NOAA technical report NMFS SSRF

TA mek
Ae AH ate
a sine
wee ear
a i a Bend Oe
¥ 3aysk ote OS Ne =
see oF. yerah Die tes

seen ae
baw
1 wk
° DE NTE? Ra te wl
: costs alten Caleta
: “ ¥ che eet.
i : : PTA EEN Ean
. . ee aps Seek
SARS
eee eee
Ska bk pee
VR Ae EN
2! SPAR Ve
. ama tebes + Bits
De yee Balk ee =
: wy
te Pre er,
tt Ot

! : 4 3 % ; Ite daetyy rere
. Seale atpt mote

ai wees 2 eras eee

HARVARD UNIVERSITY
e
Library of the

Museum of

Comparative Zoology

NOAA Technical Report NMFS SSRF-700

Expendable Bathythermograph
Observations from the NUFS/MARAD
Ship of Opportunity Program

for 1973

STEVEN K. COOK

SEATTLE, WA
JUNE 1976

al@ys| NATIONAL OCEANIC AND National Marine
ATMOSPHERIC ADMINISTRATION Fisheries Service

NOAA TECHNICAL REPORTS
National Marine Fisheries Service, Special Scientific Report —Fisheries Seri

The major responsibilities of the National Marine Fisheries Service (NMFS) are to monitor and assess the abundance and geographic i J ;
resources, to understand and predict fluctuations in the quantity and distribution of these resources, and to establish levels for optimum use of the resoure:
NMFS is also charged with the development and implementation of policies for managing national fishing grounds, development and e' y

off United States coastal waters, and the development and enforcement of leensetionn! Sener reements
and policies. NMFS also assists the fishing industry through marketing service and economic analysis programs, and mortgage insurance and vessel construction
subsidies. It collects, analyzes, and publishes statistics on various phases of the industry. ’ — “a }

The Special Scientific Report—Fisheries series was established in 1949. The series carries reports on scientific investigations that document long- rm
continuing programs of NMFS, or intensive scientific reports on studies of restricted scope. The reports may deal with applied fishery problems. The series
also used as a medium for the publication of bibliographies of a specialized scientific nature. ‘ oe

NOAA Technical Reports NMFS SSRF are available free in limited numbers to governmental agencies, both Federal and State. They are also available
exchange for other scientific and technical publications in the marine sciences. Individual copies may be obtained (unless otherwise noted) from D83, Technical
Information Division, Environmental Science Information Center, NOAA, Washington, D.C. 20235. Recent SSRF's are: ee

fisheries regulations, surveillance of foreign fishing

619. Macrozooplankton and small nekton in the coastal waters off Vancouver
Island (Canada) and Washington, spring and fall of 1963. By Donald S. Day,
January 1971, iii + 94 p., 19 figs., 13 tables.

620. The Trade Wind Zone Oceanography Pilot Study. Part IX: The sea-
level wind field and wind stress values, July 1963 to June 1965, By Gunter R.
Seckel. June 1970, iii + 66 p., 5 figs.

621. Predation by sculpins on fall chinook salmon, Oncorhynchus tshawyt-
scha, fry of hatchery origin. By Benjamin G. Patten. February 1971, iii + 14
p., 6 figs., 9 tables.

622. Number and lengths, by season, of fishes caught with an otter trawl
near Woods Hole, Massachusetts, September 1961 to December 1962. By F. E.
Lux and F. E. Nichy. February 1971, iii + 15 p., 3 figs., 19 tables. :

623. Apparent abundance, distribution, and migrations of albacore, Thunnus
alalunga, on the North Pacific longline grounds. By Brian J. Rothschild and
Marian Y. Y. Yong. September 1970, v + 37 p., 19 figs., 5 tables.

624. Influence of mechanical processing on the quality and yield of bay
scallop meats. By N. B. Webb and F. B. Thomas, April 1971, iii + ll p.,. 2

figs., 3 tables.

625. Distributionof salmon and related oceanograpic features in the North
Pacific Ocean, spring 1968. By Robert R. French, Richard G. Bakkala, Masanao
Osako, and Jun Ito. March 1971, iii + 22 p., 19 figs., 3 tables.

626. Commercial fishery and biology of the freshwater shrimp, Macrobra-
chium, in the Lower St. Paul River, Liberia, 1952-53. By George C. Miller.
February 1971, iii + 13 p., 8 figs., 7 tables.

627. Calico scallops of the Southeastern United States, 1959-69. By Robert
Cummins, Jr. June 1971, iii + 22 p., 23 figs., 3 tables.

628. Fur Seal Investigations, 1969. By NMFS, Marine Mammal Biological
Laboratory. August 1971, 82 p., 20 figs., 44 tables, 23 appendix A tables, 10
appendix B tables.

629. Analysis of the operations of seven Hawaiian skipjack tuna fishing
vessels, June-August 1967. By Richard N. Uchida and Ray F. Sumida. March
1971, v + 25 p., 14 figs., 21 tables. For sale by the Superintendent of
Documents, U.S. Government Printing Office, Washington, D.C. 20402.

630. Blue crab meat. I. Preservation by freezing. July 1971, iii + 13 p., 5
figs., 2 tables. II. Effect of chemical treatments on acceptability. By Jurgen H.
Strasser, Jean S. Lennon, and Frederick J. King. July 1971, iii + 12 p., 1 fig.,
9 tables.

