COMPARISON OF EFFECTS OF VARIOUS
TROPICAL STORMS ON THE VERTICAL
TEMPERATURE STRUCTURE OF THE OCEAN
USING PICTORIAL REPRESENTATION
Wi 1 1 iam Revesz, Jr.
*
*
United States
Naval Postgraduate School
THESIS
COMPARISON OF EFFECTS OF VARIOUS
TROPICAL STORMS ON THE VERTICAL
TEMPERATURE STRUCTURE OF THE OCEAN
USING PICTORIAL REPRESENTATION
by
William Revesz , J r
Thes is Advisor:
Dr. Dale F . Lei ppe r
September 1971
T14251
Approved faon. pub tic nzlzaHiZ; distribution witimitzd.
Comparison of Effects of Various Tropical Storms on the
Vertical Temperature Structure of the Ocean
Using
Pictorial Representation
by
William Revesz, Jr.
Lieutenant Commander. United States Navy
B.S., University of Tulsa, 1 96 2
Submitted in partial fulfillment of the
requirements for the degree of
MASTER OF SCIENCE IN OCEANOGRAPHY
from the
NAVAL POSTGRADUATE SCHOOL
September 1971
c.i
ABSTRACT
To make comparisons of the effects of tropical storms on
the ocean's vertical temperature structure, temperature-depth
c ross -sect i ons were constructed using bathythermograph data
and data from published articles.
Upwelling, downwelling and m i x i ng , caused by tropical
storms in deep and shallow water, are analyzed and compared.
For a slow-moving, intense and very intense tropical storm,
upwelling, from a depth of kO to 65 meters, is observed within
the radius of hurricane-force winds. Downwelling as much as
20 meters occurs from 45 to 110 nmi from the path of the storm.
This compares favorably with the theoretical results of
O'Brien and Reid. A fast-moving, intense tropical storm has a
similar effect on the vertical temperature structure if the
thermocline is shallow,and upwelling, of a lessor degree than
that caused by a slower-moving storm, can occur from a depth
of 35 meters within the radius of h u r r i cane- f o r ce winds. A
very fast-moving, very intense tropical storm can cause up-
welling from a depth of 30 meters if the thermocline is shallow
TABLE OF CONTENTS
I. INTRODUCTION 9
II. PROCESSING OF DATA 11
A. STEP ONE 11
B. STEP TWO 12
C. STEP THREE 13
D. STEP FOUR 14
III. ANALYSIS OF TROPICAL STORMS 17
A. CROSS-SECTION A-A1 18
B. CROSS-SECTION D-D' 19
IV. COMPARISON OF FIGURES 22
A. EFFECTS IN DEEP WATER 22
1. Upwelling 22
2. Downwelling 23
3. Mixing 2k
k. Sea Surface Temperature 2k
B. EFFECTS IN SHALLOW WATER 2k
1 . Upwel ling 2k
2. Downwelling 25
3. Mixing 25
k. Sea Surface Temperature 25
V. COMPARISON WITH THEORY 27
A. SLOW-MOVING, INTENSE AND VERY INTENSE
TROPICAL STORM 30
B. FAST-MOVING, INTENSE TROPICAL STORM 31
C. VERY FAST-MOVING, VERY INTENSE TROPICAL
STORM 32
VI. CONCLUSIONS 33
VII. RECOMMENDATIONS 3k
APPENDIX A--Cruise Track Used by GUS III for AFTER
Hilda (196*0 35
LIST OF REFERENCES 51
INITIAL DISTRIBUTION LIST 53
FORM DD H73 55
LIST OF TABLES
Table
I
Characteristics of the Tropical
Storms, the Results of Analysis, and
the Predictions of Theory
Page
50
LIST OF FIGURES
Figure
1
8
9a
9b
9c
9d
10a
Cruise Track Used by GUS III for AFTER
Hi Ida (1964)
An Example of the Construction of the
Figures Used for Analysis
Cruise Track Used by R/V ALAMINOS for
UNDISTURBED Hilda (1964) and BEFORE
Betsy (1965) in the Gulf of Mexico
Cruise Track Used by R/V ALAMINOS for
AFTER Betsy (1965), and Location of
Cross-sections C-C" through G-G"
Position of C ros s -sect i ons A- A" and
B-B" across the Track of Betsy (1965)
with Location of Rad i o- t ransm i t ted BT ■ s
Cruise Track Used by R/V HIDALGO for
Thermistor-Chain Tows of BEFORE and
AFTER Carla ( 1 9 6 1 ) and Location of
Cross-section A-A'
Cruise Track used by R/V ALAMINOS
for BEFORE and AFTER Inez (1 966) and
Location of Cross-section A-A'
Cruise Track Used by R/V ATLANTIS II
for BEFORE and AFTER Shirley (1965)
and Location of C ros s -sect i on A-A1
Temperature-Depth C ros s -sec t i on A-A',
UNDISTURBED and AFTER Hilda (1964)
Temperature-Depth C ros s -sec t i on B-B1,
UNDISTURBED and AFTER Hilda (1964)
Temperature-Depth C ros s - sect i on C-C1,
UNDISTURBED and AFTER Hilda (1964)
Tempe ra tu re- Dept h C ros s - sec t i on D-D1,
BEFORE and AFTER Hilda (1964)
Temperature-Depth C ros s - sec t i on A-A",
BEFORE and AFTER Betsy (1965), Based
on Rad i o- t ransm i t ted Data
Page
35
36
37
38
39
40
41
42
43
43
44
44
45
Fl gure
Page
10b Temperature-Depth Cross-section B-B",
BEFORE and AFTER Betsy (1965), Based on
Radio-transmitted Data ^5
11a Temperature-Depth Cross-section C-C",
BEFORE and AFTER Betsy Cl 965) in the
Gulf of Mexico ^6
lib Temperature-Depth Cross-section D-D",
BEFORE and AFTER Betsy (1965) in the
Gulf of Mexico Zj£
lie Temperature-Depth Cross-section E-E",
BEFORE and AFTER Betsy (1965) in the
Gulf of Mexico ^7
lid Tempe ra tu re- Dep th Cross-section F-F",
BEFORE and AFTER Betsy ( 1 965 ) in the
Gulf of Mexico 47
lie Tempe ra ture - Dept h Cross-section G-G",
BEFORE and AFTER Betsy (1965) in the
Gulf of Mexico 43
12 Temperature-Depth cross-section A -A",
BEFORE and AFTER Shirley (1965) k8
13 Temper a tu re- Dep th C ros s -sect i on A-A1,
BEFORE and AFTER Carla (1961),
Based on Towed The rm i s te r-Cha i n Data.... l±q
1 *» Tempe ra tu re- Dep th C ros s - sec t i on A-A1,
BEFORE and AFTER Inez ( 1 966 ) ^9
ACKNOWLEDGEMENTS
I would like to express my sincere appreciation to
Dr. Dale F. Leipper for the patience, personal interest, and
encouragement he provided in the preparation of this thesis.
I would also like to thank Professor Ken Davidson for
his encouragement and constructive criticism.
A special thank you to my friend Patti Povemba , who spent
many hours typing and retyping.
