the country, reflecting the
prevalence of nocturnal convection within much of the NSSL network. An analysis of the spatial
variations in lightning activity also confirmed the existence of distinct climatological regimes within
the network. A study of the diurnal variations in signal strength revealed that first return strokes
lowering negative charge have higher signal strengths at night and in the early morning hours, when flash
rates are normally decreasing. In addition, positive flashes were found to exhibit three distinct peaks
in signal strength, two of which are associated with late afternoon and nocturnal maxima in flash
activity. A good correspondence between lightning frequency and radar echo intensity was found for the
region within strongly correlated with the low-level moisture flux and circulation, as characterized by
favorable moisture convergence, cyclonic relative vorticity, and strong upward vertical motions in the
boundary layer. Contrary to expectations, freezing level height and wind shear were not nearly as
important as the boundary layer fields in determining thunderstorm formation and subsequent positive
lightning activity. A significant correlation was also found between the occurrence of severe local
storms and elevated rates of 30 or more positive flashes per hour within 48 km grid blocks.

NS-069

RUST, W.D. Lightning. Science 242:1713-1714 (1989).

No abstract.

125

NS-070

RUST, W.D. Utilization of a Mobile Laboratory for Storm Elect? icity Measurements. Journal of
Geophysical Research 94 : Dll , 13 , 305- 13 , 311 (1989).

Since 1978, we have been developing and using a mobile laboratory to make observations of storms.
With our mobile lab, we record electric field, slow and fast electric field changes from lightning,
optical transients, return stroke velocity, temperature, pressure, dew point, wind speed and direction,
lab position, and video images of clouds and lightning. The mobile lab idea has been key in obtaining
new information on several phenomena, e.g., field changes to compare with high-altitude airplane
measurements, electrical aspects of tornadic storms, and positive ground flashes. Mobile lab data were
critical in an evaluation of the two ground strike location networks that provide scientific and
operational data in the United States. We have documented that storms often are more dominated by
intracloud (IC) lightning than previously reported. Observations on two tornadic storms show the IC
flashes averaged > 80% and 95% of the total lightning, respectively. Mobile lab and polarization radar
data of storms producing wet microbursts in Alabama suggest that high percentages of IC flashes (95%)
occur when a larger percentage of the total storm mass is convected above the freezing level. With the
recent addition of mobile balloon launch and tracking, we also make soundings of the electric field and
meteorological parameters within storms.

NS-071

RUST, W.D. and T.C. Marshall. Mobile, high-wind, balloon- launching apparatus. Journal of
Atmospheric and Oceanic Technology 6:215-217 (1989).

In order to place instruments for measuring meteorological and electrical parameters into
thunderstorms, we developed the capability of mobile ballooning. A key component is an inexpensive
apparatus that allows us to inflate, transport, and launch balloons in high winds, rain, and hail. The
launching apparatus is a cylinder of 'bubble' plastic that is made by joining the sides of the cylinder
together with VELCRO 'rip strip.' We launch a balloon by pulling the rip strip rapidly. This allows the
balloon to pop upward into the ambient low- level wind and carry its instrumentation aloft. We construct
different-sized launch tubes to accommodate particular sizes of balloons.

NS-072

Rutledge, S.A., and D.R. MACGORMAN . Observations of positive cloud-to-ground lightning flashes from
mesoscale convective systems. Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL,
March 27-31, 1989. American Meteorological Society, Boston, 122-125 (1989).

No abstract.

NS-073

Sachidananda, M. , and D.S. ZRNIC. Efficient processing of alternately polarized radar signals.
Journal of Atmospheric and Oceanic Technology 6:173-181 (1989).

Processing of simultaneous measurements of differential polarization parameters (differential
reflectivity, ZDR and differential phase shift <£DP) and Doppler spectral moments is discussed. It is
shown how ZDR and $DP modulate the Doppler signal and what effects they have on the autocovariance at lag
1 if a sequence of alternately polarized fields (linear horizontal, H, and Vertical, V) is transmitted.
A scheme to overcome these effects is proposed and demonstrated on recorded time series data from a radar
with polarization diversity.

NS-074

Smith, S.D., and R.M. RABIN. Considerations in estimating horizontal wind gradients from an
individual Doppler radar or a network of wind profilers. Journal of Atmospheric and Oceanic
Technology 6:446-458 (1989).

Applications of Doppler weather radar data to the analysis of wind fields are reviewed. Radial
velocity measurements from a single radar are used to estimate horizontal wind vectors within small
azimuthal sectors using two different models. One assumes a uniform wind, the other a linear wind within
the sector. Errors in wind estimates owing to gradients of wind are derived using harmonic analysis.
The radar data analysis techniques are tested on complex wind patterns which were reconstructed from
dual-Doppler radar measurements.

126

NS-075

Smith, S.D., and R.M. RABIN. Estimation of divergence in the Prestorm boundary layer. Journal of
Atmospheric and Oceanic Technology 6:459-475 (1989).

An analysis technique to derive wind field parameters from single-Doppler velocity measurements, known
as. Modified Velocity-Volume Processing (MWP) is examined from both theoretical and operational
perspectives. For this technique, radar data within limited spatial volumes are fit to a model which
usually assumes linearity of the Cartesian wind components. The accuracies and limitations of this
technique are illustrated with examples from a case study of a severe storm outbreak in central Oklahoma
on 17 May 1981. Implications for use of the MWP in convective storm forecasting are considered.

NS-076

Smith, S.D., A. WITT, M. EILTS , L. Hermes, D. Klingle-Wilson, S. Olson, and J. Sanford. Gust front
detection algorithm for the terminal doppler weather radar, Part I: Current Status Preprints, 3rd
International Conference on Aviation Weather Systems (#1.6). January 30 - February 3, 1989, Anaheim,
CA. American Meteorological Society, Boston, 31-34 (1989).

No abstract.

NS-077

SMULL, B.F., and J. A. AUGUSTINE. Structure and environment of a non-squall mesoscale convective
complex observed during PRE-STORM. Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL,
March 27-31, 1989. American Meteorological Society, Boston, 502-505 (1989).

No abstract.

NS-078

Steinhorn, I., and D.S. ZRNIC . Differential propagation constant and differential reflectivity
characterize rain and hail in high reflectivity regions. Preprints, 24th Conference on Radar
Meteorology, Tallahassee, FL, March 27-31, 1989. American Meteorological Society, Boston, 367-370
(1989) .

No abstract.

NS-079

STENSRUD, D.J. and R.A. MADDOX. Opposing mesoscale circulations: A case study. Weather and
Forecasting 3:189-204 (1988).

Two mesoscale convective systems developed over the central plains in and near the OK PRE-STORM
observing network on 23-24 June 1985. Mesoscale outflows from these two systems collided in central
Kansas at 0430 UTC 24 June. Special soundings taken behind the outflow boundaries indicated a stable
atmosphere. However, a sounding taken south of the area of outflow collision sampled a conditionally
unstable atmosphere in which lifting of 90 mb was needed to release the instability. The OK PRE-STORM
forecast team monitored this situation using convectional data and special surface mesonetwork and
sounding data. They issued a forecast update at 0500 UTC 24 June that anticipated new convective
development in the conditionally unstable atmosphere near the area of outflow collision. As the outflows
moved southward, surface convergence increased near the area of outflow collision, yet no new development
of deep convection occurred. Special OK PRE-STORM upper-air soundings are utilized to compute divergence
and vertical velocity via the line integral method at various times and locations during the development
and decay of the two mesoscale convective systems. Strong rising motion is found in the lower
troposphere near the zone of outflow collision at 0430 UTC 24 June, suggesting that the outflows were
significantly impacting storm development and system propagation. However, at 0900 UTC 24 June, while
strong rising motion is found below 800 mb , there also is strong sinking motion between 800 and 400 mb .
It is hypothesized that this mesoscale downdraft occurred between the two mesoscale convective systems as
their upper- level outflows converged. This layer of sinking air may have helped maintain a capping
inversion at the top of a deepening moist layer and apparently was sufficient to inhibit development of
new convection even in the face of strong low level forcing. The case illustrates the simultaneous
development of mesoscale circulations that appear to be acting in opposition to each other, relative to
the initiation of new storms. It further illustrates the complexity of the mesoscale and why it is often
hard to anticipate the evolution of convective storm systems.

127

NS-080

Stump, G.S., and W.A. Gallus . An examination of new convective development with a PRE-STORM squall
line case. Preprints 24th Conference on Radar Meteorology, Tallahasse, FL, March 27-31, 1989.
American Meteorological Society, Boston, 506-509 (1989).

No abstract

NS-081

Trier, S.B., D.B. Parsons, and T.J. MATEJKA. An observational and numerical study of a subtropical
cold front during TAMEX. Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL, March
27-31, 1989. American Meteorological Society, Boston, 561-564. (1989)

No abstract.

NS-082

Trier, S.B., D.B. Parsons, and T.J. MATEJKA. Observations of a cold front during TAMEX. Proceedings,
Workshop on TAMEX Preliminary Scientific Results, Taipei, Republic of China, June 22-30, 1989.
National Science Council, Taipei, and National Science Foundation, Washington, DC, 186-195 (1989).

No abstract.

NS-083

Uyeda, H., and D.S. ZRNIC. Fine structure of gust fronts obtained from the analysis of single Doppler
radar data. Journal of the MeteoroloEJcal Society of Japan 66:869-881 (1988).

Doppler velocity data obtained from a single Doppler radar are used to examine fine structures of gust
fronts associated with severe thunderstorms. Fields of inflection points of velocities (on surfaces
scanned by a radar) are analyzed and are compared with the fields of spectrum width of Doppler velocity
and horizontal shear. The analysis is performed on the cases of May 9, 1981, and April 13, 1981, in
Oklahoma. In the first case, a gust front consisted of an evolving undulate bore with three separate
waves or discontinuities. Two of these waves are detected as a 60 km stretch of inflection points of
Doppler velocity, whereas the third is marginally evident. For both cases, the length representing
secondary features behind the main discontinuities are short (less than 20 km) and transient. Careful
examinations of the structures at low altitude show that large spectrum width and large shear areas exist
slightly behind the main line of inflection points. However, there is a multitude of areas with large
shear and spectrum width that have no corresponding inflection point lines. Thus, these two parameters,
spectrum width and horizontal shear, alone are not suitable for detection of gust fronts. Besides
showing the presence of gust fronts, inflection points can also be good indicators of atmospheric waves.
We discuss a pattern of such waves that are embedded in the environmental flow ahead of a gust front.

NS-084

VASILOFF, S. Vorticity dynamics of a squall line: A Doppler radar analysis of the 10-11 June 1985
squall line. Masters thesis, University of Oklahoma, Norman, 100 pp. (1989).

This study describes characteristics of the Oklahoma segment of the 10-11 June 1985 squall line as it
began to dissipate. A surging outflow ahead of the squall line appeared responsible for the decline in
the strength of the convective cells along the leading edge. Thermodynamic properties retrieved from
wind and reflectivity fields derived from both single- and dual-Doppler radar analyses are used to
evaluate the terms in the inviscid 2-dimensional Boussinesq horizontal vorticity equation. Evaluated an
hour after the outflow surge, the sum of the terms was relatively small, indicating that a balance
existed, primarily between the generation of negative vorticity by buoyancy gradients and the advection
of positive vorticity into the squall line from the environment.

NS-085

WATSON, A.I., R.L. HOLLE , R.E. LOPEZ, R. ORTIZ, and J.R. DAUGHERTY. Use of the surface wind field as
a predictor of thunderstorms and cloud- to-ground lightning at Kennedy Space Center. Preprints, 1989
International Conference on Lightning and Static Electricity, Bath, United Kingdom, September 26-28,
1989. Royal Aerospace Establishment, Farnborough, Hampshire, United Kingdom, 9B.2.1-7 (1989).

The classic Thunderstorm Project was the first to consider surface convergence as a potential
predictor of thunderstorm activity in Florida. Several studies, one at the Kennedy Space Center, have
shown that surface convergence can, in some cases, be used as a short-term predictor of thunderstorm

128

development. The prerequisites for surface convergence to be useful are first, a dense surface -wind
observing network, and second, the seeds of convective development must occur in the boundary layer so
that cne wind sensors can detect the convective life cycle. In 1986, a convergence-lightning nowcasting
technique was delivered to U. S. Air Force forecasters at KSC for operational test and evaluation. The
procedure uses surface convergence, particularly the average over the area, to identify the potential for
new thunderstorm growth. Under some weather situations, the area average technique fails to work.
Normalized cell convergence is offered as a complementary technique to be used in association with the
areal technique. Normalized cell convergence is defined as the integral of cellular convergence with
respect to its area. One day is examined in detail and the relationship of normalized cell convergence
to lightning flash counts, at 5-min intervals, is examined in a 68-day ensemble. Normalized cell
convergence appears to be a viable alternative to the areal technique . With the implementation of this
tool, the monitoring of the horizontal analyses of divergence, and the continued monitoring of areal
divergence, the likely locations and timing of new convective growth can be ascertained.

NS-086

WATSON, A.I., R.E. LOPEZ, J.R. DAUGHERTY, R. ORTIZ, and R.L. HOLLE . A composite study of Florida
thunderstorms, using radar, cloud- to-ground lightning, and surface winds. Preprints, 24th Conference
on Radar Meteorology, Tallahassee, FL, March 27-31, 1989. American Meteorological Society, Boston,
126-129 (1989) .

No abstract.

NS-087

WATSON, A.I., R.E. LOPEZ, R.L. HOLLE, J.R. DAUGHERTY, and R. ORTIZ. Short-term forecasting of
thunderstorms at Kennedy Space Center, based on the surface wind field. Preprints, 3rd International
Conference on the Aviation Weather System, January 30-February 3, 1989, Anaheim, CA. American
Meteorological Society, Boston, 222-227 (1989).

No abstract.

NS-088

WATSON, A.I., J.G. MEITIN, and J.B. CUNNING. Evolution of the kinematic structure and precipitation
characteristics of a mesoscale convective system on 20 May 1979. Monthly Weather Review 116:
1555-1567 (1988).

The relationship of vertical motion to the occurrence of precipitation from the convective and
stratiform regions of a mesoscale convective system (MCS) is presented. On 20-21 May 1979, an MCS
developed over portions of Oklahoma, Texas, and Arkansas. The uniqueness of this system was its lack of
squall-line characteristics and development of a large stratiform precipitation region. The evolution of
the system is detailed by rawinsonde observations, radar cross sections, 15-min composite analyses of six
NWS WSR-57 radars, and by raingages. The genesis stage of the MCS was described by strong convection
along an east-west cold front that was reinforced by outflow generated by two mesoscale convective
complexes (MCCs) that formed the night before in Kansas and Missouri. The mature stage of the MCS was
characterized by the development of a large stratiform precipitation region while convection was limited
to the southern and eastern flanks of the system. Finally, in the dissipative stage, a moderate
north-south squall line that developed over west Texas in the afternoon moved rapidly to the east
apparently associated with a short-wave aloft and appeared to sweep the entire system out of Oklahoma. A
modified Cheng and Houze technique is applied to the radar composites to determine stratiform and
convective regions utilizing temporal as well as areal considerations. For the system as a whole, the
stratiform region generated 30-50% of the total precipitation. The vertical-motion profiles hold the key
to the precipitation characteristics over the storm-scale network. The genesis period was characterized
by a strongly convective profile. As the system matured, low-level upward motion ceased, while
middle -level upward motion was sustained. A large area of stratiform rain developed as the deep
convection weakened. Water-budget considerations suggest that the stratiform region was maintained by a
combination of mesoscale middle -level updraft and by horizontal transfer of convective debris.

NS-089

Williams, E.R., A.I. WATSON, L.M. Maier, W. Jafferis, and J. Weems. A case study of a low lightning
rate storm during the Florida winter. Preprints, 3rd International Conference on the Aviation Weather
System, Anaheim, CA, January 30-February 3, 1989. American Meteorological Society, Boston, 393-397
(1989).

No abstract.

129

NS-090

ZACHARIAS, D. A case study of the May 10, 1985 tornado outbreak in northern Kansas. M.S. Thesis,
School of Meteorology, University of Oklahoma, Norman, 135 pp. (1989).

No abstract

NS-091

ZIEGLER, C.L., and P.S. Ray. Doppler radar retrieval of the microphysical and electrical structure of
a mountain thunderstorm. Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL, March 27-
31, 1989. American Meteorological Society, Boston, 97-99 (1989).

No abstract.

NS-092

ZRNIC, D.S., N. Balakrishnan, and M. Sachidananda. Polarimetric measurements determine the amounts of
rain and hail in a mixture. Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL, March
27-31, 1989. American Meteorological Society, Boston, 396-400 (1989).

No abstract.

NS-093

ZRNIC, D.S., AND R.J. DOVIAK. Effect of drop oscillations on spectral moments and differential
reflectivity measurements. Journal of Atmospheric and Oceanic Technology 6:532-536 (1989).

A perturbation method is applied to spheroidal oscillating drops to determine the effect of
fundamental axisymmetric oscillations on the power spectra and polarimetric measurements. It is shown
that vibration magnitudes that produce less than 10% change in equilibrium axial ratios are insufficient
to produce measurable changes in the differential reflectivity or differential phase constant, yet they
can lead to a detectable increase in sidebands of the power spectra. Larger oscillations do produce
measurable effects on the polarimetric variables.

Addendum

NS-094

WATSON, A.I., R.E. LOPEZ, and R.L. HOLLE. Surface convergence techniques and the prediction of
lightning at Kennedy Space Center. 1988 International Aerospace and Ground Conference on Lightning
and Static Electricity, Oklahoma City, OK, April 19-22, 1988. NOAA/ERL/National Severe Storms
Laboratory, Boulder, CO, 32-39 (1988).

Because the Kennedy Space Center (KSC) has a significant number of thunderstorms, especially during
the summer, lightning is a real threat to operations. Therefore, advance warning when lightning is
imminent is highly desirable. This study compares two convergence techniques leading to the prediction
of convective development and lightning: the area-averaged technique, and a convergence cell approach.
The area-averaged technique uses total area divergence across the network to identify the potential for
new local thunderstorm growth. A threshold of 75 x 10"6 change in divergence is used to define a
convergence event, and a separation of 30 minutes between flashes defines a lightning event.
Convergence- lightning life cycles are found to be on the order of 1 hour from beginning convergence to
first flash, and more than 2 hours from beginning convergence to the end of lightning. The convergence
cell technique measures the strength of the convergence cell, which in turn leads to vertical
development. Therefore, the likely lightning location and intensity can be ascertained in the larger
network. Several cells can be monitored in the recently expanded KSC forecast network at the same time.
These techniques cannot be used in isolation since the daily possibility of thunderstorms must be
determined on the basis of the larger-scale synoptic situation. The monitoring of the local divergence
will aid the forecaster to determine the timing, location, longevity, and possibly the intensity of
specific lightning events.

130

PACIFIC MARINE ENVIRONMENTAL LABORATORY

PM-001

AAGAARD, K. A synthesis of the Arctic Ocean circulation. Rapports et Proces-verbaux des Reunions,
Conseil international pour 1 ' Exploration de la Mer 188:11-22 (1989).

Moored current measurements in four different areas of the Arctic Ocean suggest that the principal
large-scale advection occurs in narrow boundary currents along the margins of the major basins. These
boundary flows are in a cyclonic sense in each basin and are therefore counter to much of the upper ocean
drift suggested by the ice motion. In the interior of the Arctic Ocean (or at least in its Canadian
Basin) the kinetic energy appears concentrated in the mesoscale eddy field, and there is evidence that
this field is primarily generated along the Arctic Ocean margins. In addition, the Arctic Ocean has
recently been found to sustain a large-scale thermohaline circulation driven by freezing along its
periphery; this circulation appears to be at least comparable in magnitude to that of the Greenland Sea.
If one also considers the major peripheral exchanges through the Fram Strait, the Barents Sea, the
Canadian Archipelago, and the Bering Strait, then the image which emerges is of an Arctic Ocean which
overwhelmingly is forced at its lateral boundaries, and in which much of the organized transport is
trapped along these boundaries.

PM-002

AAGAARD, K. Circulation: Beaufort Sea update. Proceedings, Alaska OCS Region 1987 Arctic Information
Transfer Meeting Conference, OCS Study MMS 88-0010, Minerals Management Service, Anchorage, AK, 151-156
(1988).

No abstract.

PM-003

BAKER, E.T., J.W. LAVELLE, R.A. FEELY, G.J. MASSOTH, S.L. WALKER, and J.E. Lupton. Episodic venting of
hydrothermal fluids from the Juan de Fuca Ridge. Journal of Geophysical Research 9t ( B7 ): 9237-9250
(1989).

Evidence of large-scale episodic venting of hydrothermal fluids was initially discovered in August 1986
in the form of a 130-km3 radially symmetric "megaplume" over the southern Juan de Fuca Ridge. We report
here on the discovery in September 1987 of a second, smaller megaplume about 45 km north of the location
of the first megaplume. The 3He/heat, 3He/dissolved Mn, and 3He/dissolved silica ratios in both
megaplumes were typical of high-temperature vent fluids. Evidence from long-term records of current flow
over the southern Juan de Fuca Ridge, and from the mineralogy and Mn chemistry of megaplume particles,
makes it unlikely that the second megaplume was a reencounter of the first. A plume model that relates
the heat flux to the observed plume rise height of -1000 m finds that the total heat content of the fluids
that formed the megaplumes was 1016-1017 J, or equivalently a fluid volume of 3-8 x 107 m3 at 350°C. The
geometry and suspended particle population of the first megaplume imply that such features are formed
within a few days time. The extraordinary heat and volume fluxes associated with megaplumes (102-103
greater than ordinary vent fields), as well as their typical hydrothermal chemistry, suggest that they
resulted from tectonic or hydraulic fracturing that suddenly increased the permeability of the
hydrothermal fluid reservoir in the axial crust. The flux of hydrothermal heat from continuous venting
and episodic megaplumes on the southern Juan de Fuca Ridge is presently 4-10 x 109 W, a factor of 5-10
greater than various geophysical model calculations for this ridge segment. This imbalance may be
symptomatic of a recent surge in the local cycle of magmatic activity.

PM-004

BATES, T.S. Evidence for the climatic role of marine biogenic sulfur. Ph.D. dissertation, University
of Washington, Seattle, 99 pp. (1989).

The surface ocean plays an important role in the global biogeochemical sulfur cycle. Gaseous sulfur
compounds emitted from the ocean are thought to be a major source of sulfate aerosol in the marine
troposphere. Establishing the relationship between gaseous sulfur emissions, atmospheric sulfate
concentrations, and aerosol particle populations is not only important in defining the ocean/atmosphere
flux of sulfur, but also for the effects these particles may have on local cloud reflectivity, aerosol
optical depth, and global climate. During 1982-1985, dimethylsulf ide (DMS) concentrations were measured
in over 1000 Pacific Ocean surface seawater samples. The data have been tabulated to take into account
both regional and seasonal variations in concentration. These concentration data, combined with area-
weighted summer and winter exchange coefficients, yield a net ocean to atmosphere DMS flux in the North

131

Pacific Ocean of 0.12 ± 0.06 Tmol/a. Extrapolating this Calculation by regional areas to the global ocean
yields a net DMS flux of 0.50 ± 0.25 Tmol/a, less than earlier estimates of 1.2 Tmol/a, but still
consistent with estimates of non-sea-salt sulfate deposition and model studies of the marine atmospheric
sulfur budget. Using these regional and seasonal DMS concentration data, it appears that oceanic DMS
emissions are positively correlated with atmospheric aerosol particle populations. The major components
of the atmospheric biogeochemical sulfur cycle were measured along the coast of Washington State during
May of 1987. Combining simultaneous measurements of the key oceanic and atmospheric sulfur species, it is
possible to show the importance of DMS emissions on the cycling of sulfur in the marine boundary layer.
Simultaneous measurements of oceanic DMS, atmospheric aerosol sulfate and the size-resolved physical
properties of the aerosol were made in the equatorial Pacific during July 1987. Under light and variable
winds, in an area free of continental and anthropogenic air masses, an observed increase in oceanic DMS
concentrations preceded simultaneous increases in non-sea salt sulfate aerosol, the fraction of volatile
sub-micrometer (sub-urn) aerosol, the aerosol particle population, and the mean particle diameter of the
sub-^m aerosol. These data support the hypothesis that oceanic DMS is the source of background marine
sulfate aerosols formed from gas-to-particle conversions in the atmosphere.

PM-005

Betzer, P.R., K.L. Carder, R.A. Duce, J.T. Merrill, N.W. Tindale, M. Uematsu, D.K. Costello, R.W. Young,
R.A. FEELY, J. A. Breland, R.E. Bernstein, and A.M. Greco. Long-range transport of giant mineral aerosol
particles. Nature 336(6199) :568-57l (1988).

Several recent studies have shown that large quantities of mineral dust from eastern Asia are
transported through the atmosphere to the North Pacific each spring. The paucity of information on
mineral fluxes during individual dust events prompted a coordinated effort, Asian Dust Input to the
Oceanic System (ADI0S), which simultaneously measured mineral fluxes in the atmosphere and upper water
column during such an event. In March 1986 a major dust outbreak in China moved over the North Pacific
Ocean and was detected downstream using changes in particle number, size and composition. Most striking
was the presence of "giant" (>75-u"0 silica minerals found in atmospheric as well as water-column samples
at the ADIOS sampling site (26°N, 155°W). Their appearance more than 10,000 km from their source cannot
be explained using currently acknowledged atmospheric transport mechanisms. Furthermore, the large wind-
blown minerals that dominated our samples are extremely rare in the long-term sedimentary record in the
North Pacific.

PM-006

Calhoun, J. A., and T.S. BATES. Sulfur isotope ratios: tracers of non-sea salt sulfate in the remote
atmosphere. In Biogenic Sulfur in the Environment, E.S. Saltzman and W.J. Cooper (eds.), American
Chemical Society, 367-379 (1989).

The atmospheric biogeochemical sulfur cycle is being significantly impacted by increasing anthropogenic
sulfur emissions. The effect of these emissions on the concentration of sulfate aerosol particles in the
remote marine atmosphere is difficult to assess due to uncertainties surrounding the relative
contributions of natural and anthropogenic sources. Sulfur isotope ratios can be used to determine the
relative magnitude of these sources in the remote atmosphere provided 1 ) the isotopic ratios of the
potential sulfur sources are known, 2) the isotopic compositions of the various sources are different from
one another, and 3) the isotopic changes that occur during transformations are thoroughly documented. In
the text which follows, these aspects of sulfur isotope chemistry are addressed. Isotopic interpretation
of sulfur sources to the remote atmosphere is severely limited by the absence of critical isotopic
measurements, yet it appears that continental sulfur sources are isotopically distinguishable from seasalt
or marine biogenic sulfur sources. Improved analytical techniques will soon provide the means to obtain
the necessary data.

PM-007

CANNON, G.A. Time variations of bottom-water inflow at the mouth of an estuary. Understanding the
Estuary: Advances in Chesapeake Bay Research. Proceedings of a Conference, 29~31 March 1988,
Baltimore, MD, Chesapeake Research Consortium Publication 129, CBP/TRS 21/88, 424-427 (1988).

Puget Sound is a fjord-like estuary, but its 30-km long entrance sill, Admiralty Inlet, has
characteristics very similar to coastal plain estuaries. The replacement of bottom water in Puget Sound
has been studied for many years, because it is a dominant process responsible for flushing some
contaminants. Previous studies showed bottom-water inflow increased during neap tides when mixing was
minimal over the entrance sill. Recent observations show the increased inflow starts before minimum neap
tides, and simple model calculations with these data demonstrate this is an effect of variations in the
horizontal density gradient at the mouth of the estuary caused by salinity variations outside the mouth.

132

This time-dependent process may be responsible for changing inflow characteristics at time scales between
wind effects and seasonal effects, and it may be important in other estuaries such as Chesapeake Bay.

PM-008

Charlson, R.J., and T.S. BATES. The role of the sulfur cycle in cloud microphysics, cloud albedo, and
climate. Preprints, Symposium on the Role of Clouds in Atmospheric Chemistry and Global Climate, Jan.
30-Feb. 2, 1989, Anaheim, CA, American Meteorological Society, Boston, MA, 1-3 (1989).

No abstract.

PM-009

Chen, C.T.A., R.A. FEELY, and J.F. GENDRON. Lysocline, calcium carbonate compensation depth, and
calcareous sediments in the North Pacific Ocean. Pacific Science 42(3-4) :237~252 (1988).

An extensive oceanographic investigation has been carried out in the North Pacific Ocean. The purpose
of this report is to present the results of two cruises in which we participated and to report additional
carbonate data from samples collected for us in the North Pacific. These data are combined with data from
the literature to provide an overall picture of the carbonate system in the North Pacific. The degree of
saturation of seawater with respect to calcite and aragonite was calculated from all available data
sets. Four selected cross sections, three longitudinal and one latitudinal, and two three-dimensional
graphs show that a large volume of the North Pacific is undersaturated with respect to CaC03. The
saturation horizon generally shows a shoaling from west to east and from south to north in the North
Pacific Ocean. It was found that the lysocline is at a depth much deeper (about 2500 m deeper) than the
saturation horizon of calcite, and several hundred meters shallower than the calcium carbonate
compensation depth. Our results appear to support the kinetic point of view of the CaCOa dissolution
mechanisms. Differences in the abundance of the calcareous sediments are explained by differences in the
calcium carbonate compensation depth.

PM-010

Coachman, L.K., and K. AAGAARD. Transports through Bering Strait: annual and interannual
variability. Journal of Geophysical Research 93(C12) : 1 5535-1 5539 (1988).

Reanalysis of the 1976-1977 mean monthly transport estimates for Bering Strait of Coachman and Aagaard
(1981) shows a considerably stronger wind dependence than was calculated by Aagaard et al. (1985). We
find (1) a long-term mean transport of 0.8 Sv, (2) an annual transport cycle of amplitude 0.6 Sv, with the
maximum in June, the minimum in February, and a secondary maximum in January probably associated with
North Pacific blocking-ridge activity, and (3) an interannual variability marked by a number of low-flow
years in the past two decades, including three of the four lowest-transport winter periods during this
century. In a new current time series from 1984 to 1985 we find anomalously strong and persistent
northerly flow during a 2-month period in which the current/wind correlation breaks down. This occurred
during a prolonged period with southerly winds, and we believe the data point to an asymmetry in the
dynamical response of the Bering Strait flow to major changes in wind direction.

PM-011

CURL, H.C., JR. Marine ecology: the water column. Proceedings of a Conference/Workshop on
Recommendations for Studies in Washington and Oregon: Offshore Oil and Gas Development. Minerals
Management Service, Dept. of Interior, May 23-25, 1988, Portland, OR, 65-72 (1989).

No abstract.

PM-012

EBLE, M.C., F.I. GONZALEZ, D.M. MATTENS, and H.B. MILBURN. Instrumentation, field operations, and data
processing for PMEL deep ocean bottom pressure measurements. NOAA TM ERL PMEL-89 (NTIS not yet
available), 71 pp. (1989).

The focus of this report is on the collection and processing of deep-ocean bottom pressure measurements
made using the Paroscientific Model 410K-017 digiquartz pressure transducer. The observational program
was initiated in 1986 for the purpose of collecting high quality data during the generation, propagation,
and coastal runup stages of a tsunamigenic event. Because of its diversity and flexibility, the bottom
pressure recorder (BPR) is also an important tool in many other areas of oceanic research, particularly
when coupled with other instrumentation.

133

PM-01 3

EMBLEY, R.W., S.R. HAMMOND, and K. MURPHY. The caldera of Axial Volcano— remote sensing and submersible
studies of a hydrothermally active submarine volcano. Global Venting, Midwater, and Benthic Ecological
Processes, M.P. De Luca and I. Babb (eds.), National Undersea Research Program Report 88-4, 61-70
(1988).

No abstract.

PM-01 4

FEELY, R.A., R.H. Byrne, J.G. Acker, P.R. Betzer, C.T.A. Chen, J.F. GENDRON, and M.F. LAMB. Winter-
summer variations of calcite and aragonite saturation in the northeast Pacific. Marine Chemistry
25:227-241 (1988).

New carbonate data obtained on February-March and June-July cruises in the northeast Pacific during 1985
were utilized to describe processes affecting seasonal variations of calcite and aragonite saturation.
Large gradients in saturation state occur in the region between the Subtropical and the Subarctic Fronts
in the north-south direction. These gradients are a function of large-scale mixing and biological
processes in the North Pacific. The saturation values in the upper kilometer of the water column were
observed to be significantly lower in winter than in summer. These decreases were due to a number of
processes including: (i) the seasonal decrease in the temperature of the water column; (ii) the seasonal
increase in vertical mixing causing C02-enriched deep waters to be upwelled; and (iii) the seasonal
enhancement of respiration over photosynthesis. Seasonal changes in total C02 (TC02) concentrations
appeared to have the greatest overall effect on the saturation state. Aragonite dissolution rate
experiments were conducted during the June-July cruise to provide an independent verification of the
saturation calculations. In all cases, significant increases in aragonite dissolution were observed below
the 100? saturation depth. In the northeast Pacific, shallow undersaturation horizons provide for
significant dissolution rates at depths below 400 m.

PM-01 5

FOX, C.G. Empirically derived relationships between fractal dimension and power law form frequency
spectra. PAGEOPH 131 (1/2) ;21 1-239 (1989).

Fractal analysis and Fourier analysis are independent techniques for quantitatively describing the
variability of natural figures. Both methods have been applied to a variety of natural phenomena.
Previous analytical work has formulated relationships between the fractal dimension and power law form
frequency spectrum. Mandelbrot (1985) has shown that difficulties arise when the ruler method for
measuring dimensionality is applied to other than self-similar figures. Since an investigator presumably
does not know in advance the dimensionality of a natural profile, it is essential to quantify the nature
of the discrepancy for self-affine cases. In this study, a series of experiments are conducted in which
discrete random series of specified spectral forms are analyzed using the fractal ruler method. The
various parameters of the fractal measurement are related to the parameters of the spectral model. In
this way, empirical relationships between the techniques can be derived for discrete, finite series which
simulate the results of applying the fractal method to observational data. The results of the study
indicate that there are considerable discrepancies between the results predicted by theory and those
derived empirically. The fundamental power law form of length versus resolution pairs does not hold over
the entire region of analysis. The predicted linear relationship between fractal dimension and exponent
of the frequency spectrum does not hold, and the spectral signals can be extended beyond the limits of
dimension inferred by theory. Root-mean-square variability is also shown to be linearly related to the
fractal intercept term. An investigation of the effect of nonstationary sampling is conducted by
generating signals composed of segments of differing spectral characteristics. Fractal analyses of these
signals appear identical to those conducted on stationary series. The discrepancies between theoretical
prediction and empirical results described in this study reflect the difficulties of applying analytically
derived techniques to measurement data. Both Fourier and fractal techniques are formulated through
rigorous mathematics, assuming various conditions for the underlying signal. When these techniques are
applied to discrete, finite length, nonstationary series, certain statistical transformations must be
applied to the data. Methods such as windowing, prewhitening, and anti-aliasing filters have been
developed over many years for use with Fourier analysis. At present, no such statistical theory exists
for use with fractal analysis. It is apparent from the results of this study that such a statistical
foundation is required before the fractal ruler method can be routinely applied to observation data.

PM-01 6

FOX, C.G., and M. VAN HEESWIJK. Sea Beam backscatter analysis applied to the classification of deep-sea
volcanic terrains. Global Venting, Midwater, and Benthic Ecological Processes, M.P. De Luca and I. Babb
(eds.), National Undersea Research Program Report 88-4, 71-79 (1988).

134

Hull-mounted sonar systems, such as Sea Beam, are typically used for mapping the bathymetry of the deep-
sea floor. The same digital information that is used for the measurement of depth can be evaluated for
the backscattering properties of the seafloor. The unique morphologies and petrologies of volcanic and
hydrothermal terrains may produce identifiable backscatter signatures. The Alvin support vessel Atlantis
II is equipped for digitally acquiring Sea Beam backscatter energy traces, allowing sonar remote sensing
and submersible exploration to be performed in tandem. An experiment funded by the National Undersea
Research Program, at Axial Seamount, Juan de Fuca Ridge, has produced the most extensive data set to date
from a known hydrothermal area, and these data are being calibrated using the large groundtruth data base
collected by NOAA's VENTS research program.

PM-017

FREITAG, H.P., M.J. MCPHADEN, and A.J. SHEPHERD. Comparison of equatorial winds as measured by cup and
propeller anemometers. Journal of Atmospheric and Oceanic Technology 6(2):327~332 (1989).

This study compares the performance of cup vs. propeller anemometers from surface-following taut-line
moorings in the equatorial Pacific. Vector wind components at 4 m above the sea surface were measured
from a mooring instrumented with a cup anemometer and concurrently from a nearby mooring instrumented with
a propeller anemometer. Mean wind conditions over the 115-day comparison period were typical of the
southeast trade winds with a mean speed of 6.7 m s~ ' and a steadiness factor of 0.96. Differences between
the time series measured by the two wind sensors were small. Mean speed differed by 0.02 m s~ ' and mean
direction by 1.4°. Correlation coefficients for 2-hour vector-averaged zonal component, meridional
component, speed and direction were 0.97 or above. The small differences in measurements imply that the
two systems are equally suited for near-surface wind observations under typical tradewind conditions.

PM-018

GIESE, B.S. Equatorial oceanic response to forcing on time scales from days to months. NOAA TM ERL
PMEL-87 (PB89-206775), 99 pp. (1989).

Episodes of westerly wind in the western Pacific may be an important source of sea surface temperature
variability in the eastern Pacific on monthly, seasonal and interannual time scales. In this report we
use a combination of data, linear theory and an ocean general circulation model to examine remote response
to western Pacific wind forcing. Characteristics of the wind anomaly are determined using daily averaged
observations of wind from equatorial islands near the date line. In the model, wind anomalies generate a
train of eastward propagating Kelvin pulses. When the wind anomaly is weak the Kelvin response agrees
with predictions of linear theory. For more realistic strong forcing there are three important deviations
from linear theory; the amplitude of low baroclinic modes increases, the amplitude of higher baroclinic
modes decreases, and the phase speed increases. In the presence of realistic oceanic background
conditions, response in the equatorial waveguide is complicated by the equatorial undercurrent, a sloping
thermocline and instability waves. As Kelvin pulses propagate from western to eastern Pacific surface
zonal velocity associated with the first mode decreases, whereas velocity associated with the second mode
increases. These changes can be deduced by the principle of conservation of energy flux. In the central
and eastern Pacific Kelvin pulses act to amplify and change the phase of existing instability waves.
Thermal changes brought about by enlarged instability waves can be comparable in magnitude to changes
brought about by zonal advection of the zonal temperature gradient by Kelvin pulses. At the coast of
South America, model Kelvin pulses cause a warming of 2°C for 45 days. Current observations made at 140°W
and 110°W subsequent to a strong westerly wind event in May 1986 indicate passage of Kelvin-like pulses
which agree in magnitude and timing with those modeled. At the coast of South America observations of sea
surface temperature show a warm anomaly that lasts for almost two months, comparable in duration and
magnitude to changes found in the model.

PM-019

HARRISON, D.E. Local and remote forcing of ENSO ocean waveguide response. Journal of Physical
Oceanography 1 9(5) : 691-695 (1989).

Several experiments using an ocean general circulation model have been carried out in order to explore
the degree to which the oceanic waveguide response during the 1982-83 ENSO event was locally and remotely
forced. Experiments in which the chosen monthly mean surface stress field was imposed only within three
degrees of the equator (3°N/S) and within seven degrees of the equator (7°N/S) reveal that the 7°N/S winds
reproduce the equatorial results of the full winds case to within differences small compared to the
variability of interest. The 3°N/S winds case reproduces equatorial dynamic height acceptably, but
introduces errors in SST and upper-ocean currents that approach the ENSO signal. A 7°N-S experiment in
which the meridional stress is set to zero (NOYST) shows that meridional stress plays a nontrivial, but
not dominant role, in the 1982-83 model behavior; errors generally are comparable to those of the 3°N/S

135

case. A final experiment, in which the 1982-83 winds were imposed west of the dateline and climatological
winds were imposed east of 170°W (WPAC), illustrates the extent to which the central and eastern Pacific
were forced by winds in the western Pacific. While there is nontrivial remote forcing, the locally forced
variability is roughly twice as great. Implications for coupled ocean-atmosphere modeling and for design
of future surface wind stress monitoring arrays for ENSO prediction are considered.

PM-020

HARRISON, D.E. On climatological monthly mean wind stress and wind stress curl fields over the world
ocean. Journal of Climate 2(1):57~70 (1989).

Using a version of the global surface marine observation historical data set, a new 1° spatial
resolution global ocean surface wind stress climatology has been evaluated using the Large and Pond
surface drag coefficient formulation. These new results are compared, after spatial smoothing, with those
of Hellerman and Rosenstein, who used a different drag coefficient form. It is found that the new-
stresses are almost everywhere smaller than those of Hellerman and Rosenstein, often by 20$-30$, which is
greater than the formal error estimates from their calculations. The stress differences show large-scale
spatial structure, as would be expected given the spatial variation of the surface stability parameter and
the known different wind variability regions. Basin zonally averaged Ekman transports are computed to
provide perspective on the significance of the stress differences; annual mean differences can exceed 10
Sv (Sv = 106 m3 s"1) equatorward of 20° lat, but are smaller poleward. Wind stress curl and Sverdrup
transport calculations provide a different perspective on the differences; particularly noticeable
differences are found in the regions of the Gulf Stream and Kuroshio separation. Large annual variations
in midlatitude wind stress curl suggest that study of the forced response at annual periods should be of
interest.

PM-021

HARRISON, D.E., and B.S. Giese. Comment on "The response of the equatorial Pacific Ocean to a westerly
wind burst in May 1986" by M.J. McPhaden et al. Journal of Geophysical Research 94(C4) :5024-5026
(1989).

No abstract.

PM-022

HARRISON, D.E., W.S. Kessler, and B.S. Giese. Ocean circulation model hindcasts of the 1982-83 El
Nino: thermal variability along the ship-of-opportunity tracks. Journal of Physical Oceanography
19(4): 397-41 8 (1989).

Five different analyses of 1982-83 monthly average surface wind stress fields have been used to force an
ocean general circulation model of the tropical Pacific, in a series of El Nino hindcast experiments, like
the one reported by Philander and Seigel. Although there were prominent common departures from
climatology in the surface wind stress field during 1982-83 according to each wind analysis, there are
also very substantial differences between analyses. This study was done to investigate the sensitivity of
such hindcasts to our uncertain knowledge of the surface wind stress field. We concentrate here on the
behavior along the Pacific ship-of-opportunity tracks. According to the ship-of-opportunity XBT data, the
ocean underwent major changes during this period. The vertical temperature gradients and mixed layer
temperatures, as well as the depth of the thermocline, underwent substantial changes. There were also
major changes in the geostrophic flow of the major current systems, as revealed by upper ocean dynamic
height differences. Comparing the hindcasts with observations, we find that the gross large-scale changes
of the ENSO event — surface warming in the second half of 1982, continued warmth into 1983 and cooling in
mid-1983, together with major thermocline depth changes — are found in each hindcast. However, major
quantitative differences exist between each hindcast and the observations in at least some region for some
time and some variable. Within the waveguide, dynamic height changes generally are hindcast with
quantitative skill using each wind stress field and the best hindcasts differ from the observations by
only a few dyn-cm more than the estimated uncertainty in the observations. Such hindcast skill is
unlikely to be fortuitous: evidently the major elements of the waveguide variability are forced by the
1982-83 surface wind stress field rather than evolving out of some aspect of the state of the ocean during
late 1981. Sea surface temperature changes are generally hindcast with qualitative skill, but rms errors
of 2-3°C are frequent. Subsurface temperature variability skill varies with hindcast, location and depth;
skill is greatest in the thermocline. Outside the waveguide, hindcast skill tends to be reduced, and
varies greatly with location and hindcast. Quantitative hindcast skill is found near 10°S and 10°N in
some hindcasts in the WP, and near 10°S in most hindcasts in the CP, but there is never quantitative skill
in the NECC region. The most striking inconsistency found involves the behavior of the NMC hindcast in
the region of the North Equatorial Counter Current. Wind stress curl-forced Ekman pumping appears to be a
significant factor in the variations in the more successful hindcasts. In almost every comparison, the

136

range of hindcast results brackets the observations, suggesting that the model physics is plausible.
Overall, the special research effort wind fields produced better dynamic height results than did the
operational wind product fields, but the operational fields produced generally better waveguide SST
results. Improved knowledge of the surface wind stress field (and its curl) is a minimum requirement if
we are to assess more critically model performance, and to identify needed model improvements.

PM-023

HAYES, S.P., M.J. MCPHADEN, and A. Leetmaa. Observational verification of a quasi real time simulation
of the tropical Pacific Ocean. Journal of Geophysical Research 9MC2) :21 47-21 57 (1989).