631. Occurrence of thiaminase in some common aquatic animals of the United
States and Canada. By R. A. Greig and R. H., Gnaedinger. July 1971, iii + 7
p.. 2 tables.

632. An annotated bibliography of attempts to rear the larvae of marine fishes
in the laboratory. By Robert C. May. August 1971, iii + 24 p., 1 appendix I
table, 1 appendix II table. For sale by the Superintendent of Documents, U.S.
Goverment Printing Office, Washington, D.C. 20402.

633. Blueing of processed crab meat. II Identification of some factors involved
in the blue discoloration of canned crab meat Callinectes sapidus. By Melvin E.
Waters. May 1971, iii + 7 p.. 1 fig., 3 tables.

634. Age composition, weight, length, and sex of herring, Clupea pallasit,
used for reduction in Alaska, 1929-66. By Gerald M. Reid. July 1971, iti + 25
p., 4 figs., 18 tables.

Continued on inside back cover.

-M. Gooding. May 1971, iii + 12 P. 8 figs., 2 tables. For sale
OV!

) waras

distribution of fish
nforcement of dom:

4

635. A bibliography of the blackfin tuna, Thunnus atlanticus (Le
Grant L. Beardsley and David C. Simmons. August 1971, 10 p. For sale
= ag of Documents, U.S. Government Printing aw
D.C, 20402.

636. Oil pollution on Wake Island from the tanker R. C. Stoner. By
Superintendent of Documents, U.S. ernment Printing Office, Washi
D.C. 20402.

637. Occurrence of larval, juvenile, and mature crabs in the vicinit
Beaufort Inlet, North Carolina. By Donnie L. Dudley and Mayo H. Ju
August 1971, iii + 10 p., 1 fig., 5 tables. For sale by the Superintend
Documents, U.S. Government Printing Office, Washington, D.C. 20402.

638. Length-weight relations of haddock from commercial landings in
England, 1931-55. By Bradford E. Brown and Richard C. Hennemuth.
1971, v + 13 p., 16 figs., 6 tables, 10 appendix A tables. For sale
Superintendent of Documents, U.S. Government Printing Office, Wash
D.C. 20402. 7

639. A hydrographic survey of the Galveston Bay system, Texas 1963-66. |
E. J. Pullen, W. 3 Trent, and G. B. Adams. Getober 1971, v + 3p.

figs, 12 tables. For sale by the Superintendent of Documents,
Government Printing Office, Washington, D.C. 20402. He

640. Annotated bibliography on the fishing industry and biology of the
crab, Callinectes sapidus. By Marlin E. Tagatz and Ann Bowman Hall. 4
1971, 94 p. For sale by the Superintendent of Documents, U.S. Gove

Printing Office, Washington, D.C. 20402. '

641, Use of threadfin shad, Dorosoma petenense, as live bait during ex
mental pole-and-line fishing for skipjack tuna, Katswwonus pelamis, in Haw:
By Robert T. B. Iversen. August 1971, iii + 10 p., 3 figs., 7 tables. For sale by
the Superintendent of Documents, U.S. Government Printing Office, Washing-
ton, D.C. 20402. f

642. Atlantic menhaden Brevoortia tyrannus resource and fishery —analysis of
decline. By Kenneth A. Henry. August 1971, v + 32 p., 40 figs., 5 appendix
figs., 3 tables, 2 appendix tables. For sale by the Superintendent of Documents,
U.S. Government Printing Office, Washington, D.C. 20402. 7
. \
643. Surface winds of the southeastern propical Atlantic Ocean. By John M.
Steigner and Merton C. Ingham. October 1971, iii + 20 p., 17 figs. For sale by
the Payer ag of Documents, U.S. Government Printing Office, Ws
ton, D.C. 20402. =

644. Inhibition of flesh browning and skin color fading in frozen fillets of
yelloweye snapper (Lutzanus vivanus). By Harold C. Thompson, Jr., and Mary
H. Thompson. February 1972, iii + 6 p., 3 tables. For sale by the Superinten-
dent of Documents, U.S. Government Printing Office, Washington, D.C. 20402.

645. Traveling screen for removal of debris from rivers. By Daniel W. Bate:
Ernest W. Murphey, and Martin G. Beam. October 1971, iii + 6 p., 6 figs
table. For sale by the Superintendent of Documents, U.S. Government Print
Office, Washington D.C. 20402.

646. Dissolved nitrogen concentrations in the Columbia and Snake Rivers”
1970 and their effect on chinook salmon and steelhead trout. By Wesley J. F
August 1971, iii + 7 p., 2 figs., 6 me For sale by the Superintendent of
Documents, U.S. Government Printing , Washington D.C. 20402. ja

647. Revised annotated list of parasites from sea mammals caught off the
west coast of North America. By L. Margolis and M. D. . March 1972, ii
+ 23 p. For sale by the Superintendent of Documents, U.S. Government
Printing Office, Washington, D.C. 20402. ae if _

LIBRARY

AUG 1 2 1976

Se ee ee

HARVARD
UNIVERSITY

NOAA Technical Report NMFS SSRF-700

Expendable Bathythermograph
Observations from the NUFS/MARAD
Ship of Opportunity Program

for 1973

STEVEN K. COOK

SEATTLE. WA
JUNE 1976

UNITED STATES NATIONAL OCEANIC AND / National Marine
DEPARTMENT OF COMMERCE wa ATMOSPHERIC ADMINISTRATION vA Fisheries Service <
Elliot L. Richardson, Secretary Robert M. White, Administrator Robert W. Schoning, Director =

For Sale by the Superint
t

he Su endent of Documents, U.S. Government Printing Off
Washington, D.C. 20402 Stock No. 003-017-00382-5 ee S

The National Marine Fisheries Service (NMFS) does not approve, rec-
ommend or endorse any proprietary product or proprietary material
mentioned in this publication. No reference shall be made to NMFS, or
to this publication furnished by NMFS, in any advertising or sales pro-

motion which would indicate or imply that NMFS approves, recommends
or endorses any proprietary product or proprietary material mentioned
herein, or which has as its purpose an intent to cause directly or indirectly
the advertised product to be used or purchased because of this NMFS
publication.

