283
On the Relationship between Winds and Upper Ocean Temperature
Variability in the Western Equatorial Pacific
Michael J. McPHADEN
Pacific Marine Environmental Laboratory
National Oceanic and Atmospheric Administration
7600 Sand Point Way NE
Seattle, WA 98115/0070 - U.S.A.
ABSTRACf
In this study we examine the relationship between winds and upper ocean temperature variability using data
from an equatorial mooring at 0'. 16S·E. The analysis focuses primarily daily to monthly time scale variations
during 1986 and 1987 at the height of the 1986-87 El NiftolSouthern Oscillation event. The period is one of high
mean sea surface temperatures O~29'C) and frequent outbreaks of westerly winds. We infer that in general
wind-driven vertical advection and entrainment from the thennocline are not likely 10 be important processes
affecting surface temperatures in the western equatorial Pacific. Conversely. we conclude that variations in
evaporative cooling may account for a significant percentage of the observed surface layer temperature variance
during the study period.
1. Introduction
Mean sea surface temperatures ~29°C in the western equatorial Pacific are among the
wannest in the world ocean. Thus, this region is characterized by vigorous air-sea interaction
because turbulent heat exchange between the ocean and the atmosphere is a highly nonlinear
function of sea surface temperature (SST). In extreme cases, air-sea interactions in the western
Pacific may lead to El Niiio/Southern Oscillation (ENSO) events which are coupled
ocean-atmosphere phenomena occurring every 4-7 years [Rasmusson and Wallace, 1983].
ENSO has global climatic impacts, some of which can be traced to western Pacific SST
anomalies of ~1°C (e.g. Nicholls, 1985; Palmer and Mansfield, 1984). These impacts may be
predictable months to years in advance provided the processes involved in SST change can be
understood and reliably modeled.
.While it is generally conceded that understanding SST variability is important for
understanding and predicting ENSO, little is known quantitatively about the atmospheric and
oceanic processes that control this variability. The purpose of this study therefore is to examine
the relationship between wind forcing, SST and surface layer heat content using data from an
equatorial current meter mooring at 0" 165°E. The analysis is based on data collected during
1986 and 1987 and focuses mainly on time scales of days to months. This period coincides with
the 1986-87 ENSO during which pronounced interannual variations occurred throughout the
tropical Pacific (Kous/cy and Leetmaa, 1989; McPhaden et al., 1990).
The paper is outlined as follows. Section 2 briefly describes the data used in this study.
This is followed in Section 3 by discussion of how wind variations may be related to turbulent
fluxes across the air-sea interface, vertical advection and entrainment from the thennocline.
Major results and conclusions are summarized in Section 4.
284
Temperature 165"E
100
200
Is:
0.
u
o
300
400
0"
JNI
OEe
FtB
lIAR
lIAY
APR
JUN
SEP
JUl
OCT
1987
Figure 1. ConlOllfs of daily averaged temperatures at 0·, 16S·B for 13 December 1986 to 14
October 1987. Contour interval is 2·C, except that the 29"C contour is shown as a dashed
line. Sensor depths arc indicated on the left axis: 7 days of milsing data is indicated by an
x.
9
III
<,
6
e 3
0
100
N
III
<,
e
...
III
<,
SO
0
900
600
e 300
0
30.0
u
en
CD
Cl
29.S
29.0
28.S
TISOml
J
r
N
A
N J
1987
J
A
S
Figure 2. lime seriel.af daily averaged wind speed (lUll, mnal wind pseudoslresl (IUIU(·~. wind
pseudawortc (IUI'I, SST and temperature at SOm (dashed line) from the current meter
mooring at 0·, 16S·8 for the period 13 December 198610 14 Oclober 1987.
285
2. Data
The data used in this study were collected from a surface mooring located at 0" 165°E in
the western Pacific warm pool. Winds were measured at 4 m height above mean sea level from a
wind recorder mounted on the surface toroid. Temperatures were measured at 15 depths with the
shallowest measurement at 1 m (nominally termed SST) and the deepest at 500 m (Figure 1).
Details concerning instrumental accuracies, sampling characteristics and data processing can be
found in Freitag et al. [1987] and McPhaden et al. [1990].