Time series of upper ocean temperature and currents in the equatorial Pacific simulated by a numerical
general circulation model run in nearly real time are compared to observations for the period August 1985
through May 1987. The model was forced by monthly mean wind stress and climatological air-sea heat
flux. Comparisons with observations near the equator in the western (165°E), central (140°W), and eastern
(110°W) Pacific are discussed. Simulated sea surface temperature (SST) was too cool in the eastern
Pacific and too warm in the western Pacific. Largest rms deviations were in the east and exceeded 2°C.
On and north of the equator in the eastern Pacific, SST and thermocline depth fluctuations on seasonal and
monthly time scales were prominent. South of the equator, seasonal variability dominated. The model
simulations often reproduced the amplitude and phase of the seasonal changes but not the higher-frequency
variability. Model runs which included monthly assimilation of upper ocean temperature observations were
included in the study. None of the comparison time series were incorporated in the assimilation.
Inclusion of thermal observations generally improved agreement of simulated and observed time series.
This improvement was largely due to reduction in the mean offsets of SST and thermocline depths. Data
assimilation did little to improve the month-to-month differences in thermocline depth. In addition,
south of the equator in the eastern Pacific, relatively large, systematic intra-month SST deviations
occurred. These deviations corresponded to an erroneous heat flux of about 80 W m-2 and indicated
problems in the simulated upper ocean circulation. Although no velocity data were included in the
assimilation, the improved model thermal structure led to improved velocity simulation at some
locations. No comparisons indicated large-amplitude spurious velocity variations which could be
associated with data assimilation transients.

PM-024

Hinckley, S., K. BAILEY, J. SCHUMACHER, S. Picquelle, and P. STABENO. Preliminary results of a survey
for late-stage larval walleye pollock and observations of larval drift in the western Gulf of Alaska,

1987. Proceedings of the International Symposium on the Biology and Management of Walleye Pollock, Nov.

1988, Anchorage, AK, Alaska Sea Grant Report 89-1, 297-306 (1989).

In June and July of 1987, an exploratory survey for the nursery area of the late-larval and early-
juvenile stages of walleye pollock (Theragra chalcogramma) was conducted in the western Gulf of Alaska.
The goals of the survey were to define the geographical distribution of these life stages, estimate
abundance, examine drift to their nursery area, and examine the feasibility of using these life stages in
a pre-recruit survey. This paper represents a preliminary report on results of the survey. The center of
distribution of late-larval and early-juvenile walleye pollock was between the Shumagin and the Semidi
Islands. This corresponded to concurrent locations of satellite-tracked drifters released in the center
of the egg distribution in Shelikof Strait in April. Larval numbers were low to the southwest and
northeast of the center of distribution and offshore of the 200-m depth contour. Estimated total
abundance of late-larval and early-juvenile walleye pollock in the survey area was 9.0 x 1010 individuals.

PM-025

Huyer, A., R.L. Smith, P.J. STABENO, J. A. Church, and N.J. White. Currents off southeastern

Australia: results from the Australian Coastal Experiment. Australian Journal of Marine and Freshwater

Research 39:245-288 (1989).

The Australian Coastal Experiment was conducted off the east coast of New South Wales
1983 and March 1984. The experiment was conducted with arrays of current meters spanni
margin at three latitudes (37.5°, 34.5°, and 33.0°S), additional shelf moorings at 29°
wind and sea-level measurements, monthly conductivity-temperature-depth probe/expendabl
(CTD/XBT) surveys, and two satellite-tracked buoys. Over the continental shelf and slo
component of the current generally exceeded the onshore component, and the subtidal (<0
day) current variability greatly exceeded the mean flow. Part of the current variabili
with two separate warm-core eddies that approached the coast, causing strong (>50 cm se
(>8 days), southward currents over the continental slope and outer shelf. Temperature
velocity sections through the eddies, maps of ship's drift vectors and temperature cont
the satellite-tracked drifter trajectories showed that these eddies were similar in str

between September
ng the continental
and 42°S, coastal
e bathythermograph
pe, the alongshore
.6 cpd, cycles per
ty was associated
c-1), persistent
and geostrophic
ours at 250 m, and
ucture to those

137

observed previously in the East Australian Current region. Both eddies migrated generally southward.
Eddy currents over the shelf and slope were rare at Cape Howe (37.5°S), more common near Sydney (34.5°S),
and frequent at Newcastle (33.0°S), where strong northward currents were also observed. Near Sydney, the
eddy currents over the slope turned clockwise with depth between 280 and 7^0 m, suggesting net downwelling
there. Repeated CTD sections also indicated onshore transport and downwelling at shallower levels;
presumably, upwelling occurred farther south where the eddy currents turned offshore. Periodic rotary
currents over the continental slope near Sydney and Newcastle indicated the presence of small cyclonic
eddies on the flank of a much larger anticyclonic eddy. Between early October and late January, no strong
southward currents were observed over the continental margin near Sydney. Data from this "eddy-free"
period were analyzed further to examine the structure and variability of the coastal currents. Much of
this variability was correlated with fluctuations in coastal sea-level (at zero lag) and with the wind
stress (at various lags). The coherence and phase relationships among current, wind-stress, and sea-level
records at different latitudes (determined from spectral analysis and frequency-domain empirical
orthogonal functions) were consistent with the equatorward propagation of coastal-trapped waves generated
by winds in phase with those near Cape Howe. Time-domain empirical orthogonal functions show that the
current fluctuations decayed with distance from shore and with depth, as expected of coastal-trapped
waves.

PM-026

Incze, L.S., A.W. Kendall, Jr., J.D. SCHUMACHER, and R.K. REED. Interactions of a mesoscale patch of
larval fish (Theragra c ha 1 cog r anuria) with the Alaska Coastal Current. Continental Shelf Research
9(3):269-28i( (1989).

Walleye pollock, Theragra chalcogramma, form dense aggregations during a brief spawning period from late
March to mid-April in Shelikof Strait, Alaska. Spawning produces a large (order 20 x 50 km or more)
"patch" of eggs at depth (generally >1 50 m) , and hatching larvae often produce a "patch" in the upper
50 m. Patches can be defined as coherent features using graded concentration isopleths, and the mean
concentration within patches has been observed to be as much as 68 times (for eggs) and nearly 6 times
(for larvae) the background concentration. Larval patches drift southwestward and have been identified
for about 30 days after hatching in some years. Data are presented for spawner biomass and for early life
stages, as available, for 1981, 1983 and 1985. When comparing 1985 with 1981 (2 years with the best
coverage), spawner biomass and mean egg concentration within the patch declined concordantly. Larval
concentrations about 10 days after hatching differed widely, however: concentrations in early May 1985
were more than an order of magnitude lower than expected. Unlike either 1981 or 1983, no larval patch
could be identified in late May 1985; this appears to be attributable to changes detected earlier in the
month. The "apparent" mortality rate for a 10-day period after hatching in 1985 was about 0.50 d-1
greater than in 1981. Larval feeding conditions can be excluded as a likely cause of this interannual
difference, but predatlon and advection cannot be. Our findings emphasize the short time period over
which significant changes can occur, as well as additional sampling which must be done in future
studies. We show that part of the emerging 1985 larval year class could have been removed by cross-
channel disturbances in the flow field through Shelikof Strait.

PM-027

KESSLER, W.S. Observations of long Rossby waves in the northern tropical Pacific. N0AA TM ERL PMEL-86
(PB89-196331), 169 pp. (1989).

Long baroclinic Rossby waves are potentially important in the adjustment of the tropical Pacific
pycnocline to both annual and interannual wind stress curl fluctuations. Evidence for such waves is found
in variations of the depth of the 20°C isotherm in the northern tropical Pacific during 1970 through
1987. 190,000 bathythermograph profiles have been compiled from the archives of several countries; the
data coverage is dense enough that westward-propagating events may be observed with a minimum of zonal
interpolation. After extensive quality control, 20°C depths were gridded with a resolution of 2°
latitude, 5° longitude and bimonths; statistical parameters of the data were estimated. A simple model of
low-frequency pycnocline variability allows the physical processes of Ekman pumping, the radiation of long
(non-dispersive) Rossby waves due to such pumping in mid-basin, and the radiation of long Rossby waves
from the observed eastern boundary pycnocline depth fluctuations. Although the wind stress curl has very
little zonal variability at the annual period in the northern tropical Pacific, an annual fluctuation of
20°C depth propagates westward as a long Rossby wave near 4°~6°N and 14°-18°N in agreement with the model
hindcast. Near the thermocline ridge at 10°N, however, the annual cycle is dominated by Ekman pumping.
The wave-dominated variability at J4°-6°N weakens the annual cycle of Countercurrent transport in the
western Pacific. El Nifio events are associated with westerly wind anomalies concentrated in the central
equatorial Pacific; an upwelling wind stress curl pattern is generated in the extra-equatorial tropics by
these westerlies. Long upwelling Rossby waves were observed to raise the western Pacific thermocline well
outside the equatorial waveguide in the later stages of El Niflos, consistent with the simple long-wave
model. It has been suggested that El Nifio events are initiated by downwelling long Rossby waves in the

138

extra-equatorial region reflecting off the western boundary as equatorial Kelvin waves. The
bathythermograph observations show that although such downwelling waves commonly arrive at the western
boundary (the Philippines coast), there is a low correlation between these occurrences and the subsequent
initiation of El Nifio events.

PM-028

LACKMANN, G.M., and J.E. OVERLAND. Atmospheric structure and momentum balance during a gap-wind event
in Shelikof Strait, Alaska. Monthly Weather Review 117:1817-1833 (1989).

Gap winds occur in topographically restricted channels when a component of the pressure gradient is
parallel to the channel axis. Aircraft flight-level data are used to examine atmospheric structure and
momentum balance during an early spring gap-wind event in Shelikof Strait, Alaska. Alongshore sea level
pressure ridging was observed. Vertical cross sections show that across-strait gradients of boundary-
layer temperature and depth accounted for the pressure distribution. Geostrophic adjustment of the mass
field to the along-strait wind component contributed to development of the observed pressure pattern.
Boundary-layer structure and force balance during this event was similar to that often observed along
isolated barriers. However, the Rossby radius was larger than the strait width, and atmospheric structure
in the strait exit region indicates transition of the flow to open coastline conditions. Two across-
strait momentum budgets show that the Coriolis force and across-strait pressure gradient were an order of
magnitude larger than other terms. Largest terms in the along-strait balance were the pressure gradient
force, acceleration, entrainment, and friction. Boundary-layer acceleration in the along-strait direction
was 55? of the potential limit determined by the along-strait pressure gradient. Entrainment of air into
the boundary layer was the largest retarding force and contributed to the along-strait profile of
boundary-layer depth. Large horizontal divergence was observed within the strait, yet boundary-layer
depth increased slightly following the flow. Entrainment at the inversion and sea surface fluxes
accounted for along-strait variation of boundary-layer equivalent potential temperature.

PM-029

LAVELLE, J.W., H.O. MOFJELD, E. LEMPRIERE-DOGGETT, G.A. CANNON, D.J. PASHINSKI, E.D. COKELET, L. LYTLE,
and S. Gill. A multiply-connected channel model of tides and tidal currents in Puget Sound, Washington
and a comparison with updated observations. NOAA TM ERL PMEL-84 (PB89-1 39786) , 103 pp. (1989).

Tides and tidal transports within Puget Sound have been calculated using a model in which the Sound is
represented by 79 channels connected at 43 junctions. Linearized equations of motion were used to
determine channel cross-sectionally averaged quantities for the principal tidal constituents (M2, Ki, S2,
N2, Oil Pi, MO. For the M2 tide the amplitudes and phases at the entrances to the Sound and the friction
coefficients in the channels were adjusted to bring observed and modeled tidal distributions into best
agreement; for other constituents, only the tidal amplitudes and phases at the entrances were adjusted.
Data from 47 tide stations in Puget Sound were used for fitting model parameters. Tidal amplitudes and
phases match observations with an average difference of less than 1 cm and 2° respectively for each of the
constituents indicated. Transport values from the model were subsequently compared to transports
calculated from currents measured on four sections across the Sound at both M2 and Ki frequencies. Tidal
transports at the M2 frequency match the transports calculated from the data with average difference of
less than 3? for amplitude and 4.3° for phase. The model was also used to calculate cross-sectionally
averaged tidal currents, tidal prisms, and tidal dissipation rates for the composite tide and for
constituents. As an example of those results, the composite tide and the M2 and Ki constituents have
tidal prisms of 7.69, 4 . 74 and 3-73 km3 and dissipation rates of 733,528 and 78 MW, respectively.

PM-030

Lupton, J.E., E.T. BAKER, and G.J. MASSOTH. Variable 3He/heat ratios in submarine hydrothermal
systems: evidence from two plumes over the Juan de Fuca ridge. Nature 337(6203) : 1 61 -164 (1989).

The first vent fluid samples recovered from submarine hydrothermal systems on the Galapagos Rift and at
21 °N on the East Pacific Rise (EPR) had a nearly identical ratio of 3He/heat of -0.5 x 10"12 cm3 STP
cal"1, even though the two hydrothermal systems were separated geographically and had widely differing
fluid exit temperatures (-20 and -350°C, respectively). Jenkins et al. combined this ratio with
independent estimates of the flux of mantle 3He through the oceans, to calculate a global oceanic
hydrothermal heat flux of 4.9 « 10" cal yr-1, which is in excellent agreement with geophysical estimates
for this flux. Other investigators then combined this 3He flux with measured ratios of various chemicals
in vent fluids to 3He (such as Mn/3He and Si/3He) to estimate global hydrothermal fluxes for these
species. Here we show that aHe/heat ratios vary by over an order of magnitude between submarine
hydrothermal systems, suggesting that early measurements of the 'He/heat relation are not representative
of all hydrothermal systems, and that flux calculations based on the oceanic 'He flux must be undertaken
with caution.

139

PM-031

MASSOTH, G.J., D.A. Butterf ield , J.E. Lupton, R.E. McDuff, M.D. Lilley, and I.R. Jonasson. Submarine
venting of phase-separated hydrothermal fluids at Axial Volcano, Juan de Fuca Ridge. Nature 340:702-705
(1989).

Since the discovery of high-temperature venting on the East
because of the physical properties of sea water at pressures
hydrothermal circulation, that phase-separated fluids would d
this notion is supported by the reported large deviations in
water (-40? - +200?), by observations of venting at P-T condi
(220 bar and 420°C) and by fluid-inclusion data, unequivocal
fluids has remained elusive. Here we report observations of
fluids from a shallow vent field on the Juan de Fuca Ridge wh
separated effluents are delivered to the deep ocean from some

Pacific Rise in 1979, it has been expected,
and temperatures encountered during submarine
ischarge from ridgecrest vents. Although
vent-fluid chlorinity relative to that of sea
tions clearly within the two-phase region
identification of phase-separated venting
chloride- and metal-depleted, gas-enriched
ich confirm the expectation that phase-
sea-floor venting systems.

PM-032

MASSOTH, G.J., H.B. MILBURN, S.R. HAMMOND, D.A. Butterf ield, R.E. McDuff, and J.E. Lupton. The
geochemistry of submarine venting fluids at Axial Volcano, Juan de Fuca Ridge: new sampling methods and
a VENTS Program rationale. Global Venting, Midwater and Benthic Ecological Processes, M.P. De Luca and
I. Babb (eds.), National Undersea Research Program Report 88-4, 29-59 (1988).

Observations of vent fluids collected in 1'

with the submersible Pisces IV from the ASHES vent field

at Axial Volcano, Juan de Fuca Ridge suggest that hydrothermal fluids similar to those vented at other
sediment-starved ridgecrest sites are being discharged along with unprecedented Cl-poor, gas-enriched
fluids that are likely the result of phase separation. Anomalously low concentrations of silica, calcium,
manganese and iron were also observed in the Cl-poor vent fluids. New sampling tools and protocols
conceived to overcome the interpretive limitations inherent to conventional vent fluid data were tested
during 1987 using the Deep Submersible Alvin. A Submersible-coupled In situ Sensing and Sampling System
(SIS3) enabled a more efficient collection of high quality vent fluid samples coincident with the sensing
of temperature. An In Situ Chemical Analyzer (ISCA), based on the technology of flow injection analysis
and configured to monitor the chemical output of a warm spring vent for H2S, Fe2 , pH, and temperature,
was deployed with partial success for 3 days at the ASHES vent field. The integral role of vent fluid
studies in testing the hypothesis that hydrothermal venting along the Juan de Fuca/Explorer/Gorda Ridge
system plays a major role in controlling the chemistry of the northeastern Pacific Ocean is identified and
supported.

PM-033

MCPHADEN, M.J., and R.A. Fine. A dynamical interpretation of the tritium maximum in the central
equatorial Pacific. Journal of Physical Oceanography 1 8(10) : 1 454-1457 (1988).

The tropical tritium distribution between 1974 and 1981 is characterized by a maximum along the equator
centered between 125° and 145°W. It signifies that this region has received the maximum input of high
northern latitude water. A dynamical interpretation of the maximum shows that it can be explained by the
strength of the Sverdrup circulation in the central equatorial Pacific where there is a strong zonal
convergence in the North Equatorial Countercurrent (NECC) and a strong meridional geostrophic flow towards
the equator.

PM-034

MCPHADEN, M.J., H.P. FREITAG, S.P. HAYES, B.A. TAFT, Z. Chen, and K. Wyrtki. Reply to Comment by
Harrison and Giese. Journal of Geophysical Research 94(C4) :5027-5028 (1989).

No abstract.

PM-035

MCPHADEN, M.J., and B.A. TAFT. Dynamics of seasonal and intraseasonal variability in the eastern
equatorial Pacific. Journal of Physical Oceanography 1 8( 1 1 ) : 1 71 3~1 732 (1988).

Time series measurements from surface moored buoys in the eastern equatorial Pacific are analyzed for
the period 1983-86. The data, collected as part of the EPOCS and TROPIC HEAT programs, consist of
currents, temperatures, and winds on the equator at 110°, 124.5° and 140°W. The purpose is to examine the
dynamics of seasonal and intraseasonal variability in the upper 250 m from a diagnosis of the depth
integrated zonal momentum (i.e., transport) equation. The principal conclusions of this paper are that 1)
there is an approximate balance between mean zonal wind stress and depth integrated pressure gradient;

140

nonlinear advection is significantly nonzero however and leads to an enhancement of eastward transport
along the equator; 2) there is an interannual change in zonal wind stress and pressure gradient in which
both approximately double over the record length; 3) at the annual cycle, zonal wind stress and depth
integrated pressure gradient tend to balance, though the uncertainties are large and other physical
processes (e.g., lateral diffusion) are likely to be important; and 4) there exists a very energetic
intraseasonal eastward propagating Kelvin-like wave in zonal current, temperature, and dynamic height at
periods of 60-90 days which is poorly correlated with the local winds. These waves have amplitudes that
are large enough at times to obscure the annual cycle.

PM-036

MOFJELD, H.O. Depth dependence of bottom stress and quadratic drag coefficient for barotropic pressure-
driven currents. Journal of Physical Oceanography 18(11), 1658-1669 (1988).

A level 2Y2 turbulence closure model is used to investigate the dependence on water depth H of bottom
stress xb and quadratic drag coefficient Cd for a steady barotropic pressure-driven current in
unstratified water when the current is the primary source of turbulence. For spatially uniform pressure
gradient and bottom roughness zo the magnitude |tiJ increases from small values in shallow water to a
maximum (at a depth -0.004 U0/f where U0 is the geostrophic current speed derived from the pressure
gradient and f is the Coriolis parameter) at which the dynamics changes from being depth-limited to being
controlled by similarity scales. As the depth increases further, |tv,| decreases to its deep-water value,
that is, 15? to 19? less than the maximum. The angle 9 of the bottom stress relative to the geostrophic
direction decreases rapidly from 90° in very shallow water, reaching its deep-water value (-11°-21°) at a
somewhat shallower depth than does |t>J. At the maximum stress 6 is 8° larger than the deep-water
angle. A set of computationally efficient formulas matched to the model results gives |xb| and 9 for all
combinations of Uo, H, f and bottom roughness Zo . Comparison with a variety of other models satisfying
Rossby similarity over oceanographic ranges of parameters shows agreement of -10? for |tb| and -5° for
9. The coefficient C^ of the quadratic drag law relating |tw| to the vertically averaged velocity is
found to be approximated reasonably well by a formula from nonrotating channel theory in which the
coefficient depends only on the ratio H/zo. The direction of the bottom stress relative to the vertically
averaged velocity is equal to the geostrophic veering angle (~11°-21°) in deep water and decreases to -5°
for a range of intermediate depths (-0.004-0.01 Uo/f) where it is relatively independent of external
Rossby number Uo/fz0; the angle becomes less in shallower water.

PM-037

Muench, R.D. The sea ice margins: a summary of physical phenomena. N0AA TM ERL PMEL-88 (PB89-21 2328) ,
51 pp. (1989).

No abstract.

PM-038

MURPHY, P.P., T.S. BATES, H.C. CURL, JR., R.A. FEELY, and R.S. BURGER. The transport and fate of
particulate hydrocarbons in an urban fjord-like estuary. Estuarine, Coastal and Shelf Science 27:461-
482 (1988).

Hydrocarbon concentrations were measured on suspended particulates and on surficial marine sediments in
the urban fjord-like estuary of Puget Sound, Washington. These data were combined with sediment
deposition rates, suspended particulate concentrations and circulation data to assess hydrocarbon
distributions and fates. Evaluation of major sinks for petroleum hydrocarbons (UCM) and polycyclic
aromatic hydrocarbons (PAH) in an urban estuary indicates that >90? of the hydrocarbons which are
associated with suspended particulates in the main basin of Puget Sound are deposited in the estuarine
sediments. Approximately 63? of the PAH and 100? of the UCM associated with particles in the main basin
settle directly to the sediments. The remainder is carried to the main basin sediments via horizontal
transport from other areas. Trends in PAH ratios are used to identify major sources of PAH. Estimated
sources of PAH are balanced by the estimated sinks.

PM-039

Nakata, K. , K. Tsurusaki, Y. Okayama, and J.W. LAVELLE. An attempt to evaluate the effects of an anti-
turbidity system on sediment dispersion from a Hopper dredge. N0AA TM ERL PMEL-85 (PB89-1 6251 5) , 30 pp.
(1989).

Measurements were made during six hopper dredge operations to investigate the differences in plumes of
overspilled particulates when the dredger was and was not using an anti-turbidity system. Observations
for discharge rates of suspended solids were taken aboard the dredge ship while concentration samples of

141

suspended solids were taken by survey boats in the plume and currents were metered by instruments on
moorings. Measurements were given a common framework by .the use of a dispersion model for the plume.
Modeled and observational profiles match well when the rate of discharge is reserved as a fitting
parameter. However, differences in results of the use and non-use of the anti-turbidity system are not
discernible with the field data. Consequently, the model was used under identical advection and diffusion
conditions to study the differences theoretically. Those numerical experiments suggest that there is an
increase of about 25? in the amount of deposition in the immediate area of dredging with the anti-
turbidity system, though the fractional amount of redeposition in both cases is small. The differences in
results for the two systems calculated with the model depend on the assigned initial vertical
distributions. Because these are poorly known at present, better definition of the differences with and
without the anti-turbidity system await better measurements of the vertical distributions of suspended
solids in the ocean immediately following discharge.

PM-040

OVERLAND, J.E., and C.H. PEASE.
93(C12):15619-15637 (1988).

Modeling ice dynamics of coastal seas. Journal of Geophysical Research

A coupled sea ice, barotropic ocean model with a 1-km resolution and a seaward domain of 200 km
quantifies three coastal processes: coupling of ice motion to wind-driven coastal currents, ice thickness
redistribution under compaction at the coast, and formation of coastal shear zones. The model consists of
an ice momentum balance, mass concentration and two-parameter ice thickness distribution, and equations
for horizontal water motion and continuity using vertical structure functions. An appropriate
constitutive law appears to be a hardening plastic based on qualitative observations from Alaskan
continental shelves. For first-year sea ice, strength is taken to be proportional to the square of ice
thickness. A north wind example of 10 m/s with the coastline to the west shows the depth dependence of
rotational shear in the sea ice/ocean boundary layer and sea surface tilt which contributes an alongshore
slope current. There is slight convergence of sea ice over the shelf, a coastal shear zone of 4 km, and
an alongshore ice speed seaward of the shear zone of 6? of the wind speed caused by the combination of an
undei — ice shear layer and an alongshore slope current. For an onshore wind, ice is near free drift at 3?
of the wind seaward of a ridging front, which propagates seaward. A square dependence of ice strength on
thickness is required for the rubble field to approach a limiting thickness, consistent with
observations. The hardening plastic interpretation of the rubble field has the stress state at the yield
limit in contrast with a rigid plastic of high constant strength that yields only at the coast. We
conclude that (1) ice thickness/motion feedback is important on scales less than 10 km, (2) the
observational base to discriminate between mesoscale constitutive laws is not yet available, and (3) the
relation of ice velocity to wind stress is variable because the ocean slope current responds only to the
alongshore component of the wind.

PM-041

OVERLAND, J.E., and C.H. PEASE. Prediction of vessel icing: a 1989 update. Proceedings, 10th
International Conference on Port and Ocean Engineering Under Arctic Conditions, June 12-16, 1989, Lulea,
Sweden, K.B.E. Axelsson and L.A. Fransson (eds.), Lulea1 University of Technology, Research Report TULEA
1989:08, Vol. 2, 712-723 (1989).

The NOAA vessel icing algorithm is evaluated against theoretical advances. The most difficult factor is
influence of sea temperature. Modeling demonstrates the importance of supercooling of spray during its
trajectory to extreme ice accretion. This occurs when sea temperatures are less than 2~3°C above the
saltwater freezing point. The sea surface temperature term in the NOAA algorithm is consistent with the
supercooling hypothesis and a further category of "extreme" icing is added, which can explain anecdotal
cases greater than 5 cmh"'. A wave height/wind speed threshold is 5 m s-1 for a 1 5_m vessel, 10 m s_1
for a 50-m large trawler and 15 m s_1 for a 1 00-m vessel, developed from seakeeping theory. These wind
speeds are exceeded 83?, 47$ and 15? during February in the Bering Sea.

PM-042

PAULSON, A.J., R.A. FEELY, H.C. CURL, JR., E.A. Crecelius, and G.P. Romberg. Separate dissolved and
particulate trace metal budgets for an estuarine system: an aid for management decisions.
Environmental Pollution 57: 31 7~339 (1989).

The sources and sinks of dissolved and particulate Pb, Cu and Zn were determined for the main basin of
Puget Sound to understand the effect man has had on metal concentrations in both the water column and in
the sediments. Municipal, industrial and atmospheric sources contributed about 66? of the total Pb added
to the main basin of Puget Sound during the early 1980s. Advective inputs were the major sources of total
Cu and Zn (-40?) while riverine and erosional sources contributed about 30?. The discharge of the
particle-bound trace metals from rivers minimized the influence of particulate anthropogenic sources,

142

which constituted 50?, 23? and 18? of the total particulate Pb, Cu and Zn inputs, respectively. While
advective transport was the major source of dissolved Cu and Zn (-60? of all dissolved inputs),
industrial, municipal and atmospheric inputs contributed about 85?, 30? and 38? of the dissolved Pb, Cu
and Zn inputs, respectively. The sources of dissolved and particulate Cu and Zn were comparable with the
sinks within the errors of the analyses indicating their quasi-conservative nature. Advection removed
about 60? of the total Cu and Zn added to the main basin while 40? was deposited in the sediments of Puget
Sound. Because of this quasi-conservative nature of Cu and Zn, anthropogenic inputs of Cu and Zn were
dispersed from the system more than they were contained within main basin sediments. About 75? of the
dissolved Pb discharged into the main basin of Puget Sound was lost from the dissolved phase and was
balanced by a similar gain in the particulate phase. Because of this extensive scavenging and the
effective retention of particles within the main basin, about 70? of the total Pb added to the main basin
was retained within its sediments. These separate mass balances have utility in management decisions
because they show the relative contributions from different sources and demonstrate whether the influences
of dissolved and particulate inputs are reflected solely in the water column or the sediments,
respectively.

PM-043

PAULSON, A.J., R.A. FEELY, H.C. CURL, JR., and D.A. TENNANT. Estuarine transport of trace metals in a
buoyant riverine plume. Estuarine, Coastal and Shelf Science 28:231-218 (1989).

The distributions of dissolved and particulate trace metals in Elliott Bay, Washington were determined
in April, 1985 during the period of maximum discharge of freshwater for the year. The high freshwater
discharge generated a thin buoyant plume (<2 m) which carried a high suspended load. Calculations made
from high resolution sampling of salinity and total suspended matter in the plume suggest that their
residence times in the upper 2 m of the water column ranged between 15 and 24 h. Total suspended matter,
dissolved and particulate Fe, Mn and Pb, and particulate Cu and Zn in the plume were found to be
conservative during their transit through Elliott Bay. Dissolved Cu and Zn exhibited a linear
relationship with salinity downstream of a significant anthropogenic source. The particulate phase
dominated the horizontal transport of Fe and Pb originating from freshwater sources. In contrast, the
dissolved phase contributed 66?, 75? and 35? of the respective total horizontal fluxes of Mn, Zn and Cu
that originated from riverine and anthropogenic sources. The trace metal concentrations of the suspended
matter were uniform in Elliott Bay except for Mn concentrations. Mn concentrations of suspended matter
increased with salinity due to mixing of lower concentration, riverine particulates with Puget Sound
particulates of higher Mn concentrations. The lack of trace metal enrichments of Elliott Bay surface
suspended matter during this period of high discharge was the result of the small vertical loss of
suspended matter (<2? of the horizontal transport) and the rapid transit of suspended matter through the
Bay.

PM-044

PAULSON, A.J., T.P. Hubbard, H.C. CURL, JR., R.A. FEELY, T.E. Sample, and R.G. Swartz. Decreased fluxes
of Pb, Cu and Zn from Elliott Bay. Proceedings of Sixth Symposium on Coastal and Ocean Management/ ASCE,
July 11-14, 1989, Charleston, SC , 3916-3930 (1989).

Fluxes of dissolved Pb, Cu and Zn to Elliott Bay, Washington from industrial sources were calculated
from metal-salinity plots and freshwater discharge rates. The changes in these calculated fluxes were
used to evaluate the effectiveness of pollution abatement programs. Between 1981 and 1985, initial
pollution abatement actions were directed at many commercial and industrial dischargers along the Duwamish
Waterway and on Harbor Island including a secondary lead smelter site and shipbuilding facilities.
Subsequently, the dissolved Pb flux to Elliott Bay from industrial flux of dissolved Cu decreased by a
factor of 5, and the industrial flux of dissolved Zn remained unchanged. The closure of one shipyard,
reduced activity at another and better management practices decreased the industrial fluxes of dissolved
Cu and Zn to Elliott Bay in 1986 by 75? and 90?, respectively.

PM-045

PEASE, C.H. Beaufort/Chukchi ice motion and meteorology update. Proceedings, Alaska 0CS Region 1987
Arctic Information Transfer Meeting Conference, 0CS Study MMS 88-0040, Minerals Management Service,
Anchorage, AK, 145-150 (1988).

No abstract.

PM-046

Picaut, J., S.P. HAYES, and M.J. MCPHADEN. Use of the geostrophic approximation to estimate time
varying zonal currents at the equator. Journal of Geophysical Research 94 (C3 ): 3228-3236 (1989).

143

Moored thermistor chains at 2°N and 2°S and current-temperature moorings at 0° are used to examine the
accuracy of geostrophically estimated zonal velocity on the equator in the eastern (110°W) and western
(165°E) Pacific. The meridionally differentiated form of the geostrophic balance is used to eliminate
large errors due to wind-balanced cross-equatorial pressure gradients. Statistical analyses indicate that
for time scales longer than 30-50 days, tne observed and geostrophically estimated zonal velocities are
similar (correlation coefficients of 0.6-0.9 and comparable amplitudes). Thus low-frequency equatorial
current oscillations are reasonably well represented by the geostrophic approximation. However, the mean
currents are poorly resolved with the available array. In the eastern Pacific the mean zonal speed
difference over the 10-month comparison period is 25 cm s_1 at 25 m and increases to 60 cm s-1 at 125 m.
At 165°E mean differences in the upper 250 m are typically 50 cm s~ ' over a 4-month record. The principal
reason for these large mean differences is that the meridional scale of the mean currents is smaller than
the spacing of the moorings. Comparison of observed and geostrophic velocity profiles obtained from
shipboard sampling indicates that meridional spacing of about 1° latitude would be optimum for estimating
the zonal velocity.

PM-047

QUINN, P.K., and T.S. BATES. Collection efficiencies of a tandem sampling system for atmospheric
aerosol particles and gaseous ammonia and sulfur dioxide. Environmental Science and Technology
23(6):736-739 (1989).

The collection efficiencies of aerosol particles and gaseous NHa and SO2 were tested for a tandem
sampling system consisting of a cyclone separator followed by a 1.0 ym pore size 47-mm Millipore Teflon
particle filter and four 47-mm Whatman Ml filters coated with oxalic acid and either K2CO3 or LiOH. The
collection efficiency of the cyclone was compared with an 8.0 jam pore size Nuclepore filter using NaCl
particles. Both the cyclone and the filter had a 50? collection efficiency at 0.9 urn (50 standard L/min,
55 cm s~ ' filter face velocity). Known amounts of NH3 and SO2 were generated and collected on the coated
filters. The collection efficiency of the system for NH3 was found to be 103 ± 30?. The S02 collection
efficiency on IOCOs. and LiOH-coated filters was 100 ± 21 and 88 ± 9%, respectively, and was not affected
by the presence of reduced sulfur gases or ozone in the sampled air stream.

PM-048

REED, R.K. and J.D. SCHUMACHER. Some mesoscale features of flow in Shelikof Strait, Alaska. Journal of
Geophysical Research 9M(C9): 12603-12606 (1989).

Moored current observations were obtained from a small region of Shelikof Strait during 1986-1987.
Results from two sites <4 km apart revealed very similar energy spectra and highly correlated alongstream
component flow. At separations >11 km, however, correlations were quite weak. A new feature, intense 1 3~
day spectral peaks of narrow horizontal and vertical scale, was also revealed. The feature appears to be
a baroclinic, residual flow linked to tidal currents.

PM-049

REED, R.K., and J.D. SCHUMACHER. Transport and physical properties in central Shelikof Strait,
Alaska. Continental Shelf Research 9(3):261~268 (1989).

Data from a repeated CTD section in central Shelikof Strait during 1985-1987 are used to derive volume
transport and the distribution of neai — bottom physical properties. Mean transport was 0.6 x 106 m3 s-1 to
the southwest, similar to that measured by a 5-month current-meter array. Computed transport values
varied from 0.2 to 1 .2 x 106 m3 a-1; differential Ekman pumping appeared to be important in creating large
changes in transport over short time intervals. Near-bottom temperature and salinity varied as a result
of changes in source waters to the south; during 1986 cold, low-salinity conditions prevailed. The
seasonal cycles of surface and near-bottom temperature and salinity are compared to those found off the
Kenai Peninsula.

PM-050

REED, R.K., J.D. SCHUMACHER, and A.W. Kendall, Jr. NOAA's Fisheries Oceanography Coordinated
Investigations in the Western Gulf of Alaska. Eos, Transactions American Geophysical Union: The
Oceanography Report 69(40): 890-894 (1989).

No abstract.

144

PM-051

Reynolds, R.W., K. Arpe, C. Gordon, S.P. HAYES, A. Leetmaa, and M.J. MCPHADEN. A comparison of tropical
Pacific surface wind analyses. Journal of Climate 2(1): 105-1 11 (1989).

Surface wind analyses from three data assimilation systems are compared with independent wind
observations from six buoys located in the Pacific within 8 deg of the equator. The period of comparison
is 6 months (February to July 1987), with daily sampling. The agreement between the assimilation systems
and the independent buoy data is disappointing. The long-term mean differences between the buoy and the
assimilated zonal and meridional winds are as large as 3.1 m s-1, which is comparable to the size of the
means themselves. The zonal and meridional daily wind correlations range between 0.66 and 0.17. The wind
field agreement was actually better among the different systems than between any system and the buoys.
However, the agreement among the analysis products was usually better for the zonal winds than for the
meridional winds. For the time period and locations presented, the comparisons with the independent data
show that no assimilation system is clearly superior to any of the others.

PM-052

Rothsteln, L.M., M.J. MCPHADEN, and J. A. Proehl . Wind forced wave-mean flow interactions in the
equatorial waveguide. Part I: The Kelvin wave. Journal of Physical Oceanography 1 8(10) : 1 435-1 447
(1988).

A numerical model is designed to study the effects of the strong, near-surface shears associated with
the equatorial current system on energy transmission of time-periodic equatorial waves into the deep
ocean. The present paper is confined to long wavelength, low-frequency Kelvin waves forced by a
longitudinally confined patch of zonal wind. Energy transmission into the deep ocean is investigated as a
function of mean current shear amplitude and geometry and the forcing frequency. Solutions form well-
defined beams of energy that radiate energy eastward and vertically toward the deep ocean in the absence
of mean flow. However, the presence of critical surfaces associated with mean currents inhibits low-
frequency energy from reaching the deep ocean. For a given zonal wavenumber, longitudinal propagation
through mean currents will be less inhibited as the frequency increases (phase speed increases). When the
mean current amplitude is large enough, the beam encounters multiple critical surfaces (i.e., critical
surfaces for different wavenumber components of the beam) where significant exchanges of energy and
momentum can take place with the mean currents via Reynolds stress transfers. Work against the mean
vertical shear is the dominant wave energy loss for the case of a mean South Equatorial Current-Equatorial
Undercurrent system, illustrating the need for high vertical resolution in equatorial ocean models. The
model also describes the possible induction of a mean zonal acceleration as well as a mean meridional
circulation. Eliassen-Palm fluxes are used to diagnose these dynamics. The presence of critical surfaces
result in mean field accelerations on the equator above the core of the Equatorial Undercurrent.
Implications of these results with regard to observations in the equatorial waveguide are discussed.

Addendum

PM-053

EMBLEY, R.W., I.R. Jonasson, M.R. Perfit, J.M. Franklin, M.A. Tivey, A. Malahoff, M.F. Smith, and T.J.G.
Francis. Submersible investigation of an extinct hydrothermal system on the Galapagos Ridge: Sulfide
mounds, stockwork zone, and differentiated lavas. Canadian Mineralogist 26:517-539 (1988).

Fifteen dives along the Galapagos Ridge in the region between 85°^9'W and 85°55'W were made to examine
the detailed relationships among tectonics, hydrothermal activity and lava compositions. Extensive
tectonic activity and physical weathering have exposed the inner parts of large Cu-Zn sulfide mounds and
the uppermost part of the underlying stockwork zone. The mineralization occurs at the top and southern
base of a horst block, kO to 80 m high, that separates the present Neovolcanic Zone to the north from an
older rift valley to the south. The lavas in the Neovolcanic Zone are homogeneous MORB pillows; those on
the horst block and within the southern valley are evolved MORB to andesite pillow and sheet flows. The
alteration zone exposed beneath the sulfide mounds comprises a network of fracture-controlled pipe and
sheet-like bodies of highly altered material which changes outward into relatively fresh but similarly
closely fractured rocks. The hydrothermal upflow zone is extensively brecciated on a centimeter scale and
encloses a stockwork of veinlets now filled largely by silica, clays and sulfides. The most highly
altered rocks are strongly depleted in Ca, Na, K and Mn, and are enriched in S, Fe, Cu and Zn relative to
their fresh analogs. Si and Mg are variable, the latter showing local depletions and enrichments
according to the proportion and distribution of chlorite. Depletions in 180 with increasing 87Sr/86Sr
suggest extensive seawater-rock interaction (W/R up to 100:1) at T_ up to 350°C. Deep-tow and ALVIN-based
magnetic profiles have a relative magnetization low centered over the southern valley and the horst block
that could reflect more extensive hydrothermal alteration zones associated with the older seafloor. The

145

Galdpagos stockwork is most analogous to the alteration zones associated with massive sulfide deposits in
the ophiolites of Cyprus and Oman.

PM-054

MOFJELD, H.O. Review of "Tides, Surges and Mean Sea-Level, A Handbook for Engineers and Scientists," by
D.T. Pugh. Eos, Transactions of the American Geophysical Union 69(37) :850 (1988).

No abstract.

146

SPACE ENVIRONMENT LABORATORY

SE-001

Barrow, C.H., J. Watermann, D.S. EVANS, and K. Wilhelm. Antarctic Auroral Electron Precipita-
tion Observed by the Electron Spectrometer (1ES019) on Spacelab 1. MPAE-W-100-89-25 ,
Max-Planck-Institut fur Aeronomie, 38 p. (1989).

Electron flux measurements were made in the energy range 0.1-12.5 keV, by the electron spec-
trometer 1ES019 on board Spacelab 1, during the period November 29 to December 7, 1983. The
spacecraft was in a 57° inclination circular orbit at an altitude of about 250 km with orbital
period 90 min. Although the experiment was originally designed for artificial beam response ob-
servations, several periods of natural keV electron precipitation were also recorded, and these
have been surveyed and catalogued. New and improved data presentation has also been introduced.
The data are interesting because of the high resolution of the electron spectrometer, the rela-
tively low altitude of the observations, and the path of Spacelab 1, almost along the auroral
oval. One observation, made in the southern hemisphere on November 30, 1983, is of particular
interest as the NOAA-7 satellite, which measured electron flux in the energy range 0.3-20 keV,
was then quite close in space and time. As correlative riometer and magnetometer observations
suggest that auroral conditions remained stable during the 25 min period during the two sets of
observations, the observations are used to infer the gross spatial structure of the auroral pre-
cipitation over the midnight sector. Comparison of the electron energy spectra observed by
Spacelab 1 and NOAA-7 at different local times suggests a high degree of longitudinal homogene-
ity in the precipitation.

SE-002

Bornmann, P.L., and K.T. Strong. Two-component analysis of the decay of soft X-ray line emis-
sion during solar flares. The Astrophvsical Journal . 333:1014-1025 (1988).

The light curve analysis technique of Bornmann has been extended to two components and is used
to model the soft X-ray line fluxes observed during solar flares with the Flat Crystal Spec-
trometer on board the Solar Maximum Mission satellite. This technique uses the rate of change in
flux of soft X-ray lines to derive the temperature and emission measure. The modified version of
this technique solves for two components, rather than the previous single component. This modi-
fication was introduced to compare the results with the two components found in differential
emission measure calculations. With this modification, the light curves of all observed lines
are reproduced, in contrast to the single-component applications, which could not reproduce the
lines formed at the highest temperatures. This modified light curve analysis technique has been
applied to six of the flares modeled by the previous single-component technique. Five of these
flares show significantly better fits to the observed fluxes when the two-component technique is
applied. The two components exhibit different rates of decay. The temperature and emission meas-
ure of the hotter component always decay more rapidly than those of the cool component. This be-
havior is in agreement with differential emission measure calculations we have performed using
the same soft X-ray data. Additional evidence from the two-component light curve model indicates
that the isothermal assumption is not strictly valid. The presence of plasma at temperatures in-
termediate to the derived isothermal components is suggested.

SE-003

DRYER, M. MHD modeling of solar and interplanetary processes. Final Report, AFGL Contracts
GLH7-2017 and GLH8-6004, 25 p. (1989).

Our objective has been to use magnetohydrodynamic (MHD) numerical modeling and simulations as
tools to understand the physics of energy and momentum transport from the solar surface through
the corona to interplanetary space. To achieve this goal, we have first identified possible
physical mechanisms and, second, have performed synthesis calculations using self -consistent MHD
theory via numerical and analytical methods. Solar and interplanetary (remote-sensing and in
situ) observations play important roles in our synthesis strategy. Our models, unique in the
field of solar/interplanetary physics, include both 2 1/2-D and 3-D time-dependent codes that,
we believe, will lead to future operational status in geomagnetic storm forecasting procedures.
Our strategy is oriented toward assuring that real-time observations would be used to drive
physically based models, the outputs of which would be considered by space environment forecast -

147

ers . Following a short Introduction, this Final Report consists of a Summary providing high-
lights of this research project. A Bibliography of papers, tabulated by first author for easy
reierence, follows the Summary. The various papers are categorized with a description of their
main points and conclusions. A set of representative figures, with extensive descriptive cap-
tions, is included for the reader interested in additional details. This work was prepared with
partial support from several AFGL project orders to NOAA's Space Environment Laboratory during
Fiscal Years 1987 and 1988. This support is acknowledged in each of the Bibliography's 28 papers
that are now published, in press, or under consideration in scientific refereed journals and
conference proceedings.

SE-004

DRYER, M., T.R. DETMAN , S.T. Wu , and S.M. Han. Three-dimensional, time-dependent MHD simula-
tions of interplanetary plasmoids. Advances in Space Research. 9(4) : (4)75-(4)80 (1989) .

