Research papers Response of southwest monsoon winds on shelf circulation off Kerala Coast, India Madhu Joshi, A.D. Rao Centre for Atmospheric Sciences, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India article info Article history: Received 29 December 2010 Received in revised form 21 October 2011 Accepted 24 October 2011 Available online 6 November 2011 Keywords: Coastal upwelling QSCAT winds Currents Buoy data abstract Three-dimensional Princeton Ocean Model is used to investigate the dynamics of the shelf flow response to the spatial and temporal variability of the wind stress forcing along the Kerala Coast. The model is configured for the west coast of India with higher horizontal resolution near the coast. In the vertical, a terrain following sigma coordinate is used, having finer resolution near the surface and bottom. In the present study, an attempt is made to understand the variability of the surface circulation and associated SST during July–August for 2000 and 2002 as a response of daily wind stress forcing derived from the QSCAT winds. The southerly current during July–August supports upwelling processes along the Kerala Coast. From the available buoy observations and simulations, it is noted that the coastal current reverses its direction to either off-shore or northward if the wind magnitude reduces suddenly below 3 m s 1 towards the coast. In this event, the coastal upwelling is inhibited by the reversal of currents and it results an increase in the local SST. The reversal of currents is explained in terms of local vorticity generated as a result of reduction of wind magnitude near the coast. & 2011 Elsevier Ltd. All rights reserved. 1. Introduction During south west (SW) monsoon the wind-driven circulation dominates the entire west coast of India (Shetye and Shenoi, 1988; Wyrtki, 1971). The observational study shows that there is a substantial surface cooling at the southern Indian coast (parti- cularly, Kerala Coast) during July–September that is attributed to coastal upwelling, promoted by the alongshore wind stress component (Johannessen et al., 1987; Shetye et al., 1990). The coastal upwelling is a local phenomena while, the SW monsoon is global. Hence, the local SST change due to the upwelling may not relate directly to the monsoon activity and associated precipita- tion. However, the upwelling process is of concern as there are important fisheries along this coast. The field experiments conducted by Sanilkumar et al. (2004) during July 2003 off southwest coast of India also suggests the same. Wind stress is identified as the most important driving force for coastal upwel- ling. Although the wind stress is mostly directed southerly along the coast, i.e. favorable to coastal upwelling, the observations suggest considerable variability over the South-Eastern Arabian Sea (SEAS) on spatial and temporal scales. The variability may modify the coastal circulation and hence affect the upwelling processes along the coast. The intense upwelling along the coast reduces the sea surface temperature (SST) of the region signifi- cantly by 2–3 1C. Haugen et al. (2002) studied the seasonal circulation and coastal upwelling off the southwest Indian coast using high resolution Miami Isopycnic Coordinate Ocean Model (MICOM). The model simulations by Rao et al. (2005) during SW monsoon show that the coastal upwelling predominates in south coast along the west coast of India as compared to that of north coast. Further, it is found that the upwelling is more intense when the monsoon is at its peak in July compared to May and September. Rao et al. (2006) also studied this region using satellite data and named it as Mini Cold Pool (MCP). This observed MCP primarily appears to be a consequence of coastal upwelling caused by the divergence in the near-surface circulation. Whenever coastal Kelvin waves propagate along the eastern margin of a basin (e.g. west coast of India), they radiate westward propagating Rossby waves. Johns et al. (1992) illustrated the effect made by the alongshore propagation of coastally trapped right bounded Kelvin waves on the shelf circulation and coastal upwelling. It has two indefinable effects the first of which is to exercise a coastally confining influence on the upwelling-related surface jet and the second is suppressive influence on the upwelling tendency. The westward propagating Rossby waves influence the coastal circulation in a longer time of the order of few months, when its dispersion of the coastal jet becomes important (Philander and Yoon, 1982). Luis and Kawamura (2002a,b) studied the upwelling processes near the southern tip of India as a result of gap wind event Contents lists available at SciVerse ScienceDirect journal homepage: www.elsevier.com/locate/csr Continental Shelf Research 0278-4343/$ - see front matter & 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.csr.2011.10.015 Corresponding author. Tel.: þ91 11 26522317; fax: þ91 11 26591386. E-mail address: [email protected] (A.D. Rao). Continental Shelf Research 32 (2012) 62–70