CONTENTS

Page
LOPUTRET RIED 5 2.5.6 dues hints ond CUERPO ole Bex do I ae a 1
ANREES OH STORY 5.0 410.5 1015.0 0015 0G OORT ARC Anes Al eg on 1
DAU oRACE UIST IONE ANOMDLOCESSIN Deere tthe tape eer a. aS uae ee Se OS eT rea Ee ee re aos 1
DISCUSSION MMPI nares re ee ences ee ee Law ee ae Bly tie le hava aye Goa witb ees Ms: ean: 1
{UREMEQGE MMGAISNS ~ o < 5s Sadia ateicug Oe OPO Eee SOG ie inoue. 5 6 acne en 2
CULT DO? WIEETOD « 0.6 0:9:0 0 Glo SOE SAkcre eRe nett ae ES eR RR Tr or ot ne re r= ae 2
IL@ayt) CEARDAG 6 & ahidhe eat/8: Shes ean yeah Monae ees asec erick er Neh a een eo gL 2
EG CES eee ee 7 I Pe coed cody 3, wus ead meio Board Se oe es 2
CGanippealCULce nl Mn te: Ge re ee hes eA eye clr lias cots s cad oe eat Roh odie GE ER ele 2
WieESlernmNOLUNeALantlew ey ween. pe. eae nee. te, Se, Cuts eA Slices | ait alty) Sic ee ae sea 2
CUPS CLEAUI EP Ce eee ae ee en eee eae ae. Were tesa: Sys bec eke Sem. vote oo cas 2
ColdicellPpremrrrr er rrr cc oe ne en es SARE ee Oe. eit oe. 5: 3
SHUM VALEISIODCAWALCISUCON Geer rr cin eect acme meee MCE 3
ANGE OATES) « 01 5 & G55 BRB aye aR SS eee a ee ere oe eye 3
MCE RAULERCICILEC MPEP PINS tery etree ers ry cH ek cians Sv oni cuomersachel ee Ohind ceuicnaieh de, epedunise) cutie cer qekaueueteusen sheseaeee 3
LETTERS ails ©. 0.0 0 0 Gc 36.8 24 OSS ROIS SE aR ee Cae ge eee Te 3

Figures

ipeDeltarArgentina: diallstations14-22, 1-2, January 1973.26 occ. cscs we sp oes Sie e icine wpe obernemre Saelenet 4
Pee GUS nipermiaU2) stations 1-225, 12-15 Pebruary 1978) sic ors < sistas sheane: «end .mnue ches otis ene end ayer stos sane = 5
SEG SLippen mi oU4 wstaLions 1-10. 20-24- April Old) «<< cies cveschs ce ene cic. ereie tho. eta Meuse sreuiln = eeosiorie ae ks 6
Ae GU eT Ader OU ASUALIONS 29s Lav AUPUSE LOTS: « .. 6 scxspeyecs cite © mifejene epee sere ies geeinn > eo njausieyera’s. 5 <yenene eRe oe 7
See Gaijelraden iol Os stations 1-215 14-15) October 1973: jane cis sce oe ns nn ee Oe cies eaten 8
GaeMeltaiNortewiollestations.1-205.3-5 November 1978) oy... 5 ct 66s catevceue lo. Sus ershanns oxGicrs Sroiens osu cneosraseun yo 22 9
pe MOTMAcvAT GOulSdOD sStatlonSs els, 12-13, May AOTS ss ojesccees« cseycitenes > erspeseieicncesue creel + Spthene =ySebN Soke Snel 10
See MOnmACrArGOnlGUDaSLALIONS 26214. Li-1S; JUNC 19TS: a esse cess Ae cae sees mee moe lee eee he se ee 11
Om Monnichigearolierstations” 1951 November 1973) <2... dee eaee weiss qapeye ae eegs gan es te Wns aed 12
Ome MormacrAr. gonial astations lal, 5 November 1973) .2j.o8 ice Gor = 0c5 reser eyerege © 0S tus eee euene © op eaensoush= © obke 13

iil

yaar" Ls mete ts ERS
wi wig ster pas a se 3
1 er raids RP err aie Te

a
0D (rT SCS ae Sie,

CNEL Pugh a

POt «arly
She yodppeye Ls,
Prey ve @ Shi OE ho
GVGL eral, AE PL 95-AE te
n7er ~wliwa nil Ale
TUi seeps G LTot amenity 18 oy
7 ;

ea

, 7 —“e.
ae
‘
» ms
7
a 4

Expendable Bathythermograph Observations from
the NMFS/MARAD Ship of Opportunity Program
for 1973

STEVEN K. COOK?!