Plasmoids in the interplanetary medium have been hypothesized for nearly 2 decades by many
observers. These suggestions can be classified into two categories: (1) solar-ejected diamag-
netic plasmoids that retain their closed, albeit expanding, topology to and beyond Earth; and
(2) plasmoids that are formed in the corona near the Sun or in the interplanetary medium as a
consequence of reconnection of opposite-directed IMF lines. We present a 3-D MHD, time-dependent
simulation of a plasmoid in the first category under the assumption that, before entering the
computational domain, the plasmoid already exists at or near the Sun. Also, we present a simula-
tion of a plasmoid in the second category, where a dipolar solar IMF with an initially flat
heliospheric current sheet and a representative solar wind is disturbed by a simulated shock
wave. Of particular interest is the draping of the IMF about the plasmoid in both examples. Al-
though the shock in the second example propagates across the current sheet with negligible
large-scale distortion, the strong transverse pressure gradients behind it apparently cause re-
connection and formation of a plasmoid. The code, which has a grid too coarse for examination of
kinetic reconnection studies, has both inherent and explicit numerical diffusion that allows re-
connection. A fast forward MHD shock precedes the plasmoid as it expands into heliospheric
space. We will describe the plasma and magnetic properties of the expanding plasmoid as it moves
toward an observer at 1 AU.

SE-005

Dusenbery, P.B., and L.R. Lyons. Ion diffusion coefficients from resonant interactions with
broadband turbulence in the magnetotail. Journal of Geophysical Research. 94 (A3) : 2484-2498
(1988) .

A potentially important source of hot ions within the central plasma sheet (CPS) is warm plas-
ma sheet boundary layer (PSBL) ions which interact with broadband electrostatic waves and elec-
tric field drift toward the CPS. In the PSBL, the local interaction between the waves and par-
ticles can be assumed to be unmagnetized. The effect of the magnetic field is to organize wave
and particle distributions in velocity space. Under these conditions, particle diffusion is, in
general, two-dimensional and is similar to magnetized diffusion. The general quasi-linear equa-
tions describing such diffusion are presented assuming that a spectrum of waves is excited simi-
lar to the waves observed in the boundary layer. In order to apply the general quasi -linear dif-
fusion coefficients, two particle distribution models are assumed based on PSBL observations.
One is for the outer edge and one is for the inner edge of the boundary. An expression for the
unmagnetized dielectric function is given and evaluated for wave frequency and growth rate for
the assumed particle distribution models. It is found that slow and fast mode ion-sound waves
can be unstable for the range of plasma parameters considered. The diffusion coefficients are
then evaluated for resonant warm PSBL ion interactions with ion-sound waves. The results illus-
trate how resonant ion diffusion rates vary with pitch angle and speed, and how the diffusion
rates depend upon the distribution of wave energy in k space. For the model of the outer edge of
the PSBL, pitch angle diffusion is found to dominate energy diffusion, whereas both types of
diffusion can be important for the model of the inner edge of the PSBL. It is found that the
characteristic time for resonant warm boundary layer ions to diffuse in velocity space is "10
min (for a wave electric field of 1 mV/M) , which is approximately an ion bounce period. In addi-
tion, significant pitch angle and energy diffusion should occur resulting in isotropization of
the warm PSBL ion beams to form the hot isotropic ion component in the CPS.

148

SE-006

Foster, J.C., T. Fuller-Rowell , and D.S. EVANS. Quantitative patterns of large-scale field-
aligned currents in the auroral atmosphere. Journal of Geophysical Research. 94 (3) : 2555-2564
(1989) .

Quantitative patterns of the distribution of field-aligned current (FAC) density have been
derived from gradients of the average patterns of the Hall and Pedersen currents at high lati-
tudes under the assumption that the total current is divergence- free . The horizontal currents
were calculated from empirical convection electric field models, derived from Millstone Hill ra-
dar observations, and the ionospheric Hall and Pedersen conductances, based on satellite obser-
vations of the precipitating particle energy flux and spectrum and including an average (equi-
nox) solar contribution. These independent empirical models, and the resultant patterns of the
field-aligned currents, are keyed to an auroral precipitation index which quantifies the inten-
sity and spatial extent of high-latitude particle precipitation and which is determined from a
single satellite crossing of the auroral precipitation pattern. The patterns detail the spatial
distribution of the currents as a function of increasing disturbance level. The magnitudes of
the total single-hemisphere currents into or out of the ionosphere are closely balanced at each
activity level and increase exponentially between 0.1 and 6 MA with increasing values of the
precipitation index. The interplanetary magnetic field (IMF) sector dependence of the FAC pat-
terns is investigated for disturbed conditions. A large portion of the FAC pattern is closed by
local Pedersen currents (current into the ionosphere is balanced by an equal current out of the
ionosphere at that local time) . This locally balanced portion of the FAC system is enhanced in
the prenoon (postnoon) sector for IMF B > + 1 nT (B < -1 nT) . In addition, there are net cur-
rents into the ionosphere postnoon and out of the ionosphere in the premidnight sector. Whereas
the magnitude of these nighttime net FACs increases with increasing negative IMF B , the magni-
tude and distribution of the net currents appear to be independent of the IMF B orientation.

SE-007

Foster, J.C., H.-C. Yeh, J.M. Holt, and D.S. Evans. Two-dimensional mapping of dayside convec-
tion. In Electromagnetic Coupling in the Polar Clefts and Caps. P.E. Sandholt and A. Egeland
(eds.), Kluwer Academic Publishers, pp. 115-125 (1989).

Millstone Hill radar azimuth scans have been used to map the large-scale features of the
ionospheric convection pattern in the vicinity of the cusp and cleft. Each scan covers 5 hours
of MLT and 20° of invariant latitude, A, with 30 minute temporal resolution. Individual "snap-
shots" of the convection pattern for disturbed conditions on 31 January 1982 span the entire re-
gion of convection convergence near noon and compare favorably with average model representa-
tions of the dayside region. The characteristic features of ion and electron precipitation ob-
served during satellite overflights of the radar field of view are used to identify the cusp and
cleft and to relate the location of these magnetospheric features to the pattern of ionospheric
convection electric field. Cusp precipitation is seen at 70°A and 09 MLT and the sunward/anti -
sunward convection reversal immediately after a sudden turning of interplanetary magnetic field

(IMF) B from -5 nT to +5 nT while IMF B was -10 nT .
y y

SE-008

Freeman, J.W., Jr., R.A. Wolf, G.-H. Voigt, R.W.Spiro, R.V. Hilmer, J. Shade, and T. Tascione.
Project for the development of a magnetospheric specification model. Partial funding provided
by NOAA Space Environment Laboratory. In The Effect of the Ionosphere on Communication. Navi -
gation, and Surveillance Systems. J.M. Goodman (ed.), based on Ionospheric Effects Symposium,
5-7 May 1987, National Technical Information Service, Springfield, VA. , pp. 331-336 (1988).

We are developing a comprehensive model of the Earth's magnetosphere for operational use by
the Air Weather Service and NOAA. The model is designed to specify magnetospheric conditions us-
ing real-time data and may also provide very limited forecast capability. The computational sys-
tem will include models of global magnetic and electric fields, inner-magnetospheric particles,
precipitating auroral particles, and upper-atmospheric Joule heating. It will be operated in
conjunction with radiation belt and cosmic ray models to be developed by the Los Alamos Scien-
tific Laboratory. A particle-moving algorithm will trace plasma motions in time. The system com-
bines limited theoretical calculations with quantitative rules based on distilled observational
and theoretical results to provide a comprehensive description of the magnetosphere that has a

149

significant degree of self -consistency . It is designed to accept input data from a variety of
ground- and space-based sources that are available to the Air Weather Service and NOAA.

SE-009

GARCIA, H.A. The empirical relationship of peak emission measure and temperature to peak flare
x-ray flux during Solar Cycle 21. Advances in Space Research. 8(11) : (11) 157-(11) 160 (1988) .

Approximately 180 major x-ray flares that occurred between September 1977 and May 1984 have
been examined to determine some of the outstanding trends and collective properties that charac-
terize this set of large events. This study concentrates only on the distribution of the maximum
emission measure and the distribution of maximum electron temperature with respect to the maxi-
mum radiative flux in soft x-rays generated by the flare. Two unusual, but apparently related,
phenomena appear to be revealed by these empirical relationships. The first of these is a linear
dependence of the lower limit of the log emission measure with respect to the maximum flare x-
ray flux. The second is the presence of two events arising from the same active region that
prove the exception to the rule. One of these special events produced a thermal temperature of
60 MK.

SE-010

HILDNER, E. Space Environment Laboratory Annual Report, FY 1988. NOAA Special Report
(PB89-159602) , 41 pp. (1989).

No abstract.

SE-011

HIRMAN, J.W., G.R. HECKMAN, and M.S. GREER. Solar Cycle 22 continues strong climb. EOS, pp.
674 (1989) .

No abstract.

SE-012

HIRMAN, J.W., G.R. HECKMAN, M.S.GREER, and J.B. SMITH. Solar and geomagnetic activity during
Cycle 21 and implications for Cycle 22. EOS, pp. 962, 792, and 973 (1988).

Old Cycle 21 ended and new Cycle 22 began in September 1986. As measured by its sunspots, the
new cycle of solar activity is rising more rapidly than any previous cycle in the records dating
back to 1755 A.D. Progress of the new cycle — expected to last about 11 years — is of interest be-
cause terrestrial satellite missions and other technical systems are affected by various forms
of solar activity; all forms of activity rise more or less in concert with the sunspots of the
new cycle. In consequence, the solar output also varies. For example, the slowly varying back-
ground ultraviolet flux varies, affecting the density of the terrestrial thermosphere. In turn,
satellite drag and radio propagation effects vary. Flares, energetic solar proton events, and
geomagnetic storms occur in cycles that begin and end about the same time as the sunspot cycle
but do not track it as well as the slowly varying radiation. The exceptionally rapid rise of the
new cycle is the basis for prediction of a cycle of record amplitude with smoothed sunspot num-
bers "200 and smoothed 10.7-cm solar radio flux "250, which would equal or exceed the largest
cycles of the past. Cycle 19, the largest recorded, peaked in 1958 with a smoothed sunspot num-
ber of 201. Methods based on observation of antecedent phenomena in Cycle 21 predict that Cycle
22 will have a large maximum sunspot number well above average but not record equaling. At the
present time, there is no consensus regarding which group of predictions is likely to be more
■valid. Nonetheless, it appears increasingly likely that Cycle 22 will reach a peak sunspot num-
ber well above the average of all previous cycles. In another 6-12 months we expect to have a
better idea of the maximum yet to come.

SE-013

Hones, E.W. , Jr., J.D. Craven, L.A. Frank, D.S. EVANS, and P.T. Newell. The horse-collar
aurora: A frequent pattern of the aurora in quiet times. Geophysical Research Letters.
16(l):37-40 (1989).

Reported here are DE 1 auroral imager observations of an auroral configuration which is given
the name "horse-collar aurora." The horse-collar pattern comprises the total area of auroral

150

emissions from a single hemisphere and derives its name from the shape of the emitting area. The
pattern is found in images recorded during quiet geomagnetic conditions and is possibly related
to the theta aurora, another quiet time configuration of the auroras. This initial report of the
DE 1 observations illustrates the horse-collar aurora with a 2-hour image sequence that displays
its basic features and shows an example of its evolution into a theta-like auroral pattern. The
interplanetary magnetic field was northward during this image sequence and there is some evi-
dence for IMF By influence on the temporal development of the horse-collar pattern. A preliminary
statistical analysis found the horse-collar pattern appearing in one-third or more of image se-
quences recorded during quiet conditions; it did not appear during disturbed conditions. Further
study is required to establish more fully the characteristics of the horse-collar aurora and to
determine its implications concerning solar wind-magnetosphere coupling when the IMF Bz is
northward.

SE-014

JOSELYN, J. A. Geomagnetic quiet day selection. In Pure and Applied Geophysics (PAGEOPH) .
Vol. 31, No. 3, pp. 333-341, Birkhauser Verlag, Basel (1989).

Based on published literature and the response to a questionnaire sent to geomagnetic field,
ionospheric, and magnetospheric researchers, several methods of choosing periods of quiet condi-
tions based 6n geomagnetic records, as well as other observed parameters, have been identified.
Caveats with respect to using geomagnetic indices to select quiet periods include the following:
1. Geomagnetic disturbances are strongly local. Even if the data from all available observato-
ries indicate quiet behavior, there is the distinct possibility that some other location, not
sampled, may be disturbed. 2. Geomagnetic indices are convenient but imperfect indicators of
geomagnetic activity. Indices based on a quiet-day reference level have uncertainties comparable
to the threshold value for quiet conditions. Indices representing average conditions during a
24-hr UT day may not be appropriate. 3. Geomagnetic activity does not fully reflect the range of
possible factors that influence the ionosphere or magnetosphere.

SE-015

JOSELYN, J. A., J. A. Flueck, and T. Brown. Geomagnetic climatology. Annales Geophvsicae
6(6) :595-600 (1988) .

The categorization of typical behavior in tropospheric weather, sometimes termed climatology,
provides useful information for predicting the typical future. At the Space Environment Services
Center (SESC) , the geomagnetic 3-hourly K and daily A indices are forecast for Fredericksburg,
Virginia, and College, Alaska. The K-index histories (or climatologies) for both of these loca-
tions were recently tabulated for a 29-year period (1957-1985). The results show that at
Fredericksburg, a middle- latitude station, the prevailing geomagnetic condition is quiet with
little diurnal variation. But at College, a high-geomagnetic-latitude station, a strong diurnal
variation is seen with K-index values of 5 or more present 30% of the time between 0900 and 1500
UT (approximately 0000-0300 local time) . Furthermore, a seasonal variation is evident when the
monthly data are filtered. The high K-index values show the expected semiannual variation peak-
ing at the equinoxes, but the low K-index values show, at best, only an annual variation. Fi-
nally, plots of the percent of occurrence of each K-index value over the 29 years do not corre-
late well with the sunspot cycle; phase shifts and variations of about 8 years in length are
evident .

SE-016

Li, X.-Q., and S.T. Wu , Resistive and eruptive instability by pondermotive force with high-
frequency plasma oscillations. In Laboratory and Space Plasmas . Proceedings of the Second In-
ternational Workshop on the Relation Between Laboratory and Space Plasmas, Tokyo, Japan, No-
vember 25-26, 1986, H. Kikuchi (ed.), NOAA Contract 50RANR700099 , Springer-Verlag, New York,
pp. 239-265 (1989).

In this paper we investigated the subtle interaction between the magnetohydrodynamic (MHD) and
high-frequency plasma waves and we derived the coupling equations for these phenomena. On the
basis of this formalism, we examined the modulation instabilities by an electromagnetic soliton
in a current sheet and showed that there is a resistive instability for constant-f approximation

151

(i.e., uniform magnetic field configuration) .which eventually turns into an eruptive instability
at the onset of the magnetic field reconnection.

SE-017

Martin, R.F., Jr., and T.W. SPEISER. A predicted energetic ion signature of a neutral line in
the geomagnetic tail. Journal of Geophysical Research. 93 (A10) : 11 , 521-11 , 526 (1988).

Under certain assumptions one can predict the formation of a magnetic neutral line on theo-
retical grounds, generally as a result of an unstable current sheet. Neutral points also seem to
form spontaneously in a wide variety of plasma simulations, from MHD to fully kinetic. Hence
such magnetic null regions are central to some models of magnetotail energization and magnetic
substorms. Yet the observational evidence for such regions remains controversial. In this paper
we present a new signature of a neutral line: the field-aligned ion beam characteristic of cur-
rent sheet acceleration becomes dispersed into a "ridge" in the velocity space distribution
function as a neutral line is approached. The results were obtained using single-particle simu-
lations in a fixed magnetic field model. The origin of the ridge is shown to be due to initially
earthward going ions which pass through the neutral line region. These ions come from a smaller
part of the initially antiearthward flowing distribution, generating the depletion of the dis-
tribution function below the ridge.

SE-018

Marquette, W.H., and S.F. Martin. Long-term evolution of a high- latitude active region, NOAA
Contract 50RANR600012, Solar Physics. 117:227-241, (1988).

We describe the decay phase of one of the largest active regions of solar cycle 22 that devel-
oped by the end of June 1987. The center of both polarities of the magnetic fields of the region
systematically shifted north and poleward throughout the decay phase. In addition, a substantial
fraction of the trailing magnetic fields migrated equatorward and south of the leading, negative
fields. The result of this migration was the apparent rotation of the magnetic axis of the re-
gion such that a majority of the leading polarity advanced poleward at a faster rate than the
trailing polarity. As a consequence, this region could not contribute to the anticipated rever-
sal of the polar field. The relative motions of the sunspots in this active region were also
noteworthy. The largest, leading, negative polarity sunspot at N 24 exhibited a slightly slower-
than-average solar rotation rate equivalent to the mean differential rotation rate at N 25. In
contrast, the westernmost, leading, negative polarity sunspot at N21 consistently advanced fur-
ther westward at a mean rate of 0.13 km s _1 with respect to the mean differential rotation rate
at its latitude. These sunspot motions and the pattern of evolution of the magnetic fields of
the whole region constitute evidence of the existence of a large-scale velocity field within the
active region.

SE-019

McINTOSH, P.S., and H. LEINBACH. Watching the premier star. Skv and Telescope. November,
468-471 (1988).

No abstract.

SE-020

Michels, D.J., R. Schwenn, R.A. Howard, J.-D.F. Bartoe, S.K. Antiochos, G.E. Brueckner,
C.-C. Cheng, K.P. Dere, G.A. Doschek, J.T. Mariska, N.R. Sheeley, Jr., D.G. Socker,
P.W. Daly, B. Inhester, H.U. Keller, J.R. Kramm, H. Rosenbauer, P. Lamy, A. Llebaria,
A. Maucherat, E.N. Parker, S.w. Kahler, S.L. Koutchmy, R.N. Smartt, W.J. WAGNER,
J.-L. Bougeret, M. Pick, J.-C. Noens , R.H. Giese, M.J. Koomen, F. Giovane, N.Y. Misconi,
G.M. Simnett, C. Eyles, D. Bedford, E. Priest, R. Lallement. vLASCO' — A Wide-Field White-
Light and Spectrometric Coronagraph for SOHO. In The SOHO Mission: Scientific and Technical
Aspect? of the. Instruments (ESA SP-1004) . EE.. 55-61 (1989) .

Panoramic images from the LASCO coronagraph will provide electron column densities from just
above the limb, at 1.1 R^x , out into deep heliospheric space, at 30^.. In the inner portion, the
corona will be analyzed spectroscopically by a high-resolution scanning, imaging interferometer.
The spectral profiles of three emission lines and one Fraunhofer line will be measured for each
picture point, giving temperatures, velocities, turbulent motions, and volume densities. Polar-

152

ization analysis will yield the direction of coronal magnetic fields. Scientific objectives in-
clude investigation of mechanisms for heating of the corona and acceleration of the solar wind,
causes of coronal transients, and their role in development of large scale coronal patterns and
interplanetary disturbances. The distribution and properties of dust particles, including those
released from sun-grazing comments, will also be investigated, and interactions of coronal plas-
ma with the dust.

SE-021

Osherovich, V.A. The equilibrium of the solar prominence in the external magnetic field. In
Proceedings of Workshop on Dynamics and Structure of Solar Prominences. 18-20 November 1987,
Palma de Mallorca, Spain, pp. 117-124 (1988).

The equilibrium of a solar prominence is treated analytically. For the internal structure, we
require the magnetic field to be continuous and to have finite magnetic energy per unit length
of the filament. This requirement leads to a solar prominence model based on eigenvalue solu-
tions. The set of exact magnetohydrostatic solutions describes topologically different magnetic
configurations. The external field can re-distribute plasma density excess or depletion.

SE-022

Osherovich, V.A. The physical nature of the upper subsidiary diffuse resonances. Journal of
Geophysical Research. 94 (A5) : 5530-5532 (1989).

The upper subsidiary diffuse resonances were first observed in the ionosphere in the Alouette
2 topside sounder experiment, later by the ISIS 1 satellite, and then by the JIKIKEN (EXOS B)
satellite during its electron injection experiment. The frequencies of the subsidiary resonances
are just higher than those of the diffuse resonances Dn (n = 1, 2, 3, 4). In our work we identify
the upper subsidiary diffuse resonance as a hybrid resonance of the diffuse and cyclotron reso-
nances. The corresponding frequencies are f = (f + f ) , n = 1 , 2, 3 , 4 . . . , where

T,D n D n H

f is the observed frequency of the upper subsidiary diffuse resonance, fn is the frequency

of the nth diffuse resonance, and f is the electron gyrofrequency.

H

SE-023

Osherovich, V.A. Solar prominence model based on eigenvalue solutions. II. Filaments in the
vertical magnetic fields. The Astrophvsical Journal. 336:1041-1049 (1989).

An eigenvalue approach is employed to study the equilibrium of a solar filament in a strati-
fied atmosphere with a vertical magnetic field. It is shown that the external vertical magnetic
field can redistribute plasma density and create the positive density excess or negative density
excess (cavity) above the prominence, depending on the relative width and the relative strength
of the filament's magnetic field.

SE-024

Osherovich, V.A., and H.A. GARCIA. The relationship of sunspot magnetic fields to umbral sizes
in return flux theory. The Astrophvsical Journal. 336:468-474 (1989).

We study the relationship between the relative size of a sunspot umbra and the relative magni-
tude of the magnetic field at the outer edge of the penumbra. This analysis is based on the the-
ory of return flux of round, unipolar sunspots. The essential result is that small umbrae or,
equivalently , large penumbrae (relative to the total sunspot area) are associated with large
relative magnetic return flux and with large total magnetic fields at the outer penumbral bound-
ary. Observationally , we present data from 12 unipolar and approximately round sunspots contain-
ing two-component magnetic field measurements as well as umbral/penumbral size ratios. These
data were compiled from the published papers of several authors, employing various methods for
the magnetic field measurements. One of the main characteristics of all these sunspots is that
the magnetic field at the outer penumbral boundary is close to horizontal. These observations
compare well with our theoretical predictions. We suggest, therefore, that the size ratio of um-

153

bra to penumbra or, equivalently, the ratio of return magnetic flux to total magnetic flux,
should be used as the main parameter in the classification of unipolar sunspots.

SE-025

Osherovich, V.A., and E.B. Gliner. Force-free electromagnetic waves. Solar Physics 117:391-397

(1988) .

The time-dependent Force-Free Electromagnetic Field (FFEMF) is studied. In contrast to the
case of Force-Free Magnetic Field (FFMF) , it is shown that the FFEMF can occur in the form of
waves. The FFEMF wave equation is solved in the case of one spatial dimension. Besides a peri-
odical linear FFEMF wave solution, the existence of solitary wave solutions is demonstrated. The
possible application of FFEMF solutions to solar flares is discussed.

SE-026

Rosenthal, D.A., and J.W. HIRMAN. A user's guide to the Space Environment Services Center geo-
physical alert broadcasts. NOAA Technical Memorandum ERL SEL-79 (PB89-194617) , 15 pp. (1989).

Intended for users with little or no scientific background as well as highly technical read-
ers, the User's Guide provides an overview of the National Oceanic & Atmospheric Administra-
tion's hourly short-wave radio bulletins that provide continually updated information on solar-
activity- induced effects on the near-Earth space environment. It also provides a step-by-step
explanation of the standardized format and terminology of the bulletins. Specific terms are
highlighted and defined in a glossary. Bulletins are 45 seconds or less in duration and contain
a large amount of useful data. Until now, no attempt has been made to provide a systematic
method of their use by other than highly technically trained listeners.

SE-027

RUSH, C, M. Fox, D. Bilitza, K. DAVIES, L. McNamara, F. STEWART, and M. POKEMPNER.
Ionospheric mapping: an update of foF2 coefficients. Telecommunication Journal 56 (III) : 179-182

(1989) .

No abstract.

SE-028

SAUER, H. H. , SEL monitoring of the Earth's energetic particle radiation environment. In AIP
Conference Proceedings 186: High-Energy Radiation Background in Space, Sanibel Island, Flori-
da, 1987, R. G. Lerner (ed.), American Institute of Physics, New York, pp. 216-221 (1989).

The Space Environment Laboratory (SEL) of the National Oceanic and Atmospheric Administration
(NOAA) maintains instruments on board the GOES series of geostationary satellites, and aboard
the NOAA/TIROS series of low-altitude, polar-orbiting satellites, which provide monitoring of
the energetic particle radiation environment as well as monitoring the geostationary magnetic
field and the solar x-ray flux. The data are used by the SEL Space Environment Services Center
(SESC) to help provide real-time monitoring and forecasting of the state of the near earth envi-
ronment and its disturbances, and to maintain a source of reliable information to research and
operational activities of a variety of users. The data, data sources, and products relevant to
the characterization of the near-earth radiation environment and its response to solar cosmic
ray events are briefly described, as are the laboratory's archives and uses of these data.

SE-029

SHAW, D. THEOPHRASTUS. In Fourth Annual Rocky Mountain Conference on Artificial Intelligence:
Augmenting Human Intellect by Computer, June 8-9, 1989, Denver, Colorado, J.H. Alexander

(ed. ) , pp. 7-17 (1989) .

The design of a system to perform a given complex task may proceed along many paths. This pa-
per describes the task of solar flare forecasting, and the "traditional" expert system designed
to accomplish this task. Emphasis is placed on describing the complexity and limitations of cur-

154

rent knowledge in the domain, and the associated strengths and weaknesses of the expert system
approach.

SE-030

SHAW, D, and R. GRUBB. The scientist's workbench. In proceedings of Fourth Annual Rockv
Mountain Conference on Artificial Intelligence: Augmenting Human Intellect b_y_ Computer.
June 8-9, 1989, Denver, Colorado, J.H. Alexander (ed.), pp. 241-247 (1939).

A heterogeneous scientific computing environment, containing many types of computing devices,
interfaces, data structures, and languages, presents formidable problems to the casual user.
This paper describes an attempt to ease the user's burden by fostering the concept of "generic"
computing resources. The method revolves around the notion of a local "standard" interface.

SE-031

Song, M.T. , S.T. Wu, and M. DRYER. Soliton and strong Langmuir turbulence in solar flare
processes. Astrophysics and Soace Science. 152:287-311 (1989).

The occurrence of modulational instablity in the current sheet is investigated. Particular
attention is drawn to the plasma micro-instability in this current sheet (i.e., the diffusion
region) and its relation to the flare process. It is found that the solitons or strong Langmuir
turbulence is likely to occur in the diffusion region under solar flare conditions in which the
electric resistivity could be greatly enhanced by several orders of magnitude in this diffusion
region. The result is a significant heating and stochastic acceleration of particles. Physi-
cally, the occurrence of soliton and strong Langmuir turbulence can be identified with a sudden
eruption of an electric current leading to a local vacuum in which an electric potential is
formed and results in the release of a huge amount of free energy. A numerical example is used
to demonstrate the transition of the magnetic field, velocity, and plasma density from the outer
MHD region into the diffusive (resistive) region and, then, back out again with the completion
of the energy conversion process. This is all made possible by an increase of resistivity by 4-5
orders of magnitude over the classical value.

SE-032

Tappin, S.J., M. DRYER, S.M. Han, and S.T. Wu . Expected IPS variations due to a disturbance
described by a 3-D MHD model. Planetary and Space Science. 36(11) :1155-1163 (1988) .

The variations of interplanetary scintillation due to a disturbance described by a three-
dimensional, time-dependent, magnetohydrodynamical (MHD) model of the interplanetary medium are
calculated. The resulting simulated IPS maps are compared with observations of real disturbances
and it is found that there is some qualitative agreement. We are able to conclude that the MHD
model with a more realistic choice of input conditions would probably provide a useful descrip-
tion of many interplanetary disturbances.

SE-033

Thomas, V.L., and R.D. ZWICKL. Network communities to merge. Information Systems Newsletter.
April, p. 20 (1989) .

No abstract.

SE-034

WAGNER, W.J. EUV monitoring and geomagnetic storm forecasts using the USAF-NOAA Solar X-Ray
Imagers (SXI) . In Proceedings fil 1M Atmospheric Neutral Density Specialist Conference.
Colorado Springs, CO, March 22-23, 1988, pp. 241-249 (1989).

Neutral atmosphere density models will require continuous real-time information. The histories
and prognoses from data on radiant extreme ultraviolet (EUV) solar flux and geomagnetic storm
heating are needed for advancing these operational models beyond mere climatology. The USAF-NOAA
Solar X-Ray Imagers (SXI) will be providing these data in the 1990s.

SE-035

WAGNER, W.J Observations of 1-8^ solar X-ray variability during Solar Cycle 21. Advances in
Space Research 8 (7) : f 7) 67-m 76 (1988).

One of the goals of the Solar Electromagnetic Radiation Flux Study (SERFS) for the World
Ionospheric -Thermospheric Study (WITS) is to provide a more complete record of the variation of

155

the daily 1-8^ solar soft X-ray flux. As part of this study, I will calculate the daily mean and
the daily background X-ray fluxes. The background fluxes, which I present in this paper, should
be indicators of the quiescent X-ray flux principally from active regions. In contrast to this
daily background flux, the daily mean flux includes the variable emissions from flares and
coronal mass ejections. Although the present study uses 15 years of data from the NOAA
Geostationary Operational Satellites (GOES) for 1974 to 1988, the inclusion of Solar Radiation
(SOLRAD) data could extend this type of analysis back to 1964. In this paper, daily background
X-ray fluxes in the form of monthly averages and annually smoothed (13-month) values are pre-
sented for Solar Cycle 21. Intermediate term variations (on the scale of months) of the 1-8^
background flux roughly mimic those of other chromospheric and coronal indices such as Ca K, He-
lium 10830^, and 10-cm radio flux. The annually smoothed daily background X-ray flux was unique
in peaking the latest and in showing no broad maximum. This annually smoothed behavior is best
matched by photospheric white-light facular areas. I also discuss anticipated future develop-
ments in soft X-ray monitoring. These include a new series of full-Sun soft X-ray photometers on
the non-spinning GOES I-M. Also on GOES will be the operational USAF-NOAA Solar X-ray Imagers
measuring the 8-20^, the 20-60^, and the thermospherically crucial 255-300 £ bands. Neverthe-
less, this report and that of /l/ both note the continuing existence of an "XUV flux measurement
gap," with no long-term monitoring being planned between the soft X-ray region and the Lyman-
alpha wavelengths.

SE-036

Wu, S.T., M. DRYER, S.M. Han. Three-dimensional, time-dependent MHD simulation of travelling
interplanetary phenomena with solar origin. In Proceedings of the Third International School
for Space Simulation. ISSS-3 . Part 2, Beaulieu, France, June 22-27, 1987, pp. 235-238 (1988).

A three-dimensional, time-dependent magnetohydrodynamic (MHD) numerical model was developed
for the study of travelling solar-interplanetary disturbances. This simulation model is based on
the Lax-Wendroff finite difference scheme, the initial steady-state solar wind is assumed to be
super-sonic and super-alfvenic . The background two-dimensional steady-state solar wind is ob-
tained by dropping the time-dependent terms in the unsteady MHD equations. Transient MHD distur-
bances corresponding to the solar flare-generated shocks are generated at the lower radial
boundary surface. The resulting development and propagation of three-dimensional solar distur-
bances interacting with the background solar wind are numerically simulated. A brief description
of the mathematical formulation and numerical methodology is presented. Simulation results are
shown to demonstrate the validity of the formulation and the capabilities of the model.

SE-037

Wu, S.T. , M. DRYER, R.S. Steinolfson, and E.Tandberg-Hanssen. The effect of the solenoidal
condition on the numerical magnetohydrodynamic simulation of coronal dynamics. The
Astrophvsical Journal. 333:386-394 (1988).

Several magnetohydrodynamic (MHD) simulations of coronal dynamics performed by our group more
than 10 years ago violated the solenoidality condition (V • B = 0) for an "open" magnetic field
topology. Using an improved code, we examine the effect on the physical validity of the numeri-
cal simulation (for a representative pulse disturbance) for the case when solenoidality is de-
liberately violated as compared to the case when it is preserved. We find that the error in-
curred in this specific case ("open" topology) in the energy density and in the plasma density
profiles is rather small and, hence, does not invalidate the earlier conclusions concerning mass
and wave motion.

SE-038

Wu, S.T. , S. Wang, A.H. Wang, and M. DRYER. Application of similitude principle to the numeri-
cal simulation of solar atmospheric dynamics. Advances in Space Research. 8 (11) : 221-226
(1988) .

Numerical simulation has become a tool for the investigation of detailed physical structures
of solar atmospheric dynamics. This tool has become an essential part of solar physics because
the complexity of nonlinear characteristics of much solar phenomena renders the achievement of
analytical solutions to be difficult to obtain. Although computer technology and numerical meth-
ods have made significant progress in recent years, realistic simulation for some prototype
physical systems (for example: the birth and decay of an active region) still is not possible

156

because of the wide range of spatial and time scales that must be considered. Therefore, proper
scaling rules must be recognized for the development of appropriate models. In this paper, we
shall apply the similitude principle to develop these scaling rules for problems of solar atmo-
spheric dynamics. It is found that these rules are highly dependent on the physical nature of
the specific problem under consideration. A set of "similitude critiques" is presented for some
specific physical conditions. Numerical examples of coronal dynamic response and active region
dynamics are used to demonstrate these new ideas.

SE-039

Yeh, T. Flux rope dynamics for loop prominences, coronal mass ejections, and interplanetary
magnetic clouds. In Solar System Plasma Phvsics. J.H. Waite, Jr. , J.L. Burch, and R.L. Moore
(eds.), American Geophysical Union, pp. 299-301 (1989).

No abstract .

SE-040

ZWICKL, R.D., and V.L.Thomas. SPAN: Riding the winds of change. EOS., 70, p. 194 (1989).

No abstract.

157

WAVE PROPAGATION LABORATORY

WP-001

Boe, B.A., P.L. Smith, H.D. Orville, N.C. Knight, M. Hjelmfelt, D.S. Griffith, J.L. Stith, and
R.F. REINK.ING. North Dakota Thunderstorm Project Field Operations Plan, May, 1989. 75 pp.

No abstract.

WP-002

BEDARD, A.J. A review of the evidence for strong, small-scale vertical flows during down slope
wind storms. Proceedings, 6th U.S. National Conference on Wind Engineering, Houston, TX , 8-10
March 1989, National Science Foundation, Washington, D.C., Al , 11-19 (1989).

During downslope windstorms, damage can occur on quite small scales. In the foothills near
Boulder, Colorado, individual trees or lines of trees may be uprooted or snapped off with little
or no damage to surrounding vegetation. Also, considerable damage can occur to individual
structures with no primary damage occurring nearby. Often debris will be scattered in directions
different from that of the mean flow. This paper reviews evidence for the existence of vertical
motions and other small-scale features associated with downslope windstorms. Possible mechanisms
for producing such organized regions of small-scale vorticity are suggested.

WP-003

BEDARD, A.J. Acoustic propagation in the atmosphere at low frequencies: measurement techniques
and observations. Proceedings, 12th Aeroacoustic Conference, San Antonio, TX , 10-12 April 1989,
American Institute of Aeronautics and Astronautics, Washington, D.C., 1108-1115 (1989).

We have measured low-frequency sounds related to aircraft, meteors, and other sources at long
distances. At infrasonic frequencies (below about 20 Hz) atmospheric attenuation is low, permit-
ting long distance propagation. The acoustic energy detected from meteors may be valuable not
only for characterizing meteor details, but also for improving our knowledge of propagation. As
an example we have detected a signal associated with a meteor about 1,000 km distant from the
measurement site. This paper reviews measurement techniques and provides examples of atmospheric
waves detected from distant sources. There is a need to develop methods for the measurement of
low-frequency sounds over well-defined propagation paths. The possibilities for doing this are
discussed. These include the use of Radar Acoustic Sounding Systems (RASS) for propagation stud-
ies. The design goal of RASS is to retrieve atmospheric temperature profiles. One by-product is
information on the attenuation of acoustic waves in a well-defined atmosphere.

WP-004

BEDARD, A.J., J.C. KAIMAL, and H. Zimmerman. Environmental monitoring techniques: An overview.
Proceedings, Sensors Expo West, Anaheim, CA, 23-25 May 1989, Sensors Mag., Peterborough, NH,
301A, 1-7 (1989) .

No abstract .

WP-005

Chelton, D., E.J. WALSH, and J.L. MacArthur. Pulse compression and sea level tracking in satel-
lite altimetry. Journal of Applied Meteorology. 14:407-438 (1989).

With the presently operational altimeter on the U.S. Navy satellite GEOSAT, and three new al-
timeters soon to be launched by the European, French and U.S. space agencies, satellite altimetry
promises to become a standard technique for studying oceanographic variability. Little has been
written about the instrumental technique used to determine sea surface height from altimetric
measurements. In this paper, we summarize the pulse-compression technique by which a radar al-
timeter transmits a relatively long pulse and processes the returned signal in a way that is
equivalent to transmitting a very short pulse and measuring the time history of the returned
power in a sequence of range gates. The effective short pulse enhances the range resolution that
would be obtained from the actual long pulse. The method used onboard the satellite to track the
point on the returned signal corresponding to the range to mean sea level (spatially averaged
over the altimeter footprint) is also summarized. Pulse compression and sea level tracking are
important to the overall error budget for altimetric estimates of sea level. The dominant sources
of sea level tracking errors are discussed.

158

#P-006

CHRISTIAN, T. , and R.M. Wakimoto. The relationship between radar reflectivities and clouds as-
sociated with horizontal roll convection on 8 August 1982. Monthly Weather Review,
117 : 1529-1544 (1989) .

Horizontal convective rolls (HCRs) and cloudstreets that occurred in northeastern Colorado are
studied using Doppler radar data, cloud photography, and vertical soundings. Examination of the
environment in which the HCRs form indicates a boundary layer wind speed that is much lower than
those measured in previous studies. Evidence shows that the HCRs form in a well-defined boundary
layer, yet the cloudstreets that develop seem to exist within a stable layer above. A relation-
ship between the radar reflectivity echoes and the cloudstreets is firmly established. The ech-
oes are aligned directly under the cloudstreets. The echoes at lower-levels are shown to be
caused by convergence of particulate matter into updraft portions of the HCR circulation, yet
evidence indicates the cloud-level echoes are due to backscatter from refractive index
inhomogeneit ies at the surfaces of rising thermals. Examination of the echoes show that the
strongest and tallest echoes are associated with cloud formation, and that echo maxima, spaced
3.0 to 8.0 km apart, exist along the HCR.

WP-007

CHRISTIAN, T., and R.M. Wakimoto. The relationship between radar reflectivities and clouds
associated with horizontal convective rolls. Preprints, 24th Conference on Radar Meteorology,
27-31 March 1989, Tallahassee, FL , American Meteorological Society, Boston, MA, 42-45 (1989).

No abstract.

WP-008

CHURNSIDE, J.H. Angle-of-arrival fluctuations of retroref lected light in the turbulent atmos-
phere. Journal of the Optical Society of America. 3:275-279 (1989).

A geometrical-optics formulation is used to derive expressions for the angle-of-arrival vari-
ance produced when a retroref lector is illuminated and observed through the turbulent atmos-
phere. No fluctuations are observed when the retroref lector is illuminated by collimated or
focused light. Light focused at a distance near twice the reflector range can produce large
fluctuations, whereas diverging illumination tends to produce a variance that is less than that
which would be observed on the transmitted beam at the reflector.

WP-009

CHURNSIDE, J.H., and S.F. CLIFFORD. Optical scint il lometer/Doppler radar instrument for profil-
ing turbulence. Proceedings, SPIE 1989 Technical Symposia on Aerospace Sensing, Orlando, FL ,
28-30 March 1989, SPIE, Bellingham, WA , 159-166 (1989).

The scintillation of starlight contains information about the refractive turbulence strength

Cj} in the atmosphere. The fluctuations to each two-dimensional spatial wavenumber in the scin-
tillation pattern are caused by turbulent features that have the same two-dimensional wavenumber.
Therefore, a receiver that spatially filters the scintillations in starlight can measure the
amount of turbulence in the atmosphewre in a narrow band of wavenumbers. If the entire atmos-
phere were moving with constant velocity, the dominant wavenumber would produce a constant fre-
quency as the turbulence moved across the filer. However, wind velocity typically varies with
altitude and turbuelnce at different altitudes will produce different frequencies. If the wind

velocity profile is known, the vertical profile of C„ can be inferred from the frequency distri-
bution of scintillations at a particular wavenumber.

WP-010

CHURNSIDE, J.H., AND S.F. CLIFFORD. Refractive turbulence profiling using stellar scintillation
and radar wind profiles. Applied Optics, 27:4884-4890 (1988).

The fluctuations of spatially filtered starlight contain information about refractive turbu-
lence strength n at the spatial filter wavenumber. If the turbulence at different heights in
the atmosphere is moving at different speeds, the contribution to the fluctuations from those
heights will occur at different frequencies. Therefore, the *- n profile can be inferred from the
power spectrum of the fluctuations and the wind velocity profile. Vertical resolution is ex-
pected to be in the range of several hundred meters to about a kilometer. Turbulence strength
measurements to better than 50% should be easily obtainable.

159

WP-011

CHURNSIDE, J.H., R.J. LATAITIS, and L.C. Huff. A theoretical and experimental investigation
into turbulence effects on the rapid precision leveling system (RPLS) dispersion subsystem.
NOAA TM ERL WPL-168, 65 pp. (1989).

We have calculated and measured the effects of refractive turbulence on a two-color disper-
sion technique for compensating for refraction in the Rapid Precision Leveling System. We found
that turbulence introduced a large amount of scatter in plots of optical angle-of-arrival vs. a
point measurement of temperature gradient, especially under stable atmospheric conditions. We
found that low-frequency fluctuations could be largely corrected using dispersion. This implies
averaging times longer than the inverse of this ratio must be used to obtain accurate measure-
ments .

WP-012

CHURNSIDE, J.H., and R.J. LATAITIS. Probability density function of optical scintillations
(scintillation distribution). NOAA TM ERL WPL-169, 40 pp. (1989).

The probability density function of optical scintillation in the turbulent atmosphere is inves-
tigated theoretically and experimentally. The log-normally modulated Rician (LR) is the best
available model for these fluctuations. For large apertures, this model reduces to a simple log-
normal density function, which can be used under most practical situations.

WP-013

CHURNSIDE, J.H., and R.J. LATAITIS. Statistics of a reflected laser beam in the turbulent at-
mosphere (path correlation). NOAA TM ERL WPL-172, 86 pp. (1989).

The statistics of the angle of arrival and of the irradiance of a reflected laser beam in the
turbulent atmosphere are calculated. The angle-of-arrival fluctuations of a reflected beam de-
pend strongly on the reflector characteristics; convex surfaces produce smaller fluctuations than
concave surfaces do. The irradiance fluctuations on a path folded by a "large" reflector are
generally larger than those that would be observed on a single path of the same total length.

WP-014

CHURNSIDE, J.H , and K. Shaik. Atmospheric propagation issues relevant to optical communica-
tions. NOAA TM ERL WPL-159, 51 pp. (1989).

Atmospheric propagation issues relevant to space-to-ground optical communications for near-
Earth applications are studied. Propagation effects, current optical communication activities,
potential applications, and communication techniques are surveyed. It is concluded that a di-
rect-detection space-to-ground link using redundant receiver sites and temporal encoding is
likely to be employed to transmit Earth-sensing satellite data to the ground some time in the
future. Low-level, long-term studies of link availability, fading statistics, and turbulence
climatology are recommended to support this type of application.

WP-015

Ciotti, P., G. Schiavon, D. Solimini, P. Tognolatti, and E.R. WESTWATER . Preliminary observa-
tions of atmospheric brightness temperature fluctuations at two microwave frequencies. Chapter
in Microwave Radiometry and Remote Sensing Applications, P. Pampaloni, ed. , VSP, Utrecht, Neth-
erlands, 207-214 (1989).

No abstract.

WP-016

Ciotti, P., G. Schiavon, D. Solimini, P. Tognolatti, and E.R. WESTWATER. The Microwave Radio-
metric Profiler in Integrated Atmospheric Remote Sensing Systems. Chapter in Microwave Radiome-
try and Remote Sensing Applications, P. Pampaloni, ed., VSP, Utrecht, Netherlands. 179-194
(1989) .

No abstract .

WP-017

Coakley, J. A., and J.B. SNIDER. Observed cloud reflectivities and liquid water paths — An up-
date. Extended Abstracts, FIRE Science Meeting, Monterey, CA, 10-14 July 1989, NASA Langley,
63-66 (1989).

160

No abstract.

WP-018

Coakley, J. A., and J.B. SNIDER. Observed reflectivities and liquid water content for marine
stratocumulus . Extended Abstracts, Symposium on the Fole of Clouds in Atmospheric Chemistry and
Global Climate, Anaheim, CA, 30 January-03 February 1989, American Meteorological Society, Bos-
ton, MA, 175-177 (1989) .

No abstract .