INTRODUCTION
Emphasis on the study of the effects on the sea surface
and vertical temperature structure of the ocean by the pass-
age of a tropical storm began in the mid 1950's. Evidence
of marked cooling of the sea surface following the passage of
tropical storms has been reported by several authors. These
include Uda [19S4], Fisher [1958], Jordan [1964], Leipper
[1967], Stevenson and Armstrong [1965], Landis and Leipper
[1968], and Hazelworth [1968] .
The first systematic observational studies on the
three-dimensional effect of a hurricane on the sea sur-
face and vertical temperature structure were conducted by
Leipper on the effects of hurricane Hilda, (1964). Further
studies were conducted by Landis and Leipper, and
Franceschini and El-Sayed on hurricanes Betsy (1965) and
Inez (1966), respectively.
A theory for oceanic changes due to a stationary
or slow-moving hurricane was developed by O'Brien
and Reid [196?]; and O'Brien [1967, 1968]. Although
somewhat limited by assumptions, the theory provides
an explanation of some of the time-dependent non-linear
processes involved. Basically, the initial ocean
response to a hurricane is a development of an Ekman type
flow which, in the Northern Hemisphere, leads to a diver-
gence of the ocean surface layers away from the storm. The
outward flowing warm water converges near the outer edges of
the wind circulation and leads, through downwelling, to the
formation of a deep, still warm, well-mixed layer in the ocean
The mechanical effect of the wind and the convection brought
about by heat loss from the sea surface to the atmosphere
causes the mixing which occurs in the outward moving water.
Near a coastline, the wind-induced motions are modified by
the presence of a solid boundary, Franceschini and El-Sayed
[1968].
To date, only Fisher [1958] and Hazelworth [1968] have
concerned themselves with a comparison of the effect of more
than one hurricane or typhoon. Both used sea surface temper-
ature (SST) as the basic comparison parameter. The objective
of this paper is to analyze and compare by use of selected
numerical indices and pictorial representation, the effects
on the vertical temperature structure of the ocean produced
by hurricanes Carla (1961), Hilda (1964), Betsy (1965), Inez
(1966) and typhoon Shirley (1965).
10
I I . PROCESSING OF DATA
Leipper [1967], in his study of hurricane Hilda (1964),
made observations and displayed vertical sections perpendicular
to the hurricane's path. Comparison with data collected
before the storm and with UNDISTURBED cros s -sect i ons (obtained
during the next hurricane season prior to the passage of any
storms and along the same cruise track lines) showed signifi-
cant d i ffe ren ces in temperature and salinity. These differences
appeared to be the result of the storm's action on the ocean.
The warm surface waters were displaced to either side of the
hurricane's path and a core of cold water with a shallow therm-
ocline appeared near the center of the wake, demonstrating
active upwelling. The Hilda study and further studies by
Leipper , prior to and following Betsy (1965), indicated an
area of downwelling outside the central upwelling region.
This investigation and pictorial comparison of the effect
of various tropical storms on the vertical temperature struc-
ture of the ocean was initiated using the observations of
Leipper [ 1 9 6 7 ] . A method of pictorial representation
to represent the areas of upwelling and downwelling of
Hilda 0964), was selected as follows:
A. STEP ONE
The locations of all bathythermograph (BT) observations
made AFTER Hilda and all BT observations made of the
To be published.
1 1
UNDISTURBED condition were plotted on the same chart of the
Gulf of Mexico. The track of Hilda was superimposed over
this data. Cross-sectional lines, perpendicular to the
hurricane's track, were drawn with respect to the ship's
track. For Hurricane Hilda, the placement of the cross-
sectional lines was simplified because the AFTER and
UNDISTURBED cruise tracks were made normal to the hurricane's
track for both the first (AFTER ) and second (UNDISTURBED)
cruises. In the case of Betsy in the Gulf , the BEFORE and
AFTER plots of BT stations were overlaid. Three of the
AFTER lines had been made exactly along the BEFORE lines.
The other two c ros s -sec t i ona 1 lines were drawn normal to the
path of the hurricane through the area of greatest observa-
tional density except for c ros s -sec t i ons D-D" and E-E".
All observations not falling directly on the cross-
sectional lines were projected normal to the cross-
sectional line. An example of the method of plotting the
BT stations to the c ros s -sect i ona 1 lines is shown in Figure 1,
which corresponds to the study of Hilda.
B. STEP TWO
To further refine the pictorial representation of the
UNDISTURBED and AFTER vertical temperature structure, each
Hurricane Betsy will hereafter be identified as
Betsy in the Gulf or Betsy, the latter referring to
hurricane Betsy in the Atlantic.
12
BT observation for the AFTER data was plotted with a
vertical scale of 50 meters/inch. A horizontal scale of
60 nautical miles/inch was used to represent the distance
from the path of the hurricane with the zero position
representing the center of the hurricane path. Each
BT observation was plotted at its respective distance from
the center of the hurricane path and isotherms were
connected between observations to form a temperature cross-
section. A similar method was used to plot sections for
the UNDISTURBED BT observations at their respective
distances from the center of the hurricane's path.
C. STEP THREE
The plot of the UNDISTURBED isotherms was overlaid on
the plot of the AFTER isotherms using the zero nautical mile
position and the sea surface as the common points of allign-
ment. With the vertical scales being the same, areas of
upwelling, downwelling and mixing were readily discerned by
comparing equal valued isotherms. To construct a pictorial
representation of the effects of the hurricane for use in
comparisons to other storms, the following procedure was
used. With the AFTER plot overlaid on the UNDISTURBED plot,
isotherms of the same value were compared starting from the
surface. The lower stable isotherm was selected to serve
as a reference for changes in the vertical temperature
structure; that is, the isotherm was chosen as one which
maintained the same depth within the area of upwelling both
13
In the AFTER and UNDISTURBED plot. Examination of the
isotherms above this chosen lower reference isotherm
showed that an isotherm for a 2°C greater temperature
would adequately aid in representing depth changes due to
the processes involved. In the case of Hilda, the lower
and upper isotherms were 23°C and 25°C, respectively.
Examination of the UNDISTURBED plot of isotherms indicated
that the layer of water contained between these two
isotherms, differing by 2°C, describes a layer with
generally uniform thickness in the undisturbed water.
In the case of Betsy (in the Gulf of Mexico) this index
layer was best represented by the layer contained between
the 26°C and 28°C isotherms. Henceforth, such layers
contained between the two chosen isotherms will be referred
to as the index layer.
D. STEP FOUR
The final construction of the figures used for Hilda and
Betsy for pictorial representation was accomplished in the
following manner. Dashed lines ( ) were chosen to
represent the UNDISTURBED or BEFORE condition. Solid lines
( ) were chosen to represent the AFTER condition. When
additional isotherms were needed to more clearly show the
processes involved, a dash-dot line (-.-.) was chosen to
represent the BEFORE or UNDISTURBED condition and a
dotted line C ) was chosen to represent the AFTER
condition. Large dots occurring in any of the above lines
\k
represent the location of BT stations as measured
horizontally from the path of the hurricane and the depth
of the isotherm as measured vertically from the surface.
An example of this representation appears in Figure 2. The
completed figures were then labeled and they represent
simplified views of the temperature-depth c ros s -sec t i on s
chosen for analysis and comparison.