ABSTRACT

Results of the third year of operation of the NMFS/MARAD Ship of Opportunity Program are
presented in the form of vertical distributions of sea surface temperature and salinity. Included are
descriptive analyses of the most dynamic transects showing the Caribbean/Yucatan/Loop/Florida Current
regimes, the Gulf Stream, associated eddies, and the bottom cell of cold water off the U.S. east coast.
Operational and data management procedures also are discussed.

INTRODUCTION

In midyear of 1970 a cooperative expendable bathyther-
mograph (XBT) program was initiated between the National
Marine Fisheries Service (NMFS) and the Maritime
Administration (MARAD) of the U.S. Department of
Commerce. The program, conducted in support of the
Marine Resources Monitoring Assessment and Prediction
Program of NMFS, involved the use of Maritime Cadets
from Kings Point Maritime Academy to collect XBT data on
board merchant ships operating along the east and Gulf
coasts of the United States. The objective of this cooperative
program was to identify and describe seasonal and
year-to-year variations of temperature and circulation in the
major current regimes of the eastern tropical Atlantic,
Caribbean Sea, Gulf of Mexico, and western North Atlantic,
utilizing merchant ships as relatively inexpensive platforms
for the collection of data. The program objective has been
modified recently to eliminate the tropical Atlantic and most
of the Caribbean, concentrating on the western North
Atlantic and Gulf of Mexico.

AREAS OF STUDY

Ship routes were selected to obtain regular sampling in
the most dynamic areas of the Gulf of Mexico and western
North Atlantic. The features of principal interest were the
Yucatan Current, Gulf Loop Current, Florida Current, Gulf
Stream, Shelf Water-Slope Water front, and a cold water
cell in the Middle Atlantic Bight.

DATA ACQUISITION AND PROCESSING

Subsurface temperature data were obtained by use of
Sippican XBT systems. At the same time surface water
samples were collected with bucket thermometer units for
later analysis to determine salinity. The surface water
samples were analyzed on shore using a Beckman inductive

salinometer calibrated with standard (Copenhagen) water at °

least once every 30 samples. The XBT traces were

‘Atlantic Environmental Group, National Marine Fisheries Service,
NOAA, R.R. 7A, Box 522-A, Narragansett, RI 02882.

submitted to the National Oceanographic Data Center
(NODC) where they were digitized, key punched, and
quality controlled. Finally, these processed data were listed
in printout form and machine plotted. The plots produced by
NODC were essentially camera ready and needed little hand
correcting. The few corrections necessary were made by
discarding anomalous XBT observations that could not be
supported by other associated data such as sea surface
temperature or other nearby XBT observations. Conse-
quently a vertical section plot may have one or two missing
observations resulting from the deletion of inaccurate
subsurface data.

All data collected were archived by the NODC and are
available to interested persons through the NODC,
Washington, D.C. 20235. Approximately 146 additional XBT
observations and associated surface data were archived at
the NODC, but not discussed in this report. The
observations were too scattered in time and space to be
formed into meaningful transects.

Further details concerning the acquisition or processing
of data from the cruises considered here can be obtained
from the author.

DISCUSSION

This third year of operation of the NUFS/MARAD Ship
of Opportunity Program (SOOP) was highlighted by a major
program change. Instead of transoceanic XBT transects
consisting of 4-6 observations per day, a more intense
coverage over a smaller geographical area (hourly observa-
tions for the first 24 h after leaving port and the last 24 h
before reentering port) was initiated. This has made
possible the monitoring of portions of the Shelf Water-Slope
Water front, North Wall of the Gulf Stream, Gulf Loop
Current, and associated eddies.

The SOOP effort for 1973 consisted of a total of 15
cruises, 7 sailing from New Orleans and 8 from New York.
Twenty-three transects of subsurface temperature data and
associated surface data were obtained. A total of 357 XBT’s
were launched; of these, 211 (60%) were considered of
sufficient quality to be incorporated into the transects
presented in this report. Participation of midshipmen as
data collectors does not allow for year-round coverage,

because of the transition period in January-February, when
one group of cadets goes back to school and a new group
begins sea duty.

TRANSECT ANALYSIS
Gulf of Mexico

Over the years there have been several descriptions of
the Yucatan/Loop/Florida Current regimes, but many
ambiguities still exist. For purposes of this report, I have
used the criteria of Nowlin and McLellan (1967) for
describing the Loop Current as that water within the Gulf of
Mexico that has just passed through the Yucatan Channel
and has not yet exited through the Straits of Florida (usually
about midway between Cuba and the western Florida Keys).
The current flow into the Gulf of Mexico between the
western tip of Cuba and the Yucatan Peninsula was referred
to as the Yucatan Current and the current flow upstream
from there (into the Caribbean Sea) was referred to as the
Caribbean Current.

Loop Current.—The Loop Current showed up on
transects conducted in January, February, April, August,
October, and November (Figs. 1-6). The downward slope
(southward) of the isotherms, such as between stations 16
and 17 in Figure 1 for January, indicated the approximate
position of the Loop Current as it passed from the Yucatan
Channel into the Gulf of Mexico. About a month later the
Loop Current was transected again near the Yucatan
Channel as shown by the slope of the isotherms between
stations 7 and 8 in Figure 2.

In April (Fig. 3), the Loop Current was found between
stations 5 and 6. A comparison of Figures 1, 2, and 3 shows
the Loop Current extending further into the Gulf of Mexico,
from its January position at approximately lat. 23°N to
approximately lat. 24°N in February and to lat. 25°N in
April. This northward migration was consistent with
previous observations of the behavior of this current
(Boisvert 1967).