WP-019

DERR , V.E., R.S. Stone, and L.S. FEDOR . Sensitivity of solar attenuation by continental stratus
clouds to water and ice content, and cloud albedo. Proceedings, International Radiation Sympo-
sium, Lille, France, 18-24 August 1988, A. Deepak Publishing Co., Hampton, VA, 26-29 (1989).

An evaluation of the effects clouds have on climate depends on determining their radiative
properties that are sensitive to variations in their physical and microphysical characteristics.
Cloud cover, thickness, dropsize distributions and ice or water content vary spatially and tempo-
rally making it difficult to calculate theoretically cloud radiative effects. Thus, there is a
need for simple empirical parameterizat ions to simulate cloud radiative interactions in global
climate models. In this paper we present a simple parameterization of cloud transmissivity as a
function of integrated liquid water content and solar zenith angle for continental stratus water
clouds .

WP-020

Doran, J.C., M.L. Wesely, R.T. McMillen, and W.D. NEFF. Measurements of turbulent heat and mo-
mentum fluxes in a mountain valley. Journal of Applied Meteorology. 28:438 (1989).

Measurements of heat and momentum fluxes along the valley floor of Brush Creek in Colorado are
described. The measurements were taken in the fall of 1984 as part of the Department of Energy's
Atmospheric Studies in Complex Terrain field program. The sensible heat flux to the ground de-
creased from approximately 40-60 Wm'2 prior to midnight to about 10-25 Wm~2 in the morning hours.

Surface friction velocities /<* ranged from approximately 20-15 cms'1 during the corresponding time
periods. Considerable site-to-site variability in flux values was found, and disturbances of the
upwind flow appear to be a significant contributing cause.

WP-021

EBERHARD, W.L. Doppler lidar measurement of profiles of turbulence and momentum flux. Journal
of Atmospheric and Oceanic Technology. 6:809-819 (1989).

A short-pulse C2n Doppler lidar with 150-m range resolution measured vertical profiles of tur-
bulence and momentum flux. Example measurements are reported of a daytime mixed layer with

strong mechanical mixing caused by a wind speed of 15 ms~ , which exceeded the speed above the
capping inversion. The lidar adapted an azimuth scanning technique previously demonstrated by

radar. Scans alternating between two elevation angles allow determination of <u2>, > v2 > , and

< M'2 > . Expressions were derived to estimate the uncertainty in the turbulence parameters. A new
processing method, partial Fourier decomposition, has less uncertainty than the filtering used
earlier. Substantial improvements could be had with higher pulse rate, shorter pulses and wave-
lengths (to improve spatial resolution and minimum range by up to an order of magnitude) , and
operation from an aircraft.

WP-022

EBERHARD, W.L. Doppler lidar observations of urban particulate pollution and meteorology. Pro-
ceedings, 5th Conference on Coherent Laser Radar: Technology and Application, Munich, Federal
Republic of Germany, 5-9 June 1989, German Aerospace Research Establishment, Wessling, Federal
Republic of Germany, 15-18 (1989) .

No abstract.

161

WP-023

EBEHHARD, W.L. Lidar detection and discrimination of multiple fluorescent tracers possessing
distinctive spectral characteristics. Preprint, 6th Joint Conference on Applications of Air
Pollution Meteorology, Anaheim, CA , 29 January-3 February 1989, American Meteorological Soci-
ety, Boston, MA, 128-131 (1989).

No abstract.

WP-024

EBERHARD, W.L., R.E. CUPP, and W.D. NEFF . Wind fields and aerosol distributions in the Denver

Brown Cloud observed by CO} Doppler lidar. Preprints, Sixth Joint Conference on Applications
of Air Pollution Meteorology, Anaheim, CA, 30 January-3 February 1989, American Meteorological
Society, Boston, MA, 117-119 (1989).

No abstract .

WP-025

EBERHARD, W.L. and Z.Z. Chen. Lidar discrimination of multiple fluorescent tracers of atmos-
pheric motions. Ann! ied Ontins , 28:2996-3007 (1989).

An analytical study demonstrates the feasibility of simultaneous lidar measurement and dis-
crimination of multiple fluorescent particle tracers of air motions. Equations are presented for
evaluating signal-to-noise ratio and interfering signals. Matrix methods can solve for the con-
centrations of several tracers from simultaneous measurements in at least as many spectral re-
ceiver channels, even when fluorescence spectra overlap. Two example systems, one with crosstalk
and another without, are evaluated for accuracy in the presence of shot noise and calibration
errors. Potential applications include observing the structure of complex flows and measuring
the effect of release location on atmospheric transport and dispersion.

WP-026

EBERHARD, W.L., and Z.Z. Chen. Lidar technique for measuring multiple fluorescent tracers of
atmospheric motions. NOAA TM ERL WPL-171, 60 pp. (1989).

An analytical study demonstrates the feasibility of simultaneous lidar measurement and dis-
crimination of multiple fluorescent tracers of air motions. Past work on single tracers is re-
viewed, and laboratory measurements of some candidates' fluorescence spectra are reported. The
characteristics of fluorescent materials, lidar components, and potential interfering signals are
summarized. Matrix methods are presented that can solve for the concentrations of several trac-
ers from simultaneous measurements in at least as many spectral receiver channels, even when
fluorescence spectra overlap. Two example systems, one with strong crosstalk and another with-
out, are evaluated for accuracy in the presence of shot noise and calibration errors. Schemes
for calibration are suggested. Objectives for a field demonstration of the concept are outlined.
Potential applications include measuring the effect of release location on atmospheric transport
and dispersion and observing the structure of complex flows.

WP-027

Einaudi, F., BEDARD, A.J., and J.J. Finnigan. A climatology of gravity waves and other coherent
disturbances at the Boulder Atmospheric Observatory during March-April 1984. Journal of the
Atmospheric Sciences. 46:303-329 (1989).

We present a climat ological study of gravity waves and other coherent disturbances at the
Boulder Atmospheric Observatory, during the period mid-March to mid-April 1984. The data were
collected by a network of micro-barographs and by sensors on the 300 m tower. The total obser-
vational period was divided into 522 time segments of 5120 s each. Coherent and incoherent mo-
tions were identified on the basis of a cross-correlation coefficient calculated from the
microbarograph network for each time segment and frequency band analyzed, on the assumption that
the atmospheric state can be described by an equivalent plane wave. Five passbands were consid-
ered in the period range 1-20 min. The analysis indicates that the atmospheric state at these
passbands displays highly coherent structure most of the time. During the interval from 0800 to
1800 local time, coherent motions with cross-correlation coefficient larger than 0.5 are present
about 25% of the time for periods between 1 and 5 min and more than 80% of the time for periods
between 10 and 20 min. In the remaining hours of the day, the percentages rise to more than 40%

162

and 95% of the time, respectively. A relationship is illustrated between the turbulent kinetic
energy measured on the tower and the amplitude of the pressure field at the ground for distur-
bances up to 5 min period. For longer periods, such a relationship appears to be absent, indi-
cating that at longer scales the pressure field is dominated by processes generated higher up
in the troposphere.

WP-028

FAIRALL, C.W., J.E. Hare, and J.B. SNIDER. An eight-month climatology of marine stratocumulus
cloud fraction, albedo and integrated liquid water. Extended Abstracts, FIHE Science Meeting,
Monterey, CA, 10-14 July 1989, NASA Langley, 39-43 (1989).

No abstract .

WP-029

FEDOR . L.S., G.S. Hayne , and E.J. WALSH. Airborne pulse-limited radar altimeter return waveform
characteristics over ice in the Beaufort Sea. Conference Record, Oceans 88, Baltimore, MD, 31
October-1 November 1988, American Meteorological Society, Boston, MA, 1704-1710 (1988).

Pulse-limited radar data taken in March 1978 with the 13.9 GHz AAFE altimeter from 1500 m alti-
tude over ice in the Beaufort Sea are registered to high quality photography. The variations of
the radar return waveform shape and signal level are correlated with the variation of the ice
type determined from photography.

WP-030

FEDOR, L.S., G.S. Hayne, and E.J. WALSH. Ice-type classification from airborne pulse-limited
radar altimeter return waveform characteristics. Proceedings, International Geoscience and
Remote Sensing Symposium, IGARSS 89 Digest, Vancouver, Canada, 3:1949-1952 (1989).

During mid-March 1978, the NASA C-130 aircraft was deployed to Eielson Air Force Base in Fair-
banks, Alaska, to make a series of flights over ice in the Beaufort Sea. The radar altimeter
data analyzed here were obtained northeast of Mackenzie Bay on March 14 in the vicinity of
69.9°N, 134. 2°W. The data were taken with a 13.9 GHz radar altimeter developed under the NASA
Advanced Applications Flight Experiments (AAFE) Program. This airborne radar was built as a
forerunner of the SEASAT radar altimeter and utilized the same pulse compression technique. It
has the same pulse compression ratio (1000:1) as the SEASAT altimeter and approximately the same
range resolution (0.417 m versus 0.469 m for SEASAT). One significant difference was that the
AAFE altimeter has only 24 range gates instead of the 60 that SEASAT had. Pulse-limited radar
data taken with the altimeter from 1500 m altitude over sea ice are registered to high quality
photography. The backscattered power is a function of the surface conductivity and is statisti-
cally related to the number of facets whose surface normal is directed towards the radar. The
variations of the radar return waveform shape and signal level are correlated with the variation
of the ice type determined from photography. The AAFE altimeter has demonstrated that the return
waveform shapee and signal level of an airborne pulse-limited altimeter at 13.9 GHz respond to
sea ice type. The signal level responded dramatically to even a very small fracture in the ice
as long as it occurred directly at the altimeter nadir point. Shear zones and regions of sig-
nificant compression ridging consistently produced low signal levels. The return waveforms fre-
quently evidenced the characteristics of both specular and diffuse scattering, and there was an
indication that the power backscattered at 3° off-nadir in a shear zone was actually somewhat
higher than that from nadir.

WP-031

FEDOR, L.S., M.D. JACOBSON, A.J. BEDARD, E.R. WESTWATER , D.C. HOGG, and R.T. NISHIYAMA. Dual-
channel microwave radiometer for airborne meteorological applications. NOAA TM ERL WPL-157 , 29
pp. (1988)

Cloud liquid and water vapor are important parameters in meteorological processes. This memo-
randum presents the design of a dual-channel microwave radiometer to be installed on a NOAA re-
search aircraft in order to measure these parameters. The discussion includes the utility of the
instrument in variety of research programs including cloud physics, severe storms, cloud clima-
tology, and satellite sensor validation.

WP-032

FEDOR, L.S., and E.J. WALSH. Interpretation of SEASAT radar altimeter returns from an over-
flight of ice in the Beaufort Sea. Proceedings, Oceans '88, Baltimore, MD, 31 0ctober-2 Novem-
ber 1988, IEEE and Marine Technology Society, Washington, DC, 1697-1703 (1988).

163

SEASAT radar altimeter data are examined for the effects of sea ice on the returns during an
overflight of the Beaufort Sea. Waveform parameters and their statistics are combined to form a
parameter sensitive to the presence of sea ice. Variations in the value of this ice parameter
are compared with ice charts obtained from the Canadian Atmospheric Environment Service. Par-
ticular attention is paid to the sensitivity of the radar altimeter to the open-ocean sea ice
boundary.

WP-033

FHELICH, R.G., and G.R. OCHS. Extending the range of validity of optical scintillometer meas-
urements. Proceedings, SPIE 1989 Technical Symposia on Aerospace Sensing, Orlando, Fl, 28-30
March 1989, PSIE, Bellingham, WA , 152-158 (1989).

Measurements of the level of turbulence C\ have been successfully performed with the optical
scintillometer. The successof this instrument is based on the observed fact that the variance of
aperture-averaged scintillation is described by weak scattering theory even for conditions under
which strong scintillation is observed for small apertures. However, for sufficiently long
propagation paths the aperture-averaged variance is affected by strong scattering. The effects
of strong scattering are calculated theoretically and compared to experiment. The physics of
this regime are discussed and the important parameters investigated in order to extend the range
of validity of optical scintillometer measurements.

WP-034

FRISCH, A.S., B.L. WEBER, D.B. WUERTZ, R.G. STRAUCH , and D.A. MERRITT. The variations of c\
between 4 and 14 km above sea level. Preprints, 24th Conference on Radar Meteorology, Tal-
lahassee, FL, 27-31 March 1989, American Meteorological Society, Boston, MA, 725-727 (1989).

No abstract .

WP-035

FRITZ, R.B., and W.D. NEFF . The use of an optical crosswind sensor to study urban airflows.
Preprints, 6th Conference on Applications of Air Pollution Meteorology, Anaheim, CA, 30 Janu-
ary-3 February 1989, American Meteorological Society, Boston, MA, 120-121 (1989).

No abstract .

WP-036

GAYNOR , J. A preliminary study of Boulder Valley's air quality meteorology. Preprints, 6th
Joint Conference on Applications of Air Pollution Meteorology, Anaheim, CA , 30 January 3-Febru-
ary 1989, American Meteorological Society, Boston, MA, 253-255 (1989).

No abstract.

WP-037

GAYNOR, J., and CA. Biltoft. A comparison of two sonic anemometers and fast-response thermome-
ters. Journal of Atmospheric and Oceanic Technology. 6:208-214 (1989).

In an experiment conducted at the Boulder Atmospheric Observatory (BAO) , comparisons were made
between two types of sonic anemometer and thermometer systems. One sonic anemometer was a single-
axis system manufactured by Campbell Scientific, Inc. (SCI), and the other the type routinely
used on the BAO tower. It is similar to the sensors manufactured by Applied Technologies, Inc.,
and AIR, Inc. Two identical Campbell Scientific systems were mounted on each side of the BAO sys-
tem and comparisons made over a range of atmospheric surface layer conditions. The means and
standard deviations of the vertical wind component and temperature, along with the temperature
fluctuation data due to the thermocouple filtering are noted. The effect of these differences on
the measured heat fluxes and temperature variances is significant and discussed in some detail.
It appears that the response of the CSI thermal mass to solar radiation was the major reason for
the discrepancies.

WP-038

GAYNOR, J.E., and L.K. WITTENMEIER. Short-term climatology of Boulder Valley's high-pollution
meteorology. Preprints, 6th Joint Conference on Applications of Air Pollution Meteorology,
Anaheim, CA , 30 January-3 February 1989, American Meteorology Society, Boston, MA, 250-252
(1989) .

164

No abstract .

GIBSON, J.S. Simulated and measured spectral width estimates from a meteorological radar. Mas-
ter's thesis, University of Colorado, Boulder, CO, 77 pp. (1988).

Spectral moment estimation is of importance to radar meteorologists for several reasons. Zero
moment estimates measure average power received by the radar. This can be related to total liq-
uid water content within the pulse volume by an assumed drop size distribution. First moments
are estimates of the Doppler mean velocity and thus can give the meteorologist information on
particle speed, and direction from which the wind field is inferred. Second moment estimates
lead to information on turbulent dissipation rates and wind shear. This paper describes and
compares the results of two signal processing techniques used to compute spectral moments in a
meteorological pulsed Doppler radar system operated by the Wave Propagation Laboratory, Envi-
ronmental Research Laboratories, National Oceanic and Atmospheric Administration (NOAA), in
Boulder, Colorado. Different methods of calculating noise estimates and their effects upon the
corresponding spectral moment estimates are studied. Signal transmission, data acquisition,
real-time processing of the returned echo from the analog-to-digital converter through a pulse
pair processor, and the current post spectral analysis techniques used are reviewed briefly.
Post spectral analysis techniques included are a pulse pair algorithm and a discrete fast
Fourier transform method. These two methods are used to estimate average power received, mean
Doppler velocity, and spectral width. The results of processing simulated and real data by the
two methods are compared for various ranges of spectral widths, signal-to-noise ratios, and
noise suppression algorithms. The resulting biases and errors in the estimates are examined.

WP-040

GOSSARD, E.E. Measuring drop-size distributions in clouds with a clear-air-sensing Doppler ra-
dar. Journal of Atmospheric and Oceanic Technology , 5:640-649 (1988).

The advent of Doppler clear-air radars for wind-height profiling opens the way for their use
in a variety of other applications. This paper uses knowledge of the clear-air Doppler spectrum
for a zenith-pointing radar together with the measured water droplet Doppler vertical velocity
spectrum to calculate spectra of drop number density through clouds of droplets having substan-
tial fall velocity. The method has been applied by Japanese scientists to measure drop-size dis-
tributions of precipitation particles from data acquired at the VHF MU radar facility. Here the
method is applied to records obtained with a 915 MHz wind profiler located at Denver, Colorado,
and the resulting spectra are presented and compared with the spectra that would have been ob-
tained if the clear-air information were ignored. From the number density drop-size distribu-
tion, the corresponding liquid water distribution can be calculated. It is concluded that fail-
ure to take into account turbulence in the medium can result in order-of-magnitude errors in
number density and liquid water. The requirements and limitations of a radar remote sensing drop
spectrometer are discussed.

WP-041

GOSSARD, E.E., and R.G. STRAUCH. Further guide for the retrieval of dropsize distributions in
water clouds with a ground-based clear-air-sensing Doppler radar. NOAA Technical Document. 48
pp. (1989) .

The advent of Doppler clear-air radars for wind-height profiling opens the way for their use in
a variety of other applications. This paper uses knowledge of the clear-air Doppler spectrum
from a zenith-pointing radar together with the measured water droplet Doppler vertical velocity
spectrum to calculate spectra of drop number density through clouds of droplets having substan-
tial fall velocity. The method has been applied by Japanese scientists to measure dropsize dis-
tributions of large precipitation particles from data acquired at the VHF, 7-m wavelength, MU
radar facility and by Gossard to data from the 32-cm wavelength, WPL wind, prof iler at Denver.
This report extends the methodology described in an earlier report. Specifically, methods for
unfolding and using extended spectra are discussed, and deconvolut ion of spectra by Fourier
transformation is compared with the iterative technique. Spectra measured with a 915-MHz, wind-
profiling radar are used as examples and compared with the spectra that would have been obtained
if the clear-air information were ignored. From the number density vs. dropsize distribution,
the corresponding liquid water distribution can be calculated. Failure to take into account tur-
bulence in the medium can result in large errors in number density and liquid water especially in
the neighborhood of spectral lines and large gradients. The advantages and limitations of a ra-

165

dar remote sensing drop spectrometer are described, and radar wavelength-dropsize trade-offs are
discussed .

WP-042

GOSSARD, E.E., and R.G. STRAUCH. Procedural guide for the retrieval of dropsize distributions
in water clouds from ground-based clear-air-sensing Doppler radar observations . NOAA-TM-ERL,
48 pp. (1989) .

The advent of Doppler clear-air radars for wind-height profiling opens the way for their use in
a variety of other applications. This paper uses knowledge of the clear-air Doppler spectrum
from a zenith-pointing radar together with the measured water droplet Doppler vertical velocity
spectrum to calculate spectra of drop number density through clouds of droplets having substan-
tial fall velocity. The method has been applied by Japanese scientists to measure dropsize dis-
tributions of large precipitation particles from data acquired at the VHF , 7-m wavelength, MU
radar facility and by Gossard to data from the 32 cm wavelength, WPL wind profiler at Denver.
This report extends the method and describes procedures that allow spectral lines and details to
be extracted from the radar data. Spectra measured with a 915 MHz, wind-profiling radar are used
as examples and compared with the spectra that would have been obtained if the clear-air informa-
tion were ignored. From the number density vs. dropsize distribution, the corresponding liquid
water distribution can be calculated. Failure to take into account turbulence in the medium can
result in large errors in number density and liquid water especially in the neighborhood of spec-
tral lines and large gradients. The advantages and limitations of a radar remote sensing drop
spectrometer are described. A BASIC program for the retrieval is given in Appendix C.

WP-043

GOSSARD, E.E., and R.G. STRAUCH. The retrieval of dropsize distributions in water clouds from
ground-based clear-air sensing Doppler radar observations . Proceedings, 1st European Wind
Profiler Workshop, Trappes , France, 6-8 March 1989, European Community COST Program, Brussels,
(1989) .

The advent of Doppler clear-air radars for wind-height profiling opens the way for their use in
a variety of other applications. This paper uses knowledge of the clear-air Doppler spectrum
from a zenith-pointing radar together with the measured water droplet Doppler vertical velocity
spectrum to calculate spectra of drop number density through clouds of droplets having substan-
tial fall velocity. This report describes procedures that allow spectral lines and other details
to be extracted from the radar data. Spectra measured with a 915 MHz, wind-profiling radar are
used as examples and compared with the spectra that would have been obtained if the clear-air
information were ignored. From the number density vs. dropsize distribution, the corresponding
liquid water distribution can be calculated. Failure to take into account turbulence in the me-
dium can result in large errors in number density and liquid water especially in the neighborhood
of spectral lines and large gradients. The advantages and limitations of a radar remote sensing
drop spectrometer are described.

WP-044

HALL, F.F. Wind variability measured by Doppler lidar. Short Note to Journal of Applied Meteor-
ology, 28:155-158 (1989).

Wind power spectral density measured in the lower and middle troposphere under zonal flow con-
ditions is consistent with a -5/3 slope to frequencies as high as 10 Hz. By conversion of fre-
quency to a spatial coordinate it is found that a satellite-borne lidar when averaging such winds
over a 300 km grid scale would measure the synoptic-scale wind with a 98% representativeness in-
dex .

WP-045

HARDESTY, R.M. Processing of low signal-to-noise ratio Doppler lidar returns. Proceedings, 5th
Conference on Coherent Laser Radar, Munich, Federal Republic of Germany, 5-9 June 1989, German
Aerospace Research Establishment, Wessling, FRG, 169-172 (1989).

No abstract .

166

WP-046

HARDESTY. P.M., R. BANTA , R.E. CUPP, W.L. EBERHARD, J. INTRIERI. and M.J. POST. Examples of

wind phenomena measured by a pulsed COi Doppler lidar. Proceedings, 5th Conference on Coherent
Laser Radar, Munich, Federal Republic of Germany, 5-9 June 1989, German Aerospace Research Es-
tablishment, Wessling, FRG, 3-6 (1989).

No abstract.

WP-047

HILL, R.J. Implications of Monin-Obukhov similarity theory for scalar quantities. Journal of
the Atmospheric Sciences. 46:2236-2244 (1989).

Monin-Obukhov similarity theory of surface-layer turbulence has been extended to include all
scalar quantities. The tenets of this theory, as it is presently practiced, are followed to
their logical conclusions, which produces some novel results. First, the similarity theory is
applied to the variance of a scalar quantity and its correslation with another scalar quantity.
For this similarity to apply to all scalar quantities, it is shown that the dimensionless func-
tions of stability are all equal, that the correlation coefficient of any two scalars is +1 or
-1, and that the correlation of two scalars has the same sign as the product of their fluxes.
These results also apply to structure parameters and cross-structure parameters as well as to the
dissipation rates of the scalar's variances and correlations. It is shown that the fluctuations
of all the scalar quantities are proportional to one another. On the basis of Monin-Obukhov
similarity, the Obukhov-Corrsin constants (i.e., Kolmogorov constants) fo scalar spectra and
cospectra are shown to be equal, and are expressed as a function of stability. The dimensionless
fluxes of scalar variance and correlation are shown to be the same for all ccalars. Likewise the
dimensionless functions for gradient production of scalar variance and covariance are the same
for all scalars. All the above functions for gradient production of scalar variance and covari-
ance are the same for all scalars. All the above demonstrate that internal consistency of the
similarity theory of the horizontally homogeneous surface layer. The the same for all scalars.
All the above demonstrate that internal consistency of the similarity theory of the horizontally
homogeneous surface layer. The above results, however, show in what manner the similarity theory
becomes an overidealizat ion when it is extended to all scalar quantities. In particular, the in-
ternal dynamics of the surface itself is not considered in the similarity theory; yet it is rea-
sonable that such internal dynamics causes violations of the similarity theory.

WP-048

HILL, R.J. Structure functions and spectra of advected scalar quantities in the inertial-
convective and viscous-convect ive ranges of turbulence. Journal of the Atmospheric Sciences.
46: 2245-2251 (1989) .

The Obukhov-Corrsin constants (often referred to as Kolmogorov constants) are the constants of
proportionality in formulas pertaining to the inertial-convect ive range of structure functions
(or spectra) of scalar quantities and the cross-structure functions (or cospectra) of pairs of
scalar quantities. These Obukhov-Corrsin constants are shown to be equal for all scalar quanti-
ties and pairs of scalar quantities. Ther inert ial-convect ive and viscous-convect ive range for-
mulas for cross-structure functions (or cospectra) can be deduced from those of the structure
functions (or spectra). Special attention is given to the case of dimensionless scalar quanti-
ties like refractive index for which the inert ial-convect ive range and for the spectra and
cospectra in the viscous-convective range. The structure and cross-structure functions do not
possess viscous-convective ranges distinct from their viscous-diffusive ranges, however, and di-
mensional analysis gives incorrect results in this case.

WP-049

HILL, R.J., R.A. Bohlander, S.F. CLIFFORD, and R.J. LATAITIS. Fluctuations in millimeter-wave
signals caused by clear-air turbulence and inclement weather. Proceedings, SPIE 1989 Technical
Symposia on Aerospace Sensing, Orlando, FL, 28-30 March 1989, SPIE, Bellingham, WA , 234-242
(1989) .

Observat ions and theory for millimeter-wave propagation through clear-air turbulence, rain,
fog, and snow are reviewed. Measurements have shown the effects of refractive and absorptive
fluctuation in air. Measured quantities include the intensity, the phase difference between
spaced antennas for a singl electromagnetic frequency as well as phase difference at a single

167

antenna for waves having differing frequencies. Typical statistics of these quantities are their
variances, structure functions, temporal spectra, and probability distributions.

WP-050

Hocking, W.K., P.T. MAY, and J. Rottger. Interpretation, reliability and accuracies of parame-
ters deduced by the spaced antenna method in middle atmosphere applications. Pure and Applied
Geophysics. 130:571-604 (1989).

The spaced antenna method has proved to be an important and relatively inexpensive radar tech-
nique for making measurements of atmospheric wind velocities and other parameters. This discus-
sion examines the reliability and accuracies of various parameters which can be measured with the
technique .

WP-051

HOGG, D.C. An historical perspective of microwave propagation and antenna research. IEEE Anten-
nas and Propagation Society Newsletter, 31:23-26 (1989).

No abstract .

WP-052

HOGG, D.C. and J.B. SNIDER. Microwave radiometry in measurement of radio pathlength through
the troposphere. In Brunner, F.K. (Ed.), 1988, "Atmospheric Effects on Geodetic Space Measure-
ments," Monograph 12, School of Surveying, Univ. of New South Wales, 63-70.

The design of millimeter-wave radiometers for accurate measurement of integrated water vapor on
earth-space paths to provide radiowave excess pathlength for satellite based surveying systems is
given. Effects of fluctuations in the integrated vapor are discussed. The utility of radiomet-
ric measurements in improving attainable accuracy of baseline estimation using the GPS system is
illustrated by an example.

WP-053

INTRIERI, J. Density currents in the atmosphere as observed by the NOAA Doppler lidar. Proceed-
ings, LASE '89, Society of Photo-Optical Instrumentation Engineers, Bellingham, WA , 1062:
249-256 (1989) .

Three different examples of atmospheric density currents are observed by the NOAA Doppler
lidar. The lidar has proved to be an extremely useful sensor to study the mesoscale dynamics of
these clear-air phenomena.

WP-054

KAIMAL, J.C., S.F. CLIFFORD, and R.J. LATAITIS. Effect of finite sampling on atmospheric spec-
tra. Boundarv-Laver Meteorology. 47:337-347 (1989).

The effect of a finite averaging time on variances is well known, but its effect on power
spectra is less clearly understood. We present numerical solutions for the spectral distortion

arising from sampling over a finite time interval 7" and show that the commonly used filter func-
tion (/ - sinc2nfT ) , valid for variances, is a reasonable approximation for power spectra only when
7" > I0rw. where / is the cyclic frequency, and im is the dominant time scale of the process. Our

results exhibit an increasingly steeper low-frequency roll-off as T decreases relative to Tm ,
indicating that the measured spectrum is subject to a greater suppression of the lower frequen-
cies (/<l/7") than predicted by (1 - sinc2irJT ) . This suppression is, in a sense, compensated by an
overest imation of spectral estimates in the frequency range /> 1/7*.

WP-055

KING, C.W., W.D. NEFF, and V.A. LEFEBVRE. Radiometric profiler measurements of water vapor for
use in visibility analysis. Preprints, 6th Conference on Applications of Air Pollution Meteor-
ology, Anaheim, CA, 30 January-3 February 1989, American Meteorological Society, Boston, MA,
122-124 (1989).

No abstract.

168

WP-056

KING. C.W.. and C.A. RUSSELL. Temperature structure effects on pollutant distribution in the
Denver metropolitan area. Preprints, 6th Conference on Applications of Air Pollution Meteorol-
ogy, Anaheim, CA , 30 January-3 February 1989, American Meteorological Society, Boston, MA,
243-245 (1989) .

No abstract .

WP-057

KROPFLI , P. A. Hazard index calculation for May 31, 1984 microburst at Erie, Colorado. NOAA TM
ERL WPL-155, 50 pp. (1988).

The two X-band Doppler radars, operated by the NOAA Wave Propagation Laboratory, were used to
collect high resolution data within a small, benign-looking microburst during the PHOENIX II
boundary layer experiment. The lowest 2.5 km of the microburst was observed throughout its de-
velopment and dissipation over a 15 minute period. These observations presented an excellent
opportunity to compute a quantitative threat to a hypothetical aircraft whose flight track would
carry it through the microburst. This hazard index is based on the kinetic energy loss to the
aircraft that would be produced by the microburst; it is a function of the vertical air motion,
horizontal spatial derivatives of the wind field, and the assumed aircraft air speed and direc-
tion. Indices were computed and plotted for all eight volume scans and peak values were observed
to be sufficiently high to present a significant hazard to an aircraft even though the virga-pro-
duced microburst was visually unimpressive.

WP-058

Kusters, J., B.J. RYE, and A. Walker. Spatial weighting in laboratory incoherent light scatter-
ing experiments. Aonl ied Ontics . 28:657-664 (1989).

Diffraction-based calculations of the relative spatial weighting of the observed volume in in-
coherent scattering experiments, applicable to both direct detection and heterodyne systems and
arbitrary transmitter and receiver profiles, have been largely confirmed in laboratory measure-
ments using a COi laser. The results indicate that heterodyne systems have superior spatial reso-
lution at small scattering angles for a given detector geometry and permit quantitative assess-
ment of this and the greater sensitivity of coherent systems to misalignment.

WP-059

LATAITIS, R.J., and J.H. CHURNSIDE. Propagation of an elliptical laser beam through the turbu-
lent atmosphere (vertical beams). NOAA TM ERL U(PL-165, 13 pp. (1989).

We calculate the effect of a turbulence gradient on the mean irradiance profile of an ellip-
tical beam. We conclude that in a turbulent atmosphere the peak irradiance can be shifted to a
point farther from the ground. Also, the vertical symmetry of the beam can be perturbed because
of greater horizontal beam spreading at lower heights where turbulence is stronger. However,
this effect is significant only for highly elliptical beams, and only when the horizontal beam
divergence is determined by turbulence.

WP-060

LATAITIS, R.J., and J.H. CHURNSIDE. Statistics of two-color laser beam propagation in the tur-
bulent atmosphere (spectral correlation). NOAA TM ERL WPL-167, 17 pp. (1989).

We develop expressions for the statistics of the angle-of-arrival fluctuations and of the
irradiance fluctuations for a two-color laser beam after propagation through refractive turbu-
lence in the atmosphere. The correlation, the cospectrum, and the coherence are included. We
find the fluctuations in the angle-of-arrival and irradiance at two wavelengths to be highly
correlated for most conditions of interest.

WP-061

LATAITIS, R.J., and J.H. CHURNSIDE. Turbulence effects on reflected optical patterns. NOAA TM
ERL WPL-166, 10 pp. (1989).

The vacuum irradiance pattern produced by an optical beam illuminating a distant receiving
plane is distorted by atmospheric turbulence. The distortion manifests itself as a wander and
"breathing" of the beam spot. Reflected optical patterns exhibit the same type of distortion but

169

to a degree that depends on the type of reflector. We describe the reflected irradiance pattern
in terms of several length scales of interest. Numerically derived optical patterns for a spheri-
cal wave reflected from a plane retroref lector are also presented. Various reflector diameters
and turbulence strengths are considered. These results indicate that the small-scale structure in

the reflected optical pattern is no longer discernible when i>o < Dr, where Qq is the spherical wave

coherence length and Dr is the reflector diameter.

WP-062

Li, F., W. Large, W. Shaw, WALSH, E.J., and K. Davidson. Ocean radar backscatter relationship
with near surface winds: A case study during FASINEX. Journal of Physical Oceanography.
19: 342-353 (1989) .

A case study of the ocean radar backscatter dependence on near-surface wind and wind stress is
presented using the data obtained on 18 February 1986 during the Frontal Air-Sea Interaction Ex-
periment. Our interest in this case stems from the particular wind-wave conditions and their
variations across a sharp sea surface temperature front. These are described. Most importantly,
the small change in wind speed across the front cannot account for the large change in wind
stress implying significant changes in the drag coefficient and surface roughness length. When
compared with previous results, the corresponding changes in radar backscatter cross section at
50 deg and 20 deg angles of incidence were consistent with the observed variations in wind
stress, but inconsistent with both the mean wind and the equivalent neutral wind. Although not
definitive, the results strengthen the hypothesis that radar backscatter is closely correlated to
wind stress, and, therefore, could be used for remote sensing of the wind stress itself over the
global oceans.

WP-063

MA, K. , F.F. HALL, R.M. HARDESTY , T.R. LAWRENCE, and R.E. CUPP. Heterodyne quantum efficiency
of a HgCdTe infrared Doppler detector. Applied Optics. 28:1750-1751 (1989).

Quantum efficiency of a HgCdTe photodiode was measured for both direct and heterodyne detec-
tion. Both measurements employed a blackbody radiation source; the receiver bandwidth for the
heterodyne measurements was 50 MHz to approximate a Doppler lidar receiver. The quantum effi-
ciency of the detector in the heterodyne mode was -0.3, nearly 40% lower than the direct detec-
tion efficiency.

WP-064

MARTNER , B.E. Photogrammet ric/radar analysis of the 2 July tornado during CINDE. Preprints,
24th Conference on Radar Meteorology, Tallahassee, FL, 27-31 March 1989, American Meteorologi-
cal Society, Boston, MA, 58-61 (1989).

No abstract.

WP-065

MARTNER, B.E., A.S. FRISCH, and R.A. KROPFLI . NOAA X-band radar measurements in 3CP0. NOAA TM
ERL WPL-153, 58 pp. (1988).

The NOAA Wave Propagation Laboratory participated in the Cloud Chemistry Cloud Physics Organi-
zation (3CP0) field project in east-central Illinois in the summer of 1988. The laboratory
planned to use its circular polarization diversity Doppler X-band radar to study venting of pol-
luted boundary layer air by convective clouds using a new technique known as TRACIR. The tech-
nique and the experimental plan are described and a summary of the radar operations is given.
Unfortunately, a severe drought prevented the necessary clouds from forming during the project.
Numerous measurements were made with the radar in clear air conditions using vertical scans and
the velocity azimuth display (VAD) method to obtain data on turbulence characteristics of the
planetary boundary layer. The VAD measurements and analysis procedures are described as well as
a test of the efficiency of the NOAA airborne chaff cutters. The complete radar tape log for the
project is included.

WP-066

MARTNER, B.E., and R.A. KROPFLI. A new radar technique for observing the exchange of air be-
tween clouds and their environment. Proceedings, 6th Joint Conference on Applications of Air
Pollution Meteorology, Anaheim, CA, 30 January - 3 February 1989, American Meteorological Soci-
ety, Boston, MA, 133-136 (1989).

170

A remote sensing technique which uses circular dual-polarization radar to track chaff-filled
parcels of air has been developed and tested. The chaff which acts as a as an air motion tracer
can be detected by the radar's circular depolarization ratio measurement inside clouds even
when the chaff's reflectivity signal is undetectable. A plan to employ the technique in a study
of how effectively convective clouds vent pollutants out of the boundary layer is outlined.

WP-067

MARTNER, B.E., and R.A. KROPFLI. Tracking chaff-filled air through clouds with circular polari-
zation diversity radar. Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL , 27-31
March 1989, American Meteorological Society, Boston, MA, 332-335 (1989).

No abstract.

WP-068

MAY, P.T., B.L. WEBER, R.G. STRAUCH, R.J. LATAITIS, K.P. MORAN, and D.A. MERRITT. Single-sta-
tion ocean current vector measurement: application of the spaced antenna (SA) technique. Geo-
physical Research Letters, 16:999-1002 (1989).

The Spaced Antenna (SA) technique is applied to measuring ocean surface currents for the first
time. This allows the measurement of the ocean surface current transverse to the radar beam as
well as the radial current and thus eliminates the requirement of two separate radars to measure
the full current vector as with present ocean surface current radar systems. Therefore, this
technique offers considerable advantages for ocean current mapping in terms of simplicity for
real-time operational systems and could have wide applications, for example at sites where it is
not practical to have two separate radars.

WP-069

MAY, P.T., K.P. MORAN, and R.G. STRAUCH. The accuracy of RASS temperature measurements. Journal
of Applied Meteorology. (1989) .

Temperature measurements obtained using radiosondes and Radio Acoustic Sounding Systems (RASS)
are compared to assess the utility of the RASS technique for meteorological studies. The agree-
ment is generally excellent: rms temperature differences are about 1.0 degrees C for comparisons
during a variety of meteorological conditions. Observations taken under ideal circumstances in-
dicate that a precision of about 0.2°C is achievable with the RASS technique. A processor being
designed for RASS should allow routine temperature measurements approaching this precision.

WP-070

MAY, P.T., T. Sato, M. Yamamoto, T. Tsuda, and S. Fukao. Errors in the determination of wind
speeds with Doppler radars. Journal of Atmospheric and Oceanic Technology. 118:235-242 (1989).

A numerical model to simulate radar data is used for testing various estimators of the Doppler-
shift in Doppler radar echoes. Five estimators for the Doppler shift are considered: the pulse
pair and poly-pulse pair algorithms in the correlation domain, least squares fitting to the power
spectra in linear and logarithmic coordinates, and a matched filter in the spectral domain. An
experiment with real data, to test the algorithms further and to assess the importance of small-
scale wind fluctuations on radar performance, shows that geophysical limitations on the accuracy
of the wind estimates are the dominant factor for observations with good signal-to-noise.

WP-071

MAY, P.T., AND R.G. STRAUCH. An examination of some algorithms for spectral moment estimation.
Preprint, 24th Conference on Radar Meteorology, Tallahassee, FL, 27-31 March 1989, American
Meteorological Society, Boston, MA, 429-432 (1989).

It is desirable to find algorithms for the calculation of spectral moments, especially the
first moment or mean radial velocity measured by a Doppler radar, which offer good accuracy at
both high and low signal-to-noise ratio (SNR) . When the SNR is very low, some moment estimates
will have very large errors caused by noise. A method to average data which includes outliers is
also examines. Artificially generated data are used to test various algorithms. First, we test
algorithms which simply estimate the first moment of the signal spectrum. Then, procedures where
groups of such estimates are combined to give an average value are tested. A problem that occurs
with data with poor SNR is that completely erroneous mean velocity values (outliers) are some-
times obtained. Scatter from other targets such as aircraft can also cause these outliers. An

171

averaging algorithm is desired whereby the outliers do not enter into the average value. One
such algorithm is the consensus averaging technique (Fischler and Bolles, 1981.

WP-072

MAY, P.T., and R.G. STRAUCH. An examination of wind profiler data processing algorithms. Jour-
nal of Atmospheric and Oceanic Technology. 6:731-735 (1989).

No abstract.

WP-073

MAY, P.T., R.G. STRAUCH, and K.P. MORAN. Altitude coverage of temperature measurements using
RASS with wind profiler radars. Geophysical Research Letters. 15:1381-1384 (1989).

The Radio Acoustic Sounding System (RASS) technique for measuring temperature profiles with
good time and height resolution has been applied using wind profiling radars operating at three
frequencies (49.8, 404.37, and 915 MHz). The performance of the three systems is discussed in
terms of the altitude coverage of the temperature measurements and physical processes limiting
the coverage. The lower frequencies can probe greater altitudes, but the 49.8 MHz wind
profilers have a minimum range of about 2.1 km limiting their usefulness for some studies. These
preliminary results indicate that the use of RASS in concert with wind profilers has promise for
operational meteorology.

WP-07 4

MAY, P.T., R.G. STRAUCH, and K.P. MORAN. RASS applied to wind profiler radars. Preprints,
IGARSS 89, 12th Canadian Symposium on Remote Sensing, Vancouver, B.C., 10-14 July 1989, IEEE,
New York, ( 1989) .

Radio Acoustic Sounding (RASS) has been applied with wind profiler radars. Temperature profiles
have been obtained up to several kilometers in altitude with RMS differences between the RASS
measurements and conventional radiosonde observations of 1 degree C have been obtained. The
technique shows great promise for a number of meteorological applications.

A numerical model to simulate radar data is used for testing various estimators of the Doppler
shift in Doppler radar echoes. The estimators are the pulse pair and poly-pulse pair algorithms
in the correlation domain, a least-squares fitting to the spectral peak of the power spectra, and
direct calculations of the moments from periodograms in the spectral domain. Two averaging
schemes (a consensus average and a median filter) are also examined for data with poor signal-to-
noise ratios. The data processing method used in Doppler radar wind profilers, which operate
over a very wide range of signal to noise ratios, is examined in detail. It is shown that the
direct moment calculation combined with a consensus averaging technique has the best overall per-
formance for accuracy and the ability to use data with a very low signal-to-noise ratio.

WP-075

MAY, P.T. , R.G. STRAUCH, K.P. MORAN, and W.D. NEFF. High resolution weather observations with
combined RASS and wind profiler. Preprints, 24th Conference on Radar Meteorology, Tallahassee,
FL, 27-31 March 1989, American Meteorological Society, Boston, MA, 746-749 (1989).

It has recently been shown that the Radio Acoustic Sounding System (RASS) for remotely measur-
ing atmospheric (virtual) temperature can be applied to wind profiler radars in a straightforward
manner with excellent results (May et al., 1988). The technical requirements and the application
of RASS to the wind profilers in the Colorado network was discussed in the companion paper
(Strauch et al., 1989). The purpose of this paper is two-fold: the first part of the paper fo-
cuses on some reasonably extensive comparisons of the temperature profiles obtained with RASS
using the Platteville 49.8 MHz profiler and the Denver 915 MHz profiler against profiles obtained
with radiosonde observations (RAOB) . These comparisons were made to verify that accurate tempera-
ture profiles can be obtained using the RASS profiler combination; they generally show excellent
agreement, e.g. . Figure 1. This example was taken under light wind conditions so a large height
coverage was obtained. Results from four consecutive RASS soundings are given on this figure, but
they overlap at most altitudes, showing the high precision that can be obtained. The second part
of the paper focuses on preliminary analysis of an interesting event to illustrate the utility of
the high time resolution observations.

172

WP-076

MEITIN. F.J., and R.F. FEINKING. A Doppler radar analysis of a winter mountain storm.
Preprints, 5th WMO Conference on Weather Modification and Applied Cloud Physics, Beijing, Peo-
ple s Republic of China, 8-12 May 1989, WMO, Geneva, 93-96 (1989).

No abstract .

WP-077

MEITIN, R.J., and R.F. REINKING. A preliminary radar analysis of a winter mountain storm.
Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL , 27-31 March 1989, American
Meteorological Society, Boston, MA, 490-493 (1989).

No abstract.

WP-07 8

Menzies, R.T., and R.M. HARDESTY. Coherent Doppler lidar for measurements of wind fields. Pro-
ceedings IEEE, 77:449-462 (1989).

The use of coherent Doppler lidar for remote measurements of atmospheric wind fields is receiv-
ing increasing consideration as a valuable tool for studies of atmospheric dynamics, both on a
local scale using ground-based systems and on a global scale from an earth-orbiting satellite
platform. The signal processing techniques for obtaining the velocity estimates, and the funda-
mental factors that influence coherent lidar performance in this context, are reviewed. The simi-
larities and distinctions between Doppler lidar and Doppler radar are discussed. Coherent Doppler
lidars now have the capability to map wind fields over selected regions in the lower atmosphere
and greatly enhance the capability to visualize flow patterns in real time. Examples of this ca-
pability are presented. The concluding discussion concerns several of the salient features of the
NASA concept for an earth-orbiting Doppler lidar to be launched in the late 1990s.

WP-079

MILLER, P. A., and M.J. FALLS. Pilot study of methods to decrease measurement errors of trod sea
level tracking in satellite altimetry. Journal of Atmospheric and Oceanic Technology. 6:225-234
(1989) .