To construct figures for analysis of tropical storms
Betsy (1965), Shirley (1965), Carla (1961), and Inez (1966,
results representing the BEFORE and AFTER isothermal
structure were extracted from published articles by
Landis and Leipper [1968], Wright [ 1 9 6 9 J , Stevenson and
Armstrong [1.965], and Franceshini and El-Sayed [1968]. A
search of literature showed that these articles contained
suitable results for comparison. These results were
presented In figures similar to those constructed in this
study. The figures were modified so that the depth scale
would be one inch per 50 meters and correspond to the depth
scale used in the Hilda and Betsy (in the Gulf) analyses.
The horizontal distance scale assumed the dimensions per inch
created by the one to one enlargement of the published data.
This enabled a direct comparison of changes in the thickness
caused by upwelling, downwelling and mixing of the index
layer. After the modification of the published figures,
steps three and four were completed and the figures were
used to compare the depth changes involved. To facilitate
15
ease in comparison, all depths are presented in meters,
distances in nautical miles, and temperatures in degrees
Celsius. The final pictorial representations used for
comparison were not meant to give exact values of horizontal
measurement such as the exact distances where upwelling
or downwelling occurs on either side of the hurricane's
path. The isotherms chosen were representative isotherms
and show approximate distances to the most dominant features
The vertical pictorial representation indicates the change
in depth and thickness of the index layer due to the effect
of the hurricane on the vertical temperature structure.
The isotherms for Hilda, and Betsy in the Gulf of Mexico,
were plotted within + one meter of their true depth on the
BT graph or on the value on the NODC data printout. There-
fore, the vertical scale represents the actual change in
depth and thickness of the index layer. The accuracy of
the vertical scale of Betsy , Carla, Shirley and Inez,
was assumed to be the same since original data was not used
to plot i sothe rms .
Section III explains in detail the construction of each
temperature-depth c ros s - sec t i on . Analysis of a sample cross
t
section is included. Section IV is a comparison of the
figures, and Section Visa comparison of the results of the
pictorial analysis with the theoretical model proposed by
O'Brien [1968].
16
III. ANALYSIS OF TROPICAL STORMS
Figures 1, 3 and k show the cruise track, cross-
sections, and the extent of hurricane force winds of
hurricanes Hilda [1964) and Betsy (1965) in the Gulf of
Mexico. Figures 5, 6, 7 and 8 show the same information
for tropical storms Betsy (1965), Shirley (1965),Carla (1961),
and Inez (1966), respectively. Figures 9 through 14 are
tempe ra t u re -dept h c ros s -sec t i ons of each tropical storm. Each
cross-section was constructed normal to the path of that storm
with the exception of c ros s - sec t i on s D-D" and E-E" of Betsy
in the Gulf and A-A' of Shirley. Each temperature-depth
c ros s - sec t i on was analyzed using the same procedures. The
following is a sample analysis of Hilda (1964). The analysis
examines two situations; first, a hurricane's effect on the
vertical temperature structure in deep water, (c ros s - sec t i on
A-A'); and second, the effect on the vertical temperature
structure in shallow water (c ros s - sec t i on D-D1):
The path of hurricane Hilda as it crossed the Gulf of
Mexico from 30 September to 4 October 1964, is shown in
Figure 1. When the hurricane was centered 250 nmi off shore
in waters greater than 1,000 fathoms, she became more intense
with winds up to 130 knots. The wind decreased to 105 knots
as she moved toward the coast. The width of the zone having
winds of hurricane force is shown in Figure 1. The average
propagation speed was six to eight knots, and the width of
the eye was approximately 35 nmi in the northern Gulf.
17
The data for the analysis was gathered in three
ways. Some BEFORE data was collected by RV/ALAMINOS as it
proceeded into port just ahead of the hurricane. Three bathy
thermograph (BT) observations were made near the locations
of BT ■ s 26, 21, and 18, respectively, as shown in Figure 1.
Three additional BEFORE BT observations were obtained from
the Bureau of Commercial Fisheries at locations near those
indicated for BT's 57. 63, and 65 as shown in Figure 1. The
remaining data was collected on cruise 65~A-11, conducted by
the RV/ALAMINOS from 1 0 - 2 ^ August 1 9 6 5 and represents the
UNDISTURBED condition taken eleven months later. Data was
taken over the same paths used for observations of conditions
after Hilda. The AFTER data was gathered using the 90-foot
shrimp boat, GUS lil, operated by the Galveston Biological
Laboratory, Bureau of Commercial Fisheries. The observations
after the storm were made using the same BT instruments used
on the RV/ALAMINOS.
A. CROSS-SECTION A-A' (See Figure 1 for Location)
The UNDISTURBED and AFTER data are plotted in Figure 3a,
with all stations projected to the baseline A-A', constructed
normal to and centered around Hilda's path. UNDISTURBED data
was selected for analysis from hydrographic stations two
through eight and NODC data printouts of BT's kO through 69,
gathered on cruise 65-A-ll. AFTER data was selected from
photographs of BT's 25 through 41, gathered 5 days after
HMda by GUS III.
18
The UNDISTURBED condition was represented by the index
layer contained between the 23 'C and 25 °C isotherms. The
thickness of the index layer, 60 nmi either side of the path
of Hilda, indicated a uniform, undisturbed layer approximately
10 meters thick, with the uppermost part of the index layer
being 50 meters below the surface.
The AFTER condition was represented by the same pair of
isotherms. As a result of the radial divergence of the sur-
face water, colder water was upwelled from the index layer
to the surface for a distance of k$ nmi to the left and 50 nmi
to the right of Hilda's path as shown by the surfacing of the
25°C isotherm. A reduction of SST by 3°C in this area was
observed by comparing the UNDISTURBED and AFTER BT readings.
Beyond 60 nmi to the left and right of Hilda's path there were
strong indications of downwelling, probably caused by con-
vergence of the warm surface water displaced from the area
of up welling. In these areas the 25 °C isotherm was depressed
approximately 18 meters deeper than the observed UNDISTURBED
position. At a distance greater than 120 nmi to the right of
Hilda's path, steeply sloping isotherms were observed and are
believed to be caused by horizontal advection toward the
hurricane path, Leipper [1965]. *
B. CROSS-SECTION D-D1
The BEFORE and AFTER data are plotted in Figure 9d, with
all stations projected to baseline D-D', which is normal
to and centered to the far left of Hilda's path. BEFORE data
was selected from BT ' s 10, 5 and 2, obtained by the Bureau
19
of Commercial Fisheries in 40 fathoms of water. AFTER data
was selected from photographs of BT ' s 57 through 65, gathered
nine days after Hilda by GUS III. This represents an area
where Hilda reached shallow water and the wind-induced motions
were modified by the presence of a coastline.
The BEFORE condition was represented by the index layer
defined by the 23°C and 25°C isotherms. The thickness
of the index layer from 120 nmi to the left and 30 nmi to the
right of Hilda's path represents a uniform, undisturbed
layer averaging 10 meters thick, with the uppermost part of
the index layer being about kO meters below the surface.
The AFTER condition was represented by the same pair of
isotherms. As a result of the radial divergence of the sur-
face water, colder water was upwelled from the index layer to
the surface for a distance of 20 nmi to **0 nmi to the left of
Hilda's path as shown by the surfacing of the 25°C isotherm.