3. Surface turbulent nuxes, vertical advection and entrainment
Figure 2..§hows daily time series of wind speed (IUI), zonal wind pseudostress (IUIU(x» and
pseudowork (IUI3) from the mooring at 0" 165°E for December 1986 to October 1987. Ignoring
the weak wind speed dependence of surface turbulent exchange coefficients for th~ range of
speeds shown in Figure 2 turbulent air-sea heat exchange will ~ proportional to lvI, Ekman
pumping proportional to IUIU(x), and wind work proportional to IUI3• Also shown in Figure 2 is
SST and 50 m temperature from the mooring.
Table 1 summarizes the means and standard deviations of the time series in Figure 2. The
mean wind speed is only 4.0 m s-I and the mean zonal pseudostress is westward at 8.2 m2 S-2 (for
a constant drag coefficient of 1.2 x 10-3, this pseudostress translates into a mean zonal str.sss of
0.01 N m-2) . £tandard deviations in both of these variables are also small: 2.1 m s-) for IVI and
22 m2 S-2 for 100u<x) (equivalent to 0.03 N m- 2) . SST is high on average (29.2°C) with a standard
deviation of 0.31GC. Temperature at 50 m is 29.0°C on average with a standard deviation of only
O.l1°C.
Table 1. Summary of means and standard deviations for wind speed (IVI), zonal wind
pseudostress (IVIU(x~, pseudowork (IUI3) , SST and temperature at 50 m depth from the
current meter mooring at 0°, 165°E. All statistics are calculated for the period
13 December 1986-14 October 1987, except T(50 m), which is for 13 December
1986-31 May 1987 (Le. when the 50 m level was always found in the surface layer
above the thermocline).
Wind Speed
(m S-I)
Mean
4.0
8.2
127
Standard
Deviation
2.1
22.3
188
SST
rC)
T(50 m)
rC)
29.2
29.0
0.31
0.11
286
1.00
c
.Q
"0
0.50
~o
0.00
u
11)
...:3
SST/Speed
r(-ld) "" -0.42
~~
r--
-0.50
u
-1.00
-40.
-20.
O.
20.
40.
Log (days)
1.00
c
"0
0.50
~o
0.00
u
11)
:3...
r(-ld) "" -0.50
SST/Zonol Stress
.Q
..,..........
<,V
V-
-0.50
U
-1.00
-40.
-20.
O.
20.
40.
Log (d,oys)
SST/Work
c
.Q
"0
0.50
~o
0.00
.,u
:3...
r(-ld) = -0.43
l:::::::=:::::;::';;;::;"....."-+r,.....,,::::::=::::::::::::::::::::::=4
-0.50
u
-40.
O.
-20.
20.
40.
Log (days)
Figure 3. Crosscorrelations between SST and wind speed, zonal wind pseudoseess, and wind
pseudowork. Crosscorrelation elltrema (r) and the lag (in dars) at which they occur are
shown. In each case, the lag indicates that cold SST follows high winds by one day. 95%
confidence limits foi' the null hypothesis of uncorrelated variability are indicated by
horizontal bars on the abscissa.
0°, 165°E 13 Dec 86 - 14 Oct 87
Period (days)
Period (days)
10%
101
1.0 -f"'o..............................~'--IW.Lu..L .........-+
0.8
o
10%
0.8
~
0.4
10'
0.8
Q)
Q)
e
100
10%
101
1.0 -F..............----".............-'--...................--t
101
0.8
Q)
C
Period (days)
100
t.O i"""..............---"............-'--....................-t
to'
10'
g
e
Q)
g
0.8
e
~
U
U
~
U
0.4
0.4
0.2
0.2
SST/Wind speed
0.8
Q)
Q)
SST/'T(X)
SST/Wind work
x
x
x
x
10-2
X
x
x,~.x X........
.,.
10-1
Frequency (cpd)
10- 2
1(rl
Frequency (cpd)
1(r2
Figure 4. Coherence and phase spectra (or SST and wind speed, zonal wind pseudostress, and
wind pseudoworlc at 0', 165'E (or the period 13 December 1986 to 14 October 1987.