Results of radiometer temperature profile simulations are analyzed in order to examine the hy-
pothesis that knowledge of temperature inversion parameters obtained from other instruments would
substantially improve the accuracy of radiometric temperature profiles. Five variations of a sta-
tistical retrieval method are used to produce radiometric temperature profiles. These profiles
are then compared with radiosonde data under both inversion and noninversion conditions. The
best algorithm yields consistently better results than the traditional (pure radiometric) tech-
nique, but still fails to correctly reproduce the radiosonde inversions.

WP-080

MILLER, P. A., and M.J. FALLS. The incorporation of inversion characteristics into ground-based
microwave temperature soundings: a simulation study. Chapter in Microwave Remote Sensing of the
Earth System. A. Chedin, ed . , A. Deepak Publishing, Hampton, VA, 51-73 (1989).

Results of radiometer temperature profile simulations are analyzed in order to examine the
hypothesis that knowledge of temperature inversion parameters obtained from other instruments
would substantially improve the accuracy of radiometric temperature profiles. Five different
temperature retrieval algorithms are presented and compared with radiosonde data under both in-
version and non-inversion conditions. The best algorithm yields consistently better results than
the traditional (pure radiometric) technique, but still fails to perfectly reproduce the
radiosonde inversions.

WP-081

MORAN, K.P., R.G. STRAUCH, K.B. EARNSHAW, D.A. MERRITT, B.L. WEBER, and D.B. WUERTZ . Lower
tropospheric wind profiler. Preprint, 24th Radar Meteorology Conference, Tallahassee, FL, 27-31
March 1989, American Meteorological Society, Boston, MA, 728-731 (1989).

No abstract.

173

WP-082

NEFF, WD. An overview of 1986-1988 Denver pollution studies. Preprints, 6th Conference on Ap-
plications of Air Pollution Meteorology, Anaheim, CA , 30 January-3 February 1989, American Me-
teorological Society, Boston, MA, 228-229 (1989).

No abstract .

WP-083

NEFF, VI. D. Meteorological classifications used in the 1987-1988 Denver Brown Cloud study.
Preprints, 6th Conference on Applications of Air Pollution Meteorology, Anaheim, CA, 30 Janu-
ary-3 February 1989, American Meteorological Society, Boston, MA, 74-77 (1989).

No abstract .

WP-084

NEFF, W.D. The ontogeny of Denver pollution episodes. Preprints, 6th Conference on Applications
of Air Pollution Meteorology, Anaheim, CA, 30 January-3 February 1989, American Meteorological
Society, Boston, MA, 230-234 (1989).

No abstract.

WP-085

NEFF, W.D., and W.L. EBERHARD. Doppler lidar studies of the South Platte River Valley.
Preprints, 6th Joint Conference on Applications of Air Pollution Meteorology, Anaheim, CA, 29
January-3 February 1989, American Meteorological Society, Boston, MA, 132-132 (1989).

No abstract .

WP-086

NEFF, W.D., and C.W. KING. Minisodar observations of inversion formation in the Denver urban
core. Preprints, 6th Conference on Applications of Air Pollution Meteorology, Anaheim, CA, 30
January-3 February 1989, American Meteorological Society, Boston, MA, 78-78 (1989).

No abstract.

WP-087

NEFF, W.D., and C.W. KING. The accumulation and pooling of drainage flows in a large basin.
Journal of Applied Meteorology. 27:518- (1989).

We describe a sequence of tethersonde and sodar measurements showing the effects of the pooling
of cold air drainages in a basin located along the Colorado River below the Brush Creek drainage.
Results obtained during periods of weak ambient winds show that the basin fills over a period of
several hours, then eventually overflows. The depth of the pool is such as to affect tributary
drainages, such as that of Brush Creek, and to cause the accumulating drainage jets to become
elevated as they flow down the larger drainage channels into the basin.

WP-088

NEIMAN, P.J. The Boulder, Colorado, concentric halo display of 21 July 1986. Bui letin of the

American Meteorological Society, 70:258-264 (1989).

No abstract .

WP-089

NEIMAN, P.J., R.M. HARDESTY , M.A. SHAPIRO, and R.E. CUPP . Doppler lidar observations of a
downslope windstorm. Bulletin of the American Meteorological Society. 45:2265-2275 (1988).

During January and February 1987, the NOAA/WPL pulsed Doppler lidar was deployed in the foot-
hills west of Boulder, Colorado, to study orographically induced flows over the Continental Di-
vide. On 29 January 1987, the lidar, with its unique spatial and temporal data-gathering capa-
bilities, documented a downslope windstorm affecting the Boulder area and the rest of the Front
Range. The lidar recorded in detail 1) a low-level leeside wind maximum, 2) propagating wind
gusts exhibiting two distinct periodicities, and 3) the eastern edge of a mountain wave feature
where a jumplike flow reversal occurred. Such structures have not previously been observed with

174

comparable detail by conventional in situ and remote sensing instruments. The observed phenomena
were similar to results obtained from mountain-wave numerical models. The most notable of the
structural simi lariat ies was between the observed and modeled wind gusts.

WP-090

OCHS, G.R. Measurement of the refractive-index structure parameter by incoherent aperture scin-
tillation techniques. Proceedings, SPIE 1989 Technical Symposia on Aerospace Engineering, Or-
lando. FL, 28-30 March 1989, SPIE, Bellingham, WA , 107-115 (1989).

The current status of large aperture scintillation techniques for refractive index structure
parameter measurement is reviewed, instrument design considerations and limitations are dis-
cussed, and a new incoherent aperture profiling system is described.

WP-091

OCHS. G.R., J.J. WILSON, and S.W. ABBOTT. A refractive-index structure parameter profiling sys-
tem. NOAA TM ERL WPL-161, 47 pp. (1989).

We describe an instrument that measures the refractive-index structure parameter over three
segments of optical paths from 300 to 600 meters long.

WP-092

OCHS, G.R., and R.B. FRITZ. Observations of spherical-wave scintillation in strong refractive-
index turbulence. NOAA TM ERL WPL-154, (1988).

We present some observations of the fine structure of spherical-wave intensity scintillation,
with concurrent independent measurements of refractive-index turbulence and inner scale, made
over a 1 km path. Quantitative measurements of the spatial covariance were made by continuously
cycling the spacing of two 1-nim diameter detectors, by operating continuously at fixed spacings,
and by converting the temporal frequency observed by a small-diameter detector, moving at high
speed in a circular pattern, to spatial wavelength. Qualitative information was also obtained
through high-speed photographs. Details much smaller than the inner scale, which did not arise
from the last few meters of the path, were observed by all techniques.

WP-093

Parsons, C.L., and E.J. WALSH. Off-Nadir radar altimetry. IEEE Transactions on Geoscience and
Remote Sensing. 27:215-224 (1989).

Radical changes are likely in the design of satellite radar altimeters in the post-TOPEX/
POSEIDON era. The implementation of the multiple-beam altimeter to provide off-nadir altimetry
over a wide swath would provide much better information on oceanographic features whose time
variability is more rapid than data grids that can be obtained from nadir altimetry by satellite
orbital-precession. The paper briefly reviews and contrasts the characteristics of nadir versus
off-nadir altimetry and points out a potentially serious problem that has been overlooked by ear-
lier invest igators , who focused on the nongeophysical error sources in off-nadir altimetry. Spa-
tial gradients of radar cross section on the sea surface, caused by wind or current gradients or
the variation of radar cross section with incidence angle, could introduce significant range er-
rors in off-nadir altimetry. This potentially crippling effect can be overcome by leaving the
traditional 13 GHz frequency and implementing the multibeam altimeter at 36 GHz. A multibeam
altimeter proposed for the Eos is described as well as a Multimode Airborne Radar Altimeter being
developed to study problems inherent in off-nadir altimetry.

WP-094

Porch, W.M., R.B. FRITZ, R.L. Coulter, and P.H. Gudiksen. Tributary, valley and sidewall air-
flow interactions in a deep valley. Journal of Applied Meteorology. 28:579-589 (1989).

Field experiments measuring nocturnal tributary flows have shown complex internal structure.
Variations in the flow range from short-term (8-16 min) oscillations (related to tributary/valley
flow interactions) to long-term flow changes throughout the night (related to upper ridge slope
and tributary sidewall cooling rate changes). The mean vertical structure in the tributary flow
shows a three layer structure. Outflow winds are observed near the surface and in an elevated
jet up to several hundred meters height. A flow minimum or counterflow exists at about the
height of the drainage flow maximum in the main valley. Comparisons of flow volumes and vari-
ations from a single large tributary show that 5%-15% of the nocturnal flow in the main valley

175

may be contributed through one tributary. This implies that tributaries may dominate main valley
sidewall and midvalley subsidence contributions to valley drainage flows.

WP-095

POST, M.J. Aerosol backscatter profiles at 10.59 and 9.25 micrometers near Mauna Loa, Hawaii,
1988. Proceedings, 5th Conference on Coherent Laser Hadar: Technology and Applications, Munich,
Federal Republic of Germany, 5-9 June 1989, Optical Society of America, Washington, D.C.,
239-241 (1989) .

No abstract .

WP-096

POST, M.J. Remote sensing of winds and particulates using a C02 Doppler lidar. Proceedings,
LASERS 88, South Lake Tahoe , NV , 4-9 December 1988, Society for Optical and Quantum Electron-
ics ,535-537 (1989) .

No abstract.

WP-097

PRIESTLEY, J.T. Data acquisition and analysis for the 1988 micrometeorological scintillation
experiment. NOAA TM ERL WPL-170, 74 pp. (1989).

The purpose of the 1988 Micrometeorological Scintillation Experiment was to assess the ability
of several scintillation techniques to measure the heat and momentum fluxes and the stability of
the atmospheric surface layer. This report documents the data acquisition and analysis software
used for the experiment. An overview of the software modules is given, including their purposes
and relationships to one another. A more detailed description of each module is also given. Se-
lected portions of the software source code are provided in the appendices, and the complete
source code is provided on an enclosed diskette.

WP-098

REINKING, R.F., and R.J. MEITIN. Recent progress and needs in obtaining physical evidence for
weather modification potentials and effects. Journal of Weather Modification. 21:85-93 (1989).

Statistical and numerical modeling approaches to assess the effects of cloud seeding require
the interactive input of, and understanding derived from, measurements that provide direct evi-
dence of natural and altered development of precipitation. A brief review of recent progress in
obtaining physical evidence to evaluate and verify potentials for and effects of precipitation
enhancement and hail suppression is presented. Recent findings form the National Oceanic and
Atmospheric Administration's Federal/State Cooperative Program in Weather Modification Research
are emphasized, but other related results are included. In the context of many significant new
advances toward proving hypotheses by direct measurement, a number of remaining needs for meas-
urements and corresponding technologies are identified.

WP-099

REINKING, R.F., and REBECCA J. MEITIN. Advances and challenges in obtaining physical evidence
for weather modification potentials and effects. Proceedings, WMO 5th Scientific Conference on
Weather Modification and Applied Cloud Physics, Beijing, China, WMO, Geneva, WMO/TD-No. 269, I:
7-10 (1989) .

No abstract .

WP-100

Rodriguez, E., F. Li, C.L. Parsons, and E.J. WALSH. Wide swath ocean topography mapping with
interferometric altimeters. Proceedings, 12th Canadian Symposium on Remote Sensing (IGARSS
89) .Vancouver, B.C., Canada, 10-14 July 1989, IEEE, NY, 2265-2267 (1989).

An interferometric radar altimeter is proposed to provide wide swath, high resolution ocean
topography. Several system design issues of such an interferometric altimeter are presented. We
show the tradeoffs between processing of the interferometric signal using the so-called amplitude
approach and the so-called phase approach. We also discuss the systematic errors associated with
uncertainties in the interferometer baseline and the attitude of interferometer orientation. An
approach using the measurements at orbit cross over regions, together with the topography meas-

176

urements from a traditional nadir looking altimeter which are not contaminated by the baseline
and attitude noises, is described. Preliminary simulation results show that such an approach can
generate an acceptable error level is the ocean surface does not change appreciably between the
observations .

WP-101

RUFFIEUX, D. Simulation of solar radiation of downtown Denver: the effect of building shadows
on the city's energy budget. Preprints, 6th Conference on Applications of Air Pollution Meteor-
ology, Anaheim, CA , 30 January-3 February 1989, American Meteorological Society, Boston, MA,
246-249 (1989) .

No abstract.

wp-102

RYE, B.J. Power ratio estimation in incoherent backscatter lidar;
ian noise. Applied Optics. 28:3639-3646 (1989).

direct detection with Gauss

Properties of small sample estimators for the return signal power ratio or log ratio in direct
detection incoherent backscatter lidar systems are analyzed. As for heterodyne receivers it is
usually preferable to form an estimator from the logarithmic difference of the sample averages
rather than their ratio. Calculated values of bias and noise figures are confirmed using simu-
lated data based on constant signal models and comparedwith the estimates obtained from nonlinear
Kalman filters. The latter generally provide the least bias at high noise levels at the cost of
greater computational complexity.

WP-103

RYE, B.J. A wavelength switching algorithm for single laser differential absorption lidar sys-
tems, Proceedings, SPIE, 1062:267-273 (1989).

An algorithm is presented for estimation of the logpower difference needed in DIAL observations
for a system assumed to use only a single laser that is tuned to different wavelengths sequen-
tially. Account is taken of the nonlinear measurement equation, missing observations, and signal
fluctuations by use of adaptive Kalman filter techniques, and filter performance is demonstrated
with simulated data.

WP-104

RYE, B.J.. and R.M. HARDESTY. Nonlinear Kalman filtering techniques for incoherent backscatter
lidar: Return power and log power estimation. Applied Optics. 28:3908-3917 (1989).

Recursive estimation of nonlinear functions of the return power in a lidar system entails use
of a nonlinear filter. This also permits processing of returns in the presence of multiplicative
noise (speckle). The use of the extended Kalman filter is assessed here for estimation of return
power, log, power, and speckle noise (which is regarded as a system rather than a measurement
component), using coherent lidar returns and tested with simulated data. Reiterative processing
data samples using system models comprising a random walk signal together with an uncorrelated
speckle term leads to self-consistent estimation of the parameters.

WP-105

RYE, B.J., and R.M. HARDESTY. Time series identification and Kalman filtering techniques for
Doppler lidar velocity estimation. Applied Optics . 28:879-891 (1989).

The use of recursive techniques based on Kalman filter algorithms for identification of time
series system models for Doppler lidar returns and the subsequent filtering and smoothing of
measured data is explored. The form of possible stochastic system models is reviewed, and reit-
erative maximum likelihood and innovation spectral tests are used for identification. It is
found that a random walk model is adequate for the returns here and possible explanations for
this are considered. Examples are given to illustrate extension of our method to real-time ap-
plications and on-line outlier rejection.

WP-106

Sassen, K. , D.O. Starr, and T. UTTAL. Mesoscale and microscale structure of cirrus clouds:
three case studies. Journal of the Atmospheric Sciences. 46:371-396 (1989).

177

The structure and composition of three basic cirrus cloud types are examined through coordi-
nated aircraft and ground-based polarization lidar and radar measurements. The cloud systems con-
sist of a multilayered orographic cirrus, a 6-km deep cirrostratus , and a group of fibrous cirrus
bands at the tropopause. The data reveal the presence of mesoscale generating regions with hori-
zontal dimensions ranging from — 15 km in narrow cloud bands up to -~100 km in cirrostratus.
These generating regions appear to be composed of complexes of much smaller convective struc-
tures, presumably on the — 1-km scale of cirrus uncinus cells, and so are termed Mesoscale Un-
cinus Complexes (MUC). Accumulations of ice particles within cirrus, commonly referred to as pre-
cipitation trails, are associated with generating regions at or near cloud tops, but are also
created by the local production of ice crystals within embedded convective impulses. Supercooled

cloud droplets large enough to be detected by aircraft probes ( > 5fim diameter) were sampled in
embedded convective cells near cloud base at temperatures ranging from -21° to -36°C. Ice particle
nucleation at colder temperatures is assumed to involve the homogeneous freezing of haze parti-
cles too small to be detected by the aircraft probes employed, although they appear to have been
detected by the polarization lidar technique under some conditions. Average ice mass contents are
temperature dependent in a manner consistent with the conversion of a relatively small amount of
excess water vapor (corresponding to ice supersaturat ions of a few percent) to ice mass.

WP-107

SCHROEDER , J. A. A comparison of the individual and combined performance of ground-based, radio-
acoustic, and radiometric temperature sounding systems. M.A. thesis, Colorado School of Mines,
Golden, CO, 74 pp. (1989).

An experiment was conducted to compare the accuracy of atmospheric temperature soundings ob-
tained simultaneously with a ground-based radio-acoustic sounding system (RASS) , a ground-based
microwave radiometric system and a combined RASS/ radiometric system at Denver, Colorado, during
July and August of 1988. Applying a linear statistical retrieval technique to measurements from
all three systems permitted 3-way comparisons throughout the troposphere. Accuracy was evaluated
by comparison with simultaneous in situ rawinsonde temperature measurements.

WP-108

SCHROEDER, J. A. A comparison of the individual and combined performance of ground-based, radio-
acoustic and radiometric temperature sounding systems. Proceedings, 12th Canadian Symposium on
Remote Sensing (IGARSS '89), Vancouver, B.C., Canada, 10-14 July 1989, IEEE, NY, 2300-2302
(1989) .

No abstract.

WP-109

SCHROEDER, J. A. A preliminary comparison of temperature soundings obtained from simultaneous
radiometric, radio-acoustic, and rawinsonde measurements. NOAA TM ERL WPL-173, 21 pp. (1989).

An experiment was conducted to compare the accuracy of atmospheric temperature soundings ob-
tained simultaneously with a ground-based radio-acoustic sounding system (RASS) , a ground-based
microwave radiometric system, and a combined RASS, radiometric system at Denver, Colorado, during
July and August of 1988. Applying a linear statistical retrieval technique to measurements from
all three systems permitted three-way comparisons throughout the troposphere. Accuracy was
evaluated by comparison with simultaneous in situ rawinsonde temperature measurements. Rms er-
rors for the 22 sets of soundings compared ranged from 0.5 to 2.0 C, depending on altitude.
Temperatures retrieved from the radiometer measurements were more accurate than those retrieved
from RASS above 5 km and below 0.5 km AGL, where a bias in the low-altitude RASS measurements
degraded the retrieved temperatures. Between 0.5 and 5 km the RASS temperature errors were less
than 1°C. At the 750- and 700-mb pressure levels, the RASS errors matched the reported precision
of rawinsonde measurements. Although the combined system errors were smaller than individual
system errors, at all altitudes, above 0.5 km, the differences among the three systems were too
small to conclude that the combined system performance was significantly better than that of
either system alone.

WP-110

SENGUPTA, N. , J.M. Warnock, E.E. GOSSARD, and R.G. STRAUCH, Remote sensing of meteorological
parameters using a wind profiling radar . Proceedings, 1st European Wind Profiler Workshop,
Trappes, France, 21 March 1989 (1989).

178

The described experiment tested the feasibility of (a) using a surface-based radar to measure
gradients of temperature and humidity aloft and (b) using standard radiosonde data to calculate

height profiles of the radio refractive index structure parameter, C* . The statistical model de-
veloped by NOAA's Aeronomy Laboratory was used to calculate values of cf. and i for comparison
with the radar-measured values. The radar-calculated and observed quantities was found to be in
reasonably good agreement.

WP-111

SHANG, E.C. Ocean acoustic tomography based on adiabatic mode theory. Journal of the Acoustical
Society of America. 85:1531-1537 (1989).

A new method of ocean acoustic tomography is developed on the basis of adiabatic normal-mode
theory. It is a full-wave method suitable for low frequency in a slowly varying range-dependent
waveguide. The modal phase difference perturbations are proposed as data for inverting the
sound-speed profile perturbation for a continuous-wave (cw) source. The modal travel time per-
turbations are proposed as data for a pulse source. It is shown that the "normalized depth
structure," as well as the "range-averaged strength parameter" (defined as the product of the
effective horizontal scale and the maximum sound-speed perturbation), can be retrieved from the
vertical slice modal tomography. A simulation example of inversion is presented to verify the
basic ideas.

WP-112

Smith, P.L., H.D. Orville, J.L. Stith, B.A. Boe , D.A. Griffith, M.K. POLITOVICH and F.F. REINK-
ING. Evaluation studies of the North Dakota Cloud Modification Project. Proceedings, 5th WMO
Scientific Conference on Weather Modification and Applied Cloud Physics, Beijing, China, WMO,
Geneva, WMO/TD-No. 269, 1:371-376 (1989).

No abstract .

WP-113

SNIDER, J.B., M.D. JACOBSON, and R.H. BEELER . Observations of attenuation at 20.6, 31.65, and
90.0 GHz--preliminary results from Wallops Island. Proceedings, NAPEX XIII, San Jose, CA, 29-30
June 1989, NASA and Jet Propulsion Laboratory, Pasadena, CA, 138-144 (1989).

Ground-based radiometric observations of atmospheric attenuation at 20.6, 31.65 and 90.0 GHz
were made at Wallops Island, VA during April and May 1989. Early results from the analysis of
the data set are compared with previous observations from California and Colorado. The relative
attenuation ratios observed at each frequency during clear, cloudy and rainy conditions are
shown. Plans for complete analysis of the data are described.

WP-114

Stith, J.L., M.K. POLITOVICH. Observations of the effects of entrainment and mixing on the
droplet size spectra in a small cumulus. Journal of the Atmospheric Sciences. 46, 908-919
(1989) .

Sulfur hexafluoride was released at the base of a small nonprecipitat ing, warm cumulus to study
cloud mixing and entrainment processes. The tracer gas traveled to the top of the cloud where,
during a 2.5 min period, it had mixed to produce a dilute mixture containing 30%, 19% and 51% of
air from the original tracer region, an adjacent region of the dame cloud, and the environment
surrounding the cloud, respectively. The droplet size distributions measured at the top of the
cloud represented a mixture of larger droplets that had been growing from the base and smaller,
recently activated droplets. The observations suggest that the source region for the small drop-
lets was near cloud top. The large droplet concentration was conserved during the mixing proc-
ess. These observat ions are compared with predictions from some recent models for cloud entrain-
ment and droplet evolution.

WP-115

STRAUCH, R.G., D.A. MERRITT, K.P. MORAN, P.T. MAY, B.L. WEBER, and D.B. WUERTZ. Doppler radar
wind profilers for support of flight operations. Journal of Aircraft and Aerospace Sciences, 15
(1989) .

Wind profilers are becoming an accepted component of meteorological observing systems. This
paper discusses various types of wind profilers, illustrates their capabilities and the data they

179

can provide to support flight operations, and discusses their limitations. In addition, the wind
profiler has revived the Radio Acoustic Sounding System (RASS) technique for measuring tempera-
tures. Preliminary RASS results are presented.

WP-116

STRAUCH, R.G., K.P. MORAN, P.T. MAY, A.J. BEDARD, and W.L.
techniques. NOAA TM ERL WPL-158, 12 pp. (1989).

ECKLUND. RASS temperature sounding

No abstract.

WP-117

STRAUCH, R.G., K.P. MORAN, P.T. MAY, A.J. BEDARD, and W.L. ECKLUND. RASS temperature soundings
with wind profiler radars. Preprint, 24th Conference on Radar Meteorology, Tallahassee, FL ,
27-31 March 1989, American Meteorological Society, Boston, MA, 741-745 (1989).

No abstract.

WP-118

SUMMERS, S. , W.D. NEFF , and C.W. KING. Forecasting air pollution episodes over Denver.
Preprints, 6th Conference on Applications of Air Pollution Meteorology, Anaheim, CA , 30 Janu-
ary-3 February 1989, American Meteorological Society, Boston, MA, 235-239 (1989).

No abstract .

WP-119

UTTAL, T., B.E. MARTNER , B. ORR , and R.M. Wakimoto. High resolution dual-Doppler radar measure-
ments of a tornado. Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL, 27-31
March 1989, American Meteorological Society, Boston, MA, 62-65 (1989).

No abstract .

WP-120

WALSH, E.J., D.W. Hancock, D.E. Hines, R.N. Swift, and J.F. Scott. An observation of the direc-
tional wave spectrum evolution from shoreline to fully developed. Journal of Physical Oceanog-
raphy. 19:670-690 (1989).

The Surface Contour Radar (SCR) is a 36-GHz computer-controlled airborne system, which produces
ocean directional wave spectra with much higher angular resolution than pitch-and-roll buoys.
SCR observations of the evolution of the fetch-limited directional wave spectrum are presented
which indicate the existence of a fully-developed sea state. The JONSWAP wave growth model for
wave energy and frequency was in best agreement with the SCR measurements. The model of Conelan
et al. correctly predicted the propagation direction of waves in the asymmetrical fetch situation
nearshore. The Donelan et al. parameterization is generalized to permit other growth algorithms
to predict the correct direction of propagation in asymmetrical fetch situations.

WP-121

WEICKMANN, A.M., J. P. RILEY, T.M. GEORGES, and R.M. JONES. EIGEN-
rays from HARPA/HARPO rayset . NOAA TM ERL WPL-160, 91 pp. (1989).

-A program to compute eigen-

EIGEN is a FORTRAN computer program that processes the rayset (machine-readable) output of
the HARPA and HARPO acoustic ray-tracing programs. It interpolates in elevation angle to find
the eigenrays that connect the source and a specified receiver. It also creates plots of range
vs. elevation angle and range vs. travel time.

WP-122

WESTWATER. E.R., M.J. FALLS, E, Fionda, and J.B. SNIDER. Radiometric observations at 20.6.
31.65, and 90.0 GHz: continuing observations. Proceedings, NAPEX XIII, San Jose, CA, 30 June
1989, Jet Propulsion Laboratory, Pasadena, CA, 145-151 (1989).

Ground-based radiometer measurements at 20.6, 31.65 and 90.0 GHz have been analyzed to provide
attenuation statistics, thus extending the data base of the previous NAPEX studies. Using data
from colocated radiosondes, comparisons of the measurements and calculations of brightness tem-
peratures are presented. The oxygen absorption model of Rosenkranz (1988) and the water vapor

180

absorption models of Liebe (1989) and of Waters (1976) are used in the study. Data from the July
1987 at San Nicolas Island, California, and from December 1987, August, 1988 and November 1988 at
Denver. Colorado are included in the study. Joint-attenuation statistics at 20.6 and 31.65 GHz
are presented for two locations of the Colorado Research Network (Denver and Platteville) for
December 1987 and August 1988.

WP-123

WESTWATER, E.R., M.J. FALLS, and I. A. POPA FOTINO. Ground-based microwave radiometric observa-
tions of precipitable water vapor: a comparison with ground truth from radiosonde observing
systems. Journal of Atmospheric and Oceanic Technology. 6:724-730 (1989).

Dual-channel microwave radiometric measurements of precipitable water vapor are compared with
values determined from two types of radiosondes. The first type is used in conventional sound-
ings taken by the National Weather Service. The second is used by the CLASS system, as operated
by the National Center for Atmospheric Research. The standard deviations of the two comparisons
are nearly equal, being about 0.1 cm, but statistically significant biases occur between the ra-
diometer and the radiosondes. A bias of 0.162 cm is present between radiometer and NWS values
during the day and 0.075 cm during the night. The comparison shows that significant differences
exist between the radiometer and the NWS moisture soundings when the relative humidity drops be-
low 20 percent for pressures greater than 500 hPa. When this situation occurs, the NWS soundings
contain a default dewpoint depression value of 30°C. After such data are removed from the com-
parisons, agreement between radiometer and NWS radiosonde data is excellent.

WP-124

WESTWATER, E.R., M.J. FALLS, J. A. SCHROEDER , D. BIRKENHEUER, J.S. SNOOK, and M.T. DECKER. Com-
bined ground- and Satellite-based radiometric remote sensing. Proceedings, International Work-
shop on Remote Sensing Retrieval Methods, 1988, A. Deepak Publishing Co., Norfolk, VA, 215-228
(1989) .

The Wave Propagation Laboratory is currently operating a ground- based 5-channel microwave radi-
ometer at Stapleton International Airport, Denver, Colorado. Combined soundings from the NOAA
TOVS and the ground-based radiometer are shown to determine temperature profiles with rms errors
less than 2.0 k from the surface to 300 mb. Operational VAS data acquisition and real-time
sounding processing are now being performed by PROFS. Observations are represented from the
ground-based radiometer. VAS soundings within 100 km of Denver, and ground truth provided by
radiosondes. Combined thermal retrievals from the VAS and ground-based system are also pre-
sented. The Wave Propagation Laboratory also operates a limited network of four ground-based
dual-frequency radiometers that measure precipitable water vapor and cloud liquid. An example
illustrates how data from this system can be used to constrain the precipitable water analysis
obtained from VAS.

WP-125

WESTWATER, E.R., and KROPFLI , R.A. Remote sensing techniques of the Wave Propagation Laboratory
for the measurement of supercooled liquid water: applications to aircraft icing. NOAA TM ERL
WPL-163 , 28 pp. (1989) .

No abstract.

WP-126

WESTWATER, E.R., and J.B. SNIDER. Ground-based radiometric observations of atmospheric emis-
sion at 20.6, 31.65 and 90.0 GHz. Proceedings, 6th International Conference on Antennas and
Propagation ICAP-89, IEE, Hart fordshire , England, 229-233 (1989).

Over the past decade, the Wave Propagation Laboratory (WPL) has designed, constructed, and
field tested several ground-based microwave radiometers to observe the atmosphere [Hogg et al.
(1); Westwater and Snider (2)]. In particular, extensive experience has been gained by using
both zenith-viewing and steerable dual-frequency instruments operating at 20.6 and 31.65 GHz.
These instruments provide unique and meteorologically useful observations of precipitable water
vapor V and integrated cloud liquid L. Perhaps equally as useful, but certainly not as well
studied are the microwave attenuation characteristics that these devices can easily provide.
Within the last year, WPL extended its radiometric capabilities by adding a channel at 90.0 GHz
to the steerable and transportable radiometer. All three channels on this radiometer have equal
beamwidths of 2.5°, and point in the same direction from the same location; hence, they are capa-

181

ble of simultaneously measuring emission and deriving attenuation for the same volume of air. We
present here examples of some of the data taken with the new system at San Nicolas Island, Cali-
fornia, USA, and at Denver, Colorado, USA. From these data, several statistical and physical
quantities, relative to radio propagation studies, are derived and compared with theory.

WP-127

WESTWATER, E.R.. J.B. SNIDER, and M.J. FALLS. Observations of atmospheric emission and attenu-
ation at 20.6, 31.65, and 90.0 GHz by a ground-based radiometer. NOAA TM EHL WPL-156, 16 pp.
(1988) .

During 1987 and 1988, ground-based zenith-viewing observations of atmospheric thermal emission
were made at frequencies of 20.6, 31.65, and 90.9 GHz. At the locations of the experiments--San
Nicolas Island, California, and Denver, Colorado--radiosonde observations of temperature and hu-
midity were also available. The data, after conversion to attenuation by use of the mean radiat-
ing temperature approximation, were processed to derive attenuation statistics. Both clear and
cloudy attenuation characteristics are examined and compared with results from most recent theo-
ries. The predictability and interdependence of the three separate channels are also examined.
It is found that attenuation for any two channels can predict that of the third to within 25%.

WP-128

WICKERS, M.T., W.P. SCHOENFELD, M.K. PAGOAGA , and R.J. HILL. How to extract data from the an-
swer file of the millimeter-wave experiment. NOAA TM ERL WPL-164, 66 pp. (1989).

The method of retrieving data from the millimeter-wave experiment conducted at Flatville,
Illinois, is described. It is assumed that the reader has a basic understanding of FORTRAN and
is able to read and understand short FORTRAN programs. A few commands of the job control lan-
guage for the Cyber Network Operation System (NOS) are also discussed.

WP-129

WILCZAK, J.M. Case study of an orographical ly induced, mesoscale vortex (Denver Cyclone) during
CINDE. Preprint, International Conference on Mountain Meteorology and ALPEX , Garmisch-Par-
tenkirchen, Federal Republic of Germany, 5-9 June 1989, German Aerospace Research Establishment
(DFVLR), Oberpfaffenhofen, 114-115 (1989).

Observations taken during the Convection Initiation and Downburst Experiment (CINDE) are used
to describe the formation and structure of an orographically induced mesoscale vortex that fre-
quently occurs in northeastern Colorado. This vortex, locally known as the Denver Cyclone due to
its proximity to the Denver metropolitan area, occurs in the lee of the Palmer Divide, an 800 m
amplitude ridge of elevated terrain. We present a case study of the Denver Cyclone of 25 June
1987, that formed in a nighttime, stably stratified environment, approximately 4-6 hours after a
synoptic southeast wind began to flow over the Palmer Divide. The 100 km diameter lee vortex
remained stationary for over 24 hours.

WP-130

WILCZAK, J.M., and J. Glendening. Observations and mixed-layer modeling of a terrain-induced
mesoscale gyre: the Denver Cyclone. Monthly Weather Review. 16:2689-2711 (1988).

In northeastern Colorado a frequently observed feature of the surface wind field is a station-
ary, terrain-induced mesoscale gyre, which is often associated with the formation of severe
weather. Because of the gyre's proximity to the Denver metropolitan area, local weather fore-
casters frequently refer to it as the "Denver Cyclone." The development of one such cyclone,
which occurred on 1 August 1985, is documented with mesonet , , radiosonde, wind-profiler, radiome-
ter and tower data. Mixed-layer model simulations of this event closely agree with the observed
gyre structure and indicate that the gyre is associated with a plume of warmer potential tempera-
ture air, which originates from a ridge of higher terrain to the south of Denver, and advects
northward into the area of gyre formation. A mixed-layer vorticity budget demonstrates that the
formation of the gyre results from the baroclinic and slope effects on the turbulent stress di-
vergence profile.

WP-131

WILCZAK, J.M., D.E. WOLFE, and S.C. Albers. The 2 July 1987 tornado observed during CINDE: im-
plications for NEXRAD. Preprints, 24th Conf. on Radar Meteorology, 27-31 March 1989, Tal-
lahassee, FL, American Meteorological Society, Boston, MA, 251-254 (1989).

182

No abstract.

WILSON. J.W., J. A. Moore, G.B. Foote, B. MARTNER , A.R. Rodi, T. UTTAL, and J.M. WILCZAK. Con-
vection initiation and downburst experiment (CINDE) . Bulletin of the American Meteorological
Society. 69:1328-1348 (1988).

The Convection Initiation and Downburst Experiment (CINDE) was conducted in the Denver, Colo-
rado area from 22 June to 2 August 1987 to study processes leading to the formation of deep con-
vection and the physics of downbursts. A total of 6 Doppler radars, 87 mesonet stations, 3 re-
search aircraft, 8 sounding systems and numerous photographic facilities were deployed within an
85 km x 85 km area. A comprehensive data set was obtained including measurements of convergence
lines, downbursts, and tornadoes that occurred on 35, 22, and 11 days, respectively.

WP-13 3

WOLFE, D.E. A case study of a high pollution episode during the Denver Brown Cloud study.
Preprints, 6th Joint Conference on Applications of Air Pollution Meteorology, Anaheim, CA, 30
January-3 February 1989, American Meteorological Society, Boston, MA, 240-242 (1989).

No abstract .

WP-134

WOLFE, D.E., and L.K. WITTENMEIER. An analysis of sonic anemometer vertical diffusion measure-
ments in a complex urban environment. Preprints, 6th Joint Conference on Applications of Air
Pollution Meteorology, Anaheim, CA , 30 January-3 February 1989, American Meteorological Soci-
ety, Boston, MA, 139-141 (1989).

No abstract .

WP-135

WUERTZ, D.B. and B.L. WEBER. Editing wind profiler measurements. NOAA TR-ERL WPL-438, 78 pp.
(1989) .

An algorithm is described for editing profiler measurements of wind components over height and/
or over time. The algorithm identifies and edits those measurements that do not fall within a
continuously connected pattern. The algorithm is based on the premise that a fundamental compo-
nent of any editor is a model that defines continuity. A simple continuity model is used to pro-
vide many examples to demonstrate that wind profiler measurements can be edited automatically and
objectively with confidence.

WP-136

Young, J.W., F.D. Lane, and A.J. BEDARD. The effect of a ground-based inversion layer on an
impacting microburst. Proceedings, 27th Aerospace Sciences Meeting, Reno, NV, 9-12 January
1989, American Institute of Aeronautics and Astronautics, Washington, D.C., (1989).

Present knowledge of hazardous microbursts is limited, and physical scale modeling can help
improve our understanding. Dimensional analysis indicates that it is possible to model a
microburst in a water tank using saline solutions of various densities. Furthermore, complicat-
ing factors such as a ground-based inversion layer can prevent microbursts from reaching the
ground, greatly reducing the effectiveness of ground-based wind sensors. Bedard reviews evidence
that even larger-scale gust fronts are influenced by ground-based inversions. Ground-based in-
versions can be created by introducing a layer of denser fluid along the bottom of the tank and
microbursts created by dropping a negatively buoyant dyed fluid into the tank, using a release
mechanism designed to create a puff of fluid with minimum initial vortex rollup. Tests show that
the presence of an inversion layer will cause one of three events to occur: a mid-air
microburst, a nondiverging microburst, or a diverging microburst. The Froude number provides an
index predicting which of the three conditions is likely to occur. Added complexity such as an
inversion layer can increase the danger of microbursts preventing warnings if surface wind
speed sensors are used, and reemphasizes the need for improved warning methods so that aircraft
may avoid dangerous wind shears under a variety of conditions.

WP-137

ZHAO, Y., M.J. POST, and R.M. HARDESTY. Receiving efficiency of pulsed coherent lidars. Confer-
ence on Lasers and Electro-Optics, 24-28 April 1989, Baltimore, MD, IEEE, NY, 362 (1989).

183

No abstract.

WP- 1 38

ZHAO, Y., and M.J. POST. Receiving efficiency for pulsed coherent lidars. Proceedings, 5th Con-
ference on Coherent Laser Radar: Technology and Applications, Munich, Federal Republic of Ger-
many, 5-9 June 1989, Optical Society of America, Washington, DC, 147-150 (1989).

No abstract.

WP-139

ZHOU, J., G.T. MCNICE, and W.L. EBERHARD. Lidar observations on the stratospheric aerosol:
Boulder, CO, 1985 to 1987. NOAA TM ERL WPL-162, 50 pp. (1989).

The lidar observations presented consist of 86 vertical profiles of backscatter measured by a
ruby lidar (694.3-nm wavelength). Also presented are plots of scattering ratio profiles and ta-
bles containing values of the scattering ratio, aerosol backscattering coefficient, Rayleigh
backseat tering coefficient, and estimated aerosol optical depth versus altitude. Data acquisi-
tion and processing are briefly described. Some simple analyses of the lidar data are also dis-
cussed, including mean and peak aerosol backscatter characteristics, temperature versus aerosol
structure, and trends in stratospheric aerosol optical depth.

Addendum

WP-140

Augustinus, A., J. Kusters, B.J. RYE, J. Dijk, and W. Wolters. Computer control of frequency

tunable CO2 lasers. Infrared Phvs . . 28:397-403 (1988).

Application of active frequency stabilization and cavity scanning techniques, under computer

control, to C'j, lasers has been demonstrated. The methods avoid the need for passive stabiliza-
tion and are appropriate for automated medium resolution spectroscopic systems including lidars.
Procedures for self-adjustment of low pressure lasers and securing double mode laser outputs from
high pressure lasers are described.

WP-141

BEDARD, A.J., G.E. GREEN, J. INTRIERI , and R. RODRIGUEZ. On the feasibility and value of de-
tecting and characterizing avalanches remotely by monitoring radiated sub-audible atmospheric
sound at long distances. Proceedings, A Mult idisciplinary Approach to Snow Engineering, 11-14
July 1988, Santa Barbara, CA , National Science Foundation, Washington, DC, 267-275 (1988).

Because avalanches frequently occur in remote areas, it is often difficult to establish the
timing or extent of snow movement. Such information is valuable for verifying avalanche predic-
tion models, as well as establishing regional statistics. We summarize techniques developed for
measuring low-frequency, small-amplitude sound waves in the atmosphere. Infrasonic observations
made along the front range near Boulder, Colorado, suggest that it may be possible to detect low-
frequency sound waves related to avalanches at distances of hundreds of kilometers. Several
acoustic radiation mechanisms are possible. Source region acoustic measurements should be made
of controlled avalanches in an effort to understand the acoustic radiation sources, and optimize
measurement techniques.

WP-142

Coakley, J. A., and J.B. SNIDER. Dependence of marine stratocumulus reflectivities on path-in-
tegrated liquid water. Proceedings, FIRE Science Experiment Team Meeting, July 1988, Vail, CO,
NASA Langley, 355-359 (1988).

Simple parameterizat ions that relate cloud liquid water content to cloud reflectivity are often
used in general circulation climate models to calculate the effect of clouds on the earth's en-
ergy budget. Such parameterizat ions have been developed by Stephens (1978) and by Slingo and
Schrecker (1982) and others. Here we week to verify the parametric relationship through the use
of simultaneous observations of cloud liquid water content and cloud reflectivity. The column
amount of cloud liquid water was measured using a microwave radiometer on San Nicolas Island fol-

184

lowing techniques described by Hogg et al. (1983). Cloud reflectivity was obtained through spa-
tial coherence analysis of AVHRR imagery data (Coakley and Beckner, (1988). We present the de-
pendence of the observed reflectivity on the observed liquid water path. We also compare this
empirical relationship with that proposed by Stephens (1978).

WP-143

Conforti, G., A. Consortini, J.H. CHURNSIDE, and R.J. HILL. Effects of the receiving aperture
size on atmospheric laser scintillation measurements. Proceedings, Scattering and Diffraction
(vol. 1029), Hamburg, Federal Republic of Germany, 22-23 September 1988, SPIE, Bi 1 1 ingham , WA ,
119-122 (1988) .

No abstract.

WP-144

INTRIERI, J.M., A.J. BEDARD, and R.M. HARDESTY. Doppler lidar observations of colliding out-
flow boundaries. 15th Conference on Severe Local Storms, 22-26 February 1988, Baltimore, MD,
American Meteorological Society, Boston, MA, 249-252 (1988).

No abstract .

WP-145

Lenschow, D.H., Xing Sheng Li, Cui Juan Zhu , and B.B. STANKOV. The stably stratified boundary
layer over the Great Plains. Part I: Mean and turbulence structure. Boundarv-Laver Meteorol-
ogy. 42 : 95-121 (1988) .

We present airplane measurements of the stably stratified nocturnal boundary layer obtained
during the Severe Environmental Storms and Mesoscale Experiment (SESAME) in 1979. The cases pre-
sented here were obtained over rolling terrain in central Oklahoma, with a mean slope of about
0.003. The results are in general agreement with previous modeling and observational studies for
the mean and turbulence structure of the nocturnal boundary layer, with the exception that the
eddy diffusivity of heat, and consequently the flux Richardson number are less than expected.

WP-146

Lenschow, D.H., S.F. Zhang, and B. STANKOV. The stably stratified boundary layer over the Great
Plains. Part II: Horizontal variations and spectra. Boundarv-Laver Meteorology. 42:123-135
(1988) .

Airplane measurements of the stably stratified boundary layer obtained during the Severe Envi-
ronmental Storms and Mesoscale Experiment (SESAME) over rolling terrain in south-central Oklahoma
indicate that considerable horizontal variability exists in the flow on scales of several kilome-
ters. Much of this wave-like structure appears to be tied to the terrain. The criteria for ex-
istence of stationary gravity waves indicate that these waves can exist under the observed condi-
tions. The spectrum of terrain variations also supports the existence of these waves. Observed
spectra of the vertical velocity have two peaks: one at wavelengths of several kilometers, which
is due to waves and the other at wavelengths of about 100 m, which is due to turbulence. The
variance at several kilometers wavelength increases somewhat with height at least up to about 800
m, but the variance contributed by turbulence decreases rapidly with height.

WP-147

Lenschow, D.H., M. Zhou, and B. STANKOV. The scalar gradient near +he top of the convective
boundary layer. Acta Oceanologica Sinica. 7:132-139 (1988).

The flux-gradient relationship for temperature in the unstably stratified atmospheric surface
layer is well established, and seems to apply also to other scalars, such as humidity. Throughout
the rest of the boundary layer, however, a flux-gradient relationship based on a flux at the sur-
face is not well defined if a significant entrainment flux exists at the boundary-layer top. Wyn-
gaard (see Wyngaard and Brost, 1983; Moeng and Wyngaard, 1984) has developed a model which as-
sumes that a flux-gradient relationship can be defined separately for bottom-up transport due to
a flux at the surface, and for top-down transport due to a flux through the boundary-layer top.
He has shown, by means of large-eddy numerical simulations, that the model can successfully pre-
dict the flux-gradient relationship for scalars throughout most of the boundary layer. We have
used aircraft profile measurements of temperature, humidity, and ozone concentration near the top
of the boundary layer, and aircraft vertical flux measurements at several levels in the boundary

185

layer, as well as temperature profiler measurements from an elevator on the Boulder Atmospheric
Observatory tower, flux measurements at several levels on the tower, to test the top-down flux-
gradient relationship obtained from the numerical simulations. The shape of the observed scalar
profiles agrees well with the shape obtained from numerical simulation, but the observed constant
of proportionality predicts a somewhat larger gradient than that obtained from numerical simula-
t ion .