A reduction of SST in this area of 5°C was indicated by
comparing BEFORE and AFTER BT ' s . Seventy nautical miles to
the left of Hilda's path there were strong indications of
downwelling, probably caused by convergence of warm surface
water displaced from the area of upwelling. In this area,
the 25°C isotherm is depressed approximately 10 meters
deeper than the observed BEFORE position. From 110 nmi
to the left and 10 nmi to the right of Hilda's path, large
areas of mixing were indicated by the equal distribution
of the index layer above and below the BEFORE data position.
20
The data obtained from the analysis of all of the
temperature-depth cross-sections prepared in this way is
summarized in Table 1.
21
IV. COMPARISON OF FIGURES
The comparison of figures is considered in two parts:
hurricane effects in deep water and hurricane effects in
shallow water. In each part, comparisons are made of upwell-
ing, downwelling, mixing, sea-surface temperature decrease,
and the extent of winds of hurricane force.
A. EFFECTS IN DEEP WATER:
1 . Upwe 1 1 ? ng
As a result of radial divergence of the surface
water in all directions, sub-surface water is usually
upwelled to compensate for the initial loss at the surface.
O'Brien [1970] shows that the upwelling is a result of the
influence of the radial component of wind stress. The
component of wind stress was viewed as a steady state
component by O'Brien, which enabled him to adequately describe
the ocean dynamics under the core of the hurricane.
Table 1 shows the comparison of the various cyclonic
disturbances. In each case, the area immediately beneath the
path of the hurricane was upwelled from a depth of at least
kO meters to the surface. This is demonstrated by the surfac-
ing of the upper portion of the chosen index layer. Currents
have also had an effect on the observed location of the upwelled
water. This is demonstrated in cros s -sec t i ons C-C", D-D", and
E-E" of Betsy (in the Gulf). In the upwelled area, the chosen
lower isotherm has remained essentially stable. This
22
indicates that water is brought in from below the mixed sur-
face layer probahly causing a decrease in thickness of the
index layer in areas near the outer limits of the hurricane
force winds. Most cross^sect ions studied exhibited upwelling
beneath the path of the storm and were offset to the left
of the path of the storm as shown in cross-sections A-A1,
B-B', C-C, D-D' of Hilda; B-B", C-C", D-D", F-F" of Betsy
Cin the Gulf); A-A' of Shirley; A-A' of Carla; and A-A1 of
Inez. The upwelling effect is a lasting effect, with
indications, in at least the Hilda case, that it may last
for up to twenty days.
2 . Downwe 1 1 i ng
As a result of the radial divergence of the surface
waters from the storm centers, still warm water displaced from
the upwelled area converges near the outer area of the wind
stress component. Leipper in his study of Hilda, and Betsy
(in the Gulf of Mexico) found that downwelling was signifi-
cant outside the upwelled area. Table 1 shows that an area
of downwelling occurs near the outer edge of hurricane force
winds which would agree with the onset of downwelling as
described in theory by O'Brien [1967]- The mechanisms
involved in downwelling are not as simple as those occurring
directly beneath the hurricane and downwelling cannot be
treated with the simple dynamic steady-state model used for
upwelling. A common effect in the downwelled areas was a
decrease in the thickness of the index layer and an increase
in the depth of the index layer.
23
3 . Mixing
As a result of the radial divergence of the surface
water from the upwelled area and the combined effect of wind
stress and turbulence in the diverging surface water, areas
of deep, well-mixed waters are often encountered inside the
storm area, and usually in concurrence with areas of
maximum downwelling. An area of mixing is easily recognized
by equal displacement of the upper and lower isotherm,
thickening the BEFORE or UNDISTRUBED index layer. Mixing was
not a common occurrence in deep water, but will be discussed
in greater detail under EFFECTS IN SHALLOW WATER.
k . Sea Surface Temperature
A decrease in sea surface temperature was observed
in the wake of each hurricane, and has been noted by many
authors. The amount of decrease of sea surface temperatures
is dependent upon the conditions existing prior to passage,
the speed of passage, and the intensity of the cyclonic
disturbance. The total decrease in the SST can not always
be attributed to the effect of upwelling, but may be the
result of heat loss to the hurricane, if no upwelling occurred
B. EFFECTS IN SHALLOW WATER:
1 . U pwe 1 1 i ng
Three c ros s -sect i on s demonstrate that the
decrease in ocean depth and the presence of a coastline
apparently alter the effects of a hurricane. C ros s - sec t i on
D-D' of Hilda; cross-section G-G" of Betsy (in the Gulf),
2k
and cross-section A-A' of Inez each show similar features.
Upwelling is mostly confined beneath or slightly offset to
the left of the hurricane centers. Also, these areas
exhibit extensive upwelling.
2 . Downwe 1 1 ? ng
Downwelling, as a result of the divergence of the
warm water from the upwelled area, is not as clearly defined
as in the deep water case. The extent of downwelling is
less, being only several meters, as compared to observed
effects in deep water. Areas where extensive downwelling
was noted, such as c ros s -sec t i on A-A' of Carla, were
possibly associated with areas of convergence of an induced
current with an already present current in an opposite
direction.
3 . Mixing
The mixing in the areas of upwelling and downwelling
is more common in shallow water as evidenced by c ros s - sec t i ons
D-D' of Hilda, G-G" of Betsy (in the Gulf) and A-A' of Inez.
The extensive mixing exhibited in the case of Betsy is
probably a result of the effect of the geographical coastal
boundary and the effect of the outflow of the Mississippi
River . *
k . Sea Surface Temperature
The presence of a coastal boundary and the added
complication of the outflow of a major river makes SST
analysis difficult. The outflow of the Mississippi River
places a warm, less saline tongue of water over the area
25
where Betsy had immediately passed. This tongue of water
soon masks any effects of Betsy on the SST.
26
V. COMPARISON WITH THEORY
O'Brien and Reid [1967] developed a theoretical decryp-
tion of upwelling induced in a stratified, rotating, two-
layered ocean by momentum transfer from an intense stationary,
ax i a 1 1 y-symme t r i c atmospheric vortex. The dynamic internal
response of the ocean was assumed to be ax i a 1 1 y-symme t r i c .
Transfer of momentum between the air and the sea and between
the upper and lower layers was allowed.
O'Brien and Reid found that the results predicted by the
model agree qualitatively with the following observations
taken in the Gulf of Mexico after hurricane Hilda, 1967.
Intense upwelling was confined within the radius of
hu r r i cane- force winds. The displaced warm, central waters
produced some downwelling outside the upwelled region. The
maximum upwelling occurred at approximately 16 nmi from
the hurricane path, which is an expected response to the
maximum value of surface wind stress. The displaced
warmer waters accounted for downwelling and thickening
of the upper layer between h$ and 100 nmi from the hurri-
cane path. A shallow mixed layer less than 25 meters deep
was observed along the hurricane path and a deeper mixed
layer ^60-80 meters) along the edges of the c ros s - sec t i on.