Transcript
Continental Shelf Research 32 (2012) 62–70
Contents lists available at SciVerse ScienceDirect
Continental Shelf Research
0278-43
doi:10.1
� Corr
E-m
journal homepage: www.elsevier.com/locate/csr
Research papers
Response of southwest monsoon winds on shelf circulation off KeralaCoast, India
Madhu Joshi, A.D. Rao �
Centre for Atmospheric Sciences, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
a r t i c l e i n f o
Article history:
Received 29 December 2010
Received in revised form
21 October 2011
Accepted 24 October 2011Available online 6 November 2011
Three-dimensional Princeton Ocean Model is used to investigate the dynamics of the shelf flow
response to the spatial and temporal variability of the wind stress forcing along the Kerala Coast. The
model is configured for the west coast of India with higher horizontal resolution near the coast. In the
vertical, a terrain following sigma coordinate is used, having finer resolution near the surface and
bottom. In the present study, an attempt is made to understand the variability of the surface circulation
and associated SST during July–August for 2000 and 2002 as a response of daily wind stress forcing
derived from the QSCAT winds. The southerly current during July–August supports upwelling processes
along the Kerala Coast. From the available buoy observations and simulations, it is noted that the
coastal current reverses its direction to either off-shore or northward if the wind magnitude reduces
suddenly below 3 m s�1 towards the coast. In this event, the coastal upwelling is inhibited by the
reversal of currents and it results an increase in the local SST. The reversal of currents is explained in
terms of local vorticity generated as a result of reduction of wind magnitude near the coast.
& 2011 Elsevier Ltd. All rights reserved.
1. Introduction
During south west (SW) monsoon the wind-driven circulationdominates the entire west coast of India (Shetye and Shenoi,1988; Wyrtki, 1971). The observational study shows that there isa substantial surface cooling at the southern Indian coast (parti-cularly, Kerala Coast) during July–September that is attributed tocoastal upwelling, promoted by the alongshore wind stresscomponent (Johannessen et al., 1987; Shetye et al., 1990). Thecoastal upwelling is a local phenomena while, the SW monsoon isglobal. Hence, the local SST change due to the upwelling may notrelate directly to the monsoon activity and associated precipita-tion. However, the upwelling process is of concern as thereare important fisheries along this coast. The field experimentsconducted by Sanilkumar et al. (2004) during July 2003 offsouthwest coast of India also suggests the same. Wind stress isidentified as the most important driving force for coastal upwel-ling. Although the wind stress is mostly directed southerly alongthe coast, i.e. favorable to coastal upwelling, the observationssuggest considerable variability over the South-Eastern ArabianSea (SEAS) on spatial and temporal scales. The variability maymodify the coastal circulation and hence affect the upwellingprocesses along the coast. The intense upwelling along the coast
ll rights reserved.
x: þ91 11 26591386.
.
reduces the sea surface temperature (SST) of the region signifi-cantly by 2–3 1C. Haugen et al. (2002) studied the seasonalcirculation and coastal upwelling off the southwest Indian coastusing high resolution Miami Isopycnic Coordinate Ocean Model(MICOM). The model simulations by Rao et al. (2005) during SWmonsoon show that the coastal upwelling predominates in southcoast along the west coast of India as compared to that of northcoast. Further, it is found that the upwelling is more intense whenthe monsoon is at its peak in July compared to May andSeptember. Rao et al. (2006) also studied this region usingsatellite data and named it as Mini Cold Pool (MCP). This observedMCP primarily appears to be a consequence of coastal upwellingcaused by the divergence in the near-surface circulation.