WP-148

STRAUCH, R.G. A modulation waveform for short-dwel 1-t ime meteorological Doppler radars. Journal
of Atmospheric and Oceanic Technology. 5:512-520 (1988).

A modulation waveform for meteorological Doppler radars that obtain estimates of radar refle-
ctivity, mean velocity, and Doppler width with dwell time much shorter than that used with con-
ventional meteorological Doppler radars is described. The transmitted signal is a sequence of
three identical chirp pulses; signal parameters can be estimated from the radar echoes of a sin-
gle sequence with standard deviation similar to that of conventional meteorological radars that
use dwell times more than an order of magnitude longer. This waveform would be particularly use-
ful for radars with electronically steered antennas where the antenna scan rate is not limited by
mechanical constraints and there is no spectral boadening caused by antenna motion.

WP-149

WEBER, B.F., F.F. HALL, and R.M. HARDESTY. A positively buoyant downburst investigated in two
dimensions with Doppler lidar. 15th Conference on Severe Local storms, 22-26 February 1988,
Baltimore, MD, American Meteorological Society, Boston, MA, 403-406 (1988).

No abstract.

186

APPENDIX: FEDERAL-STATE COOPERATIVE PROGRAM
IN WEATHER MODIFICATION RESEARCH

AP-001

Boe, B.A., P.L. Smith, H.D. Orville, N.C. Knight, M. Hjelmfelt, D.S. Griffith, J.L. Stith, and
R.F. REINKING. North Dakota Thunderstorm Project Field Operations Plan, May, 1989. 75 pp.

No abstract.

AP-002

Chai, Steven., William G. Finnegan, Richard L. Pitter and Joseph A. Waterburton. A mechanistic
interpretation of a winter orographic cloud seeding program. Proceedings, 5th WMO Scientific
Conference on Weather Modification and Applied Cloud Physics, Beijing, China. WMO, Geneva,
WMO/TD-No. 269, I: 179-183 (1989).

No abstract.

AP-003

Changnon, S.A. Climate-based representations of summer rainfall in Illinois. J . Clim. . 1,
1041-1046 (1988) .

Historical (1901-85) summer rainfall data in central Illinois were used to construct three
typical rain conditions: one representing the typical dry summer, another a typical wet, and a
third the near-average summer rainfall conditions. Monthly rain totals were established, then daily
rain frequencies were used to define all individual rain day amounts, and historical rain-day
amounts by date were used to assign rain days and amounts to individual dates throughout the types
of summers. In-day conditions relating to rainfall rate, time of rainfall and duration were
constructed for each day of rain. The resulting 3 types of summer rainfall conditions were used to
guide applications of water onto agricultural test plots (protected from natural rains) to measure
crop yields effects from simulated rainfall modification.

AP-004

Changnon, S.A., and S.E. Hollinger. Use of unique field facilities to simulate effects of
enhanced rainfall in crop production. .1 . Wea . Mod . . 18, 108-112 (1988).

The simulation of various levels of rainfall increase on types of summer rainfall controlled
through the use of covered agricultural plots was conducted during 1987 in central Illinois.
Effects on corn and soybeans were tested in this experimentation, and plots received rainfall
conditions representing dry, wet, and normal summers with additional rainfall applied at levels
ranging from 10 to 40%, and varied based on the magnitude of individual daily rain amounts. These
unique field experiments produced unusual results. The dry summer with added rainfall above 25%
indicated major yield increases in both soybeans and corn. Corn yields were decreased by added
rainfall in the typical wet summers of Illinois.

AP-005

Changnon, S.A., Hollinger, S. , and Garcia P. Analyzing the effects of additional rainfall on corn
and soybeans yields. Preprints 6th Conference on Applied Climatology, AMS , Boston, MA, 6 pp.
(1989) .

No abstract.

AP-006

Changnon, S.A., F.A. Huff, and C.-F. Hsu. Relations between precipitation and shallow ground
water in Illinois. J. of cl imats. l, 1239-1250 (1988).

The statistical relationships between monthly precipitation (P) and shallow ground water levels
(GW) in 20 sampling wells scattered across Illinois (with data for 1960-84) were defined using
autoregressive integrated moving average modeling. A lag of one month between P and GW was the
strongest temporal relationship found across Illinois, followed by no lag in the northern two-

187

thirds of Illinois where mollisols predominate. A lag of 2 months was found in the alfisols of
southern Illinois. Spatial comparisons of the 20 P-GW correlations with several physical conditions
revealed that the parent soil materials including outwash alluvium, glacial till, thick loess, and
thin loess best defined regional relationships. These relationships allow studies of how altered
precipitation, particularly in the summer season, affect the shallow ground water levels in Illinois
under any precipitation conditions. The techniques of this equation should be transferrable to
regions of comparable soil and climate.

AP-007

Changnon, S.A., Czys, R., Garcia, P., Hollinger, S. , Huff, F., Nespor, J., Scott, H., and N.
Westcott. The Precipitation Augmentation for Crops Experiment: Phase II. Final Report to
ERL/NOAA under Cooperative Agreement NA87-RAH07077 , 82 pp, Illinois State Water Survey (1988).

No abstract.

AP-008

Czys, R.R. The visualization of cloud droplet spectra. J. Atmos. and Oceanic Technol.. 16, 1,
182-185 (1989).

This paper draws attention to the use of readily available, wire cage graphics for inspecting
cloud droplet spectra measured using a Forward Light-Scattering Spectrometer Probe. The high
resolution cloud droplet spectra from two different clouds are presented to illustrate the clarity
with which microphysical processes can be visualized.

AP-009

Czys, R.R. Physical models used in the Precipitation Augmentation for Crops Experiment.
Preprints 5th WMO Conference on Weather Modification and Applied Cloud Physics, Beijing, China,
221-224 (1989) .

No abstract.

AP-010

Czys, R.R. Ice initiation by collision-freezing in warm-based cumuli. J . Appl . Meteor. . 28,
1098-1104 (1988) .

The mechanical shock of collision between supercooled water drops is explored as a mechanism for
the origin of ice in the warm-based cumuli of the central United States. The results of laboratory
experiments using groups of 3-mm diameter hemispherical drops supported on a petroleum substrate and
cooled to either -10° or -15°C, are presented to demonstrate that supercooled drops can be caused to
freeze mechanically. Cavitation is examined as a mechanism closely associated with ice nucleation
in supercooled water. Pressure differences extrapolated from the Weber number for collisions
between precipitation-size collector drops and a wide size range of smaller drops were found to
exceed the criteria for cavitation and hence, freezing. This finding suggests that
collision-freezing may occur in clouds and is worthy of further attention.

AP-011

Doneaud, A. A., A. Makarau, and L.R. Johnson. A modified ATI technique for nowcasting convective
rain volumes over areas. J. Appl . Meteor. . 27, 491-502 (1988).

Digital radar data from the North Dakota Cloud Modification Project (NDCMP)-the 1981 and 1982
summer experiments- are used to further investigate the relationship between convective rain volumes
and are-time-integral (ATI). The ATI technique provides a means of estimating total rain volumes
using area covered by rain events (for relectivities >25 dBZ) integrated over the cluster duration
(Doneaud et al., 1984a). The purpose of this investigation is twofold: (a) to estimate ATIs only for
the growth portion of a convective storm (while the rain volume is computed using the entire life
history of the convective event); and (b) to nowcast the total rain volume of a convective system at
the stage of its maximum development. For the aforementioned purpose, the ATIs were computed using
the maximum echo area >25 dBX (ATIA) , the maximum reflectivity (ATIR) , and the maximum echo height
(ARIH) as the end of the growth portion of the convective event. A simple linear regression analysis
demonstrated that correlations between total rain volume (TVR) or the maximum rain volume (MVR)
versus the ATIA were the strongest. In a log-log plot, the correlation coefficient and the standard
error of estimates of total rain volume versus ATIA were 0.98 and 0.23 for the summer 1982 data, and
0.96 and 0.24 for the summer 1981 data, respectively. In percentage terms, the corresponding range

188

of variation of the rain volume for a given ATIA lies between 70% and -41% (1982 data) and between
74% and -44% (1981 data). That is comparable to the uncertainties which typically occur in rain
volume estimates obtained from radar data employing Z-R conversion followed by space and time
integration. This demonstrates that the total rain volume of a storm can be nowcast at is maximum
stage of development (max ATIA). The scatter in the rain volume and in the maximum volumetric rain
rate estimates are somewhat smaller if a multiple linear regression instead of a simple linear
regression is considered, but the improvement is of little significance. The tests with independent
data confirmed the consistency of the results for the regions considered.

AP-012

Feng, D. and W.G. Finnegan. An efficient, fast-functioning nucleating agent -- Agl AgCl 4NaCl.
J. Weather Mod. . 21:41-45, (1989).

A composite ice nucleus aerosol, AgIcl-4NaCl, has been generated and characterized for nucleation
efficiencies, rates of ice crystal formation, and mechanisms of nucleation, under water saturation
and transient supersaturat ion conditions. The addition of NaCl to the highly efficient contact
nucleus, AgI0.8Cl0.2, changed the nucleation mechanism to condensation-freezing at water saturation
and increased the rates of ice crystal formation dramatically, while retaining the high efficiency
of the Aglcl nucleus aerosol. Under transient supersaturat ion conditions, this new aerosol
demonstrated improved ice nucleation efficiencies at T 12 °C, and even faster ice crystal formation
rates, suggesting a change of nucleation aerosol should be advantageous for use in weather
modification field programs under conditions where low cloud droplet concentrations suggest the use
of a condensation-freezing nucleant.

AP-013

Finnegan, W.G. and R.L. Pitter, A postulate of electric multipoles in growing ice crystals:
Their role in formation of ice crystal aggregates. Atmos. Has. . 22:235-250 (1988).

This paper describes the basis of the postulate of electric multipoles in growing ice crystals.
The postulate was initially developed to describe the orientation of aggregated ice crystals, for
the purpose of learning about rate-determining forces involved in the initiation of ice crystal
aggregation. A series of laboratory experiments were undertaken to test the postulate. A 6.7 -m3
controlled-temperature chamber was used to investigate the aggregation of growing ice crystals. The
results show that small changes in dissolved salts are important in the orientation of initial ice
crystal aggregates. We interpret these results to strongly support our hypothesis of electric
multipoles in growing ice crystals.

AP-014

Finnegan, W.G. and R.L. Pitter. Ice crystal morphology: what makes snowflakes different, or
alike? AMS, Symposium on the Role of Clouds in Atmospheric Chemistry and Global Climate,
Anaheim, California. Amer. Meteorol. Soc . , Boston, MA, 108-109 (1989).

No abstract .

AP-015

Finnegan, W.G., R.L. Pitter and L.G. Young. Reduction-oxidation (REDOX) reactions in growing ice
crystals. Proceedings, 5th WMO Scientific Conference on Weather Modification and Applied Cloud
Physics, Beijing, China. WMO, Geneva, WMO/TD- no. 269, II: 655- 658 (1989).

No abstract.

AP-016

Huggins, A.W., A.B. Long, and B.A. Campistron. The impact of mesoscale precipitation bands on
liquid water and precipitation efficiency in a winter storm in Utah. Proceedings. 5th WMO
Scientific Conference on Weather Modification and Applied Cloud Physics, Beijing, China, 55-58
(1989) .

No abstract.

AP-017

Johnson, J.E., R.C. Coon, and J.W. Enz. Economic Benefits of Crop Hail Reduction Efforts in North
Dakota. North Dakota State University Agricultural Economics Report No. 247, April, 1989. 26
pp. (1989) .

189

No abstract .

AP-018

Knapp, H.V., Durgunoglu, A., and S.A., Changnon. Effects of added summer rainfall on the
hydrologic cycle of Midwestern watersheds. J. Wea . Mod, . 18, 112-118 (1988).

The effects of added summer rainfall on agricultural areas in Illinois were investigated using a
quasi-distributed-parameter watershed model. Increases in summer rainfall during July and August
were simulated and used in the model to describe the changes in soil moisture, crop water use,
shallow ground water, and streamflow conditions which could potentially occur from precipitation
augmentation. Two historical periods, representing 4 dry years and 4 wet years of the past, were
used in the simulations with 10% and 25% increases in precipitation applied. The greatest portion
of the additional summer rainfall eventually percolated into ground water, and that less than 25% of
the precipitation increase was used by crops.

AP-019

Long, A.B. On the precipitation efficiency of a winter mountain storm in Utah. Preprints, 11th
Conference on Weather Modification, Edmonton, Alberta, Canada, American Meteorological Society,
Boston. MA, 64-67 (1988).

No abstract.

AP-020

MEITIN, R.J., and R.F. REINKING. A Doppler radar analysis of a winter mountain storm. Preprints,
5th WMO Conference on Weather Modification and Applied Cloud Physics, Beijing, People's Republic
of China, 8-12 May 1989, WMO, Geneva, 93-96 (1989).

No abstract .

AP-021

MEITIN, R.J., and R.F. REINKING. A preliminary radar analysis of a winter mountain storm.
Preprints, 24th Conference on Radar Meteorology, Tallahassee, FL , 27-31 March 1989, American
Meteorological Society, Boston, MA, 490-493 (1989).

No abstract .

AP-022

Mitchell, D.L. and R.D. Borys . The effect of cloud and seeding on snow-size spectra and cloud

droplet removal. Proceedings, 5th WMO Scientific Conference on Weather Modification and Applied

Cloud Physics, Beijing, China. WMO, Geneva. WMO/TD-No. 269, 1:217-220 (1989).

No abstract .

AP-023

Ochs , H.T., and S.Q. Kidder. A forecast ing/nowcast ing system for remote field locations. J^.
Atnios. Oceanic Technol . . 6:218-221 (1989).

Vast quantities of frequently updated weather data for both forecasting and nowcasting are
generally required in meteorological field programs. The continuing synthesis of this data to suit
specific operations is best accomplished using computers. Recent advances in telecommunications and
computer hardware have allowed improved assimilation and presentation of weather data to remote
field sites at significantly reduced costs. This paper describes a forecast ing/nowcasting system
designed and assembled to support a weather modification field project in Illinois. With minor
modifications, this system can be located anywhere that has access to electrical power and standard
telephone lines. The use of new technology with on-site computer capabilities allow rapid
generation of products specifically tailored to meet the requirements of individual field projects,
both for forecasting the operations and nowcasting during operations.

AP-024

Pitter, R.L. and W.G. Finnegan. Another role for CCN in clouds. Symposium on the Role of Clouds
in Atmospheric Chemistry and Global Climate, Anaheim, California. Amer. Meteorol. Soc . , Boston,
pp. 108-109 (1989) .

190

No abstract .

AP-025

Pitter, R.L. and W.G. Finnegan. Development of heterogeneous nucleation theory for application
in weather modification. 5th WMO Scientific Conference on Weather Modification and Applied Cloud
Physics, Beijing, China. WMO, Geneva. WMO/TD-No. 269, 1:131- 132 (1989).

No abstract.

AP-026

Pitter, R.L. and W.G. Finnegan. Influence of chemical impurities on atmospheric ice crystal
processes. Annual Meeting of the Pacific Northwest Division of AAAS, Chico, CA , June (1989).

No abstract.

AP-027

Pitter, R.L., W.G. Finnegan and L.G. Young. Electrochemical oxidation-reduction reactions in
growing ice crystals: Freezing induced chemical reactions. International Conference on Global
and Regional Environmental Atmospheric Chemistry, Beijing, China, p. 70, May (1989).

No abstract.

AP-028

Pitter, R.L. and R. Zhang. Effect of internal charge distribution in ice crystals on scavenging
of aerosol particles. Proceedings, 5th WMO Scientific Conference on Weather Modification and
Applied Cloud Physics, Beijing, China. WMO. Geneva. WMO/TD-No. 269, 11:643-646 (1989).

No abstract .

AP-029

REINKING, R.F., and R.J. MEITIN. Recent progress and needs in obtaining physical evidence for
weather modification potentials and effects. Journal of Weather Modification. 21:85-93 (1989).

Statistical and numerical modeling approaches to assess the effects of cloud seeding require the
interactive input of, and understanding derived from, measurements that provide direct evidence of
natural and altered development of precipitation. A brief review of recent progress in obtaining
physical evidence to evaluate and verify potentials for and effects of precipitation enhancement and
hail suppression is presented. Recent findings form the National Oceanic and Atmospheric
Administration s Federal/State Cooperative Program in Weather Modification Research are emphasized,
but other related results are included. In the context of many significant new advances toward
proving hypotheses by direct measurement, a number of remaining needs for measurements and
corresponding technologies are identified.

AP-030

REINKING, R.F., and REBECCA J. MEITIN. Advances and challenges in obtaining physical evidence
for weather modification potentials and effects. Proceedings, WMO 5th Scientific Conference on
Weather Modification and Applied Cloud Physics, Beijing, China, WMO, Geneva, WMO/TD-No. 269, I:
7-10 (1989) .

No abstract.

AP-031

Sassen, K. Supercooled liquid cloud distribution over complex mountainous terrain. Proceedings,
Fifth WMO Scientific Conference on Weather Modification and Applied Cloud Physics, Beijing,
China, WMO, Geneva. WMO/TD No. 269, 1:51-54 (1989).

No abstract .

AP-032

Sassen, K., M.T. Davies and L. Liao. Remote Sensing observations of seeded winter storms from t^he
1989 Utah/NOAA Cooperative Weather Modification Program. Final Report to the Utah Division of
Water Resources, University of Utah, Salt Lake City, UT, 35 pp. (1989).

191

No abstract.

AP-033

Scott, R.W. Forecasting convection intensities in Illinois from rawinsonde signatures.
Preprints, 5th WMO Conference on Weather Modification and Applied Cloud Physics, Beijing, China,
221-224 (1989) .

No abstract.

AP-034

Shang, R. A numerical study of aerosol scavenging bv ice crystals. M.S. Thesis, Atmospheric
Physics, University of Nevada, Reno, NV , 93 pp., (1989).

Two theoretical models are presented which allow computing the efficiency with which aerosol
particles are collected by simple ice crystal plates. The present models incorporate gravitational,
inertial, diffusive and electrostatic effects. The effect of an internal charge distribution, due
to differential incorporation of ionic substances into ice crystal lattice, on aerosol scavenging is
also investigated. Some calculations were performed using a low density for ice particles, to
simulate scavenging efficiency is considerably affected by such an internal charge distribution for
aerosol particles 0.1 £ r £ 1.0 m. The present results imply that growing ice crystals containing
dilute concentrations of ionizable salts may exhibit higher collision efficiencies. The present
theoretical results reconcile the previously widely diverging results of snow crystal scavenging
reported by many researchers. This study suggests that as aggregates form and grow, the internal
charge distribution effect diminishes, while the net charge effect increases.

AP-035

Smith, P.L., M.W. Huston, and L.R. Johnson. Development of Evaluation Techniques for Operational
Convective Cloud Modification Projects: 1987-88 Studies. Report SDSMT/IAS/R-89/03 , South Dakota
School of Mines and Technology, Rapid City. March 1989, 43 pp. (1989).

No abstract .

AP-036

Smith, P.L., L.R. Johnson, and F.J. Kopp. Development of Evaluation Techniques for Operational
Convective Cloud Modification projects: 1986-87 sTudies. Report SDSMT/IAS/R-89/02 , South Dakota
School of Mines and Technology, Rapid City. March, 1989, 33 pp. (1989).

No abstract.

AP-037

Smith, P.L., H.D. Orville, J.L. Stith, B.A. Boe , D.A. Griffith, M.K. POLITOVICH and R.F.
REINKING. Evaluation studies of the North Dakota Cloud Modification Project. Proceedings, 5th
WMO Scientific Conference on Weather Modification and Applied Cloud Physics, Beijing, China, WMO,
Geneva, WMO/TD-No. 269, 1:371-376 (1989).

No abstract.

AP-038

Stith, J.L., M.K. POLITOVICH. Observations of the effects of entrainment and mixing on the
droplet size spectra in a small cumulus. Journal of the Atmospheric Sciences. 46, 908-919
(1989) .

Sulfur hexafluoride was released at the base of a small nonprecipitat ing, warm cumulus to study
cloud mixing and entrainment processes. The tracer gas traveled to the top of the cloud where,
during a 2.5 min period, it had mixed to produce a dilute mixture containing 30%, 19% and 51% of air
from the original tracer region, an adjacent region of the dame cloud, and the environment
surrounding the cloud, respectively. The droplet size distributions measured at the top of the
cloud represented a mixture of larger droplets that had been growing from the base and smaller,
recently activated droplets. The observations suggest that the source region for the small droplets
was near cloud top. The large droplet concentration was conserved during the mixing process. These
observations are compared with predictions from some recent models for cloud entrainment and droplet
evolution.

192

AP-039

Stone, R. and J. Warburton. The dispersion of silver iodide in mountainous target areas of the
western United States. Proceedings, 5th WMO Scientific Conference on Weather Modification and
Applied Cloud Physics, Beijing, China. WMO, Geneva. WMO/TC- No. 269, I: 167-169, (1989).

No abstract.

AP-040

Warburton, J., R. Stone and L. Young. A new scientific method employing ice-nucleating and non
ice-nucleating aerosols simultaneously for assessing the effects of cloud seeding on
precipitation. Proceedings, 5th WMO Scientific Conference on Weather Modification and Applied
Cloud Physics, Beijing, China. WMO, Geneva. WMO/TD-No. 269, 1:191-194 (1989).

No abstract.

AP-041

Warburton, J., R. Stone and B. Demoz. A conceptual model for determining seeded/not-seeded
ratios in weather modification experiments based on stable oxygen isotopic ratios and snow
chemistry. Proceedings, 5th WMO Scientific Conference on Weather Modification and Applied Cloud
Physics, Beijing, China. WMO, Geneva. WMO/TD-No. 269, 1:187-190 (1989).

No abstract.

AP-042

Westcott, N. Influence of mesoscale winds on the turbulent structure of the urban boundary layer
over St. Louis. Boundary Layer Meteor.. 48:283-292 (1989).

Two fair weather afternoons have been examined, where the urban boundary layer over St. Louis,
though exhibiting similar thermal characteristics, had a markedly different kinematic structure.
The turbulent nature of the boundary layer was examined through analysis of double theodolite wind
profiles at an urban and at a rural site on each day. On 14 July 1975, the winds increased with
height above the inversion at both sites and on the following day, the winds decreased above the
boundary layer in the same region. While the mean wind speed in the lowest 0.8 km Agl was similar
on both days, the turbulence characteristics of the urban boundary- layer winds were distinctly
different on these two afternoons. This was evidenced by the variance of the wind and is in
agreement with simultaneous aircraft measurements reported by Hildebrand and Ackerman (1984). A
similar difference in turbulence was not found over the rural site. It is suggested that the
enhanced turbulence at the urban site on 14 July is likely associated with the wind profile
immediately above the boundary layer, where the downwind flux of high momentum air from above the
inversion may have resulted in stronger mechanical mixing within the boundary layer.

AP-043

Westcott, N.E. Differential reflectivity (ZDR) measurements. Preprint, 24th AMS Conf. on Radar
Meteorology, Tallahassee, 388-390 (1988).

No abstract.

AP-044

Westcott, N.E. Growth habits of seeded and non-seeded radar echoes from the 1986 Precipitation
Augmentation for Crops (PACE) field program. Preprint, 5th WMO Sci. Conf. on Weather
Modification, Beijing, China. (1988)

No abstract.

AP-045

Westcott, N.E., and S.A. Changnon, Jr. Properties of echoes at first detection resulting in
multicelled storms. Preprint, International Symposium on Hydrological Applications of Weather
Radar. Univ. of Salford, Salford, England, 8 pp. (1989).

No abstract.

AP-046

Westcott, N., and P. Kennedy. Cell development and merger in an Illinois thunderstorm observed by
Doppler radar. J. Atmos. Sci , , 46:117-131 (1989).

193

A reflectivity and triple-Doppler radar study of the development of several cells and their
successive union within a nonsevere thunderstorm is presented. Two characteristic separations were
found in response to the collapse of an active cell and the more distant cells forming in a
previously existing storm-modified area characterized by mesoscale convergence and rain cooled air.
The manner in which these cells evolved appeared to be partially related to differences in the
environment in which they formed. As suggested by peterson, the cells that formed closer to the
main storm resembled the "weakly evolving" cells of Foote and Franks. The updraft of the "weakly
evolving" cell analyzed here merged with the updraft in a cell in the main storm as one cell was
decreasing in intensity and the other was increasing.

Later in the life cycle of the storm, two cells which initially formed further away from the main
storm appeared more like classical "strongly evolving" cells. While the vertical air velocity
analyses of these cells were incomplete, a trend towards the maintenance of a discrete cell updraft
was noted. The ways in which the reflectivity cores of these two cells became merged with the main
storm differed. In one case the development of a new cell between two existing cells produced the
merger, in the second case differential cell motion played an important role. Additionally, periods
of significant intercell flow at 4 km coincided with the times when the midlevel reflectivity bond
linking the cell cores showed a rapid intensification. It is proposed that the intercell flow is a
result of radial outflow observed at heights above the maximum updraft level in the actively growing
echoes. The strengthening of the reflectivity bridge may have been the result of both particle
transfer and environmental modification brought about by this radial outflow.

AP-047

Zhang, H., H.L. Pitter and D.L. Mitchell. Ground-based snowflake observations for analysis of
orographic winter storms. Proceedings, 5th WMO Scientific Conference on Weather Modification and
Applied Cloud Physics, Beijing, China. WMO, Geneva. WMO/TD- No. 269, 1:47-49 (1989).

No abstract.

194

ABOUT THE AUTHOR INDEX

All authors of all publications are listed.

An asterisk indicates a first author.

ERL authors' names are typed in all capital letters.

The words "et al . " indicate that a publication had more than one author.

The alphanumeric code following an author's name gives the location of the
bibliographic entry. Example: WP-061 is the sixty- first entry in the Wave
Propagation Laboratory section.

Following are the codes used, their meanings, and inclusive pages.

Code Laboratory or Publishing Group Pages

AL Aeronomy Laboratory 1-20

AO Atlantic Oceanographic and Meteorological Laboratory 57-73
AP Appendix: Federal -State Cooperative Program in Weather

Modification Research 187-194

AR Air Resources Laboratory 21-56

FS Forecast Systems Laboratory 74-83

GF Geophysical Fluid Dynamics Laboratory 84-95

GL Great Lakes Environmental Research Laboratory 96-109

NS National Severe Storms Laboratory 110-130

PM Pacific Marine Environmental Laboratory 131-146

SE Space Environment Laboratory 147-157

WP Wave Propagation Laboratory 158-185

195

196

AUTHOR INDEX

AAGAARD, K., PM-001
AAGAARD, K„ PM-002
AAGAARD, K„ et al., PM-010
ABBOTT, S.W., et al., WP-091
Acker, J.G., et al., PM-014
ACKERMANN, G.R., et al., AR-127
Adams, L.H., et al., AR-103
Aissa, M.,etal.,AR-151
Albers, S.C.FS-001
Albers, S.C.,etal.,FS-051
Albers, S.C., etal.,WP-l 31
Allwine, E., et al., AR-054
Alvo, M.,etal.,AR-144
Anderson, J.G., et al., AL-024
Anderson, J.G., et al., AL-057
Andreae, M.O., et al., AL-044
Andrews, J.T, et al., AR-037
ANGELL,J.K.,AR-001
ANGELL, J.K., AR-002
Anthes, R.A., et al., AL-001
Antiochos, S.K., et al., SE-020
Arbuzova, V.N., et al., AR-086
Arpe, K.,etal., PM-051
ARTZ, R.S., et al., AR-003
ARTZ, R.S., et al., AR-004
ARTZ, R.S., et al., AR-056
ARTZ,R.,etal.,AR-142
Arya, S.P.S., et al., AR-023
Ascher, S.C., et al., GF-026
ASSEL, R.A., GL-001
Atlas, D„ et al., NS-045
AUGUSTINE, J.A., et al., FS-002
AUGUSTINE, J.A., et al., NS-077
Augustinus, A., et al., WP-140
Austin, J., et al., AL-024
Austin, I, et al., AL-070
Avery, S.K., et al., AL-003
Avery, S.K., et al., AL-029
Bai, L.S.,etal.,FS-013
BAILEY, K.,etal„PM-024
BAKER, E.T., et al., PM-003
BAKER. E.T., et al., PM-030
Balakrishnan, N., et al., NS-001
Balakrishnan, N., et al., NS-002
Balakrishnan, N., et al., NS-003
Balakrishnan, N., et al., NS-092
BALDOCCHI, D.D., AR-005
BALDOCCHI, D.D., AR-006
BALDOCCHI, D.D., AR-007
BALDOCan, D.D., AR-008
BALDOCCIH, D.D., et al., AR-009
BALDOCCHI, D.D., et al., AR-010
BALDOCCHI, D.D., et al., AR-011
BALDOCCHI, D.D., et al., AR-076
BALDOCCHI, D.D., et al., AR-097
BALDOCCHI, D.D., et al., AR-131
BALDOCCHI, D.D., et al., AR-147
BALSLEY, B.B., AL-092
BALSLEY, B.B., et al., AL-002
BALSLEY, B.B., et al., AL-003
BALSLEY, B.B., et al., AL-008
BALSLEY, B.B., et al., AL-013
BALSLEY, B.B., et al., AL-019
BALSLEY, B.B., et al., AL-020

BALSLEY, B.B., et al„ AL-021
BALSLEY, B.B., et al., AL-027
BALSLEY, B.B., et al., AL-028
BALSLEY, B.B., et al., AL-029
BALSLEY, B.B., et al., AL-030
BALSLEY, B.B., et al., AL-043
BALSLEY, B.B., et al., AL-049
BALSLEY, B.B., et al., AL-060

* BALSLEY, B.B.,etal.,AL-093
BALSLEY, B.B., et al., AL-094
BANTA, R., et al., WP-046

* Barnes, G.M., et al., AO-001
Bames, G.M., et al., AO-074

* BARNES, S.L., et al., FS-003
BARNES, S.L., et al., FS-013
BARNES, S.L., et al., FS-050
BARNES, S.L., et al„ NS-028

* Barrow, C.H., et al., SE-001
BARRY, W.P., et al., AO-083

* BARTELS, D.L., NS-004
BARTELS, D.L., et al., FS-049
Bartoe, J.D.F.. et al., SE-020

* BATES, JJ.,etal.,AR-012

* BATES, T.S., PM-004
BATES, T.S., et al., PM-006
BATES, T.S., et al., PM-008
BATES, T.S., et al., PM-038
BATES, T.S., et al., PM-047
Baumgartner, D.J.,et al., AR-113
Baumgartner, D.J., et al., AR-114
Baumgartner, D.J., et al., AR-115

* BEDARD, A.I, WP-002

* BEDARD, AJ..WP-003
BEDARD, A.J., et al., AL-066

* BEDARD, AJ.,etal.,WP-004
BEDARD, A J. , et al., WP-027
BEDARD, A.J., et al., WP-031
BEDARD, A.J., et al., WP-1 16
BEDARD, A.J., et al., WP-1 17
BEDARD, A.J., et al., WP-1 36

* BEDARD, A.J.,etal.,WP-141
BEDARD, A.J., et al., WP-144
Bedford, D., et al., SE-020
Beecher, K., et al„ AL-044
BEELER, R.H., et al., WP-113
BEETON, A.M., et al, GL-015
Beland, R.R., et al„ AL-036
Beland, R.R., et al„ AL-084
Bender, L.W., et al., AR-140

* Benjamin, S.G..FS-004

* Benjamin, S.G., FS-005

* Benjamin, S.G., et al., FS-006
Benjamin, S.G, et al., FS-011
Benjamin, S.G, et al., FS-027

* BENNETT, I.R., et al.,GL-053

* BERAN, D.W., et al., FS-007

* BERAN, D.W.,etal.,FS-008
Bernstein, RE., et al., PM-005
Berresheim, H., et al., AL-044
Bettge, T.W., et al., AL-001

* Betzer, P.R.,etal., PM-005
Betzer, PR, etal, PM-014
BEZDEK, H.F., et al., AO-059
Biggerstaff, ML, et al., NS-030

197

Bilitza, D., et al.. SE-027
Biltoft, C.A.. et al., WP-037
BINKOWSKI, F.S., et al, AR-102
BIRKENHEUER, D., FS-009
BIRKENHEUER, D., et al., WP-124
Birth, T.,etal.,AR-100
BITTERMAN, D.S., et al., AO-002
BLACK, ML, AO-003
BLACK, ML., et al., AO-004
BLACK, M.L., et al., AO-008
BLACK, ML., et al., AO-009
BLACK, P.G., et al., AO-005
BLACK, RG.etal, AO-006
BLACK, PC, et al., AO-039
BLACK, PC, et al., AO-067
BLACK, PC, et al., AO-072
BLACK, PC, et al., AO-078
BLANCHARD, D.O., et al., NS-045
BOATMAN, J.F..AR-013
BOATMAN, J.F., et al., AR-014
BOATMAN, J.F., et al., AR-015
BOATMAN, J.F., et al., AR-016
BOATMAN, J.F., et al., AR-056
BOATMAN, J.F., et al., AR-082
BOATMAN, J.F., et al., AR-093
BOATMAN, J.F., et al., AR-094
BOATMAN, J.F., et al., AR-095
BOATMAN, J.F., et al., AR-150
BOATMAN, J., et al., AR-124
BOATMAN, J., et al., AR-126
BODHAINE, B.A., et al., AR-064
BODHAINE, B.A., et al., AR-017
Bodner, P.M., et al., AR-138
Boe,B.A.,etal.,AP-001
Boe, B.A.,etal.,AP-037
Boe,B.A.,etal.,WP-001
Boe,B.A.,etal.,WP-112
Boehm,T.L.,etal.,AR-151
Bograd, S.J., et al., AO-086
Bohlander, R.A., et al., WP-049
BOLSENGA. S.J., GL-002
BOLSENGA, S.J., et al., GL-003
BOLSENGA, S.J., et al., GL-004
Bommann, PL., et al., SE-002
Borys, R.D., etal., AP-022
Bougeret, J.L., et al., SE-020
Bourbonniere, R.A., et al., GL-042
Bourbonniere, R., et al., GL-013
Bouwer, S.D., et al., AR-135
Bowne, N.E., et al., AR-01 8
Bradley, R.S., et al., AR-038
Brady, R.H., etal., FS-010
Brady, R.H., et al., FS-047
BRANDES, E.A., et al., NS-005
Brasseur, G.P., et al., GF-001
BRAVO, N.J., et al., AO-047
Breland, J.A., et al., PM-005
Brewster, K.A., et al., FS-006
Brewster, K.A., et al., FS-01 1
Breyfogle.T, etal.,FS-034
BRIGGS,GA.,AR-019
BRIGGS, G.A., AR-020
BRODE, R.W., AR-021
BRODE, R.W., et al., AR-022
Browell, E.V., et al., AL-045
Browell, E. V, et al., AL-070
Brown, B.C. et al., FS-048
Brown, J.H., et al., AL-036

Brown, J.H., et al., AL-084
BROWN, J.M.. et al., FS-025
BROWN, J.M., et al., FS-049
Brown, J., et al., AL-016
Brown, M.G.. et al., AO-059

* Brown, M.J., et al., AR-023
Brown, P.W., etal., NS-061

* BROWN, R.A., NS-006

* BROWN, R.A., NS-007

* BROWN, R.A., et al., NS-008
Brown, R.M., et al., AR-102
Brown, T.,etal.,NS-066
Brown, T, etal., SE-015
Brueckner, G.E., et al., SE-020
Brummer, R., et al., FS-006
Brune,W.H.,etal.,AL-057
Branson, CM., et al., AR-024
BRYAN, K., et al., GF-032
BRYAN, K., et al., GF-033
Buechler, D.E., et al., NS-026
Buechler, D.E., et al., NS-027
BULLOCK, C, et al., FS-034
BURGER, R.S., et al., PM-038

* BURGESS, D.W., et al., NS-009
BURGESS, D.W., et al., NS-024
BURGESS, D.W., et al., NS-049

* Burkholder, J.B., et al., AL-004
Burkholder, J.B., et al., AL-035
Burkholder, J.B., et al., AL-050
Burkholder, J.B., et al., AL-091
Bums, D.J., et al., AR-103

* BURPEE, R.W., AO-007

* BURPEE, R.W., et al., AO-008

* BURPEE, R.W., et al., AO-009
BUSHNELL, M., et al., AO-050
BUSHNELL, M., et al., AO-079
Busness, K.M, et al., AR-092

* Butler, J.H., et al., AR-024

* Butler, J.H., et al., AR-025
Butterfield, D.A., et al., PM-031
Butterfield, D.A., et al., PM-032
Byrne, R.H., et al, PM-014

* Calhoun, J.A.,et al., PM-006
CAMPBELL, J.E., et al., GL-053
Campistron, B.A., et al., AP-016

* CANNON, GA..PM-007
CANNON, G.A., et al., PM-029
Capel,P.D., etal., GL-013

* CARACENA,F.,etal.,NS-010

* Carbone,R.E.,etal.,AO-010

* Carder, K.L., et al., AO-011
Carder, K.L., et al., PM-005

* Carissimo, B.C., et al., GF-002

* CARRICK, H.J., et al., GL-005

* CARRICK, H.J., et al., GL-006
CARRICK, H.J., et al., GL-014

* CARROLL, M.A.,etal.,AL-005

* CARROLL, M.A., et al., AL-006

* CARROLL, M.A., et al., AL-007
CARROLL, M.A., et al., AL-061
CARROLL, M.A., et al.. AL-065
CARTER, D.A., et al., AL-002
CARTER, D.A., et al., AL-003

* CARTER, D.A.,etal.,AL-008

* CARTER, D.A.,etal.,AL-009
CARTER, D.A., et al., AL-013
CARTER, D.A., et al., AL-019
CARTER, D.A., et al., AL-020

198

CARTER, D.A., et aL, AL-021
CARTER, DA., et aL, AL-022
CARTER, D.A., et al., AL-023
CARTER, DA., et al., AL-027
CARTER, DA., et al., AL-028
CARTER, D.A., et al., AL-031
CARTER, DA., et al., AL-032
CARTER, D.A., et al., AL-093
CARTER, D.A., et al., AL-094
Castelle, A.J., et al., AO-064
Castro, LP., etal.,AR-026
Castro, M., et al., AL-044
CAVALETTO, J.F., et al., GL-007
Chagnon, S.A., AP-003
Chai, S., et al., AP-002
Chan, K.R., et al., AL-025
Chan, K.R., et al., AL-045
Chan, K.R., et al., AL-053
Chan, K.R., et al., AL-058
CHANDLER, J.F., et aL, GL-01 6
CHANDLER, J.F., et aL, GL-017
Chang, J.S., et al., AR-036
Chang,P.,etal.,GF-003
Changnon, S.A., Jr., et al., AP-045
Changnon, S.A., et al., AP-004
Changnon, S.A., et al., AP-005
Changnon, S.A., et al., AP-006
Changnon, S.A., et al., AP-007
Changnon, S.A., et al., AP-01 8
Changnon, S.A., et al., GL-038
Chao, Y„ et aL, GF-021
Chappell, C.F, et aL, FS-012
Charlson, R.J., et al„ PM-008
Chelton,D.,etal.,WP-005
Chen, C.T.A., et al„ PM-009
Chen, C.T.A.,etal.,PM-014
Chen, S.J.,etal.,FS-013
Chen, Z.Z., et al., WP-025
Chen, Z.Z., et al., WP-026
Chen, Z., et al., PM-034
Cheng, C.C., et al., SE-020
Chimonas, G, et al., AR-027
CHIN, J.F.S., et al., AR-085
CLUNG, J.K.S.,AR-028
CHING, J.K.S., et al., AR-018
CHING, J.K.S., et al„ AR-126
CHING, J.K.S., et al., AR-145
CHING, J.S.,etal.,AR-l 53
Christian, HI., et al., NS-01 1
Christian, H.J., et al., NS-025
CHRISTIAN, T, et al., WP-006
CHRISTIAN, T, et al., WP-007
Christie, DR., et aL, NS-018
Church, J.A., et al., PM-025
CHURNSIDE, J.H., WP-008
CHURNSIDE, J.H., et al., WP-009
CHURNSIDE, J.H., et al., WP-010
CHURNSIDE, J.H., et al., WP-011
CHURNSIDE, J.H., et al., WP-012
CHURNSIDE, J.H., et aL, WP-013
CHURNSIDE, J.H., et al., WP-014
CHURNSIDE, J.H., et al., WP-059
CHURNSIDE, J.H., et al., WP-060
CHURNSIDE, J.H., et al., WP-061
CHURNSIDE, J.H., et al., WP-143
Ciotti, R.etaL, WP-015
Ciotti,P.,etal.,WP-016
CLARK, T.L., et al., AR-029

CLARK, T.L., et al., AR-030
CLARK, T.L., et al., AR-144
CLARK, W.L., et al., AL-010
CLARK, W.L., et al., AL-01 1
CLARK, W.L., et al., AL-016
CLARK, W.L., et al., AL-022
CLARK, W.L., et al., AL-036
CLARK, W.L., et al., AL-037
CLARK, W.L., et al., AL-038
CLARK, W.L., et aL, AL-039
CLARK, W.L., et al., AL-054
CLARK, W.L., et al., AL-079
CLARK. W.L., et al., AL-084
CLARK, W.L., et al., AL-095
CLARKE, T.L, et al., AO-012
CLAWSON,K.L.,AR-031
CLAWSON, K.L., et al., AR-032
CLAWSON, K.L., et al., AR-033
CLAWSON, K.L., et al., AR-127
CLIFFORD, S.F., et al., WP-009
CLIFFORD, S.F, et aL, WP-010
CLIFFORD, S.F, et al., WP-049
CLIFFORD, S.F, et al., WP-054
CLITES, A.H., GL-008
CLJTES, A.H., et aL. GL-045
Coachman, L.K., et al., PM-010
Coakely, J.A., et al., WP-142
Coakley, I.A., et al., WP-017
Coakley, J.A., et al., WP-018
Coats, C.J., Jr., etal.,AR-151
Cohn, R.D., et al., AR-030
COKELET, E.D., et aL, PM-029
Cole, C.F, etal.,AR- 136
Cole.H, etal.,AL-014
COLMAN.B.R..FS-014
COLMAN, B.R., et al., FS-003
COLQUHOUN, JR., et aL, FS-015
Condon, E.P., et al., AL-005
Condon, E.P., et al., AL-006
Condon, E.P., et al., AL-071
Conforti, G., et al., WP-143
Conley. D.J., et al., GL-042
Consortini, A., et al., WP-143
CONWAY, T.J., et al„ AR-024
CONWAY, T.J., et al., AR-063
CONWAY, T.J., et aL, AR-130
COOK, K.H., et al., GF-004
Coon.R.C, etal.,AP-017
Costello, D.K., et al., PM-005
Coulter, R.L., et al., WP-094
Cox,R.A.,etal.,AL-048
Craven, J.D.,et al., SE-01 3
Crawford, R., et aL, FS-011
Crecelius, E.A., et al., PM-042
Crochet, M., et al., AL-008
CROLEY, T.E., n, GL-009
CROLEY,T.E.,n.GL-010
CROLEY, TE.,n,GL-054
CROLEY, T.E., H, et al., GL-01 1
CROLEY, T.E., II, et al., GL-01 2
Crouch, K.,etal.,NS-011
Crutzen, P.J., et al., AL-048
CUMMINGS, S.R., et al., AO-057
CUNNING, J.B., et aL, NS-088
CUPP,R.E.,etal.,WP-024
CUPP,R.E.,etal..WP-046
CUPP,R.E.,etal.,WP-063
CUPP,R.E.,etal„WP-089