O'Brien [ 1 9 6 7 3 continued the study with a second model
that included mixing. He found that the velocities of the
two models are essentially the same and mixing had little
influence on the dynamic response of the system but that the
27
dynamic response does influence mixing. Mixing tends to
lower the temperature and increase the salinity of the
surface layer of the ocean oyer a broad region. Comparing
the theoretical results to Hilda observations, O'Brien
noted that in observations the mixing and upwelling were
not symmetric about the hurricane path. He concluded that
this may be due to the observed asymmetry of the wind stress
distributions in a moving cyclone- The latter was not
incorporated in the model.
In a later study, O'Brien [1968], two important limitations
to the above models were relaxed. They were; first, a
specifically defined tropical storm was used to drive the
ocean; and the second, this tropical storm was constrained to
be stationary and symmetric. He relaxed these limitations to
some extent and varied the initial layer depth from 30-150
meters (previous model 100 meters), the radius of maximum winds
from 5~110 nmi (previous model 16 nmi), and varying the speed
of the storm from three to eight knots.
The relationships used by O'Brien were:
du ou du dh r
dv dv dv dh r
^ — + u^ — + v — + g^— = — ru-
at 3x dy y^y
^n + ahu ahv 0
aPa + Tx /Ph - Tx /ph
:*P Tb / ph T1 /Ph
d „ a ■ + v y v
ay
at ax ay
(1)
(2)
(3)
whe re
p is the density of the ocean
f is the Coriolis parameter
g is the acceleration of gravity
28
°a is the pressure at a radius in the hurricane
h is the thickness of surface layer of the ocean
t is the independent temporal coordinate
u is the radial velocity in the ocean
v is the tangential velocity in the ocean
e is the density contrast
T^, "m are the wind stress components at sea surface
x y
T , T' are the components of internal shearing
x y stress at interface between layers.
The results we re :
1. Cold wakes associated with upwelling occur sooner
if the tropical storm acts on a shallow layer than if it
acts on a deep layer.
2. As the tropical storm intensifies, upwelling is
enhanced .
3. As the tropical storm intensifies, the extent of
maximum upwelling becomes independent of the effective
thermocline depth. For weak tropical storms, the extent
of upwelling is highly dependent on the undisturbed thermo-
cline depth.
k . A slowly-moving tropical storm, even though not
too intense, would tend to produce upwelling in its wake.
A fast-moving storm might not produce much upwelling if the
thermocline is deep, simply because there is too much water
to move in a short time and the rate of momentum transfer
to the ocean would be too slow.
O'Brien's [1968] model for the response of the ocean to
a slow-moving tropical storm was used for comparison with
the data contained in Table 1, taken from Figures 9 through
\k. Actual comparison with theory can only be made with slow
moving, intense, and very intense tropical storms, when the
speed of propagation falls within the three to eight knot
range used in the development of theory. However,
29
conclusions reached by O'Brien can be extended to apply to
faster propagating and more intense tropical storms,, since
speed and intensity were independent variables, and varia-
tions of these showed some specific tendencies; that is,
that a tropical storm's increase in propagation speed lessens
the amount and extent of upwelling, but an increase in
intensity increases the amount and extent of upwelling.
The comparison between results from theoretical model
and conclusions drawn from observations of the present study
is considered in three parts: first: slow-moving, intense
tropical storms (Hilda, Betsy), and a very intense tropical
storm, (Carla). Second: a fast-moving, intense tropical
storm (Betsy in the Gulf); and third: very fast-moving,
very intense tropical storm (Shirley). Observations from
tropical storm Inez and c ros s - sec t i ons D-D' of Hilda and
G-G" of Betsy (in the Gulf), were not compared to results
from theory, since the nearness of the coastline and the
shallow depth of water imposed boundary conditions not used
i n theory .
A. SLOW-MOVING, INTENSE AND VERY INTENSE TROPICAL STORM
O'Brien and Reid and O'Brien have shown from numerical
studies that the upwelled isotherm may decrease in depth
from its original position as much as 80 to 90 meters and
that the downwelling isotherm may increase in depth as
much as 10 to 20 meters. Maximum upwelling occurs within
the area of hu r r i cane- force winds and maximum downwelling
occurs k5 to 100 nmi from the path of the tropical storm.
30
Comparison of c ros s -sec t i ons A-A1, B-B' and C-C' of
Hilda and cross section A-A" and B-B" of Betsy to show the
expected variations. As the intensity of the winds of Hilda
decreased, the depth to which upwelling occurred (Sec. C-C1)
also decreased. An examination of c ros s -sect ion A-A1 of Carla
shows that the greater intensity of this hurricane resulted
in upwelling from a deeper depth than in Hilda. This is as
intuition and theory would predict.
B. FAST-MOVING, INTENSE TROPICAL STORM
Theory predicts that as the propagation speed increases,
the amount and extent of upwelling and downwelling decreases
for a given thermocline depth. Theory also predicts that as
the depth of thermocline decreases, the amount and the extent
of upwelling increases for a given speed of propagation.
Hurricane Betsy in the Gulf of Mexico was of the same
intensity as Hilda, but the depth of the thermocline was
shallower. Examination of c ros s - sec t i on s C-C", D-D", E-E",
and F-F", shows extensive upwelling and downwelling, but for
a shallower depth than that of slower-moving hurricanes Hilda
and Carla. This agrees with what theory predicts. Compari-
son of the extent of upwelling and downwelling with that
predicted for a slow-moving tropical storm of the same
intensity shows agreement in c ros s - sec t i on s D-D" and F-F".
C ros s -sec t i on C-C" and E-E" do not show this agreement, and
is possibly due to the effect of the eddy described by
Wunderly [1970] .
31
C. VERY FAST-MOVING, VERY INTENSE TROPICAL STORM
This case has not been examined theoretically, but
conclusions from theory of slower and less intense storms
and observations imply that even with a very high speed
of propagation, the high intensity of typhoon winds would
cause a significant influence on the vertical temperature
structure. C ros s -sec t i on A-A' of Shirley shows that
Shirley, a storm of these characteristics, did affect the
vertical temperature structure and caused water to be
upwelled from 30 meters to the surface.
32
VI . CONCLUSIONS
Previous studies of upwelling, downwelling and mixing
caused by a tropical storm indicate the effects to be
governed by several parameters. They are:
1. Initial depth of the thermocline
2. Propagation speed of the hurricane
3. Intensity of the hurricane
k . Depth of water
5. Nearness of shallow water and coastal boundaries
Comparison of tropical storms Hilda, Betsy, Carla, Inez
and Shirley show that:
1. Observational data for slow-moving, intense trop-
ical storms is relatively consistent from storm to storm,
and agrees qualitatively with the theory of O'Brien, and
O'Brien and Re i d .
2. Observations show that an increase in propagation
speed, while maintaining the same intensity, results in
less upwe 1 1 i ng .
3- Observations show that a decrease in intensity,
while maintaining the same propagation speed, decreases
upwe 1 1 i ng .
k. Observations show that the presence of a coastal
boundary and the shallow depth of water results in exten-
sive mixing. This lends support to the validity of the
assumptions of Franceschini and El-Sayed concerning hurri
cane Inez.
5. The simple-index layer method of comparison is a
useful method for comparing the effects on the vertical
temperature structure caused by a tropical storm.
6. A search of literature shows that observational
data suitable for this type of study is extremely scarce
considering the number of hurricanes observed each year.