Positive phase indicates that high winds lead high SST. Observed negative phases imply
that high winds lead low SST.
100
lq-l
'Frequency (cpd)
I
287
Figure 3 indicates that crosscorrelations of the three wind constructs with SST are
significantly nonzero at the 95% level of confidence and range between -0.42 (for zonal
pseudostress) and -0.50 (for wind speed). The negative correlation indicates that high wind
speed, high wind work and westerly wind stress (relative to the mean) are associated with cool
SST; and that low wind speed, wind work and easterly wind stress (relative to the mean) are
associated with warm SST. In each case the maximum crosscorrelation occurs with SST lagging
the winds by 1 day, consistent with the atmosphere forcing the ocean on these time scales.
Although not presented, the magnitude of the crosscorrelation between meridional wind
pseudostress and SST is generally ~0.2 over the range of lags shown in Figure 3.
Another way to view these relationships is in the frequency domain. Figure 4 shows the
coherence and phase as a function of frequency between the 3 wind constructs and SST. Two
bands of high and statistically significant coherence are evident. These are at periods between
approximately 3-8 days and 3~60 days; to a lesser extent, variations at 1~20 days are also
coherent. Consistent with the crosscorrelation statistics, the phase in most frequency bands is
between _90· and -180· implying that maxima in the winds are followed by cold SST and
minima by warm SST. Coherence at periods shorter than 20 days may be related to westerly
wind burst activity. Coherence at periods of 3~ days could be related to atmospheric
fluctuations associated with Madden and Julian [1972] waves.
Note that although there are differences among the coherence and phase diagrams in
Figure 4 and the crosscorrelation analyses summarized in Figure 3, the statistical relationships of
the 3 wind constructs with SST share many similarities; indeed, wind speed, zonal wind
pseudostress and wind work are highly correlated among themselves (0.61-0.90). Based on
these statistics alone, one cannot unambiguously identify which of the processes related to the
wind field are most important in affecting SST. Hence, we now examine the coherence structure
as a function of depth for temperature and the 3 wind constructs in Figure 2.
Figure 5 shows coherence amplitude as a function of depth in the 3-8 day period band.
The coherence profiles in other period bands, e.g. for the 3~ day band, are similar to those
shown in Figure 5. Also shown in Figure 5 is the mean temperature profile for December
1986-October 1987. Wind speed, wind stress and wind work are all significantly coherent with
temperature variations between 1-10 m. Coherence drops rapidly below these depths however,
and is statistically insignificant at the 95% level in the lower part of the surface layer between
5~75 m.
In the thermocline, wind speed and wind work are generally incoherent with
temperature fluctuations; on the other hand, zonal pseudostress shows a clear pattern of
coherence between 125-300 m. Figure 6 shows that the phase of zonal pseudostress coherence
is such that warm thermocline temperatures lag relative westerly winds by 90· and cold
thermocline temperatures lag relative easterly winds by the same amount. This is consistent with
an Ekman pumping hypothesis for thermocline variations. However, phase changes by 180·
across the base of the surface layer, indicating the temperature variations are of opposite sign in
the surface layer and thennocline. Vertical advection from the thermocline is therefore not likely
to be the principal mechanism controlling SST on these time scales. Similarly, the rapid decrease
in coherence with depth below 10 m in Figure 5 suggests that entrainment from the thermoclige
is not important in controlling SST. One would expect coherence between temperature and 1013
to be much higher at 5~75 m if the thermocline were the s~urce of cold water for the surface
layer. This leaves turbulent surface fluxes proportional to 101 as the most likely candidate for
affecting SST and surface layer heat content.
Further evidence to support the role of wind related surface turbulent heat flux variations
can be found in an examination of upper ocean heat content, defined as H = pC hT. We
calculated ()Hfc)t over 2 depth ranges: ~ 10 m (where coherence with the wind speed fs highest)
and ~75 m (the average depth of the surface layer). Heat content standard deviations are
34 W m-2 in the ~ 10 m layer and 102 W m-2 in the ~75 m layer. As expected from our earlier
288
Mean Temperature (DC)
Coherence with Temperature
3 - 8 day Periods
12
6
0
\
18
24
30
0
~
"
\
100
'-------
100
.........