199

CURL,HC.,JR.,PM-011
CURL, H.C., JR., et al., PM-038
CURL, H.C., JR., et al., PM-042
CURL, H.C., JR., et al., PM-043
CURL, H.C., JR., et al., PM-044
Currier, P.E., et al„ AL-009
Currier, P.E., et al., AL-012
Currier, P.E., et al., AL-013
Currier, P.E., et al., AL-019
Currier, P.E., et al., AL-020
Currier, P.E., et al., AL-022
Currier, P.E., et al., AL-023
Czys, R.R., AP-008
Czys, R.R., AP-009
Czys,R.R.,AP-010
Czys, R., et al., AP-007
Dabberdt, W.F., et al., AL-014
Daly, P.W., et al., SE-020
DAMMANN, W.P., et al., AO-063
DAUGHERTY, J.R., et al., NS-048
DAUGHERTY, J.R., et al., NS-085
DAUGHERTY, J.R., et al., NS-086
DAUGHERTY, J.R., et al., NS-087
Davidson, K., et al., WP-062
DAVJJES-JONES, R.P., NS-012
DAVJES,K.,etal.,SE-027
Davies, M.T., et al., AP-032
Davis, J.M., et al., AO-014
Dayan, U., et al., AR-056
DE FOOR, T.E., et al., AR-117
DECKER, M.T., et al., WP-124
deLorenzis, B., et al., FS-040
DELUISI, J.J., et al., AR-034
DELUISI, J.J., et al., AR-047
DELWORTH, T.L., et al., GF-005
DEMARIA.M..AO-013
DEMARIA, M., et al., AO-014
Demoz, B., et al., AP-041
Dennis, M.G., et al., AR-103
DENNIS, R.L., et al., AR-029
DENNIS, R.L., et al., AR-035
DENNIS, R.L., et al., AR-036
DENNIS, R.L., et al., AR-096
DENNIS, R.L., et al., AR-144
Derber,J.,etal.,NS-043
Dere, K.P., et al., SE-020
DERR, V.E., et al., WP-019
DETMAN, T.R., et al., SE-004
DIAZ, HE, et al„ AR-037
DIAZ, H.F., et al., AR-038
DIAZ, H.F., et al., AR-079
DIAZ,H.F.,etal.,AR-081
DIAZ,H.F.,etal.,AR-152
DICKE,J.L.,etal.,AR-134
DICKE,J.L.,etal.,AR-136
DICKE,J.L,etal.,AR-137
DICKE,J.L.,etal.,AR-156
DICKSON, C.R., et al., AR-032
DICKSON, C.R., et al.. AR-127
Dijk,J.,etal.,WP-140
DDCON,K.,etal.,GF-032
DDCON,K.,etal.,GF-033
Dlugokencky, E.J., et al., AL-015
Dobosy, R.J., et al., AR-039
Dobosy, R.J., et al., AR-049
Dobosy, R.J., et al., AR-073
DODGE, P.P., AO-015
DOLL, D.C., et al., AR-040

Dolske, D.A., et al., AR-072

* Doneaud, A.A., et al., AP-01 1

* DONNELLY, R.F. , AR-041

* DONNELLY, R.F..AR-042

* DONNELLY, RE, AR-043

* Doran.J.C, et al.,WP-020
Doschek, G.A., et al., SE-020

* DOSWELL, C.A., BJ, NS-013

* DOSWELL, C.A., BJ, NS-014

* DOSWELL, C.A., HI, NS-015

* DOSWELL, C.A., BJ, NS-016
DOSWELL, C.A., BJ, et al., NS-010

* DOSWELL, C.A., BJ, et al., NS-01 7
DOSWELL, C.A., et al., NS-028

* DOVIAK, R.J., et al., NS-01 8

* DOVIAK, R.J., et al., NS-01 9
Doviak, R.J., et al., NS-093

* DRAXLER, R.R., AR-044

* DRAXLER, R.R., AR-045

* DRAXLER, R.R. , et al. , AR-046

* DRYER, M..SE-003

* DRYER, M., et al., SE-004
DRYER, M.,etal., SE-031
DRYER, M.,etal., SE-032
DRYER, M, etal., SE-036
DRYER, M,etal.,SE-037
DRYER, M.,etal.,SE-038
Duce, R.A., et al., PM-005
DUNLAP, D.D., et al., AL-005

* Dunn,L.B.,FS-016
Durgunoglu, A., et al., AP-01 8

* Dusenbery, P.B., etal.,SE-005

* DUTTON, E.G., et al., AR-047
DUTTON, E.G., et al., AR-064
EADffi,B.J.,etal.,GL-017
EADffi, B.J., et al.. GL-025
EARNSHAW, K.B., et al., WP-081
Eaton, F.D., et al., AL-036
Eaton, F.D., et al., AL-084

* Eaton,F.,etal.,AL-016

* EBERHARD, W.L., WP-021

* EBERHARD, W.L., WP-022

* EBERHARD, W.L., WP-023

* EBERHARD, W.L., et al., WP-024

* EBERHARD, W.L., et al., WP-025

* EBERHARD, W.L., et al., WP-026
EBERHARD, W.L., et al., WP-046
EBERHARD, W.L., et al., WP-085
EBERHARD, W.L., et al., WP-139

* Eberhart,G.L.,etal.,AO-016

* EBLE,M.C.,etal.,PM-012

* ECKLUND.W.L..AL-017

* ECKLUND, W.L..AL-018
ECKLUND, W.L., et al., AL-003
ECKLUND, W.L., et al., AL-008
ECKLUND, W.L, et al., AL-009
ECKLUND, W.L, et al„ AL-012
ECKLUND, W.L , et al., AL-01 3
ECKLUND, W.L, et al., AL-014

* ECKLUND, W.L, etal., AL-019

* ECKLUND, W.L, et al., AL-020

* ECKLUND, W.L. , et al., AL-021

* ECKLUND, W.L, etal., AL-022

* ECKLUND, W.L, etal., AL-023
ECKLUND, W.L, et al.( AL-027
ECKLUND, W.L, et al., AL-028
ECKLUND, W.L, et al., AL-029
ECKLUND, W.L, et al., AL-030

200

ECKLUND, W.L., et al., AL-031
ECKLUND, W.L., et al., AL-032
ECKLUND, W.L., et al., AL-066
ECKLUND, W.L, et al., AL-093
ECKLUND, W.L, et al., AL-094
ECKLUND. W.L., et al„ WP-1 16
ECKLUND, W.L., et al., WP-1 17

* ECKMAN, R.M.AR-048
ECKMAN, R.M., et al., AR-039

* ECKMAN, R.M., et al., AR-049
ECKMAN, R.M., et al., AR-110

* EDER, B.K., AR-050

* EDER,B.K„etal.,AR-051
Edgington, D.N., et al., GL-040
Egan,K.B.,etal.,AR-024
Ehhalt, D.H., et al., AL-048
Eichinger, J.R., et al., AR-151

* EILTS, M.D., NS-020

* EILTS, M.D.,etal.,NS-021

* EILTS, MD.,etal.,NS-022

* EILTS, M.D.,etal.,NS-023
EILTS, M.D., et al., NS-038
EILTS, M.,etal.,NS-076

* Einaudi, R, et al., WP-027
Eischeid, J.K., et al., AR-038

* Eischeid, J.K., et al., AR-052

* Eisenreich, S.J., et al., GL-01 3
ELKINS, J.W., et al., AR-024

* ELLIOTT, W.P., AR-053
Ellison, E., et al., FS-040
Elsberry, R.L., et al., AO-005
Elsberry, R.L., et al., AO-006
Elsberry, R.L., et al., AO-072

* EMBLEY,R.W.,etal.,PM-013

* EMBLEY,R.W.,etal.,PM-053

* ENFIELD, DB..AO-017

* ENnELD,DB.,AO-018
ENFIELD, D.B., et al., AO-051
Enz,J.W.,etal.,AP-017
Escribano, R., et al., AL-035

* ESKRIDGE, R.E., et al.. AR-054
EVANS. D.S.,etal..SE-001
EVANS. DS.,etal..SE-006
EVANS, D.S., et al., SE-007
EVANS.DS..etal..SE-013
Evans. W.E.etal., AR-1 19
Eyles.C.etal., SE-020

* FAHEY. D.W., et al., AL-024

* FAHEY, D.W., et al., AL-025
FAHEY, D.W., et al., AL-045
FAHEY, D.W., et al., AL-058
FAHNENSTIEL, G.L, et al., GL004

* FAHNENSTIEL, G.L, etal.,GL014
Fairall,C.W.,etal.,AR-072

* FAIRALL, C.W., et al., WP-028
Fall, R., et al., AL-034

Falls, M.J., et al., FS-028
Falls, M.J., et al., FS-029
FALLS, M.J., et al., WP-079
FALLS, M.J., et al., WP-080
FALLS, M.J.. et al., WP-122
FALLS, M.J., et al., WP-123
FALLS, M.J., et al., WP-124
FALLS, M.J., et al., WP-127
FANNING. ML., et al., AR-084
Fannan, J.C., et al., GF-001
Farmer, C.B., et al., AL-024
Farmer, J.C., et al., AL-044

FAUST. W.R.,etal.,GL-025
Favier, D.,etal„ AL016
Fivier, L.D., et al.. AL036
Favier. L.D.. et al.. AL084
FEDOR. L.S., et al., WP-019

* FEDOR, L.S., et al., WP-029

* FEDOR, L.S.,etal.,WP-030

* FEDOR, L.S.,etal.,WP-031

* FEDOR, L.S.,etal.,WP-032
FEELY. R.A., et al., PM-003
FEELY, R.A., et al., PM-005
FEELY, R.A., et al.. PM-009

* FEELY, R.A.,etal.,PM-014
FEELY, R.A., et al., PM-038
FEELY, R.A., et al., PM-042
FEELY, R.A., et al., PM-043
FEELY, R.A., et al., PM-044
FEHSENFELD, EC, et al., AL-034
FEHSENFELD, EC, et al., AL-046
FEHSENFELD, EC, et al., AL-056
FELS,S.B.,etal.,GF-031

* Feng,D.,etal.,AP-012
Ferry, G.V.etal., AL-025
Ferry, G.V.etal., AL-045
FESTA,J.F.,etal.,AO-066
Fine, R.A., et al., PM-033
FINKELSTEIN, PL., et al., AR-05 1
Finnegan, W.G., et al., AP-002
Finnegan, W.G., etal., AP-012

* Finnegan, W.G., etal., AP-01 3

* Finnegan, W.G.etal., AP-014

* Finnegan, W.G.etal., AP-01 5
Finnegan, W.G., et al., AP-024
Finnegan, W.G., et al., AP-025
Finnegan, W.G., et al., AP-026
Finnegan, W.G., et al., AP-027
Finnigan, J.J., et al., WP-027
Fionda.E., etal., WP-122
FISCHER. C.J., et al.. AO-060
FISCHER, C.J.. et al., AR-108
Fisher. BD.,etal.. NS-011
Fisher, B.D., et al., NS-061
Fisher, B., et al., NS-066
Flueck,J.A., etal..FS-019
Flueck.J.A., etal.,FS-035
Flueck,J.A., etal..NS-017
Hueck,J.A.,etal..SE-015
Flueck, J., et al., FS-040
FONTAINE, T.D., IJJ, et al., GL-027
Foote, G.B., etal., WP-1 32

* FORSYTH, D.E.,etal.,NS-024

* Foster, J.C., et al., SE-006

* Foster, J.C., et al., SE-007

* FOX,CG.,PM-015

* FOX,CG.,etal.,PM-016

* Fox,M.G.,etal.,GL-015
Fox, M., et al., SE-027
Franchois, PR., et al.. AR-084
Francis, T.J.G., et al., PM-053
Frank, LA., et al., SE-01 3

* FRANKLIN, J.L., AO-01 9

* FRANKLIN, J.L. , et al. , AO-020
Franklin, J.M., et al., PM-053

* Freeman, J.W., Jr., et al., SE-008

* FRFJTAG, H.P., et al., PM-01 7
FRFJTAG, HP, et al.. PM-034

* FRELICH, R.G., et al., WP-033
Frenzel, P., et al., GL-029

201

Friedl,R.R.,etal.,AL-083
FRIEDMAN, H.A., et al., AO-030

* FRISCH, A.S., et al., WP-034
FRISCH, A.S., et al., WP-065

* Fritts,D.C.,etal.,AL-026
Fritts, D.C., et al., AL-067
Fritts,D.C.,etal.,AL-078
Fritts, D.C.,etal.,AL-081

* FRITZ, R.B., et al., WP-035
FRITZ, R.B., et al., WP-092
FRITZ, R.B., et al., WP-094

* Fryrear,D.W.,etal.,AR-055
Fukao, S., et al., AL-026
Fukao, S., et al., AL-067
Fukao, S., et al., AL-068
Fukao, S.,etal.,AL-081
Fukao, S., et al., WP-070
Fuller-Rowell, T, et al., SE-006
Furtney.D., etal.,FS-034
GAGE,K.S.,etal.,AL-003
GAGE, K.S., et al., AL-008
GAGE, K.S., et al., AL-014
GAGE,K.S.,etal.,AL-016
GAGE, K.S., et al., AL-020
GAGE, K.S., et al., AL-021
GAGE,K.S.,etal.,AL-022

* GAGE,K.S.,etal.,AL-027

* GAGE,K.S.,etal.,AL-028

* GAGE,K.S.,etal.,AL-029

* GAGE,K.S.,etal.,AL-030

* GAGE,K.S.,etal.,AL-031

* GAGE, K.S., et al., AL-032

* GAGE,K.S..etal.,AL-033
GAGE,K.S.,etal.,AL-036
GAGE,K.S.,etal.,AL-039
GAGE,K.S.,etal.,AL-049
GAGE, K.S., et al., AL-054
GAGE,K.S.,etal.,AL-055
GAGE,K.S.,etal.,AL-059
GAGE,K.S.,etal.,AL-060
GAGE,K.S„etal.,AL-079
GAGE,K.S.,etal.,AL-080
GAGE,K.S.,etal.,AL-084
GAGE, K.S., et al., AL-085
GAGE, K.S., et al., AL-086

* GAGE, K.S., et al., AL-094
GAGE, K.S., et al., AL-095
Galloway, J.N., et al., AL-044
Galloway, J.N., et al., AO-064

* Galloway, J.N., et al., AR-056
Galloway, J.N., et al., AR-094
Galloway, J.N., et al., AR-095
Gallus, W.A., et al., NS-080
Galperin,B.,etal.,GF-011

* GAMACHE.J.F..AO-021

* GAMACHE.J.F..AO-022
Gannon, J.E., et al., GL-003

* GARCIA, H.A., SE-009
GARCIA, H.A., et al., SE-024
Garcia, P., etal.,AP-005
Garcia, P., etal.,AP-007
GARDNER, W.S., et al., GL-007

* GARDNER, W.S.,etal.,GL-016

* GARDNER, W.S.,etal.,GL-017
GARDNER, W.S., et al., GL-01 8
GARDNER, W.S., et al., GL-042
Gardlo, R., et al., AL-008
Gary, B.L., et al., AL-058

Gautier, C, et al., AR-012

* GAUVIN, J.M., et al., GL-018
GAUVIN, J.M., et al., GL-034

* GAYNOR, I., WP-036

* GAYNOR, J.E., et al., WP-038

* GAYNOR, J., et al. , WP-037
GENDRON, J.F., et al., PM-009
GENDRON, I.F., et al., PM-014
Gentry, R.C., et al., AO-039
Gentry, R.C., et al., AO-078

* GEORGES, T.M., et al., AO-023
GEORGES, T.M., et al., AO-058
GEORGES, T.M, et al., WP-121

* GIBSON, J.S., WP-039

* Giese,B.S.,PM-018
Giese, B.S., etal.,PM-021
Giese, B.S., etal.,PM-022
Giese, R.H., et al., SE-020
Gilbert, K.E., et al., NS-057
Gill, S., et al., PM-029

* Gillani,N.V.,etal.,AR-153

* GILLETTE, D.A., AR-057

* GnLLETTE,D.A.,AR-058
GILLETTE, D.A., et al„ AR-055

* GnTJETTE, D.A., et al., AR-059

* GDLLETTE, D.A., et al., AR-060
Giovane, F, et al., SE-020
Giovanoli, E, et al., GL-029
Glendening, J., et al., WP-130
Gliner, E.B., et al., SE-025

* GODOWITCH,J.M.,AR-061

* GODOWTTCH, TNI., AR-062
GODOWITCH, J.M., et al., AR-1 12

* GOLDAN, P.D., et al., AL-034
GOLDAN, P.D., et al., AL-046
GOLDER, D.G., et al., GF-008
GOLDER, D.G, et al., GF-009
Goldhirsh, J., et al., NS-003
Goldman, A., et al., AL-004

* Goldman, A., et al., AL-035
GONZALEZ, F.I. , et al., PM-01 2

* Goodman, S.J., et al., NS-025

* Goodman, S.J., et al., NS-026

* Goodman, S.J., et al., NS-027
Gordon, C.etal., PM-051
Gordon, L.I., et al., AR-025

* GOSSARD, E.E., WP-040
Gossard, E.E., et al., AL-062

* Gossard, E.E. , et al., WP-041

* Gossard, E.E. , et al., WP-042

* Gossard, E.E., et al., WP-043
Gossard, E.E., et al., WP-110
GRASS, R.D., et al., AR-083
GRASS, R.D.,etal.,AR-084
GRASS, R.D., et al., AR-155
Grassia,J.,etal..FS-047
Greco, A.M., et al., PM-005
GREEN, G.E., et al., WP-141
GREEN, J.L., et al., AL-010
GREEN, J.L,etal.,AL-011
GREEN, J.L., et al., AL-016
GREEN, J.L., et al., AL-022

* GREEN, J.L., et al., AL-036

* GREEN, J.L., et al., AL-037

* GREEN, I.L,etal.,AL-038

* GREEN, J.L., et al., AL-039
GREEN, J.L.. et al., AL-054
GREEN, I.L., et al., AL-055

202

GREEN, J.L.,etal.,AL-079
GREEN, J.L.,etal.,AL-080
GREEN, J.L., et al., AL-084
GREEN, J.L., et al., AL-085
GREEN, J.L., et al., AL-086

* GREEN, J.L.,etal.,AL-095

* Greenblatt, G.D., et al., AL-040

* GREENHUT,G.K.,etal.,FS-017
GREENHUT, G.K., et al., FS-023
GREER, M.S.,etal.,SE-011
GREER, M.S.,etal.,SE-012
Gregory, G.L., et al., AL-005
Gregory, G.L., et al., AL-006
Gregory, G.L., et al., AL-007
Gregory, G.L., et al., AL-045

* Grice, G.K., et al., NS-028

* GRIFFITH, C.G..FS-01 8
GRIFFITH, C.G., et al., FS-041
Griffith, DA., et al., AP-037
Griffith, D.A.,etal.,WP-112
Griffith, D.S., et al., AP-001
Griffith, D.S., et al., WP-001
Grimes, D.J., et al., AR-151
GRUBB,R.,etal.,SE-030
GUDGEL, R., et al., GF-021
Gudiksen, PH., et al., WP-094
Guicherit, R., et al., AL-048
GUNTER, R.L.. et al., AR-01 5
GUNTER, R.L., et al., AR-01 6
GUNTER, R.L., et al., AR-157
Haagenson, PL., et al„ AR-120
Hall,B.D.,etal.,AR-024

* HALL.F.F.,WP-044
HALL, F.F., et al., WP-063
HALL, F.F., et al., WP-149
Hallyburton, S.W., et al., AR-151

* HALTER, B ,C. , et al. , AR-063

* HAMILTON, K., GF-007

* HAMILTON, K„ et al., GF-006
Hammer, P.D., et al., AL-004
HAMMOND, S.R., et al., PM-013
HAMMOND, S.R., et al., PM-032
Han, S.M., et al., SE-004
Han.S.M., etal.,SE-032
Han,S.M.,etal.,SE-036
Hancock, D.W., et al., WP-120

* HANE>C.E.,etal.,NS-029

* Hansen,A.D.A.,etal.,AR-064
Hansen, A.D.A., et al., AR-078

* HANSEN, D.V., AO-024
HANSEN, D.V., et al., AO-002

* HANSEN, D.V., et al., AO-025

* HANSEN, D.V., et al., AO-026
HANSON, K.J., et al., AO-060
HANSON, K.J., et al., AR-059
HANSON, K.J., et al., AR-108

* HANSON, K., et al., AO-027

* HANSON, K., et al., AO-028
HANSON, K., et al., AO-048
HANSON. K., et al., AO-050

* HANSON, K..etal.,AR-065
Hanson, P.J.,etal., AR-131
Harder, J.W., et al., AL-041

* HARDESTY, R.M., WP-045

* HARDESTY, R.M., et al., WP-046
HARDESTY, R.M., et al., WP-063
HARDESTY, R.M., et al., WP-078
HARDESTY, R.M., et al., WP-089

HARDESTY, R.M., et al., WP-104
HARDESTY, R.M., et al., WP-105
HARDESTY, R.M., et al., WP-137
HARDESTY, R.M., et al., WP-144
HARDESTY, R.M., et al., WP-149
Hare,J.E.,etal.,WP-028
HARRIS, J.M., et al., AR-063
HARRIS, J., et al., AR-004
HARRIS, T.B., et al., AR-085

* HARRISON, D.E., PM-01 9

* HARRISON, D.E., PM-020

* HARRISON, D.E., et al., PM-021

* HARRISON, D.E. , et al. , PM-022

* HARTMANN, H.C. , GL-0 1 9
HARTMANN, H.C., et al., GL-011
HARTMANN, H.C, et al., GL-012
HARVEY, G.R., et al., AO-011

* HARVEY, G.R., et al., AO-029
Hastings. J.T., et al., FS-007
Hatch, W.H., et al., AL-036
Hatch, W.H., et al., AL-084
Hatch, W.,etal.,AL-016
Hawkins, J.D., et al., AO-005
Hawkins, J.D., et al., AO-006

* HAYASHI, Y, et al., GF-008

* HAYASHI, Y, et al., GF-009
Hayden, CM., et al., AO-020
Hayden, C, et al., NS-043

* HAYES, S.P., et al., PM-023
HAYES, S.P.,etal.,PM-034
HAYES, S.P.,etal., PM-046
HAYES, S.R.etal., PM-051
Hayne, G.S., et al., WP-029
Hayne, G.S., et al., WP-030
Hayton, W.L., et al., GL-046
Hayton, W.L., et al., GL-047
HECKMAN. G.R., etal., SE-011
HECKMAN, G.R., et al., SE-012

* HEFFTER, J.L., AR-066
HEFFTER, J.L., et al., AR-046

* Heideman,K.F.,etal.,FS-019
Heidt,L.E.,etal.,AL-024
Heidt, L.E.. et al., AL-045
Heilman, W.E., et al., AR-151
HELD.I.M.,etal.,GF-004

* HELD,I.M.,etal„GF-010
HELD,I.M.,etal.,GF-013
HEMLER, R.S., et al., GF-019
Herbert, T.D., et al., GF-029
Herbert, T.D., et al., GF-030
HERCHE, L.R., et al., GL-048
HERCHE, L.R., et al., GL-049
Herdendorf, C.E., et al., GL-003
Hereford, J.V., et al., AL-041
HERMAN, A., et al., AO-025
HERMAN, A., et al., AO-026
Hermes, L, et al., NS-076
Herrick, C.N., et al., AR-096
Herwehe, J. A., et al., AR-073
Herwehe, J.A., et al., AR-098
Herwehe, J.A., et al., AR-128
Herwehe, J.A., et al., AR-132
Heymsfield, A.J., et al., AO-080
Heymsfield, A.J., et al., AO-081

* HICKS, B.B., AR-067
HICKS, B.B., et al., AR-009

* HICKS, B.B.,etal.,AR-068

* HICKS, B.B.,etal.,AR-069

203

HICKS, B.B.,«al.,AR-070
HICKS. B.B.,etal.,AR-071
HICKS, B.B.,etal.,AR-072
HICKS, B.B.,etal.,AR-073
HILDNER.E., SE-010
Hill, G.F., et al„ AL-006
HJLL,L.C.,etal.,AO-057
HILL, R.J.. WP-047
HILL, R.J., WP-048
HILL,R.J.>etal.>WP-049
HILL,RJ.,etal.,WP-128
HILL, R.J., et al., WP- 143
Hilmer.R.V.etal., SE-008
Hinckley, S„ et al., PM-024
Hines,D.E.,etal.,WP-120
Hines, J.R., et al., AL-036
Hines, J.R., et al., AL-084
Hines, J., et al., AL-016
Hinkelman,J.W.,FS-020
HIRMAN, J.W., et al., SE-Oll
HIRMAN, J.W., et al., SE-012
HIRMAN, J.W., et al., SE-026
HJRSH, M.A.,etal.,AO-030
Hjelmfclt, M., et al., AP-OOl
Hjelmfelt, M., et al., WP-OOl
Hocking, W.K., et al., WP-050
Hoffmann, MR., et al., AL-044
Hofmann, D.J., et al., AL-041
Hofmann, D.J., et al., AL-042
Hofzumahaus, A., et al., AL-048
HOGG, D.C.,WP-051
HOGG.D.C.,etal.,WP-031
HOGG,D.C.,etal.,WP-052
HOLLE,R.L..etal.,NS-010
HOLLE,R.L„etal.,NS-045
HOLLE,R.L.,etal.,NS-046
HOLLE,R.L.,etal.,NS-047
HOLLE,R.L.,etal.,NS-048
HOLLE,R.L.,etal.,NS-085
HOLLE,R.L.,etal.,NS-086
HOLLE,R.L..etal.,NS-087
HOLLE,R.L.,etal.,NS-094
Hollinger, S.E., et al., AP-004
Hollinger, S., et al., AP-005
Hollinger, S., et al., AP-007
Holt, J.M., et al., SE-007
Hones, E.W., Jr., etal.,SE-013
Honnorez, J., et al., AO-016
HOSKER, R.P., JR., et al., AR-073
HOSKER, R.P., JR., et al„ AR-1 10
HOSKER, R.P., et al., AR-039
Houze,R.A.,Jr.,AO-031
Houze, R.A.. Jr., et al., AO-086
Houze,R.A.,etal.,NS-030
HOWARD, C.J., et al., AL-004
HOWARD, C.J., et al., AL-015
HOWARD, C.J., et al., AL-035
HOWARD, C.J., et al., AL-040
HOWARD, C.J., et al., AL-050
HOWARD. C.J., et al., AL-072
HOWARD, K.W., et al., NS-028
HOWARD, K.W., et al., NS-031
HOWARD, K.W., et al., NS-032
HOWARD, K.W., et al., NS-05S
HOWARD, K.W., et al., NS-056
Howard, R.A., et al., SE-020
Howes, J.E.. Jr., et al.. AR-018
Hoyt, S.D.,etal.,AR-120

HSIE,E.-Y.,etal.,AL-001
Hsu, C.-E, et al., AP-006
Hubbard, T.P., et al., PM-044

* HUBER.A.H..AR-074

* HUBER,A.H.,etal.,AR-075
Huff, F.A., et al., AP-006
Huff, E.etal., AP-007
Huff,L.C..etal.,AO-012
Huff,L.C.,etal.,WP-011

* Huggins,A.W.,etal.,AP-016
Hughey, L.R., et al., AR-091
HUKARI, N.R., et al., AR- 1 27
Humphris, S.E., et al., AO-077
HURLIN, W.J., et al., GF-027
Huston, M.W., et al., AP-035

* Hutchison, B.A., et al., AR-076

* Huyer, A., et al., PM-025
Ignatowski, A., et al., FS-033

* Incze, L.S., et al., PM-026
Inhester, B., et al., SE-020
Inoue,T.,etal.,AL-067
Insley, E.M., et al., AR-103

* INTRIERI,J.,WP-053

* INTRJJ£RI,J.M.,etal.,WP-144
INTRIERI, J., et al., WP-046
INTRIERI,J.,etal.,WP-141
Ireson, R.G., et al., AR-1 37
Isaac, G.,etal.,AR-126
Isaksen, I.S.A., et al., GF-001
Jackson, R.D., et al., AR-033
JACOBSON, MD.,etal., WP-031
JACOBSON, M.D., et al, WP-113
Jafferis,W.,etal.,NS-089
JAIN, MR, et al., NS-024
JAKOUBEK, R.O., et al., AL-051
JAKOUBEK, R.O., et al., AL-064
JAKOUBEK, R.O., et al., AL-082
JAMISON, B.D., et al., FS-002

* JESUROGA.R.T..FS-021
Jewett, B.F., et al., FS-006

* JOHNS, E., et al.. AO-032
JOHNS, E., et al., AO-034
JOHNS, E., et al., AO-079
Johnson, B.C., et al., NS-049

* Johnson, J.E., et al., AP-017
Johnson, L.R., et al., AP-01 1
Johnson, L.R., et al., AP-035
Johnson, L.R., et al., AP-036
JOHNSON, R.C., et al., AR-127
Jonasson, I.R., et al., PM-031
Jonasson, I.R., et al., PM-053
Jones, R.D., et al., AR-025
Jones, R.L., et al., AL-024
Jones, R.L., et al., AL-045
Jones, R.L., et al., AL- 070
JONES, R.M., et al., AO-023
JONES, R.M., et al., AO-058
JONES, R.M., et al., WP-1 21

* JORGENSEN, D.P., et al.. NS-033

* JORGENSEN. D.P., et al.. NS-034

* JORGENSEN. D.P., et al.. NS-035

* JORGENSEN. D.P., et al., NS-036
JORGENSEN, D.P.. et al., NS-037
JORGENSEN. D.P.. et al., NS-040
JORGENSEN. D.P.. et al., NS-041

* JOSELYN.J.A..SE-014

* JOSELYN.J.A..etal.,SE-015
Joseph, D.B., et al„ AR-137

204

Jou, B., et al., NS-036

* Jou,B.,etal.,NS-037

* Judasz, T.J., et al., AL-043

* Kahl, J.D., AR-077

* Kahl,J.D.,etal.,AR-078
Kahler, S.W., et al., SE-020
KAIMAL, J.C, et al., WP-004

* KAIMAL, J.C., et al., WP-054
Kaimal, L.M., et al., FS-008

* Kantha,L.H.,etal.,GF-011
KAPLAN, J., et al., AO-020
Karl,T.R.,etal.,AO-028
Karl,T.R.,etal.,AR-065

* Karl,T.R.,etal.,AR-079
Kato, S., etal.,AL-026
Kato, S.,etal.,AL-067
Kato, S.,etal.,AL-068
Kato, S.,etal.,AL-081
KAVANAGH, N.M., et al., AO-049
Keen, C.S., et al., AO-078

* Keene, W.C,etal.,AL-044
Keene, W.C., et al., AR-094
Keene, W.C., et al., AR-095

* KEILTY, T.J., GL-020

* KEILTY, T.J., et al., GL-021

* KEILTY, T.J., et al., GL-022

* KEILTY, T.J., et al., GL-023
KEILTY, T.J., et al., GL-040
Keller, H.U., et al., SE-020
KELLY, K.K., et al., AL-024
KELLY, K.K., et al., AL-025

* KELLY, K.K., et al., AL-045
KELLY, K.K., et al., AL-053
KELLY, K.K., et al., AL-058

* Kelsch, M., FS-022

Kendall, A.W., Jr., et al., PM-026
Kendall, A.W., Jr., et al., PM-050
Kennedy, G, et al., GL-003
Kennedy, P., et al., AP-046

* Kessler,W.S.,PM-027
Kessler, W.S., et al., PM-022
Khalsa,S.J.S.,etal.,AR-052

* Khalsa,S.J.S.,etal.,AR-080

* Khalsa,S.J.S.,etal.,FS-023
Khalsa, S.J., et al., AR-149
Khattatov, V.U., et al., AR-086
Kidder, S.Q., et al., AP-023

* Kiladis, F.N. , et al. , AR-08 1

* Kim,Y.J.,etal.,AR-082
Kim,Y,etal.,AR-016

* KING,C.W.,etal.,WP-055

* KING,C.W.,etal.,WP-056
KING, C.W., et al., WP-086
KING, C.W., et al., WP-087
KING,C.W.,etal.,WP-118
Kleiner, J., etal., GL-029
Kley,D.,etal.,AL-048

* Klingle- Wilson, D., etal.,NS-038
Klingle- Wilson, D., et al., NS-076

* Knapp,H.V,etal.,AP-018
Knight, N.C., et al., AP-001
Knight, N.C., et al., WP-001
Kolb, C.E., et al., AR-068

* KOMIIYR. W.D., et al., AR-083

* KOMHYR, W.D., et al., AR-084

* KOMHYR, W.D.,etal.,AR-085

* KOMHYR, W.D., et al., AR-086

* KOMHYR, W.D.,etal.,AR-087

KOMHYR, W.D., et al., AR-133
KOMHYR, W.D., et al., AR-155
Koomen, MJ., et al., SE-020
KOPCEWICZ, B., et al., AR-101
Kopp,F.J„etal.,AP-036
Kostkowski, H.J., et al., AR-091
Koutchmy, S.L., et al., SE-020
Kramm, JR., et al., SE-020

* KROPFLI, R.A., WP-057
KROPFLI, R.A., et al., WP-065
KROPFLI, R.A., et al., WP-066
KROPFLI, R.A., et al., WP-067
KROPFLI, R.A., et al., WP-125
Krueger, A.J., et al., AL-058
Krueger, A.J., et al., AL-070
Kruger, B.C., et al., GF-001
Ku,J.-Y,etal.,AR-105
Ku,J.-Y,etal.,AR-lll
Ku,J.-Y,etal.,AR-112
KUESTER, S.E., et al., AR-084
Kukla,G.,etal.,AR-079
Kuo,Y-H.,etal.,AL-001
KUSTER, W.C., et al., AL-034

* Kusters,J.,etal.,WP-058
Kusters,J.,etal.,WP-140
Labitzke,K, etal., GF-001

* LACKMANN, G.M., et al., PM-028
LAIRD, G.A., et al., GL-016
Lallement., R., et al., SE-020
Lamb,B.,etal.,AR-054
Lamb.D., etal., AR-142
LAMB, ME, et al., PM-014

* LAMB, R.G., AR-088

* LAMB.R.G.AR-154
Lampru, P.D., et al., FS-040
Lamy, P., et al., SE-020

* LANDRUM, P.F., GL-024
LANDRUM, P.F., et al., GL-022
LANDRUM, P.F., et al., GL-023

* LANDRUM, P.F.,etal.,GL-025

* LANDRUM, P.F., et al., GL-026

* Landsea, C.W., et al., AO-033
Lane, F.D., etal., WP-136

* LANG, G.A., et al., GL-027
LANG,GA.,etal.,GL-035

* Lang, S.L., et al., NS-039

* Langford.A.O.,etal.,AL-046
Large, W., et al., WP-062
LATAITIS, R.J., et al., WP-01 1
LATAJTIS, R.J., et al., WP-01 2
LATAITIS, R.J., et al., WP-01 3
LATAITIS, R.J., et al., WP-049
LATAITIS, R.J., et al., WP-054

* LATAITIS. R.J., et al., WP-059

* LATAITIS, R.J., et al., WP-060

* LATAITIS, R.J., et al., WP-061
LATAITIS, R.J., et al., WP-068
LATHROP, J.A., et al., AR-086
LATHROP, J.A., et al., AR-087

* LAU.N.-C..GF-012

* LAU,N.-C.,etal..GF-013
LAVELLE, J.W., et al., PM-003

* LAVELLE, J. W.,etal.,PM-029
LAVELLE, J.W., et al., PM-039
LAWRENCE, T.R., et al., WP-063
LAWSON, RE, JR., et al., AR-026

* LAWSON, RE., JR., et al., AR-089
Leach, M.J., et al.. AR-102

205

Leaitch,R.,etal.,AR-126

Leaman, K.D., et al„ AO-034

Leaman, K.D., et al., AO-069

Lean,J.,AR-090

Lean,J.L.,etal.,AR-091

Lee, H.S., et al., AO-051

Lee,R.N.,etal.,AR-092

Leetmaa, A., et al., AO-084

Leetmaa, A., et al., PM-023

Leetmaa, A., et al., PM-051

LEFEBVRE, V.A., et al., WP-055

LEINBACH, R, et al., SE-019

LeMone, M.A., et al., NS-029

LeMone, M.A., et al., NS-033

LeMone, M.A., et al., NS-034

LeMone, M.A., et al, NS-035

LeMone, M.A., et al., NS-036

LeMone, M.A., et al., NS-040

LeMone, M.A., et al., NS-041

LEMPRIERE-DOGGETT, E., et al., PM-029

Lenhard, A., et al„ GL-029

Lenschow, D.H., et al., AR-068

Lenschow, D.H., et al., WP-145

Lenschow, D.H., et al., WP-146

Lenschow, D.H., et al., WP-147

Leonard, R.K., et al., AR-083

LEVITUS, S..GF-014

LEVITUS,S.,GF-015

LEVITUS, S., et al., GF-026

LEVY,H.,II,GF-016

LEVY,H.,II,etal.,GF-017

LEWIS, J.M..NS-042

LEWIS, J.M., et al., NS-043

LEWIS, J.M., et al., NS-044

Li,F.,etal.,WP-062

Li,F.,etal.,WP-100

Li, S-M., et al., AL-044

Li,X.Q.,etal.,SE-016

Li, X.S.,etal., WP-145

Liao, L.,etal.,AP-032

Liao, Q., et al., AO-035

LIEBIG, J.R., et al.. GL-050

Lilley,M.D.,etal.,PM-031

Lin,S.-J.,etal.,GF-018

Lin, X., et al., AL-047

Lindner, G, et al., GL-028

Lindner, G., et al., GL-029

Lindsey, C.L., et al., AR-126

LIPPS, F.B., et al., GF-019

Lipschutz, R.C., et al., FS-024

Lipschutz, R.C., et al., FS-037

LIU, P.C.. GL-030

LIU. P.C., GL-031

LIU. S.C.etal., AL-047

LIU. S.C., et al., AL-048

Llebaria, A., et al., SE-020

Loewenstein, M., et al., AL-025

Loewenstein, M., et al., AL-045

Loewenstein, M., et al., AL-053

Loewenstein, M., et al., AL-058

Long,A.B.,AP-019

Long,A.B.,etal.,AP-016

LONG, R.B., et al., AO-036

LONG,R.B..etal., AO-037

Longenecker, D.U., et al., AR-034

LOPEZ, R.E.,etal.,NS-045

LOPEZ, R.E., et al., NS-046

LOPEZ, R.E..etal.,NS-047

LOPEZ, R.E., et al., NS-048
LOPEZ, R.E., et al., NS-065
LOPEZ, R.E., et al., NS-085
LOPEZ, R.E., et al., NS-086
LOPEZ, R.E., et al., NS-087
LOPEZ, R.E., et al., NS-094
LORD, S.J., AO-038
LORD, S.J., et al., AO-043
Low-Nam, S., et al., AL-001
Lowe, R.L., et al., GL-005
Lowe, R.L., et al., GL-006
Lupton, J.E., et al., PM-003
Lupton, J.E., et al., PM-030
Lupton, J.E., et al., PM-031
Lupton, J.E., et al., PM-032
Luria, M„etal., AR-014
Luria, M., et al., AR-016
Luria, M., et al., AR-093
Luria, M., et al., AR-094
Luria, M., et al., AR-095
Luria, M.,etal.,AR-l 24
Luria, M.,etal.,AR-141
Luria, M.,etal., AR-150
Luria, M.,et al., AR-1 57
Lusk,C.,etal.,FS-035
Lusk, C, et al., FS-040
Lyons, L.R., et al., SE-005
Lyons, S.W., et al.,GF-010
Lyons, W.A., et al., AO-039
Lyons, W.A., et al., AO-078
LYTLE,L.,etal., PM-029
MA,K.,etal.,WP-063
Maben, J.R., et al., AL-044
Mabres, A., et al., AL-003
MacArthur, J.L., et al.. WP-005
MACGORMAN, D.R., et al., NS-049
MACGORMAN, D.R., et al., NS-050
MACGORMAN, D.R.. et al., NS-051
MacGORMAN, D.R., et al., NS-063
MACGORMAN, D.R., et al., NS-068
MACGORMAN, DR., et al., NS-072
Mach,D.M.,etal.,NS-052
Mach, D.M., et al., NS-054
Mach, D., et al.. NS-053
MADDOX, R.A., et al., NS-031
MADDOX, R.A., et al., NS-032
MADDOX, R.A., et al., NS-055
MADDOX, R.A., et al., NS-056
MADDOX, R.A., et al.. NS-079
MAHLMAN, J.D., et al., GF-001
MAHLMAN, J.D., et al., GF-006
MAHLMAN, J.D., et al.. GF-009
Mahoney. W.P., m. et al., NS-038
MaieT,LM,etal.,NS-089
Makarau, A., et al., AP-01 1
Maki,A.G.,etal.,AL-035
Malahoff, A., et al., PM-053
Malanchuk, I.L., et al., AR-096
MALCZYK, J.M., et al., GL-017
MANABE, S., et al., GF-005
MANABE, S., et al., GF-020
Mapes, B., et al., AO-086
Margitan, J.J., et al., AL-058
Margitan, J.J., et al., AL-071
Mariska, J.T., et al., SE-020
MARKS, F.D., JR.. AO-040
MARKS, F.D., JR., AO-041
MARKS, F.D., JR., AO-042

206

MARKS, F.D., JR., et al., AO-004
MARKS, F.D., JR., et al., AO-009
MARKS, F.D., JR., et al., AO-010
MARKS, F.D., JR., et al., AO-043
MARKS, F.D., JR., et al., AO-085
Marquette, W.H., et al., SE-018
MARROQUIN, A., et al., FS-025
Marshall, T.C., et al., NS-057
Marshall, T.C.etal., NS-071
Martin, R.F., Jr., et al., SE-017
Martin, S.E.etal., SE-018
MARTNER, B.E., WP-064
MARTNER, B.E., et al., WP-065
MARTNER, B.E., et al., WP-066
MARTNER, B.E., et al., WP-067
MARTNER, B.E., et al., WP-1 19
MARTNER, B., et al., WP-1 32
Marwitz, J., et al., NS-009
Mascart, P., et al., FS-036
Mascart, P., et al., FS-038
Mascart, P., etal.,FS-039
MASSOTH, G.J., et al., PM-003
MASSOTH, G.J., et al., PM-030
MASSOTH, G.J., et al., PM-031
MASSOTH, G.J., et al., PM-032
Masters, J.M., et al., AO-033
Mastrantonio, G., et al., FS-017
Mateer, C.L., et al., AR-034
MATEJKA,T.,NS-058
MATEJKA, T.J., et al., NS-081
MATEJKA, T.J., et al., NS-082
MATT, DR., et al., AR -069
MATT,D.R.,etal.,AR-070
MATTENS, D.M.. et al., PM-012
Maucherat, A., et al., SE-020
MAUL, G.A., AO-044
MAUL.G.A..AO-045
MAUL, G.A., AO-046
MAUL,G.A.,etal.,AO-027
MAUL, G.A., et al., AO-028
MAUL, G.A., et al., AO-047
MAUL, G.A., et al., AO-048
MAUL, G.A., et al., AO-049
MAUL, G.A., et al., AO-050
MAUL, G.A., et al., AR-065
May, P.T.,etal.,AL-066
MAY,P.T.,etal.,WP-050
MAY,P.T,etal.,WP-068
MAY,P.T..etal.,WP-069
MAY,P.T.,etal.,WP-070
MAY,P.T.,etal.,WP-071
MAY, P.T., et al., WP-072
MAY, P.T., et al., WP-073
MAY, P.T., et al„ WP-074
MAY,P.T,etal.,WP-075
MAY,P.T.,etal.,WP-115
MAY,P.T.,etal.,WP-116
MAY,P.T..etal.,WP-U7
MAYER, D.A., et al., AO-050
MAZUR, V, NS-059
MAZUR, V, NS-060
MAZUR,V.,etal.,NS-011
MAZUR, V, et al., NS-049
MAZUR,V.,etal.,NS-061
MAZUR,V.,etal.,NS-066
MCAFEE, J.R., et al., AL-027
MCAFEE, J.R., et al., AL-028
MCAFEE, J.R., et al., AL-049

MCAFEE, J.R., et al., AL-059
MCAFEE, J.R., et al., AL-094
McCORMICK, M.J., GL-032
McCormick, M.P., et al., AL-045
McCormick, M.P., et al., AL-070
McCormick, M.P., et al., GF-001
McCreary, J.P., Jr., et al., AO-05 1
McCurdy, K.E., et al., AL-091
McDuff, R.E., et al., PM-031
McDuff, R.E., et al., PM-032
McGEHAN, B.J., FS-026
McGINLEY, J.A., et al., FS-027
McGINLEY, J., et al., FS-054
McHenry, J.N., et al., AR-035
McHenry, J.N., et al., AR-036
McINTOSH, P.S., et al„ SE-019
McKellar, A.R.W., et al., AL-050
McKenna, D.S., et al., AL-070
Mcleod, J.C., et al., FS-040
McMJLLEN, R.T., et al., AR-069
McMJLLEN, R.T., et al., AR-070
McMillen, R.T., et al., WP-020
McNamara, L, et al., SE-027
McNaughton, D.J., et al., AR-138
MCNICE, G.T., et al., WP-139
MCPHADEN, MJ., et al., PM-017
MCPHADEN, MJ., et al., PM-023
MCPHADEN, MJ., et al., PM-033
MCPHADEN, ML, et al., PM-034
MCPHADEN, MJ., et al., PM-035
MCPHADEN, MJ., et al., PM-046
MCPHADEN, MJ., et al., PM-051
MCPHADEN, MJ., et al., PM-052
Meadows, G.A., et al., GL-045
Meadows, L.A., et al., GL-045
MEITIN, J.G., et al., NS-062
MEJTIN, J.G., et al., NS-088
MEITIN, R.J., et al., AP-020
MEITIN, R.J., et al., AP-021
MEITIN, R.J., et al., AP-029
MEITIN. R.J.. et al., AP-030
MEITIN, R.J., et al., WP-076
MEITIN, R.J., et al., WP-077
MEITIN, R.J., et al., WP-098
MEITIN, R.J., et al., WP-099
Menzies, R.T., et al., WP-078
MERREM, F.H.. et al., FS-047
MeirUl, J.T., et al., PM-005
MERRITT. D.A., et al., WP-034
MERRITT, D.A., et al., WP-068
MERRITT, D.A., et al.. WP-081
MERRITT, D.A., et al., WP-1 15
Metz, S.,etal.,AO-052
Meyer, E.L., et al., AR- 109
MEYERS, T.P., et al., AR-009
MEYERS, T.P., et al., AR-010
MEYERS, T.P., et al., AR-01 1
MEYERS, T.P., et al., AR-071
MEYERS, T.P.. et al.. AR-072
MEYERS, T.P., et al., AR-097
Michels, D.J., et al., SE-020
MILBURN, H.B., et al., PM-012
MILBURN, H.B., et al., PM-032
MILLER, G.S., et al., GL-033
Miller. H.L.. et al., AL-063
MILLER, P.A., et al., FS-028
MILLER, P.A., et al., FS-029
MILLER, PA., et al., WP-079