33
VII. RECOMMENDATI ONS
It is recommended that:
1. Procedures be set up to take aircraft expendable
bathythermographs (XBT's), prior to, and after severe
tropical storms. Tracks normal to the projected path of
tropical storms could be predicted with a fair degree of
confidence at times, and XBT drops made. The ready avail-
ability of data gathered this way would simplify and enhance
the study of the effects of tropical storms on the vertical
temperature structure of the ocean.
2. A computer study based on the model proposed by
O'Brien [1968] should be conducted, incorporating the effects
of evaporation, precipitation, sensible and turbulent heat
transfer, and radiation exchanges with the atmosphere. The
propagation speed of the tropical storm should be extended
beyond the present value of eight knots.
3A
APPENDIX A
CRUISE HILDA TRACK
SECTIONS AND B.T NOS.
GUS m, OCT, 1964
Fig. 1. Cruise track used by GUS Ml for AFTER HI Ida (1964) .
This figure represents the method of selection of cross-
sectional lines A-A' through D-D' and the method of projection
35
JLL
120
6T
1—
60
8T
0
ST"
r-
60 NMi
120
50
X
a.
UJ
O
100
150
REPRESENTS BEFORE OR UNDISTURBED ISOTHERMS
ADDED FOR CLARITY
BEFORE
CC
Ul
5
LU
o
50
100
150
A0 NMi 1?0
«r " a - er
— I — f
REPRESENTS AFTER ISOTHERMS
'ADDED FOR CLARITY
AFTER
Fig. 2. An example of the construction of the figures
used for analysis.
36
o
oo
Fig. 3. Cruise Track Used by R/V ALAMINOS for UNDISTURBED
Hilda (1964) and BEFORE Betsy (1965) in the Gulf of Mexico,
(after Leipper [1967] ) .
37
Fig. A. Cruise Track Used by R/V ALAMINOS for AFTER
Betsy (1965), and Location of Cross-sections C-C" through
G-G", (after Leipper [ 1968J ) .
38
z
2. lO
o
o
CO
m
CN
o
CN
to
'£><>
in
o
Z
>
X" CO
/ <Ouj
/ 0. CO.-
^J^'O
Ftg. 5. Position of Cross-sections A-A" and B-B" across
the Track of Betsy (1965) with Location of Radio-Transmitted
BT' s,
(after Landis and Leipper [1968]).
39
Fig. 6. Cruise Track Used by R/V HIDALGO for Thermistor-
Chain Tows of BEFORE and AFTER Carla (1961 ) and Location
of Cross-section A-A', (after Stevenson and Armstrong [ 1965 3 )
*»0
Fig. 7. Cruise Track used by R/V ALAMINOS for BEFORE
and AFTER Inez (1966) and Location of Cross-section A-A1,
(after Franceschini and El-Sayed [1968]).
k]
134
Fig. 8. Cruise Track Used by R/V ATLANTIS II for BEFORE
and AFTER Shirley ( I 9 6 5 ) and Location of C ros s - sec t i on
A-A' , (after Wright [ l 969] ) .
hi
SFC £
120
60
60
120NML/
A
Fig. 9a. Temperature-depth cross-section A-A1, UND
and AFTER Hilda (1964). (See Fig. 1 for location.)
V23°C
I STURBED
120 N.Mi^/
D
«/>
X
>-
a.
ui
Q
200 -
DASHED LINE IS UNDIS
Fig. 9b. Temperature-depth c ros s -sec t i on B- B ' , UND I S i URBED
and AFTER H i l da (l 964) . (See Fig. 1 for location.)
43
Fig. 9c. Temperature-depth cross-section C -C ' , UND I STURBED
and AFTER H i 1 da (1 964) . (See Fig. 1 for location.)
SFC
OS
UJ
- 50
UJ
2
100
MIXING
PATH OF HILDA
DASHED LINE IS BEFORE ISOTHERM
Fig. 9d . Temperature-depth c ros s - sec t i on D-D', BEFORE
and AFTER H i 1 da (1 964 ) . (See Fig. 1 for location.)
kk
SFC
60
i
0
—r
60
— 1—
120 N.Mi //
A
I
50
X 100
»-
o.
HI
Q
150
y-
26°C
---26°C
24°C
24°C
UPWELL !NG y'
PATH OF BETSY
DASHED LINE IS BEFORE ISOTHERM
Fig. 10a. Temperature-depth cross-section A-A", BEFORE
and AFTER Betsy(1965) based on radio transmitted data. (See
Fig. 5 for 1 oca t i on . )
sfc£
180
120
50
OS
UJ
—100
o.
ui
a
150
60
i
0
60 H.Mi
DOWNWELLING
UPYVELLING
PAn BETSY
DASHED LINE IS BEFORE ISOTHERM
Fig. 10b. Temperature-depth c ros s -sec t i on B-B", BEFORE
and AFTER Betsy(1965) based on radio transmitted data. (See
Fig. 5 for 1 oca t i on . )
45
SFC
50
UJ
Ul
X
100
X
►-
UJ
a
150
120 N. Mi'/
UPWELLIHG
UPWELLING /"
\ /
\ / PATH OF BETSY
\
\ / DASHED LINE IS BEFORE ISOTHERM
Fig. lla. Temperature-depth c ros s -sec t i on C-C", BEFORE
and AFTER Betsy(l965) in the Gulf of Mexico. (See Fig. k
for l.oca t i on . )
120
N. Mi
DOWNWELUNG
28°C 28°C
46°C
I)
-T
DASHED LINE IS BEFORE ISOTHERM
Fig. II b. Temperature-depth cross-section D-D", BEFORE
and AFTER Betsy(l965) in the Gulf of Mexico. (See Fig. k
for l oca t ? on . )
kG
SFC
50
2
.100
150
120 N.Mi c''
PATH OF BETSY
DASHED LINE IS BEFORE ISOTHERM
Fig. 11c. Temperature-depth cr os s -sec t i on E-E", BEFORE
and AFTER Betsy(l965) in the Gulf of Mexico. (See Fig. k
f or 1 oca t i on . )
SFC
50
d:
uj
UJ
2
100
Ui
O
150
120 N.Mi "
DOWNWFLLING
28°C
DASHED LINE IS BEFORE ISOTHERM
Fig. lid. Temperature-depth cross-section' F-F", BEFORE
and AFTER Betsy(l965) in the Gulf of Mexico. (See Fig. *t
for location.)
hi
SFC
50
cc
Ui
Ul
1100
►-
Q.
UJ
O
150 -
120M.jftl
TzFcT
MIXING
MIXING
UPWELLING
PATH OF BETSY
DASHED LINE IS BEFORE ISOTHERM
Fig. lie. Temperature-depth c ros s - sec t i on G-G", BEFORE
and AFTER Betsy(l965) in the Gulf of Mexico. (See Fig. h
for location.)
ctr
_100
Ul
Q
150
PATH OF SHIRLEY
DASHED LINF IS BEFORE ISOTHERM
^_s
Fig. 12. Terppera tu re-depth c ros s - sec t i on A-A1', BEFORE
and AFTER Sh i r 1 ey (J 965 ) . (See Fig. 6 for location.)
1*8
SFC
— 50
cc
UJ
Ul
2
100
o.