I
!:
,
I
......
E 200
........
........
200 E
s:
.-
s;
0-
~
300
400
300
(b)
(a)
Wind Speed
(c)
Zonal Wind
Stress
Wind Wor1<
,+- 95%
500 +-'-------.----..--+
0.0
0.5
1.00.0
Coherence
(d)
t.Aeon-Std Dev
3-8d----
400
+-'1--.---.------.-----1- 500
0.5
Coherence
1.00.0
0.5
Coherence
1.0 0.0
0.4
0.8
Temperature
Standard Deviation
(DC)
Figure 5. Coherence amplitude as a function of depth averagedover periods of approximately
3-8 days (i.e. 36-65 frequency bands depending on depth) for temperature and wind
speed, zonal wind pseudostress, and wind pscudowork at 0', 165'E. 95% confidenee
limits for the null hypothesis of incoherent variability an: indicated by the dashed lines.
Note that the temperature record lengths for this analysis were chosen such that the
statistics were stationary; e.g. the period June.()clObcr 1987 was excluded at SO m and
75 m. Shown on the right arc the mean tCDlperature profile (solid curve) and the standard
deviation of temperature variations at periods of approximately 3-8 days (dashed curve)
for 13 December198610 14 October 1987.
Temperature/Zonal Wind Stress
3 - 8 day Periods
O.
O.
100.
100.
........
........
E 200.
........
200. E
........
s;
.0-
.c
.-
~
0-
300.
400.
300.
(a)
Coherence
:+- 95%
0.50
Coherence
~
(b)
Phase
400.
+--J-,r---r-'""T"'-+ 500.
1.00 O.
180.
360.
Phase (Deg)
Figure 6. ~hercnce amplilUd~ and phase as a function of depth averaged over periods of
approxlmate.ly 3-8 days (i.e, 36-65 frequency bands depending on depth) for temperature
!IDd zonal Wlll~ p~udos~ss .at 0'. 16S'E. 95% confidencelimits for the null hypothesisof
mcoherentvanablhty arc IIldicated by the dashed lines.
~
0.
~
289
results, the crosscorrelation with IVI is negative, and higher over the shallower layer (-0.38) than
over the deeper layer (-0.29). wpen multiplied together, these standard deviations and
crosscorrelation statistics imply that 101 accounts for 13 W m-2 in the layer 0-10 m and 30 W m- 2
in the layer 0-75 m. The 0-75 m estimate is comparable to what would be expected for latent
heat flux variations (QL) and typical observed parameter values. Specifically, QL. =35 W m- 2 for
wind speed variations of 2.1 m S-I (Table I), an exchange coefficient of 1.2 x 10-3 [Large and
Pond, 1982] and a typical air-sea specific humidity difference of 5 g kg-I [Reed, 1985; Liu,
1988].
These calculations, and Figure 5, indicate that surface cooling associated with QL
converges nonlinearly in the upper 75 m. The upper 10 m (13% of the surface layer depth) takes
up 13 W m- 2 (43% of the latent heat flux forcing). The remaining 17 W m- 2 (57% of the
forcing) is absorbed over 10-75 m, which represents 87% of the surface layer depth. Using an
integral time scale (tj ) for wind speed and temperature variations of 3-4 days (based on the
crosscorrelation analysis in Figure 3) and a
~~Of 13 W m- 2 (0-10 m) and
17 W m- 2 (10-75 m),
we find the expected magnitude of temperature variations associated with latent heat flux
variations in each of these depth ranges to be 0.1°C and 0.02°C, respectively. The latter number
is close to the instrumental accuracy of our temperature sensors (e.g. McPhaden et al., 1990) and
probably accounts for the insignificant temperature and wind coherences on a pointwise basis for
depths greater than 10 m in the surface layer.