Whenever coastal Kelvin waves propagate along the easternmargin of a basin (e.g. west coast of India), they radiate westwardpropagating Rossby waves. Johns et al. (1992) illustrated theeffect made by the alongshore propagation of coastally trappedright bounded Kelvin waves on the shelf circulation and coastalupwelling. It has two indefinable effects the first of which is toexercise a coastally confining influence on the upwelling-relatedsurface jet and the second is suppressive influence on theupwelling tendency. The westward propagating Rossby wavesinfluence the coastal circulation in a longer time of the order offew months, when its dispersion of the coastal jet becomesimportant (Philander and Yoon, 1982).
Luis and Kawamura (2002a,b) studied the upwelling processesnear the southern tip of India as a result of gap wind event
M. Joshi, A.D. Rao / Continental Shelf Research 32 (2012) 62–70 63
(blowing in the Palk Strait) during pre-monsoon season. The gapwinds are generally low-level strong winds of 20–40 knotsblowing through a gap between mountains. Gan and Allen(2002a,b) studied the upwelling processes and correspondingcirculation along the California coast. Their study demonstratesthe existence of northward currents during relaxation of south-ward upwelling favorable winds. The coastal upwelling along thewest coast of India is recently studied (Rao et al., 2008) duringpre-monsoon and monsoon seasons using Princeton Ocean Model(POM). The study includes temperature inversions, reversal ofsurface and sub-surface currents in the SEAS region. Luis andKawamura (2003) noticed that during SW monsoon the surfacecooling due to coastal upwelling promoted by the alongshorewind stress overwhelms the surface heat loss. In the presentstudy, an attempt is made to comprehend coastal variability ofshelf circulation and associated upwelling processes as a responseof wind alone on the temporal and spatial scales.
2. Numerical experiments
The POM model (described in detail by Blumberg and Mellor,1987) is implemented for the eastern Arabian Sea (AS). As shownin Fig. 1, the analysis area (bounded by dashed line) extendsapproximately from 41N to 24.51N along the eastern AS, which isalmost parallel to the coast with a maximum offshore extent of�800 km on the southern open boundary and reduces towardsnorth. The model is fitted with realistic bottom topographyderived from modified ETOPO2 (Sindhu et al., 2007). The modifieddataset is more accurate in depths below 200 m and therefore
12108642
LONG
16 Aug 2000
ms-1
16 Jul 2000
4
8
2
6
0
4
4
8
2
6
0
4
INDIA
INDIA
Kerala Coast
Kerala Coast
60 64 68 72 76 80
LONG60 64 68 72 76 80
July—August 2000.
M. Joshi, A.D. Rao / Continental Shelf Research 32 (2012) 62–7064
improves the performance of the numerical model in the coastalzone. Resolution in zonal direction varies from 6 to 9 km withfiner resolution near the coast while, it is �10 km in meridionaldirection with 175�250�26 computational grid points. Themodel grid size near the coast resolves internal Rossby radius ofdeformation. The model uses mode splitting technique for solvingbarotropic and baroclinic modes separately in order to savethe computational time. The two dimensional external modeuses a short time-step of 11.25 s based on the Courant–Freidrch–Levy condition and the external wave speed, while,three-dimensional internal mode uses a long time-step of 480 sbased on the internal wave speed. Along the open-boundaries,radiation type of conditions are used to allow disturbancesgenerated from the interior to travel outwards as progressivewaves. For temperature and salinity, upstream advection schemeis applied. Initial data fields of temperature and salinity areobtained from World Ocean Atlas 2001 (Conkright and Boyer,2002). Detailed description about the model setup and boundaryconditions can be referred from Rao et al. (2008). The modelsurface forcing is derived from the daily QuickSCAT winds of 0.251horizontal resolution.
To study the variability in shelf circulation and associatedthermal response during July–August for 2000 and 2002, twoexperiments have been carried out keeping the same initialconditions for temperature and salinity. The model is forcedwith the corresponding wind stress after interpolating at themodel grid points. Initially, the model is integrated in thediagnostic mode for 25 days until the kinetic energy of the systemachieves nearly a steady state (Ezer and Mellor, 1994). The model
INDIA
INDIA
16 Jul 2002
02 Aug 2002
Fig. 3. QSCAT winds for
integration is then further carried out for 50 days starting from 21June and simulations are analyzed from 1 July focusing the resultsalong the Kerala Coast. Four coastal stations A–D are selected asshown in Fig. 1 to study the circulation at different latitudes. Thebuoy observations of SW4, which is located near to the station C isused for validation of the model simulations.