Ul
O
150
0
T
60
N.Mi
120A'
DOWNWE LNNG
-s26vC
26*fc
-'^24 C
PATH OF CARLA
DASHED LINE IS BEFORE ISOTHERM
Fig. 13. Temperature-depth c ros s - sec t i on A-A', BEFORE
and AFTER Car 1 a (l'96l ) based on towed t her mister chain dat<
(See Fig. 7 for location.)
60 NMi
Fig. 1 ^ . Temperature-depth c ros s -sec t i on A-A', BEFORE
and AFTER Inez(l966), (See pfg. 8 for location.)
hS
01 STANCE
FROM PATH
TO MAX.
DOWNWELL ING
■1
65 80
75 30
70 50
70 '
NOT OBS
60 NOT OBS
NOT OBS
18 120
ON PATH
85 90
110 110
NOT OBS 20
50 50
60 60
1.5-100 1.5-100
OEPTH
OF
WATER
(METERS)
1000
1000
loo- iooo
100
1000
1000
1000
iooo
1000
1000
200- 1000
500
200- 2000
200
INFINITE
TIME DATA WAS
GATHEREO
(DAY)
O
03
UN O ^~~
cni rN O — -3- _
UN r^ <-, ON . , CO UJ - - • ~ f ? £
J; V + + m un * + + ■+ « + + z
~* "+ * u.
cccz^'^ ' ~ !C o
OOO* UN un fM r*
£i:_=5 7 . on r^ ao uj un f*- *r
+ + +■ >~* w 1 1 w V ' ' ' ' z
EXTENT OF
HURRI CANE
WINDS
(NMI)
o
70 8f
70 80
80 85
80 80
85 85
85 85
85 90
90 90
90 90
90 90
90 90
UKN
90 90
60 60
5- 100 5-100
MAXIMUM
FORCE
OF WINOS
(KNOTS)
oooo o o o o o o un o o O
^(s,_o f^^^rvjrM — o un un _^
PROPAGATION
SPEED OF
HURRI CANE
(KNOTS)
— *. -r *■ -^ -* ^T O OO OO CO
CO CO CO CO j-uj^J-JJ-I O <=
< U- I
uj o h-
uT _1 tt
< < t- u. uj
u> Z O >-
C — UJ <
uj i- x r _i
_j «r uj O
uj > < h- uj
3 _J o o
^3 X UN —
h* — UJ
z ox
.- 1-
4.
4
o
60 65
60 65
55 50
50 50
110 70
90 85
120 55
1.0 25
1.1. UO
NO DATA
35 <tS
1.5 50
35 15
115 60
70 70
50 1.5
DECREASE IN DEPTH
.-
X
o
or:
C9
z
z
3
o
a
e
tr.
I5A5 10/60
20/1.0/ 10/60
10/50 8/70
6/50 35/<.0*
NOT OBS
NOT OBS
NOT OBS
8/28 25/1.8
NO DATA
8/35 15/60
32/ 5 27/U
20/1.5 15/75
15/75 10/90
8/55 15/65
DECREASE/ INCREASE
UP TO 20
GE IN THICKNESS/OEPT
THE INDEX LAYER (M)
UPWELLING
II
O
o
« on
a£ oc tc at: a: a: a: or. a: ^ ^ orujo
U O U => OUN3Z3IJ15313 => ^ "^ O U>00
UN 1/1 UI M l~« ^N J,^, UI UI UI ^ ""^ <". UI <
UN UN UN O O UN UN UN O O UN ^ ^^ ° O CC(-
UJ UN J UN -JT f\ .3" r^\ J- rsj ^T — — UN UNuj
O 2J
< ^
O O UN O UN UN UNO UN < O ° °° ^ O <
UN UN -x -J vOUJJ-'-N^NO^N'^ r^ON UJ -JT UJ
OO^OOOD UNUN0UN00O00 <°° ^ OO
CHAN
OF
OOWNWELLING LEFT
<
c
3/1.5 15/70
30/50 20/95
8/1.0 20/65
10/35 50/65*
NOT OBS
1.0/65 20/80
NOT OBS
30/65 50/1*5*
25/30 1.0/55
8/30 12/1.0
8/30 8/38
NO DATA
6/70 15/80
10/35 10/11.0
OECREASE/INCREASE
UP TO 20
MAX 1 MUM
SEA
SURFACE
TEMPERATURE
CC)
u> ui <
oou»u> oooooo0 *-* ° U»UJ
a
^.
z z
< o
ui O
— X
• c
v. a
o ~
^r un UJ — — .
uj - - --vO" ------ ON - UJ - UJ -
ON<a3u^OON<o^u>OuJU.c, — <t on «I UJ <
~<cooo-'<a3oouju.el >- < ~-- < — < >
c
CD
</»
>-
ro
c
<
v.
0)
o
4->
fD
o
Q.
O
!_
I—
<u
•
J=
>-
4-J
s_
O
4-
0)
O-C
1—
10
04-
—
O
4-J
00
tn
.—
C
1_
o
0)
—
4-J
4J
o
o
fD
—
S-XI
fD
0)
x:
1-
OQ_
fD
50
1 .
2.
LIST OF REFERENCES
Uda, M., On the Variation of Water Temperature Due to
the Passage of Typhoon, Misc. Papers No . %~, Tokyo
University of Fisheries, pp. 297-298, 1954.
Fisher, E. L., "Hurricanes and the Sea-surface
Temperature Field," J . Me teoro 1 . , v. 15, pp
333, 1958.
328-
3. Jordan, C. L., "On the Influence of Tropical Cyclones
on the Sea Surface Temperature Field," P roc . Symp .
Trop . Meteor., New Zealand Meteor. Service, Wellington,
pp. 614-622, 1964.
4. Leipper, D. F., "Observed Ocean Conditions and Hurricane
Hilda, 1964." J . Atmos . Sci . , v. 24, pp. 182-196, 1967.
5. Stevenson, R.E., and R. S. Armstrong, "Heat Loss from
the Waters of the Northwest Gulf of Mexico During
Hurricane Carla." Geofis. Intern., v. 5, pp. 49-57,
1965.
6. Landis, Robert C. and D. F. Leipper, "Effects of Hurricane
Betsy upon Atlantic Ocean Temperature, Based on Radio-
Transmitted Data." J. Applied Meteorol., v. 7, pp.
554-562, 1968.
7.
8.
Hazelworth, John B. "Water Temperature Variations
Resulting from Hurricanes," " J. Geophys. Res. , v
No. 16, pp. 5105-5123, 1968.
73,
O'Brien, J. J., and R. 0. Reid, "The Non-Linear Response
of a Two-Layer Baroclinic Ocean to a Stationary,
Ax i a 1 1 y- Symme t r i c Hurricane: Part I. Upwelling
Induced by Momentum Transfer." J . Atmos . Sc ? . , v. 24,
pp. 197-207, 1967.
9. O'Brien, J. J., "The Non-Linear Response of a Two-Layer
Baroclinic Ocean to a Stationary, Ax i a 1 1 y- Symme t r i c
Hurricane: Part II. Upwelling and Mixing by Momentum
Transfer." J . Atmos . Sci . , v. 24, pp. 208-215, 1967.