4. Conclusions
We have inferred that wind-related latent heat flux variations of about 30 W m-2 lead to
temperature changes in the upper 75 m of 0.02°-0.1 GC. The largest of these variations occur in
the upper 10 m, perhaps because of the existence of surface layer salinity stratification as
discussed in Lukas and Lindstrom [1987] and Godfrey and Lindstrom [1989]. Salinity
stratification would act to isolate the near surface from the thermocline, trapping surface heat
fluxes while at the same time reducing the effect of vertical advection and entrainment on SST.
These results are consistent with those of Meyers et al. [1986], who found that evaporative fluxes
led to significant surface cooling in the western Pacific during the 1982-83 ENSO, whereas
entrainment from the thermocline was relatively unimportant. This would also explain why
surface layer temperature variations at 50 m are less than those for SST as noted in Table 1.
It is however clear that evaporative cooling accounts for only a fraction of SST and surface
layer heat content changes. Other processes, e.g. lateral advection and radiative heating and
cooling, must also be important. A complete analysis of the upper ocean heat budget in the
western equatorial Pacific thus requires information on the velocity field and on the surface
radiation balance.
s.
References
Freitag, H. P., M. 1. McPhaden and A. J. Shepherd, Equatorial current and temperature data:
108°W to 110
October 1979 to November 1983, NOAA Data Report, ERL PMEL-17,
99 pp., 1987.
0W;
Godfrey, 1. S. and E. J. Lindstrom, The heat budget of the equatorial western Pacific surface
mixed layer, J. Geophys. Res., 94,8007-8017, 1989.
290
Kousky, V. E. and A. Leetmaa, The 1986-87 Pacific wann episode: Evolution of oceanic and
atmospheric anomaly fields,J. Climate, 2, 254-267,1989.
Liu, W. T., Moisture and latent heat flux variabilities in the tropical Pacific derived from satellite
data, J. Geophys. Res., 93, 6749-fJ7ffJ, 1988.
Lukas, R. and E. Lindstrom, The mixed layer of the western equatorial Pacific Ocean, Proc. 'Oha
Huliko'a Hawaiian Winter Workshop on the Dynamics of the Ocean Surface Mixes Layer,
University of Hawaii, Honolulu, January 1987,67-94.
Madden, R. A. and P. Julian, Description of global scale circulation cells in the tropics with a
40-50 day period, J. Atmos. Sci.~ 29, 1109-1123, 1972.
McPhaden, M. J., S. P. Hayes, L. 1. Mangum and J. Toole, Variability in the western equatorial
Pacific during the 1986-87 El Nifio/Southern Oscillation event, J. Phys. Oceanogr., 1990.
Meyers, G., 1.-R. Donguy and R.K. Reed, Evaporative cooling in the western equatorial Pacific
Ocean by anomalous winds, Nature, 323, 523-526, 1986.
Nicholls, N., Impact of the Southern Oscillation on Australian crops, J. Climatology, 5, 553-5ffJ,
1985.
Palmer, T. N. and D. A. Mansfield, Response of two atmospheric general circulation models to
sea-surface temperature anomalies in the tropical east and west Pacific, Nature, 310,
483-488, 1984.
Rasmusson, E. M. and J. M. Wallace, Meteorological aspects of the El Niflo/Southern
Oscillation, Science, 222, 1195-:-2002, 1983.
Reed, R. K., An estimate of the climatological heat fluxes over the tropical Pacific Ocean, J.
Climate Appl. u«, 24,833-840, 1985.
WESTERN PACIFIC INTERNATIONAL MEETING
AND WORKSHOP ON TOGA COARE
Noumea, New Caledonia
May 24-30, 1989
edited by
Joel Picaut *
Roger Lukas **
Thierry Delcroix *
* ORSTOM, Noumea, New Caledonia
** JIMAR, University of Hawaii, U.S.A.
INSTITUT FRANCAIS DE RECHERCHE SCIENTIFIQUE
POUR LE DtVELOPPEMENT EN COOPtRATlON
Centre de Noumea
vii
TABLE OF CONTENTS
ABSTRACT
i
RESUME
iii
ACKNOWLEDGMENTS
vi
INTRODUCTION
1. Motivation
2. Structure ....................................................................................... ...
1
2
LIST OF PARTICIPANTS
5
AGENDA
7
WORKSHOP REPORT
1. Introduction ......................................................................................
2. Working group discussions, recommendations, and plans
a. Air-Sea Fluxes and Boundary Layer Processes
b. Regional Scale Atmospheric Circulation and Waves
c. Regional Scale Oceanic Circulation and Waves
3. Related prograDlS ..............................................................................
a. NASA Ocean Processes and Satellite Missions
.. .