The complex temperature structure of the section made
in August (Fig. 4) requires a close examination of the data to
discern the difference between Yucatan Current, Loop
Current, and an associated eddy. At this time, I feel the
Yucatan/Loop Current system was transected four times.

Following the temperature structure from south to
north, the downward tilting of the isotherms between
stations 29 and 28 indicated the normal westward flow of the
Caribbean Current just prior to entering the Yucatan
Channel. The upward tilting of the isotherms between
stations 26 and 23 indicated an eastward flow (into the page
in the vertical section), and the downward tilt of the
isotherms between stations 20 and 19 indicated a westward
flow. Finally, the structure between stations 16 and 12
indicated eastward flow, apparently the northernmost
crossing of the Loop Current. The configuration of the
isotherms between stations 10 and 1 suggest the presence of
a warm core eddy and are discussed in the following section.

Another possibility was that the flow pattern through
the Yucatan Channel had diverged and become multiaxial as
suggested by Cochrane? in 1963, with more eastward

“Cochrane, J. D. 1963. Yucatan Current. Texas A&M College,
Department of Oceanography and Meteorology, Ref. 63-18A. Unpubl.
rep., 25 p. Atlantic Environmental Group, National Marine Fisheries
Service, NOAA, Narragansett, RI 02882.

divergence flowing around Cuba and into the Straits of
Florida; and the western axis looping through the Gulf
between stations 16 and 12 at about lat. 25°N.

In later crossings the Loop Current appeared to recede
from the Gulf. In October it was crossed at about lat. 24°N
(Fig. 5, stations 16-21) and in November at about lat. 22°N
(Fig. 6, stations 14-16).

Eddies.—Eddy structures were detected in the north-
eastern Gulf of Mexico on transects conducted in January,
February, August, and October (Figs. 1, 2, 4, 5). In January
(Fig. 1) the temperature structure between stations 17 and
21 showed some evidence of a weak anticyclonic eddy with a
diameter of approximately 125 nautical miles.

In February (Fig. 2), the doming effect of the isotherms
between stations 1 and 7 suggested the existence of a warm
core anticyclonic eddy, possibly a recrossing of the same
eddy seen the previous month. Unfortunately, the lack of

XBT observations to the north of station 1 prevent the |

positive identification of this structure as a remnant
anticyclonic eddy.

In August (Fig. 4), the temperature structure found
between stations 10 and 1 was an indication of a warm core,
anticyclonic eddy that has possibly broken off from the main
flow of the Loop Current. This was consistent with past
observations of Loop Current activity (Leipper 1970). The
width of the eddy at this crossing was about 125 nautical
miles and extended to depths of greater than 700 m.

In October (Fig. 5), another warm core, anticyclonic
eddy was transected. The transect crossed through the eddy
between stations 5 and 11 (approximately 125 nautical miles)
and the eddy extended to a depth of greater than 750 m.

Caribbean Current.—The Caribbean Current, described
by Boisvert (1967) as one of the most persistent and well
defined of the major currents, is broad and relatively slow
moving. It was seen in the SOOP transects south of the
Yucatan Channel as a northward declination of isotherms.
Utilizing this characteristic, we found the Caribbean
Current in February, April, August, and November (Figs.
2730456):

In February (Fig. 2), the Caribbean Current was crossed
between stations 13 and 22. Temperature structure between
stations 19 and 21 indicated an area of possible counterflow.

In April (Fig. 3), the Caribbean Current was again
indicated by the general upward incline of the isotherms
between stations 9 and 15.

In August (Fig. 4), the upward incline of the isotherms
between stations 28 and 29 indicated the westward flow of
the Caribbean Current just prior to entering the Yucatan
Channel.

In November (Fig. 6), an indication of the Caribbean
Current appears between stations 16 and 20.

Western North Atlantic

Features described in the western North Atlantic include
the North Wall of the Gulf Stream, Shelf Water-Slope Water
front, bottom cold cell, and eddies formed by the Gulf
Stream. Temperature sections obtained on four New York
to Bermuda sections made during May, June, and November
(Figs. 7-10) show some of these features.

Gulf Stream. — Using the criterion of 15°C at 200-mdepth
(Worthington 1964) to indicate the North Wall of the Gulf

Stream, we found four crossings of the North Wall in May,
_ June, and November (Figs. 7-10).

In mid-May (Fig. 7), the North Wall was indicated just to
the east of station 13 (approximately lat. 37°00'N, long.
69°00'W). Unfortunately, there are not enough observations
to completely describe the crossing.

In June (Fig. 8), just the opposite occurred. Observa-
tions were made from the east right up to the North Wall,
discontinued for about 130 nautical miles, then recommenc-
ed. A crossing of the North Wall is detectable, but not well
defined, between stations 19 and 18 (approximately lat.
87°15'N, long. 69°30'W). The November section (Fig. 9)
shows the North Wall of the Gulf Stream between stations
15 and 16 (lat. 37°30'N, long.71°00'W). In the transect made
4 days later (Fig. 10) the North Wall of the Gulf Stream
showed up at station 10 (lat. 38°00'N, long.71°00'W).

Cold Cell.—The cold cell, sometimes referred to as
winter water (water less than 8°C), has been described by
Ketchum and Corwin (1964) and Whitcomb (1970). This
feature was transected on four occasions (Figs. 7, 8, 9, 10).
These four crossings show how the cold cell degenerates
throughout the summer. The first crossing in May (Fig. 7)
shows a cold cell with a temperature range of 6°-8°C until
finally in the last of November (Fig. 10) the cell structure is
barely detectable and has warmed to 14°C.