10. O'Brien, J. J., "The Response of the Ocean to a Slowly-
Moving Cyclone." Annalen der Me teoro 1 og ? e , v. 4,
pp. 60-66, 1968.
11. Francesch i n i , G . A , and Sayed Z. El-Sayed, "Effect of
Hurricane Inez (1966) on the Hydrography and Productiv
ity of the Western Gulf of Mexico," Deutsche
Hyd rog raph i sche Zeitschrift , v. 5, pp. 193"202, 1 9 6 8 .
51
12. Wright, Redwood, "Temperature Structure Across the
Kuroshio Before and After Typhoon Shirley," Te 1 1 us XXI
v. 3, pp. 409-i*l 3 , 1969.
13. Wunderly, W. L., Indicated Geostrophic Velocities and
Volume Transports, Central and Eastern Gulf of Mexico,
Warmest and Coldest Months., Master's Thesis, United
States Naval Postgraduate School, Monterey, 1970.
14. Leipper, D. F., Hydrographic Station Data, Gulf of
Mex i co , Texas A&M University Department of Ocean-
ography reports 6 8 - 1 3 T , 1 9 6 8 .
52
INITIAL D ISTRI BUTI ON L I ST
1. Defense Documentation Center
Came ron Station
Alexandria, Virginia 2 2 31^
2. Department of Oceanography
Naval Postgraduate School
Monterey, California 939^0
3. Oceanog raphe r of the Navy
The Madison Building
732 North Washington Street
Alexandria, Virginia 223H
k . Dr. Ned A. Ostenso
Office of Naval Research
Code ^80 D
Ar 1 i ngton , Va . 222 1 7
5 . Dr. D. F. Leipper
Department of Oceanography
Naval Postgraduate School
Monterey, California 939 -iO
6. Professor Ken Davidson
Department of Oceanography
Naval Postgraduate School
Monterey, California 939^0
7. Professor Robert 0. Re i d
Department of Oceanography
Texas ASM University
College Station, Texas 778^3
8. Professor James J. O'Brien
Department of Meteorology
and Oceanography
Florida State University
Tallahassee, Florida 32306
9. Li brary , Code 021 2
Naval Postgraduate School
Monterey, California 939^0
1 0 . LCDR William Revesz , Jr .
306 Genesee Street
Trenton, New Jersey 08611
No . Cop i es
2
53
11. Commanding Officer
Fleet Numerical Weather Central
Naval Postgraduate School
Monterey, California 939^0
12. Graduate Department
Scripps Institution of Oceanography
Box 109
LaJolla, California 92037
13- Dr. C. L. Jordan
Department of Meteorology
Florida State University
Tallahassee, Florida 32306
14. Mr . I . Per 1 roth
National Oceanog raph i c Data Center
Washington, D.C. 20390
15. Mr. Henry Odom
National Oceanog raph i c Data Center
Wash i ngton , D.C. 20390
16. Dr . R. Cec i 1 Gentry
National Hurricane Research Laboratory
Box 8265
Coral Gables, Florida 33124
17. Dr. H. Burr Stei nbach
Dean of Graduate Studies
Woods Hole Oceanog ra ph i c Institution
Woods Hole, Massachusetts 0 2 5 ^.3
18. Dr . R. Wr i ght
Woods Hole Oceanog ra ph i c Institution
Woods Hole, Massachusetts 025^3
19. Dr. G. A. Granceschini
Department of Oceanography
Texas A&M University
College Station, Texas 7 7 8 ^ 3
l
20. Dr. R. F. Stevenson
Scripps Institution of Oceanography
Box 109
LaJolla, California 92037
21. Department of Physics
The University of Tulsa
600 South Col 1 ege
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No . Copies
1
5*
Security Classification
DOCUMENT CONTROL DATA -R&D
[Security classification of title, body of abstract and indexing annotation must be entered when the overall report is classified)
Originating activity (Corporate author)
Naval Postgraduate School
Monterey, California 939^0
2a. REPORT SECURITY CLASblFICATIOf
Unclassified
2b. GROUP
I REPORT TITLE
Comparison of Effects of Various Tropical Storms on the Vertical
Temperature Structure of the Ocean Using Pictorial Representation
* DESCRIPTIVE NOTES (Type of report and,inclusive dates)
Master's Thesis; September 1971
5 *u tmORiSI (First name, middle initial, last name)
William Revesz , Jr.
. REPOR T DATE
Septembe r 1971
7m. TOTAL NO. OF PAGES
57
76. NO. OF RE FS
»«. CONTRACT OR GRANT NO.
6. PROJEC T NO
9a. ORIGINATOR'S REPORT NUMBER(S)
9b. OTHER REPORT NO(S) (Any other numbers that may be assigned
this report)
10 DISTRIBUTION STATEMENT
This document has been approved for public release and sale;
Its distribution is unlimited.
II SUPPLEMENTARY NOTES
12. SPONSO RING Ml LI T AR Y ACTIVITY
Naval Postgraduate School
Monterey, California 939^0
3. ABSTRACT
To make comparisons of the effects of tropical storms on
the ocean's vertical temperature structure, temperature-depth
cross-sections were constructed using bathythermograph data
and data from published articles.
y t rop i ca 1
nd compa red .
i ca 1 storm,
bserved within
g as much as
h of the storm,
u 1 ts of
al storm has
ucture if the
r degree than
f rom a depth
e winds. A
n cause up-
line is shall ow
Upwe 1 1 i ng ,
d
ownwe 1 1
i ng and m i x i
ng , caused b
s torms in deep
an
d shal 1
ow water, are analyzed a
For a si ow-mov i
ng
, intense and very
intense trop
upwe 1 1 i ng , f rom
a
depth
of hO to 65
meters, is o
the radius of h
urricane-
force winds.
Downwe 1 1 i n
20 me te r s occurs
from kS
to 110 nm i
from the pat
Th i s compa res f
a vorab 1 y
with the the
ore t i ca 1 res
O'Brien and Re i
d .
A fas t-mov i ng , in
tense t rop i c
a similar ef feet
on the
vertical tern
perature str
the rmoc line is
sh
allow, and upwelling
, of a 1 es so
that caused by
a
s 1 owe r-
mov i ng storm
, can occur
of 35 meters wi
th
i n the
radius of hu r r i cane- for c
ve ry fa s t-mov i n
g,
very i
ntense tropi
cal storm ca
we 1 1 i ng f rom a
de
pth of
30 meters if
the thermoc
FORM
1 NO V 68
/N 0101 -807-681 1
1473
(PAGE 1)
55
Security Classification
A-3M08
Security Classification
KEV WORDS
Hurricanes
Typhoon
U pwe 1 1 i ng
Air-Sea Interactions
FORM
1 NOV 69
1473 (BACK
101-507-682 1
56
Security Classification
IS
;t»tf
130324
Thesis I
R365 Revesz Qf effects
. compans troo-,Cal
°f Var'°n the vertical
storms on the i '
temperature struct _
* the ocean usany^K-
"t-gjfii represented.
25700 '
4
Thesis ^.30324
R365 Revesz
c.l Comparison of effects
of various tropical
storms on the vertical
temperature structure
of the ocean using pic-
torial representation.
thesR365
Comparison of effects of <
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