207

MILLER, P.A., et al., WP-080
Mills, MT.,etal.,AR-103
Misconi, N.Y., et al., SE-020
Mitchell, D.L., et al., AP-022
Mitchell, D.L, et al., AP-047
Miyahara, S., et al., GF-009
MIYAKODA, K., GF-023
MIYAKODA, K., et al., GF-021
MTYAKODA, K., et al., GF-022
MOFJELD, H.O., PM-036
MOFJELD,H.O.,PM-054
MOFJELD, H.O., et al., PM-029
Mohnen, V.A., et al., AR-072
Molinari, J., et al., AO-053
Molinari, J., et al., AO-054
MOLINARI, R.L., et al., AO-055
MOLINARI, R.L., et al., AO-066
MOLINARI, R.L., et al., AO-069
MONINGER, W.R., FS-030
MONINGER, W.R., FS-031
MONINGER, W.R., FS-032
MONINGER, W.R., et al., FS-033
MONINGER, W.R., et al., FS-034
MONINGER, W.R., et al., FS-035
MONINGER, W.R., et al., FS-040
MONINGER, W.R., et al., FS-047
Mooney, L.E., et al., NS-024
Moore, J.A., et al., WP-1 32
MORAN, K.P., et al., AL-066
MORAN, K.P., et al., WP-068
MORAN, K.P., et al., WP-069
MORAN, K.P., et al., WP-073
MORAN, K.P.. et al., WP-074
MORAN, K.P., et al., WP-075
MORAN, K.P., et al., WP-081
MORAN, K.P., et al., WP-1 15
MORAN, K.P., et al., WP-1 16
MORAN, K.P., et al., WP-1 17
MORAN, K., et al., AL-023
Morrison, J., et al., AO-055
MORTON, J.A., et al., GL-027
MOUNT, G.H., et al., AL-051
MOUNT, G.H., et al., AL-063
MOUNT, G.H., et al., AL-064
MOUNT, G.H. , et al. , AL-082
MOXIM W.J., et al., GF-017
Muench, R.D., PM-037
Mugica, R., et al., AL-003
MULLEN, TO., et al., AR-087
Munger, J.W., et al., AL-044
MURPHY, D.M., AL-052
MURPHY, D.M., et al., AL-024
MURPHY, D.M., et al., AL-025
MURPHY. D.M., et al., AL-045
MURPHY, D.M., et al., AL-053
Murphy, E.A., et al., AL-036
Murphy, E.A., et al., AL-084
Murphy, E., et al., AL-01 6
MURPHY, K., et al., PM-01 3
MURPHY, PP., et al., PM-038
Murthy, C.R., et al., GL-045
MUZZI, R.W., et al., GL-033
NAGAMOTO, C.T., et al., AR-120
NAGAMOTO, C, et al., AR-101
Nakata, K., et al., PM-039
Nakazawa, T., et al., AR-130
NALEPA, T.F., et al., GL-034
NAPPO, C.J., et al., AR-027

* NAPPO, CJ.,etal.,AR-098
Nastrom, G.D., et al., AL-033
Nastrom, G.D., et al., AL-036
Nastrom, G.D., et al., AL-039

* Nastrom, G.D. , et al. , AL-054

* Nastrom, G.D., et al., AL-055
Nastrom, G.D., et al., AL-079
Nastrom, G.D., et al., AL-080
Nastrom, G.D., et al., AL-084
Nastrom, G.D., et al., AL-095
Nastrom, G., et al., AL-01 6
Neelin,J.D.,etal.,GF-013

* NEFF,W.D.,WP-082

* NEFF.W.D..WP-083

* NEFF,W.D.,WP-084
NEFF, W.D., et al., WP-020
NEFF, W.D., et al., WP-024
NEFF, W.D., et al., WP-035
NEFF, W.D., et al., WP-055
NEFF, W.D., et al., WP-075

* NEFF, W.D., et al., WP-085

* NEFF, W.D., et al., WP-086

* NEFF, W.D., et al., WP-087
NEFF, W.D.,etal., WP-1 18

* NEIMAN, P. J., WP-088

* NEIMAN, PJ. , et al., WP-089
NELSEN, T.A., et al., AO-052
Nespor, J., et al., AP-007
Newell, P.T, et al., SE-013

* NICKERSON,E.C.,etal.,FS-036
NICKERSON, E.C., et al., FS-038
NICKERSON, E.C., et al., FS-039
Nielsen, K.E., et al.. NS-027

* Nielsen, K.,etal.,NS-063
Nigam, S., et al., GF-010
NISHIYAMA, R.T., et al., WP-031
Noens,J.C.,etal., SE-020
NORTON, D.C., et al., GL-003
NORTON, R.B., et al., AL-044
Notosuyidno, S.M, et al., AL-030

* NOVAK,J.,AR-099
NOVAK, J.H., et al., AR-109

* NOVAK, J.N. , et al. , AR- 1 00
Nonon, J.F., et al., AL-063
Nureyev, P.G., et al., AR-086
Oakland, S.K., et al., NS-021

* OCHS, G.R., WP-090
OCHS, G.R., et al., WP-033

* OCHS,G.R.,etal.,WP-091

* OCHS, G.R., et al., WP-092

* Ochs, H.T., et al., AP-023
Okayama, Y, et al., PM-039
Olerud, D.T., Jr., et al., AR- 15 1
Olson, M.P., et al., AR-144
Olson, S.H.,etal.,NS-038
Olson, S., et al., NS-076
OLTMANS, S.J., et al., AR-1 19

* OLTMANS, S.J.,etal., AR-1 55

* OORT, A.H., GF-024

* OORT, AH., GF-025

* OORT, A.H., et al., GF-026

* OOYAMA, K.V., AO-056
Orlando, J.J., et al., AL-050
ORR,B.,etal.,WP-119
ORTIZ, R., et al., NS-046
ORTIZ, R., et al., NS-085
ORTIZ, R., et al., NS-086
ORTIZ, R., et al., NS-087

208

ORTNER, P.B., et al., AO-011

* ORTNER, P.B.,etal.,AO-057
Orville, H.D., et al.. AP-001
Orville, H.D.. et al.. AP-037
Orville, H.D.,etal.,WP-001
Orville. H.D., et al., WP-1 12

* Osherovich, V.A.. SE-021

* Osherovich. V.A., SE-022

* Osherovich, V.A..SE-023

* Osherovich, V.A., et al., SE-024

* Osherovich. V.A.. et al.. SE-025
OTTO. W.D., et al.. NS-046
OTTO. W.D., et al.. NS-048
OVERLAND, J.E., et al., PM-028

* OVERLAND. J.E., et al.,PM-040

* OVERLAND. J.E.. et al., PM-041
Owens, M.A.. et al., AR-128
Owens, M.A., et al., AR-132
Paffenhofer, G-A., et al., GL-050
PAGOAGA, M.K., et al., WP-1 28
Paine, R.J.,etal.,AR- 103
PALMER, D.R., et al., AO-023

* PALMER, DR., et al., AO-058

* PALMER, DR., et al.. AO-059
PALMER, D.R., et al., AO-065
Pardede, M., et al., AL-030
Parker, E.N.. et al.. SE-020
Parker, T.S., et al., AR-152
PARRISH. C.C., et al.. GL-017

* PARRISH, D.D.,etal.,AL-056

* Parsons, C.L., et al.. WP-093
Parsons, C.L., et al., WP-100
Parsons, D.B.. et al., NS-081
Parsons, D.B., et al., NS-082
Partridge, R.M, et al., AO-005

* PARUNGO. E, et al., AR-101
PARUNGO, F„ et al.. AR-120
PASHINSKI, D.J., et al., PM-029

* PassareUi,R.E..Jr.,etal.,NS-064

* PASSI. R.M.. et al., NS-065
Pa»i, R., et al., AR-060

* Patrino«,A.A.N.,etal.,AR-102

* PAULSON, A.J. , et al. , PM-042

* PAULSON. A. J. , et al. . PM-043

* PAULSON, A. J. , et al. . PM-044
PAZOS. M.C., et al.. AO-035

* PEASE, C.H., PM-045
PEASE. C.H.. et al.. PM-040
PEASE, C.H..etal., PM-041
Peixsoto, J.P., et al., GF-026
PENDERGRASS, W.R., et al., AR 073
Penkett, S.A., et al„ AL-048
Pequegnat, J.E., et al., AR-025
Perala.R.P., etal.,NS-011

Perfit. MR., et al.. PM-053

* PERRY, S.G., et al., AR-103

* PERRY, S.G..etal.,AR-104
PETERSEN, W.B., et al., AR-075

* PETERSEN, W.B., et al., AR-105
PETERSEN, W.B., et al.. AR-140
Peterson, MR., et al., AL-055
Peterson, W.A., et al., AL-036
Peterson, W.A., et al., AL-084
Peterson, W., et al., AL-016
Pfeiffer, W., et al., GL-028
Pfeiffer, W., et al., GL-029
Pham, H.L., et al., GF-002
PHILANDER, S.G.H., et al., GF-003

* PHILANDER. S.G.H.et al„ GF-027
Phillips. L.F., et al. AL-048

* Picaut. J., et al., PM-046
Pick, M., et al., SE-020
Picquelle, S., et al, PM-024

* PIERCE, TE..AR- 106

* PIERCE, T.E..AR-107
PIERCE, T.E., et al., AR-022
PIERCE, T.E.. et al.. AR-040
PIERCE, T.E., et al., AR-140
PIERCE, TE.,etal.,AR-151
PIERREHUMBERT, R.T., et al., GF-002
PIERREHUMBERT. R.T., et al.. GF-01 8
Pinter, P.J., Jr., et al., AR-033

Pinty, J.P., et al., FS-036

* PIOTROWICZ,S.R.,etal.,AO-060

* PIOTROWICZ,S.R.,etal.,AR-108
Pitter, R.L., et al., AP-002

Pitter, R.L., et al., AP-013
Pitter, R.L.etal., AP-014
Pitter, R.L., etal.,AP-015

* Pitter, R.L., et al., AP-024

* Pitter, R.L., et al., AP-025

* Pitter, R.L., et al., AP-026

* Pitter. R.L., et al., AP-027

* Pitter, R.L., et al., AP-028
Pitter. R.L., et al.. AP-047

* Pitts, F.,etal.,NS-066
Podolske, J.R., et al., AL-045
Podolske, J.R., et al., AL-053
Podolske, J.R., et al., AL-058
POKEMPNER, M., et al.. SE-027
Politovich, M.K., et al.. AP-037
POLITOVICH. M.K.. et al., AP-038
POLITOVICH, M.K.. et al., WP-1 12
POLITOVICH, M.K., et al., WP-1 14
Poole-Kober, EM., et al., AR-143
Poole, L.R., et al., AL-025
POOLER, F, JR., et al., AR-018
POORE.R..etal..GL-026

POPA FOTINO. I. A., et al.. WP-1 23
Poppe, D., et al., AL-048

* Porch, W.M.,etal.,WP-094
POSSIEL, N.C., et al., AR-040

* POSSIEL, N.C.,etal.,AR-109

* POST, ML, WP-095

* POST, ML, WP-096
POST, MJ.,etal.,WP-046
POST, MJ.,etal.,WP-137
POST, MJ.,etal.,WP-138
POSTON, R.W., et al., AR-087
Powell, J.A.,etal., AL-058

* POWELL, M.D., AO-061

* POWELL, M.D., AO-062
PRATTE, J.F., et al., FS-024
PRATTE, J.F., et al.. FS-037
Priest, E.,etal., SE-020

* PRIESTLEY, J.T., WP-097
Proehl, J.A., et al., PM-052
Proffitt, M. H, et al., AL-053
Proffitt, M.H., et al., AL-024
Proffitt, M.H., et al., AL-045

* Proffitt, M.H., et al., AL-057

* Proffitt, M.H.,etal., AL-058
PRONI,LR.,etal.,AO-012

* PRONI, J.R., et al., AO-063
Przybylowicz, J.W., et al., AR-039
Pszenny, A.A.P., et al„ AL-044

209

* PSZENNY,A.A.P.,etal.,AO-064
Pueschel,R.F.,etal.,AR-157
Puxbaum, H., et al., AL-044
QUIGLEY, M.A., et al., GL-004
QUIGLEY, M.A., et al., GL-01 8

* QUIGLEY, M.A.,etal.,GL-035

* QUINN,F.H.,GL-036

* QUnSN,F.H.,GL-037

* QUINN, F.H. , et al., GL-038

* QUINN, P.K.,etal.,PM-047
QUINTANA, B., et al., AR-1 20

* RABIN, R.M., NS-067
RABIN, R.M., et al., NS-005
RABIN, R.M., et al., NS-074
RABIN, R.M., et al., NS-075
Radokov, V.V., et al., AR-086
RAHN, M.E., et al., AO-083
RAMAGE, C.S., et al., AR-1 52
Ramanathan, V, et al., GF-028

* Ramaswamy, V., etal., GF-028
Ramis, C, etal.,FS-036

* RAMOS, P.A., et al., AO-065
Rao.K.S.,etal..AR-039
Rao,K.S.,etal.,AR-073
Rao,K.S.,etal.,AR-098

* Rao,K.S.,etal.,AR-110

* Rao,K.S.,etal.,AR-lll

* Rao,R.R.,etal.,AO-066
Rao, ST., etal., AR-1 05
Rao, S.T., etal., AR-1 11

* Rao.S.T., etal., AR-1 12

* Rappaport. E.N., etal.,AO-067
Rasmussen, E.N., et al., FS-024

* Rasmussen, E.N., etal., FS-037
Rasmussen, E.N., et al., FS-052
Rasmussen, R.A.. et al., AO-060
Rasmussen, R.A., et al., AR-1 08
RAVISHANKARA, A.R., et al., AL-073
RAVISHANKARA, A.R., et al., AL-074
RAVISHANKARA, A.R., et al„ AL-075
RAVISHANKARA, A.R., et al., AL-082
RAVISHANKARA, A.R., et al., AL-083
Ray,J.D.,etal..AR-016
Ray,P.S.,etal.,NS-039
Ray,P.S.,etal.,NS-091

* Reap, R.M., et al., NS-068
Recknagel, E., et al., GL-028
Recknagel, E., et al., GL-029
REED, R.K., et al., PM-026

* REED. R.K., et al., PM-048

* REED, R.K., et al., PM-049

* REED, R.K., et al., PM-050

* REID, G.C., et al., AL-059
REINKING, R.F., et al., AP-001
REINKING, R.F., et al., AP-020
REINKING, R.F., et al., AP-021

* REINKING, R.F., et al., AP-029

* REINKING, R.F., et al., AP-030
REINKING, R.F., et al., AP-037
REINKING. R.F., et al., WP-001
REINKING, R.F., et al., WP-076
REINKING, R.F.. et al., WP-077

* REINKING, R.F., et al., WP-098

* REINKING, R.F., et al., WP-099
REINKING, R.F., et al., WP-1 12
RFJTELBACH, P.J.. et al., AR-084

* Reynolds, R.W., et al., PM-051
Richard, E., etal., FS-036

* Richard, E.,etal.,FS-038

* Richard, E., etal., FS-039
Riddle, A.C., et al., AL-008

* Riddle, A.C., et al., AL-060
Riddle, A.C.,etal.,AL-093
Riddle, A.C.,etal.,AL-094
Ridley, B.A., et al., AL-005
Ridley, B.A., et al., AL-006
Ridley, B.A., et al., AL-007
RILEY, J.P., et al., AO-023
RILEY, J.P.,etal.,WP-121

* ROBBINS, J.A., GL-039
ROBBINS, J.A., et al., GL-013
ROBBINS, I.A., et al., GL-028
ROBBINS, J.A., et al., GL-029

* ROBBINS, J.A., et al., GL-040
ROBBINS, J.A., et al., GL-042

* Roberts, P.J.W., etal., AR-1 13

* Roberts, P.J.W., et al., AR-1 14

* Roberts, P.I.W., etal., AR-115
Roberts, W.F., et al., FS-035

* Roberts, W.E.etal., FS-040

* ROBINSON, E., AR-1 16

* ROBINSON, E.,etal.,AR-117
RODGERS, D.M., et al., FS-012

* RODGERS, D.M.,etal.,FS-041
Rodi,A.R., etal., WP-1 32

* Rodriguez, E., etal., WP-100
Rodriguez, R., et al., AL-003
RODRIGUEZ, R., et al., WP-141
ROLPH, G.D., et al., AR-003
ROLPH, G.D.i et al., AR-004

* ROLPH, G.D., etal., AR-1 18
Romberg, G.P., et al., PM-042

* RONA, PA., AO-068
RONA, P.A., et al., AO-016
RONA, P.A., et al., AO-073
RONA, P.A., et al., AO-077
ROSATI,A.,etal.,GF-011
ROSATI,A.,etal.,GF-021
Roselle,S.J.,etal.,AR-151
Rosen, J.M., et al., AL-041

* Rosen, J.M., etal., AR-1 19
Rosenbauer, H., et al., SE-020
Rosenfeld, D., et al., NS-045

* Rosenfeld, L.K., et al., AO-069

* Rosenthal, D.A., et al., SE-026

* Rosinski,J., etal., AR-1 20
Rossby, H.T., et al., AO-032
Rossby,T.,etal.,AO-034
ROSSON, R.M., et al., AR-017
Rotenberry, J.T., et al., GL-006

* Rothstein, L.M,etal., PM-052
Rottger, I., et al., WP-050
Rowland., F.S., et al., AL-048
Rowland, J., et al., NS-003

* RUFFIEUX,D.,WP-101
Ruhnke, L.H., et al., NS-01 1

* RUSH, C, etal., SE-027
RUSSELL, C.A., et al., WP-056

* RUST, W.D., NS-069

* RUST, W.D., NS-070
RUST, W.D., et al., NS-025
RUST, W.D., et al., NS-026
RUST, W.D., et al., NS-027
RUST, W.D., et al., NS-049
RUST, W.D., et al., NS-050
RUST, W.D., et al., NS-052

210

RUST, W.D., et al„ NS-053
RUST, W.D., et al., NS-054
RUST, W.D., et al., NS-057

* RUST, W.D., et al.. NS-071
Rutledge, S.A., et al., NS-030

* Rutledge, S.A., et al., NS-072
Ryan,B.,etal.,AO-001

* RYE.B.J..WP-102

* RYE.B.J..WP-103
RYE,B.J.,etal.,WP-058

* RYE.B.J., etal.,WP-104

* RYE,B.J.,etal.,WP-105
RYE,B.J.,etal.,WP-140

* Sachidananda, M., et al., NS-073
Sachidananda, M., et al.. NS-092
Sachse, G.W., et al„ AL-005
Sachse, G.W., et al., AL-006
Sachse, G.W., et al., AL-007
SAGENDORF, J.F., et al., AR-127
Sample, T.E., et al., PM-044
SANDALL, J.E., et al.. GL-045
Sander, S.P., et al., AL-083
SANDERS, R.W., et al., AL-051

* SANDERS, R.W., et al., AL-061
SANDERS, R.W., et al., AL-063
SANDERS, R.W., et al., AL-064
SANDERS, R.W., et al., AL-065
Sanford,J.,etal., NS-076

* Sarmiento,J.L.,etal., GF-029

* Sarmiento,J.L.,etal., GF-030

* Sassen,K.,AP-031

* Sassen, K., et al., AP-032

* Sassen, K„ et al., WP-106
Sato,T,etal.,AL-026
Sato,T.,etal.,AL-067
Sato, T.,etal.,AL- 068
Sato,T.,etal.,AL-081
Sato,T.,etal.,WP-070

* SAUER, H.H.. SE-028
Saunders, R.D., et al., AR-091

* SCAVIA, D., GL-041
Scheffe, R.D., et al., AR-112

* Schelske, C.L., et al., GL-042
SCHERE, K.L., et al., AR-109
SCHERE, K.L., et al., AR-112

* SCHERE, K.L.,etal.,AR-121

* SCHERE, K.L., et al., AR- 1 22
SCHERE, K.L., et al., AR-146
Schewe, G.J., et al., AR-139
Schiavon, G., et al., WP-015
Schiavon, G, et al., WP-016

* SCHIERMEffiR,EA.,AR-123

* SCHLATTER, T.W..FS-042

* SCHLATTER, TW..FS-043
SCHLATTER, T.W., et al., FS-006
SCHMELTEKOPF, A.L., et al.. AL-051
SCHMELTEKOPF, A.L., et al., AL-061
SCHMELTEKOPF, A.L., et al., AL-063
SCHMELTEKOPF, A.L., et al., AL-064
SCHMELTEKOPF. A.L., et al., AL-065
SCHMELTEKOPF, A.L., et al., AL-082
Schnell,R.C.,etal.,AR-064
Schoeberl, M.R., et al., AL-058
SCHOENFELD, W.P., et al., WP-128
Schroeder, B.. et al., AO-077

* SCHROEDER, J.A..WP-107

* SCHROEDER, J.A..WP-108

* SCHROEDER, J.A..WP-109

SCHROEDER, J.A., et al, WP-124
Schufmann, G, et al., AR-126
SCHULTZ, P., FS-044
SCHUMACHER, J.D., et al., PM-026
SCHUMACHER, J.D., et al., PM-048
SCHUMACHER, J.D., et al., PM-049
SCHUMACHER, J.D., et al., PM-050
SCHUMACHER, J., et al., PM-024
SCHWAB, D. J., GL-043
SCHWAB, D.J..GL-044
SCHWAB, D.J., et al., GL-045
SCHWARTZ, BE., FS-045
Schwenn, R., et al., SE-020
Scott, J.F,etal.,WP-120
Scott, R.W., AP-033
Scott, R., et al., AP-007
Seiler, W.,etal., AR-126
Seilkop, S.K., et al., AR-029
Seilkop,S.K.,etal.,AR-035
Seilkop, S., et al., AR-030
Seilkop, S.,etal.,AR-144
Sengupta, N., et al., AL-062
SENGUPTA, N, et al., WP-1 10
Shade,J.,etal., SE-008
Shaik,K.,etal.,WP-014
SHANG, E.C.WP-111
Shang, R., AP-034
SHAPIRO, L.J..AO-070
SHAPIRO, L.J., AO-071
SHAPIRO, MA., et al., WP-089
SHAW, D., SE-029
SHAW,D.,etal.,SE-030
Shaw,R.,etal.,FS-040
Shaw, W., et al., WP-062
Shay, L.K., et al., AO-005
Shay. L.K., et al., AO-006
Shay, L.K., et al., AO-072
Sheeley, N.R., Jr., et al., SE-020
SHEPHERD, A.J., et al., PM-017
Shepherd, D.J., et al., FS-015
Short. S.K.,etal.,AR-037
SHOWELL, L.C., et al.. NS-044
Sievering, H, et al., AR-016
Sievering, H, et al., AR-082
Sievering, H, et al„ AR-094
Sievering, H, et al., AR-124
Simnett, G.M., et al„ SE-020
Sirois.A., etal.,AR-142
SIRUTIS,J.,etal.,GF-022
Sistla, G, et al, AR-112
SMART, J., FS-046
Smartt, R.N., et al., SE-020
SMITH, J.B.,etal„ SE-012
Smith. JX.etal., FS-024
Smith. J.K.,etal..FS-037
Smith, J.P., et al., AL-063
Smith, M.F.etal.,PM-053
Smith, PL., etal.,AP-001
Smith, PL., et al., AP-035
Smith, P.L., et al., AP-036
Smith, PL., et al., AP-037
Smith, PL., et al., WP-001
Smith, PL., etal.,WP-112
Smith, R.L., et al., PM-025
Smith, S.A., et al., AL-026
Smith, S.A.,etal.,AL-081
Smith, S.D., et al., NS-022
Smith, S.D., et al., NS-023

211

Smith, S.D., et al., NS-038

* Smith, S.D., et al., NS-074

* Smith, S.D.. et al., NS-075

* Smith, S.D., et al., NS-076
Smith, T.L., et al„ FS-006
Smith, W.L.,etal.,AL-014
SMULL, B.F., et al., NS-030
SMULL,B.F..etal.,NS-037

* SMULL, B.F.,etal.,NS-077
SNIDER, J.B., et al., WP-017
SNIDER, J.B., etal.,WP-018
SNIDER, J.B.,etal.,WP-028
SNIDER, J.B.,etal.,WP-052

* SNIDER, J.B.,etal.,WP-l 13
SNIDER, J.B., et al., WP-122
SNIDER, IB., et al., WP-126
SNIDER, J.B.. et al.. WP-127
SNIDER, J.B., et al.. WP-142

* Snieder,R.K.,etal., GF-031
SNOOK, J.S.,etal..WP-124

» SNYDER, W.H..AR-125

SNYDER, W.H., et al., AR-023
SNYDER, W.H., et al., AR-026
SNYDER, W.H., et al., AR-089
SNYDER, W.H., et al., AR-104
SNYDER, W.H.. et al„ AR-105
SNYDER, W.H. , et al. , AR- 1 1 3
SNYDER. W.H.. et al., AR-114
SNYDER. W.H.. et al.. AR-1 1 5
Socker, D.G., et al., SE-020
Soegijo,J.,etal., AL-030
Solimini, D., et al.. WP-015
Solimini, D., et al., WP-016
Solomon, P., et al., GF-001
SOLOMON, S., et al., AL-042
SOLOMON. S., et al., AL-051
SOLOMON, S„ et al., AL-061

* SOLOMON, S.. et al., AL-063

* SOLOMON, S., et al., AL-064

* SOLOMON. S., et al., AL-065

* Song, M.T.,etal.,SE-031

* Speer,K.,etal..AO-073
SPEISER, T.W., et al., SE-017

* Spicer,C.W.,etal.,AR-126
Spiro,R.W.,etal.,SE-008
Stabel, H.H., et al., GL-029
STABENO, P.J., et al., PM-025
STABENO, P., et al.. PM-024
Stamus, P.A., et al., FS-006
STANKOV. B.B., et al., WP-145
STANKOV, B., et al.. WP-146
STANKOV, B., et al., WP-147
Starr, D.O., et al., WP-106
START, G.E.,etal.,AR-032

* START, G.E.,etal.,AR-127
STEHLY, G.R., et al., GL-021

* STEHLY, G.R.. et al., GL-046

* STEHLY, G.R..etal.,GL-047

* Steinhom, I., et al., NS-078
Steinolfson, R.S., et al., SE-037

* STENSRUD,D.J.,etal..NS-079
Steward, R.G., et al., AO-01 1
STEWART, F, et al., SE-027

* Stewart. R.W., et al. AR-1 28
Stewart, R.W., et al., AR-132
Stewart, T.R., et al., FS-040

* Stewart. T.R., et al., FS-047
Stith,J.L,etal.,AP-001

Stith,J.L,etal.,AP-037
Stith,J.L.etal.,AP-038
Stith,J.L,etal.,WP-001
Stith,JL.,etal..WP-U2
Stith,J.L,etal.,WP-114
Stogner, R.E., et al., AR-036
Stolarski, R.S., et al., GF-001
Stone, R.S.,etal.,AR-047
Stone, R.S., etal.,WP-019
Stone, R.,etal.,AP-039
Stone. R.,etal., AP-040
Stone, R.,etal.,AP-041
Stossmeister, G.J., et al., AO-074
STOUFFER, R.J., et al., GF-020
Stout, J.E.,etal.,AR-055
Strahan, S.E., et al., AL-045
Strahan, S.E., et al., AL-053
STRAUCH,R.G.,WP-148
STRAUCH, R.G., et al., AL-062
STRAUCH, R.G., et al., AL-066
STRAUCH, R.G., et al., WP-034
STRAUCH, R.G., et al., WP-041
STRAUCH, R.G., et al.. WP-042
STRAUCH, R.G., et al., WP-043
STRAUCH, R.G., et al., WP-068
STRAUCH, R.G.. et al.. WP-069
STRAUCH. R.G.. et al.. WP-071
STRAUCH. R.G., et al.. WP-072
STRAUCH. R.G., et al.. WP-073
STRAUCH, R.G.. et al., WP-074
STRAUCH, R.G., et al.. WP-075
STRAUCH, R.G., et al.. WP-081
STRAUCH, R.G., et al.. WP-110
STRAUCH, R.G., et al., WP-115
STRAUCH, R.G.. et al.. WP-116
STRAUCH. R.G., et al., WP-117
Strimaitis, D.G., et al., AR-1 03
Strong, K.T,etal.,SE-002
Stump, G.S.,etal., NS-080
STUNDER, B.J.B., AR-129
STUNDER, B .J.B ., et al., AR- 1 1 8
STUNDER, B., et al., AR-092
Sulanowska, M., et al.. AO-077
SUMMERS, S.. et al., WP-118
Swartz, R.G., et al„ PM-044
Swift. R.N.,etal.,WP-120
Szoke, E J., et al., FS-010
TAFT, B.A., et al., PM-034
TAFT. B.A., et al., PM-035
Talbot, R.W.. et al., AL-044
Tandberg-Hanssen, E., et al., SE-037
Tanner, R.L., et al., AR-102
Tans. P.P., Mil, AR-1 30
Tans. P.P., etal., AR-133
Tappert, F.D., et al., AO-059
Tappin, S.J., et al., SE-032
TARAPCHAK, S.J., et al.. GL-048
TARAPCHAK, S.J., et al.. GL-049
Tascione, T„ et al., SE-008
Tattleman, P., et al., AO-082
Taylor, G.E., Jr., et al., AR-131
Taylor, W.L., et al.,NS-049
Taylor, W.L., et al.,NS-051
Templeman, S.M., et al., AR-139
TENNANT, D.A., et al., PM-043
THACKER, W.C., AO-075
THACKER, W.C., AO-076
THACKER, W.C., et al., AO-036

212

THACKER, W.C., et al., AO-037
Thomas, J.L., et al., NS-045
Thomas, K.W., et al., NS-019
Thomas, V.L., et al., SE-033
Thomas, V.L., et al., SE-040
Thompson, A.M., et al., AR-128
Thompson, A.M., et al., AR-132
Thompson, G., et al., AO-077
Thompson, R.S., et al., AR-089
THOMPSON, T.M., et al., AR-024
Thoning, K.W., et al., AR-085
Thoning, K.W., et al., AR-1 33
Tikvart, J.A., etal., AR-109
Tikvart, J.A., et al., AR-1 34
Tikvart, J.A., et al., AR-156
Tindale, N.W., et al., PM-005
Tivey, MA., et al., PM-053
Tobiska, W.K., etal., AR-1 35
TOGGWEILER, J.R., GF-034
TOGGWEILER, JR., et al., GF-029
TOGGWEILER, J.R., et al., GF-030
TOGGWEILER, J.R., et al., GF-032
TOGGWEILER, J.R., et al., GF-033
Tognolatti, P., et al., WP-015
Tognolatti, P., et al., WP-016
TOLLERUD, E.I., et al., FS-048
TOLLERUD, E.I., et al., FS-002 -
TOLLERUD, E.I., et al., FS-049
TOLLERUD, E.I., et al„ FS-053
Toon, O.B., et al., AL-071
TotTes, A.L., et al., AL-006
TOUMA.J.S., etal., AR-1 34
TOUMA.J.S., etal., AR-1 36
TOUMA.J.S., etal., AR-1 37
TOUMA.J.S., etal., AR-1 38
TOUMA.J.S., etal., AR-1 39
TOUMA.J.S., etal., AR-156
Trainer, M., et al., AL-005
Trainer, M., et al., AL-047
Trefry,J.H.,etal.,AO-052
Trier, S.B., etal., NS-081
Trier, S.B., et al.,NS-082
TRUPPI, L.E., et al., AR-051
Tsuda.T, etal.,AL-026
Tsuda.T., etal., AL-067
Tsuda.T, etal.,AL-068
Tsuda.T, etal.,AL-081
Tsuda.T, etal.,WP-070
Tsurusaki, K., et al., PM-039
TUCK.A.F..AL069
TUCK, A.F., et al., AL-024
TUCK,A.F.,etal.,AL-053
TUCK, A.F., et al., AL-058
TUCK, A.F.. et al., AL-070
TUCK, A.F., etal., AL-071
Turco, A., et al., GF-001
TURNER, D.B., et al., AR-140
Tyndall, G.S., et al., AL-072
Tyndall, G.S., et al., AL-073
Uematsu, M., et al., PM-005
Uno, I., etal.,AR-146
UTTAL,T.,etal.,WP-106
UTTAL,T,etal.,WP-119
UTTAL,T,etal.,WP-132
Uyeda,H.,etal.,NS-083
Vaghjiani, G.L., et al„ AL-074
Vaghjiani, G.L., et al., AL-075
VAN DE KAMP, D.W., FS-055

VAN HEESWUK, M., et al., PM-016
Van Meter, A.R., etal., AR-151
VAN VALIN, C.C., et al., AR-014
VAN VALIN, C.C., et al., AR-016
VAN VALEM, C.C, et al., AR-093
VAN VALIN. C.C, et al., AR-094
VAN VALIN, C.C, et al., AR-095
VAN VALIN, C.C, et al., AR-124
VAN VALIN, C.C, et al., AR-141
VAN VALIN, C.C, et al., AR-1 50
VAN VALDJ, C.C, et al., AR-1 57
VAN VALIN, C, et al., AR-015
VANDERPLOEG, H.A., et al., GL-004
VANDERPLOEG, H.A., et al., GL-007
VANDERPLOEG, H.A., et al., GL-050
VANDERPLOEG, H.A., et al., GL-051
VANDERPLOEG, H.A., et al., GL-052
VANZANDT, T.E., AL-076
VANZANDT, T.E., AL-077
VANZANDT, T.E., et al., AL-016
VANZANDT, T.E., et al., AL-026
VANZANDT, T.E., et al., AL-036
VANZANDT, T.E., et al., AL-039
VANZANDT, T.E., et al., AL-054
VANZANDT, T.E., et al., AL-055
VANZANDT, T.E., et al., AL-067
VANZANDT, T.E., et al., AL-068
VANZANDT, T.E., et al., AL-078
VANZANDT, T.E., et al., AL-079
VANZANDT, T.E., et al., AL-080
VANZANDT, T.E.. et al., AL-081
VANZANDT, T.E., et al., AL-084
VANZANDT, T.E.. et al., AL-095
VASILOFF, S„ NS-084
Vedder, J.F., etal., AL-024
Vedder, J.F., et al., AL-045
Velden,CS.,etal.,AO-020
Venne, M.G., et al., AO-039
Venne, M.G., et al., AO-078
Vet.R.J.,etal.,AR-142
VIEBROCK, H.J., et al., AR-143
Violette, E.J., et al., AL-003
Voigt, G.H., et al., SE-008
Voldner, E.C., et al., AR-144
Vollaro, D., et al., AO-053
VoUaro,D.,etal., AO-054
Vukovich, F.M.. et al., AR-145
Wade, C.G., et al., FS-050
WAGNER, W.J., SE-034
WAGNER, W.J., SE-035
WAGNER, W.J., et al., SE-020
Wahl,U„etal.,GL-029
Wahner,A.,etal.,AL-082
Wahner,A.,etal.,AL-083
Wakamatsu, S., et al., AR-146
Wakimoto, R.M., et al., WP-006
Wakimoto, R.M., et al., WP-007
Wakimoto, R.M., et al., WP-119
Walker, A., etal.,WP-058
WALKER, DC, et al., FS-019
WALKER, S.L., et al., PM-003
WALSH, E.J., et al.. WP-005
WALSH, E.J., et al., WP-029
WALSH, E.J., et al., WP-030
WALSH, E.J., et al., WP-032
WALSH, E.J., et al., WP-062
WALSH, E.J.,etal.,WP-093
WALSH, E.J., et al., WP-100

213

, et al., AL-022
, et al., AL-036
, et al., AL-039
, AL-062
, AL-079
, AL-084
, AL-085

, et al.,
, et al.,
, etal.,
, et al.,

WALSH, E.J., et al., WP-120
Wang, A.H., et al., SE-038
Wang, H.,etal.,AR- 147
Wang, S., etal., SE-038
Warburton, J., et al., AP-039
Warburton, J., et al., AP-040
Warburton. J., et al., AP-041
WARNOCK, J.M., et al., AL-01 1
WARNOCK, J.M., et al., AL-01 3
WARNOCK, J.M., et al., AL-016
WARNOCK, J.M.
WARNOCK, J.M
WARNOCK, J.M
WARNOCK, J.M
WARNOCK, J.M
WARNOCK, J.M
WARNOCK, J.M
WARNOCK, J.M., et al., AL-086
WARNOCK, J.M., et al., AL-095
WARNOCK, J.M., et al., WP-110
Waterburton. J.A., et al., AP-002
WATERMAN, L.S., et al., AR-085
Watermann, J., et al., SE-001
WATSON, A.I., et al., NS-047
WATSON, A.I., et al., NS-062
WATSON, A.I., et al., NS-085
WATSON, A.I., et al., NS-086
WATSON, A.I., et al„ NS-087
WATSON, A.I., et al., NS-088
WATSON, A.I., et al., NS-089
WATSON, A.I., et al., NS-094
Watson, R.T.. et al., AL-071
Watson, RT,etal.,GF-001
Watts, D.R.,etal.,AO-032
Wayland, R.A., et al., AR-121
Wayland, R.A., et al., AR-122
Wayland, R.A., et al., AR-151
Weaver, J., et al., FS-040
WEBER, B.L., et al., WP-034
WEBER, B.L., et al., WP-068
WEBER, B.L„etal.,WP-081
WEBER, B.L.,etal.,WP-l 15
WEBER, B.L.,etal.,WP-135
WEBER, B.L., et al., WP-149
WEBER, B.,etal.,AL-023
Weems, J., etal., NS-089
WEICKMANN, A.M. et al., WP-121
WEICKMANN, KM.. AR-148
WEICKMANN, K.M, et al.. AR-052
WEICKMANN, K.M, et al.
WEICKMANN, K.M., et al.
WEINSTOCK, J., AL-087
WEINSTOCK, J„ AL-088
WEINSTOCK, J., AL-089
WEINSTOCK, J., AL-090
WELLMAN, D.L., et al., AR-014
WELLMAN, D.L.. et al., AR-016
WELLMAN, D.L., et al., AR-094
WELLMAN, D.L., et al., AR-095
WELLMAN, D.L., et al., AR-150
WELLMAN. D.L.. et al., AR-157
Wesely, ML., et al., WP-020
Westberg, H., et al.. AL-044
Westcott, N.. AP-042
Westcott, N.E., AP-043
Westcott, N.E., AP-044
Westcott, N.E., et al., AP-045
Westcott, N., et al., AP-007

AR-080
AR-149

Westcott, N„ et al., AP-046
WESTWATER, E.R., et al., WP-015
WESTWATER, E.R., et al., WP-016
WESTWATER, E.R., et al., WP-031
WESTWATER, E.R. , et al., WP-1 22
WESTWATER, E.R., et al., WP-123
WESTWATER, E.R., et al., WP-124
WESTWATER, E.R., et al., WP-1 25
WESTWATER, E.R., et al., WP-126
WESTWATER, E.R., et al., WP-127
White, D.S., etal., GL-022
White, D.S., et al., GL-023
White, D.S.,etal.,GL-040
White, N.J., et al., PM-025
White, W.H.,etal.,AR-153
WICKERS, M.T., et al., WP-128
WILBURN, A.M., et al., AO-079
WILCZAK, J.M., WP-129
WILCZAK, J.M., et al., FS-051
WILCZAK, J.M., et al., WP-1 30
WILCZAK, J.M., et al., WP-131
WILCZAK, J.M., et al., WP-132
Wilhelm.K., etal., SE-001
WILKISON, S.W., et al., AR-016
Williams, E.R., et al., NS-089
WILLIAMS, G.P., GF-035
Williamson, C.E., et al., GL-052
WILLIS, P.T., et al., AO-080
WILLIS, P.T., et al., AO-081
WILLIS, P.T., et al., AO-082
WILLOUGHBY. HE., AO-087
WILLOUGHBY, HE., et al., AO-033
WILLOUGHBY. H.E.. et al., AO-083
WILSON, D., et al.. AO-084
Wilson, J.C., et al., AL-025
WILSON, J.J., et al., WP-091
WILSON, J.W., et al., WP-132
Wilson, W., et al., NS-038
Windsor, C.R.. et al., FS-024
Winges,K.D.,etal.,AR-136
Winiwarter, W., et al., AL-044
Winn, W.P., et al., NS-057
Winston, H.A., et al., FS-052
WITT, A., et al., NS-038
WITT, A., et al.. NS-076
WITTENMEIER, L.K., et al., WP-038
WITTENMEIER, L.K., et al.. WP-1 34
Wojtak. D.M., et al.. AO-014
Wolf. R.A., et al., SE-008
WOLFE, D.E..WP-133
WOLFE. D.E., etal, FS-051
WOLFE, D.E., et al.. WP-131
WOLFE. D.E., et al., WP-1 34
Wolters,W.,etal.,WP-140
Wood,V.T.,etal.,AO-085
Wood, V.T., etal., NS-008
Woodman, R.F., et al., AL-003
Woodman, R.F., et al., AL-029
WOODRUFF, S.D., et al., AR-152
Wormhoudt, J., et al., AL-091
Wright, P.D.,etal.,NS-026
Wright, P.D., et al., NS-027
Wu. S.T., et al., SE-004
Wu, S.T.,etal..SE-016
Wu, S.T.,etal.,SE-031
Wu, ST., et al., SE-032
Wu, ST., et al., SE-036
Wu, ST., et al., SE-037

214

Wu, ST., a al., SE-038
Wuebbles. D.J., et al., AR-034
WUERTZ, D.B., et al., WP-034
WUERTZ, D.B., et al., WP-081
WUERTZ, D.B., et al., WP-115
WUERTZ, D.B., et al„ WP-135
WUERTZ, D., et al., AL-023
Wyrtki, K., et al., PM-034
Yamamoto, M., et al., WP-070
Yamartino, R.J., et al, AR-103
Yeh, H.C., et al., SE-007
Yeh, T, SE-039
Young, J.O.,etal.,AR-151
Young, J.W.,etal.,WP-136
Young, K.C., et al., FS-040
Young,L.G.,etal.,AP-015
Young, L.G.,etal.,AP-027
Young, L., et al., AP-040
YOUNG, MS., et al., AO-029
Young, R.W., et al., PM-005
ZACHARIAS, D., NS-090
Zamyshlayev, I.V., et al., AR-086
Zhang, R.,etal.,AP-028
Zhang, R, et al., AP-047
Zhang, S.F., etal.,WP-146

ZHAO,Y.,etal..WP-137
ZHAO, Y.,etal.,WP-138
Zhong, X.P., et al.. FS-048
Zhong, X.P., etal.,FS-053
ZHOU.J., etal.,WP-139
Zhou, M.,etal.,WP- 147
Zhu, C.J.,etal.,WP-145
ZIEGLER, C.L., et al., NS-039
ZIEGLER, C.L., et al., NS-091
Zimmerman, H., et al., WP-004
Zipser,E.J.,etal.,AO-001
ZRNIC, D.S., et al., NS-001

et al., NS-002

et al.,

et al.,

et al.,

et al..

et al.,

ZRNIC, D.S,
ZRNIC, D.S.,
ZRNIC, D.S,
ZRNIC, D.S.,
ZRNIC, D.S,
ZRNIC, D.S,
ZRNIC, D.S,
ZRNIC, D.S,

, NS-003
.NS-064
,NS-073
, NS-078
, NS-083
, et al., NS-092
,etal.,NS-093
Zubrick, S.,etal.. FS-040
Zupanski, M, et al., FS-054
ZWICKL, R.D., et al., SE-033
ZWICKL, R.D., et al., SE-040

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