As the wind stress has a direct bearing on the upper layers of theocean and hence on the upwelling processes, it is pertinent here tohave an overview of the wind field in the analysis region. In order tostudy spatial and temporal variations of the winds over the region,selected dates are picked up during July and August when the winddirection is almost uniform but the magnitude vary significantlytowards the Kerala Coast in 2000 and 2002. Fig. 2 shows the QSCATdaily winds of 2000 for selected days, that is, July 7, 16 and August10, 16. The magnitude of the winds is shown in color code and thedirection by the vectors. During this period, the general winddirection is mainly westerly. Strong winds (410 m s�1) over thecentral AS indicate the low-level jet (Findlater, 1977), whichextends up to the northern part of the west coast of India. Thewinds over the SEAS are found to be ranging from 2 to 10 m s�1
with a maximum variability in wind magnitude off Kerala Coast.The high intensity winds (46 m s�1) are noticed from 1 July to 12July (figures for all these dates are not depicted here). It can be seenclearly from Fig. 2 that the winds along the Kerala Coast arestronger (�10 m s�1) on 7 July. It suddenly reduces and becomeso3 m s�1 on 16 July. The low-wind field over the SEAS remains fora period of 3–5 days. It started picking up the strength slowly andmaintains the wind strength more than 6 m s�1 till 12 August.Another representative field of high-wind intensity on 10 August is
INDIA
INDIA
23 Jul 2002
08 Aug 2002
July–August 2002.
M. Joshi, A.D. Rao / Continental Shelf Research 32 (2012) 62–70 65
presented here in Fig. 2. The strength of the winds reduces again(o3 m s�1) on 16 August.
Similar trend of sudden reduction in winds is noticed in 2002during July to August. The winds on the selected days, that is, 16,23 July and 2, 8 August is presented in Fig. 3. The winds over theSEAS region remain high (46 m s�1) with a maximum intensityon 16 July. The intensity reduces towards the coast suddenly after20 July and becomes below 3 m s�1 on 23 July. The similar low-wind field over the area remains for less than a week and picks upthe strength again. Another representative wind of high-intensitywas seen on 2 August followed by sudden reduction on 8 August.As the coastal upwelling process is transient phenomenon, it istherefore analyzed the coastal circulation and associated SST as aresponse of real-time winds prevailing over the region.
3. Results and discussion
Fig. 4 gives the model simulation of surface currents for 7 and16 July and 10 and 16 August of 2000. The simulated coastalcurrent is found to be southward along the Kerala Coast when thewinds are uniform over the SEAS region on 7 July and 10 August.
50 cms-1
E
10 Aug 2000
50 cms-1
E
N
7 Jul 2000
N
7
9
11
13
15
17
7
9
11
13
15
17
Lat
Lat
Kerala Coast
Kerala Coast
68Long
70 72 74 7876
68Long
70 72 74 7876
Fig. 4. Model surface current (ve
However, it is interesting to note that the simulated currents varyits direction on 16 July and 16 August when the wind strength isreduced towards the Kerala Coast. The near-shore current direc-tion shifted to either offshore or northward when the wind speedfell below 3 m s�1. In the case of 16 August, as the windmagnitude reduces significantly to 2 m s�1 over the larger area(about 400 km) near to the coast, the simulated currents becomenorthward along the Kerala Coast. It is well known that thesouthward current along this coast produces coastal upwelling(Rao et al., 2008). Hence, it is expected that the coastal surfacewaters would be cooled. Since the coastal currents along the coastare either off-shore or northward on 16 July and August, it is notconducive to coastal upwelling. Hence, the associated SST issupposedly warm compared to that of 7 July and 10 August. Thisis supported qualitatively by the TRMM Microwave Imager (TMI)SST as shown in Fig. 5. In the absence of AVHRR SST data due tocloud coverage most of the time during this period, the TMI datais used here, which is a available at a spatial resolution ofabout 25 km (3-day mean) for corresponding dates. Particularly,significant warming of about 30 1C is seen along the coast on 16August compared to that of 16 July. This can be explained throughthe model simulated northward currents along the coast on 16
50 cms-1
E
16 Aug 2000
50 cms-1
E
N
N
16 Jul 2000
7
9
11
13
15
17
7
9
11
13
15
17
Lat
Lat
Kerala Coast
Kerala Coast
68Long
70 72 74 7876
68Long
70 72 74 7876
ctors) 2000 with wind only.