In May (Fig. 7), a cell of bottom water extended 80
nautical miles offshore to a maximum depth of 75 m, with a
temperature range of 6°-8°C. In June (Fig. 8), the cold cell
of bottom water was still evident, although by this time the
cell had begun to warm and extend out to the shelf break.

The November section (Fig. 9) shows still a further
warming and decay of the cold cell. The extent of the cold
cell had decreased to less than 60 nautical miles and warmed
to a range of 12°-14°C.

The second November section (Fig. 10) showed the cold
cell had eroded to less than 30 nautical miles extent and
warmed to 14°C.

Shelf Water-Slope Water Front.—The Shelf Water-
Slope Water front was transected in May just to the east of
station 5 (Fig. 7), indicated by a thermal change from 10° to
17°C in about 18 nautical miles. Low sea surface salinities
and temperatures out to station 5 also indicated the extent
of the shelf water.

In June (Fig. 8), the front appeared between stations 25
and 24. At this time there was less sea surface temperature
change to indicate the front, instead the most pronounced
surface signature of the front was in the form of the strong
surface salinity gradient changing slope and sign at station 23.

The November section (Fig. 9), shows that the Shelf
Water-Slope Water front had no expression in either surface
temperature or salinity, but a weak temperature gradient
between stations 7 and 8, at about 50-m depth, suggests that
the front might have been present there.

In the transect made 4 days later (Fig. 10), a definite
surface signature of the shelf water was apparent in both sea
surface salinity and temperature. The Shelf Water-Slope
Water front did not show up in the subsurface data on this
transect, but surface salinities of less than 34%o readily
identify the shelf water region.

ACKNOWLEDGMENTS

Appreciation is extended to the Maritime Academy
Training representatives in New York and New Orleans, M.
Chicurel and D. Thompson, respectively. Their diligent
efforts to place midshipmen on board ships that were
scheduled to traverse preselected oceanic areas were
instrumental to the success of this program. In addition,
thanks are extended to the Moore McCormack Lines and
Grace Prudential Lines of New York and the Delta
Steamship Company and Lykes Brothers of New Orleans.

LITERATURE CITED

BOISVERT, W. E.

1967. Major currents in the North and South Atlantic Oceans
between 64°N and 60°S. U.S. Nav. Oceanogr. Off., Tech. Rep.
TR-193, 92 p.

KETCHUM, B. H., and N. CORWIN.

1964. The persistence of “winter” water on the continental shelf

south of Long Island, New York. Limnol. Oceanogr. 9:467-475.
LEIPPER, D. F.

1970. A sequence of current patterns in the Gulf of Mexico. J.
Geophys. Res. 75:637-657.

NOWLIN, W. D., JR., and H. J. McLELLAN.

1967. A characterization of the Gulf of Mexico waters in winter.
J. Mar. Res. 25:29-59.

WHITCOMB, V. L.

1970. Oceanography of the Mid-Atlantic Bight in support of
ICNAF. September-December 1967. U.S. Coast Guard Oceano-
graphic Report No. 35, CG 373-35, 157 p.

WORTHINGTON, L. V.

1964. Anomalous conditions in the Slope Water area in 1959. J.

Fish. Res. Board Can. 21:327-333.

FIGURES

The figures are grouped by geographical location and
time. They consist of two vertical sections of temperature, a
plot of surface temperature and salinity versus distance
along the transect, and a locator chart.

GULF OF MEXICO TRANSECTS
Figures Vessels Date
i Delta Argentina 1- 2 Jan. 1973
2 Gulf Shipper 12-15 Feb. 1973
3 Gulf Shipper 20-24 Apr. 1973
4 Gulf Trader 1- 2 Aug. 1973
5 Gulf Trader 14-15 Oct. 1973
6 Delta Norte 3- 5 Nov. 19738

WESTERN ATLANTIC TRANSECTS

7 Mormac Argo 12-13 May 1973
8 Mormac Argo 17-18 Jun. 1973
9 Mormac Rigel 1 Nov. 1973
10 Mormac Argo 5 Nov. 1973

{C)

*® TEMPERATURE DEGREES

(METERS)

¢@ DEPTH

(METERS)

4 DEPTH

GULF OF MEXICO TRANSECTS

PARAMETER AT SURFACE

27

26

(0/700)

2s

24u

23

GSALINITY

22

21

0. 60. 120. 180. 240. 300. 360. 420. 480. S4O.

DISTANCE (N. MILES)

22

21
20
18
17
16
15
14

22.0.

so _] 27 50
100

100

180 —} 150

18.0.
- OS UL
14 <a
200 {tes wy Dice Nok Balin Woo Suro Nun Nip Nondors Ahh eee

0. 60. 120. 160; 2uO. S005) .3605 58420. SUSO Ske:

CRUISE TRACK PLOT

200

300
Horizontal distribution of sea surface
temperature (°C) and sea surface salin-
ity (%o), and vertical distribution
of temperature (°C) in the upper 200
and 800 m.

400

S00

600

700

800

0. 60. 120. {80.2405 s300 558 S60 9 420r) SNS0 7 esiG.

Figure 1.—Delta Argentina, 7211, stations 14-22, 1-2 January 1973.