.. ..
.
b. Tropical Rainfall Measuring Mission .. .
..
.
.
c. Typhoon Motion Program
.. .
..
..
.
d. World Ocean Circulation Experiment
4. Presentations on related technology
....................... ...........................
5. National reports
6. Meeting of the International Ad Hoc Committee on TOGA COARE
19
20
20
24
30
35
35
37
39
39
40
40
40
APPENDIX: WORKSHOP RELATED PAPERS
Robert A. WeUer and David S. Hosom: Improved Meteorological
Measurements from Buoys and Ships for the World Ocean
Circulation Experiment
........................................................................... 45
Peter H. Hildebrand: Flux Measurement using Aircraft
and Radars
57Waiter F. Dabberdt, Hale Cole, K. Gage, W. Ecklund and W.L. Smith:
Determination of Boundary-Layer Fluxes with an Integrated
Sounding System
81·
viii
MEETING COLLECTED PAPERS
WATER MASSES. SEA SURFACE TOPOGRAPHY. AND CIRCULATION
KJaus Wyrtki: Some Thoughts about the West Pacific Warm Pool..................
Jean Rene Donguy, Gary Meyers, and Eric Lindstrom: Comparison of
the Results of two West Pacific Oceanographic Expeditions FOC (l971)
and WEPOCS (1985-86)
Dunxin Hu, and Maochang Cui: The Western Boundary Current in the
Far Western Pacific Ocean
Peter Hacker, Eric Firing, Roger Lukas, Philipp L. Richardson. and
Curtis A. Collins: Observations of the Low-latitude Western Boundary
.. . . ..
.. ..
Circulation in the Pacific during WEPOCS ill ................
Stephen P. Murray, John Kindle, Dharma Arief, and Harley Hurlburt:
Comparison of Observations and Numerical Model Results in the Indonesian
Throughflow Region
Christian Henin: Thermohaline Structure Variability along 165 e E
in the Western Tropical Pacific Ocean (January 1984 - January 1989)
David J. Webb. and Brian A. King: Preliminary Results from
Charles Darwin Cruise 34A in the Western Equatorial Pacific
Warren B. White, Nicholas Graham. and Chang-Kou Tai: Reflection of
Annual Rossby Waves at The Maritime Western Boundary of the Tropical
Pacific ..................................................................................................
William S. Kessler: Observations of Long Rossby Waves in the Northern
Tropical Pacific .......................... ..... .... ... ... ... ............ .. .................. ..... ... ..
Eric Firing, and Jiang Songnian: Variable Currents in the Western
Pacific Measured During the US/PRC Bilateral Air-Sea Interaction Program
and WEPOCS
John S. Godfrey, and A. Weaver: Why are there Such Strong
Steric Height Gradients off Western Australia?
John M. Toole, R.C. Millard, Z. Wang, and S. Po: Observations
of the Pacific North Equatorial Current Bifurcation at the Philippine Coast
99
111
123
135
145
155
165
173
185
205
215
223
EL NINO/SOUTHERN OSCILLATION 1986-87
Gary Meyers, Rick Bailey, Eric Lindstrom, and Helen PhiUips:
Air/Sea Interaction in the Western Tropical Pacific Ocean during
1982/83 and 1986/87
Laury Miller, and Robert Cheney: GEOSAT Observations of Sea
Level in the Tropical Pacific and Indian Oceans during the 1986-87
El Nino Event
Thierry Delcroix, Gerard Elmn, and Joel Picaut: GEOSAT Sea
Level Anomalies in the Western Equatorial Pacific during
the 1986-87 El Nino. Elucidated as Equatorial Kelvin
and Rossby Waves
Gerard Eldin. and Thierry Delcroix: Vertical Thermal Structure
Variability along 165e E during the 1986-87 ENSO Event
Michael J. McPhaden: On the Relationship between Winds and
Upper Ocean Temperature Variability in the Western Equatorial
Pacific ..................................................................................................