Long
Lat
6
8
10
12
14
16
1816 Jul 2002
Long
Lat
6
8
10
12
14
16
1823 Jul 2002
Kerala Coast
Kerala Coast
Kerala Coast
Kerala Coast
Long
Lat
6
8
10
12
14
16
18
50 cms-1
50 cms-150 cms-1
50 cms-1
02 Aug 2002
Long
Lat
6
8
10
12
14
16
1808 Aug 2002
68 7876747270 68 7876747270
68 787674727068 7876747270
Fig. 6. Model surface current (vectors) 2002.
Fig. 5. TMI SST for 2000. The area of interest is circled.
M. Joshi, A.D. Rao / Continental Shelf Research 32 (2012) 62–7066
2 Aug 2002 8 Aug 2002
23 Jul 200216 Jul 2002
Fig. 7. TMI SST for 2002. The area of interest is circled.
Jul Aug Jul Aug
Jul Aug Jul Aug
A B
C D
Fig. 8. Wind speed (m s�1) and direction of surface current (deg.) for 2000.
M. Joshi, A.D. Rao / Continental Shelf Research 32 (2012) 62–70 67
M. Joshi, A.D. Rao / Continental Shelf Research 32 (2012) 62–7068
August, which would unable to favor the local upwelling. In thiscase, it is expected that the temperature of the surface waterswould not decrease locally as the Ekman transport is not in thefavorable direction.
Similar experiment is carried out for 2002 for which SW4 buoyobservations (located near the station C) on currents, winds andSST are available. In Fig. 6, simulated surface currents (vectors)are shown on the selected dates chosen (refer Fig. 3). Accordingly,the currents are southerly on 16 July and 2 August when thewinds are mostly uniform over the SEAS region. These currentsalong the Kerala Coast enhance the prospects of coastal upwellingand hence a reduction in SST is expected. As shown in Fig. 7,
Jul Aug
Jul Aug
A
C
Fig. 9. Wind speed (m s�1) and directio
000
060
120
180
240
300
360Current Dir Wind Speed
Jul
Cur
rent
Dire
ctio
n (d
egre
e)
1 3 5 7 9 11 13 15 17 19 21
Fig. 10. SW4 Buoy wind speed and cu
a qualitative trend of low SST is seen in the TMI data on 16 July,while, it is not clearly seen on 2 August as most of the data in theregion is missing. The simulated currents along the region on 23July and 8 August are northward and off-shore, respectively. Asmentioned earlier, this is due to decrease of winds towards thecoast. The change of current direction to either off-shore ornorthward along the coast inhibits the upwelling processes ofthe region, thereby; the SST is seen locally high. A warming ofcoastal waters up to 30 1C along the region is seen in the TMI SSTon the respective dates depicted in Fig. 7.
To investigate further, the cause of reversal of coastal currentsin the month of July and August, time variation of QSCAT wind
Jul Aug
Jul Aug
B
D
n of surface current (deg.) for 2002.
0
1
2
3
4
5
6
Aug
Win
d Sp
eed
(ms-1
)
23 25 27 29 31 2 4 6 8 10
rrent direction July–August 2002.
WINDS
Coa
stal
Bou
ndar
y
CURRENTS
Coa
stal
Bou
ndar
y
CURRENTS
WINDS
Fig. 11. Schematic of local vorticity due to zonal variation in wind magnitude (a) decreases towards the coast (b) increases towards the coast.