* TEMPERATURE DEGREES (C)

(METERS)

+ DEPTH

(METERS)

4 DEPTH

28
27
26
25
2u
23
22
21

so

100

150

200

200

300

400

0)0)

600

700

800

0. 150.

PARAMETER AT SURFACE

300° 450. 600. 750: ‘900: 1050. 1200.

DISTANCE (N.

MILES)

37.

36.

35)

1350.

sO

100

150
200
a) 150. 300. 450. 600. 750. 900 1050. 1200. 1350.
uM wu Dee x pie Sey nN ae
b cb p> sohbet = dcbatind b> + 0
a7 ie ae
S.0
aan 100
2).0. 2.0
19.0. 8
re He
a cee 200
s.o
1§.0) 4.0
1§.0. 3.0
0. 2.0 300
12.0, 1.0
i}.0 a | 4oo
19.0, oJ
' fe |_ soo
0
slo aa 6 |_ 600
1.0 0
a ne 700
i A =
= 0
800
0. 150. 300. 450. 600. 750. 900. 1050. 1200. 1350.

(0/00)

GSALINITY

30 60 70

30 30

20 20

30 60 70

CRUISE TRACK PLOT

Horizontal distribution of sea surface
temperature (°C) and sea surface salin-
ity (%0), and vertical distribution
of temperature (°C) in the upper 200
and 800 m.

Figure 2.— Gulf Shipper, 7302, stations 1-22, 12-15 February 1973.

{C

DEGREES

mM TEMPERATURE

(METERS)

¢ DEPTH

(METERS)

4 DEPTH

PARAMETER AT SURFACE

ne were ——* ; 3:
27 as ~ - 7
c Or files! ro —= =} ih 3°: ©
pe q 33: 8
: 32.
oo 4 31. =
Yu ees
24 4 on =
3. 5
li 26.
>> ron BIE fo)
eat gee 3i:
ee + Ean

T 92 vy he. apt ee eee
0. 160. 320. 480. 640. 800. 960. 1120. 1280. 1440.

DISTANCE (N. MILES)

oS 30 80 70
0 sop sb 0
50 bo 8)
100 100
150 150
200 200
0. 160. 320. 480. 640. 800. 960. 1120. 1280. 1440.
CRUISE TRACK PLOT
0
100
200
300
Horizontal distribution of sea surface
uoo temperature (°C) and sea surface salin-
ity (%o), and vertical distribution
of temperature (°C) in the upper 200
S500 and 800 m.
600
700
800

Q. 160. 320. 480d. 640. 800. 960. W200. Wesdh war
Figure 3.—Gulf Shipper, 7304, stations 1-15, 20-24 April 1973.

(C)

* TEMPERATURE DEGREES

(METERS)

4 DEPTH

(METERS)

4 DEPTH

30

2g

28

27

10)

100

150

200

200

300

4OO

S00

600

700

800

PARAMETER AT SURFACE

Sie
=)
oO
a
2
>
=
z
=
lou
wm
©
36.
Os go. 180. 270. 360. 4SO. Suo. 630. 720.
DISTANCE (N. MILES
30 60
0 30 30
SO
Lie
20 20
| 150
|_ 200 = ae
720.
CRUISE TRACK PLOT
O-—-WUNMI MN OFromMo —-UMSTNWORr- @WO [op]
OOD SOE OTD a wt wt se Mw ccc CCC WJ fav)

Horizontal distribution of sea surface
temperature (°C) and sea surface salin-
ity (%o), and vertical distribution
temperature (°C) in the upper 200 and
800 m.

Q. 90. 180. 270. 360. 4so. S40. 630. 720.

Figure 4.— Gulf Trader, 7308, stations 1-29, 1-2 August 1973.

DEGREES

*M TEMPERRTURE

(METERS)

4 DEPTH

(METERS)

4 DEPTH

PARAMETER AT SURFACE

Sir.

36.

a5.

34.

| T

180. 240. 300. 360. 420. 4860.

DISTANCE (N. MILES)

m s> Mo OTF On0O—-
= -— Re RR RR WN

120.

16)

100

150

180. 240. 300. 360. 420. 480.

|_ 200

| 300

| 400

| S00

| 600

700

800

I | T
180. 240. 300. 360. 420. 480.

(0/00)

GSALINITY

30 60
30 Ke —~ 30
1
8)
i, Ne
20 20
90 80

CRUISE TRACK PLOT

Horizontal distribution of sea surface
temperature (°C) and sea surface salin-
ity (%o), and vertical distribution
of temperature (°C) in the upper 200
and 800 m.

Figure 5. — Gulf Trader, 7310, stations 1-21, 14-15 October 1973.

PARAMETER AT SURFACE

o 30 a7.
= 2g 36. 5
ig) 28 35. S
al
a 27) Su boos
=
e Pee
c . Fa
2 25 Sie =
24
a Jie
= 23 29.
= 22 28.
*
0. 120. 240. 360. 480. 600. 720. 840. 960. 1080.
DISTANCE (N. MILES)
100 30 60
0 0 30
= 150 so
wn
c
(ee)
—
b ee
— 160
- ion
3=
e
a
=]
~ 150 150
SY
200 200 10
100 390 80
Q. 120. 240. 360. 4so. 600. 720. 840. 960. 1080.
CRUISE TRACK PLOT
OoO-W TOW wo ~-ono
“ AM wzlro Daas A el -
CM
———————
100 Fis an
> 6.0
= ———_ tgiee 5.0
© ea Z
ad . 2 w £8
lu pS WEE Tee = 0.0
wu 8.0
= 5 NE SE 5 £ 8.0
x 300 a ae
a 12—,2.0 Horizontal distribution of sea surface
9 yoo = temperature (°C) and sea surface salin-
* ity (%0), and vertical distribution
of temperature (°C) in the upper 200
Soo }o.0 and 800 m.
600 ms
700
800 800
0. 120. 240. 360. 480. 600. 720. 840. 960. 1080.