229
247
259
269
283
i"'{
John S. Godfrey, K. Ridgway, Gary Meyers, and Rick Bailey:
Sea Level and Thennal Response to the 1986-87 ENSO Event in the
Far Western Pacific
Joel Picaut, Bruno Camusat, Thierry Delcroix, Michael
J. McPhaden, and Antonio J. Busalacchi: Surface Equatorial Flow
Anomalies in the Pacific Ocean during the 1986-87 ENSO using GEOSAT
Altimeter Data
291
301
TIlEORETICAL AND MODELING STUDIES OF ENSO
AND RELATED PROCESSES
Julian P. McCreary, Jr.: An Overview of Coupled Ocean-Atmosphere
313
Models of El Nino and the Southern Oscillation
Kensuke Takeuchi: On Wann RossbyWaves and their Relations
to ENSO Events
329
Yves du Penhoat, and Mark A. Cane: Effect of Low Latitude Western
335
Boundary Gaps on the Reflection of Equatorial Motions
Harley Hurlburt, John Kindle, E. Joseph Metzger, and Alan Wallcraft:
Results from a Global Ocean Model in the Western Tropical Pacific
343
John C. Kindle, Harley E. Hurlburt, and E. Joseph Metzger: On the
Seasonal and Interannual Variability of the Pacific to Indian Ocean
Throughflow
355
Antonio J. Busalacchi, Michael J. McPhaden, Joel Picaut, and Scott
Springer: Uncertainties in Tropical Pacific Ocean Simulations: The
Seasonal and Interannual Sea Level Response to Three Analyses of the
Surface Wind Field
367
Stephen E. Zebiak: Intraseasonal Variability - A Critical Component
of ENSO?
379
Akimasa Sumi: Behavior of Convective Activity over the "Jovian-type"
Aqua-Planet Experiments
389
397
Ka-Ming Lau: Dynamics of Multi-Scale Interactions Relevant to ENSO
Pecheng C. Chu and Roland W. Garwood, Jr.: Hydrological Effects
on the Air-Ocean Coupled System
407
Sam F. Iacobellis, and Richard CJ. Somerville: A one Dimensional
Coupled Air-Sea Model for Diagnostic Studies during TOGA-COARE
419
AlIan J. Clarke: On the Reflection and Transmission of Low Frequency
Energy at the Irregular Western Pacific Ocean Boundary - a Preliminary
Report
423
Roland W. Garwood, Jr., Pecheng C. Chu, Peter Muller, and Niklas
435
Schneider: Equatorial Entrainment Zone: the Diurnal Cycle
Peter R. Gent: A New Ocean GCM for Tropical Ocean and ENSO Studies
445
Wasito Hadi, and Nuraini: The Steady State Response of Indonesian
Sea to a Steady Wind Field ...................................................................... 451
Pedro Ripa: Instability Conditions and Energetics in the Equatorial Pacific
457
Lewis M. Rothstein: Mixed Layer Modelling in the Western Equatorial
Pacific Ocean
465
Neville R. Smith: An Oceanic Subsurface Thermal Analysis Scheme with
Objective Quality Control
475
Duane E. Stevens, Qi Hu, Graeme Stephens, and David Randall: The
hydrological Cycle of the Intraseasonal Oscillation
, 485
Peter J. Webster, Hai-Ru Chang, and Chidong Zhang: Transmission
Characteristics of the Dynamic Response to Episodic Forcing in the Wann
Pool Regions of the Tropical Oceans .. _
493
x
MOMENWM, REAT, AND MOISlURE FLUXES BETWEEN
ATMOSPHERE AND OCEAN
W. Timothy Liu: An Overview of Bulk Parametrization and Remote
Sensing of Latent Heat Flux in the Tropical Ocean ......................................
E. Frank Bradley, Peter A. Coppin, and John S. Godfrey: Measurements
of Heat and Moisture Fluxes from the Western Tropical Pacific Ocean
Richard W. Reynolds, and Ants Leetmaa: Evaluation of NMC's
Operational Surface Fluxes in the Tropical Pacific
Stanley P. Hayes, Michael J. McPhaden, John M. Wallace, and Jail
Picaut: The Influence of Sea-Surface Temperature on Surface Wind in the
Equatorial Pacific Ocean
T.D. Keenan, and Richard E. Carbone: A Preliminary Morphology of
Precipitation Systems In Tropical Northern Australia
Phillip A. Arkin: Estimation of Large-Scale Oceanic Rainfall for TOOA
Catherine Gautier, and Robert Frouin: Surface Radiation Processes in
the Tropical Pacific
Thierry Delcroix, and Christian Henin: Mechanisms of Subsurface
Thermal Structure and Sea Surface Thermo-Haline Variabilities in the South
Western Tropical Pacific during 1979-85 - A Preliminary Report
Greg. J. Holland, T.D. Keenan, and MJ. Manton: Observations from the
Maritime Continent: Darwin, Australia
Roger Lukas: Observations of Air-Sea Interactions in the Western Pacific
Warm Pool during WEPOCS
M. Nunez, and K. Michael: Satellite Derivation of Ocean-Atmosphere Heat
Fluxes in a Tropical Environment .............................................................
513
523
535
543
549
561
571
581
591
599
611
EMPIRICAL SlUDIES OF ENSO AND SHORT-TERM CLIMATE VARIABILITY
Klaus M. Weickmann: Convection and Circulation Anomalies over the
Oceanic Warm Pool during 1981-1982
Claire Perigaud: Instability Waves in the Tropical Pacific Observed with
GEOSAT
Ryuichi Kawamura: Intraseasonal and Interannual Modes of Atmosphere;.
Ocean System Over the Tropical Western Pacific
David Gutzler, and Tamara M. Wood: Observed Structure of Convective
Anomalies
Siri Jodha Khalsa: Remote Sensing of Atmospheric Thermodynamics in
the Tropics
Bingrong Xu: Some Features of the Western Tropical Pacific: Surface Wind
Field and its Influence on the Upper Ocean Thermal Structure
Bret A. Mullan: Influence of Southern Oscillation on New Zealand
Weather
Kenneth S. Gage, Ben Basley, Warner Ecklund, D.A. Carter, andJohn R.
McAfee: Wind Profiler Related Research in the Tropical Pacific
John Joseph Bates: Signature of a West Wind Convective Event in
SSM/I Data
David S. Gutzler: Seasonal and Interannual Variability of the MaddenIulian Oscillation
Marie-H~lene Radenac: Fine Structure Variability in the Equatorial Western
Pacific Ocean
George C. Reid, Kenneth S. Gage, and John R. McAfee: The Oimatology
of the Western Tropical Pacific: Analysis of the Radiosonde Data Base
623
637
649
659
665
677,
687
699
711
723
735
741
xi
Chung-Hsiung Sui, and Ka-Ming Lau: Multi-Scale Processes in the
Equatorial Western Pacific
,
Stephen E. Zebiak: Diagnostic Studies of Pacific Surface Winds
747
757
MISCELLANEOUS
Rick J. Bailey, Helene E. Phillips, and Gary Meyers: Relevance to TOGA
of Systematic XBT Errors
Jean Blanchot, Robert Le Borgne, Aubert Le Bouteiller, and Martine
Rodier: ENSO Events and Consequences on Nutrient, Planktonic Biomass,
and Production in the Western Tropical Pacific Ocean
Yves Dandonneau: Abnonnal Bloom of Phytoplankton around weN in the
Western Pacific during the 1982-83 ENSO
Ceclle Dupouy: Sea Surface Chlorophyll Concentration in the South Western
Tropical Pacific, as seen from NIMBUS Coastal Zone Color Scanner from
1979 to 1984 (New Caledonia and Vanuatu)
Michael Szabados, and Darren Wright: Field Evaluation
of Real-Time XBT Systems
Pierre Rual: For a Better XBT Bathy-Message: Onboard Quality Control,
plus a New Data Reduction Method
775
785
791
803
811
823