Figure 6.—Delta Norte, 7311, stations 1-20, 3-5 November 1973.

S (C)

DEGREE

M TEMPERATURE

(METERS)

¢ DEPTH

(METERS)

¢ DEPTH

WESTERN ATLANTIC TRANSECTS

PARAMETER AT SURFACE

aie apes ay:
4
ae a
ey =
50 TI 35.
19
18 = 34.
1
is = 33.
1
iN 4 a2
1
| 31.
ies
10 30.
T T [e
QO. 4Oo. 80. 120. 160. 200. 240. 280. 320.
DISTANCE (N. MILES)
0 0
50 so
100 100
150 150
200 200
0. 40. 80. 120. 160. 200. 240. 260. 320.
0 0
100 100
200 200
300 300
yoo _ 400
500 — 500
600 _| 600
0
7Ah) zoe
Boc __| 800

80.

120. 160. 200. 240. 280. 320.

(0/00)

GSALINITY

60 70 60

CRUISE TRACK PLOT

Horizontal distribution of sea surface
temperature (°C) and sea surface salin-
ity (%o), and _ vertical distribution
of temperature (°C) in the upper 200
and 800 m.

Figure 7.—Mormac Argo, 7305, stations 1-13, 12-13 May 1973.

10

(C)

*X TEMPERATURE DEGREES

(METERS)

¢+ DEPTH

(METERS)

4 DEPTH

2s
2u
23
22
21
20
19
18
17
16
15
14

SO

100

150

200

PARAMETER AT SURFACE

eli/e
silsic
bess.
134,
=33).
E32.
Shilo
130.
e29F

(0/00)

GSALINITY

I T

60. 120. 180. 240d. 300.
DISTANCE (N. MILES
= oO oD

un -

60. 120. 180. eyo. 300.

60. 120. 180. 2u0. 300.

28.
|

360. 420. 480.

80 70 60

so so

vo | SO

4O 4O

200

30 30
80 70 60

360. 420. 480.

CRUSE TRACKS SG

Horizontal distribution of sea surface
temperature (°C), and sea surface salin-
ity (%0), and vertical distribution
of temperature (°C) in the upper 200
and 800 m.

360. 420. 480.

Figure 8.—Mormac Argo, 7305, stations 28-14, 17-18 June 1973.

11

{C)

*M TEMPERATURE DEGREES

(METERS)

4 DEPTH

(METERS)

4 DEPTH

PARAMETER AT SURFACE

2s —-
24u
23
22
21
20
19
18
17

120. 160. 200. 240.

DISTANCE (IN.

MILES)

= Le LO = oOo o
“we we _—

50

100

150

200

300

4o0o

500

600

700

800

160. 200.

240.

0. uO. 80. 120.

280.

280.

ST

34.

320.

50

200

320.

200

300

4OO0

S00

600

700

800

320.

(0/00)

GSALINITY

60 70 60

CRUISE TRACK PLOT

Horizontal distribution of sea surface
temperature (°C) and sea surface salin-
ity (%o), and vertical distribution
of temperature (°C) in the upper 200
and 800 m.

Figure 9.—Mormac Rigel, 7311, stations 1-19, 1 November 1973.

12

26
2s
2yu
23
22
21
20
19
18
17
16
1S
14
13

(C)

* TEMPERATURE DEGREES

(METERS)

¢ DEPTH

200

(METERS)

300

4OO

¢ DEPTH

500

600

700

800

PARAMETER AT SURFACE

37
36. &
Sea
oO
35. =
lk s
Bye a
=
+33. 2
wn
Eee og =e.
Sil.
i ] ea ls eae als =
60. 120. 180. 240. 300. 360. 420. 4so. suo.
DISTANCE (N. MILES)
es 2 oy 80 70 50
. — = 0} so
|_so
22 | 100
2.0 4a
0.0
| 150
0.0
bed 200
30 =
nT ie S 3 2

300. 360. 420. 480. S40.

CRUISE TRACK PLOT

w (fay Jem
+ 0
20 |_ 100
2) Sars aig
200
9.0
ay | 300
Horizontal distribution of sea surface
| yoo temperature (°C) and sea surface salin-
ity (%c), and vertical distribution
ios of temperature (°C) in the upper 200
|. S00 and 800 m.
16 —18.0 | 600
ES TA0KGI
800
| I “aA I |
60. 120. 180. 240. 300. 360. 420. 480. S4Q.

Figure 10.—Mormac Argo, 7311, stations 1-17, 5 November 1973.

13

t% U.S. GOVERNMENT PRINTING OFFICE: 1976—697-340/93 REGION 10

so

40

30

vy
‘
be

H.owy

Acme

Bookbinding Co., Inc.
100 Cambridge St. |
| Charlestown, MA 02129.

erences
Mahet

PAG
NaS
eels

z=
Averitt
Panto atey need 9

we Ae en

tae

pee

vt

’
on hut

VR yee

wee