M. Joshi, A.D. Rao / Continental Shelf Research 32 (2012) 62–70 69
speed (used in the study) and associated simulated surfacecurrent is plotted for 2000 and 2002 in Figs. 8 and 9, respectively,at the locations of A–D. As shown in Fig. 1, stations A and B arelocated north of Kerala; stations C and D are located along theKerala Coast. If the current direction is between 1401 and 2201,the flow direction is then considered as southward and if thedirection is between 2701 and 3601 or 01 and 451, it is northward.The variation in wind magnitude is noticed along all the pointswith a maximum range at C and D locations. It is evident from thefigures that flow pattern at A and B is southward throughout theperiod but its direction varies at C and D. It is noticed wheneverthe wind speed near the coast (within 50 km from the coast)decreases (o3 m s�1) there is reversal of currents in the region.Strength of the reversed current is also inversely proportional tostrength of the wind near the coast. Particularly, the windmagnitude reduces to 2 m s�1 on 16 July 2000 at the location Cand hence the corresponding off-shore current (Fig. 4) is verystrong at this location. It is also observed that there is a lag ofabout a day between the reduction in winds and the reversal ofcurrents.
To verify further existence of reversal of currents near thecoast, time variation of SW4 buoy wind speed and currentdirection for July–August 2002 are depicted in Fig. 10. To avoidthe land and sea breeze effect, the early evening to late morningdata is removed. That means the observations between 9 a.m. and4 p.m. are considered here to get the daily variations from thebuoy data. It is noticed from the observations that the currentstending to change its direction either off-shore or northwardwhenever the winds fell below 3 m s�1 near the coast. This isparticularly observed during 7–9 and 17–27 July. It is found thatthe correlation coefficient is 0.8 between model simulated andobserved currents for 2002. The time lag is also seen about a daybetween the reduction in winds and reversal of currents in theobservations. It is important to mention here that the decrease/increase in temperature due to variation in wind speed andcurrent direction is also noticed in the buoy SST data (figure notincluded here). Hence, the model simulations described above areconsistent with the feature noticed in the observations.
It is also important to understand the possible mechanism forreversal of coastal currents in the event of any decrease of windstrength towards the coast. To make this point more apparent, aschematic diagram is shown in Fig. 11(a, b) depicting anti-clock-wise and clockwise eddy formation as result of zonal windvariation. As it understands from Fig. 11(a), the distribution ofwind field when its magnitude decreases towards the coast, it
would help to form a local anti-clockwise vorticity leading toreversal of coastal currents. On the contrary to the above situationwhen the winds increases towards the coast, the circulationfavors a clockwise vorticity (Fig. 11b) causing a southern flownear the coast. As the winds modulate on synoptic scale, thevorticity would play an important role on the local coastaldynamics. Hence, it may be concluded that the weak windsprevailing near the coast compared to that of far away from thecoast is the main cause for the reversal of the coastal currents.
4. Conclusions
Variability of winds over the SEAS is observed on both spatialand temporal scales. The variability affects the shelf circulation ofthe region significantly. During July–August, the winds over theSEAS generate, in general, southerly current, which is conduciveto coastal upwelling of the region. However, the reversal of thecurrents is observed from the buoy data whenever the windmagnitude decreases towards the coast. This has been demon-strated by a numerical model using QSCAT daily wind data for2000 and 2002 and explained a mechanism for the reversal ofcurrents in terms of a local vorticity in the region. Moreover,strength of the reversed current depends on the gradient of thewinds in the zonal direction. The reversal of the currents inhibitsthe local coastal upwelling and hence increases the SST of theregion. Both the simulations and observations suggest that thereis time delay of about a day between the reduction in winds andreversal of currents near the coast.
Acknowledgments
The research is supported under INDOMOD program by theINCOIS, Ministry of Earth Sciences, Government of India. Theauthors are thankful to Dr. Shailesh Nayak, Secretary, Ministry ofEarth Sciences for supporting the study. Thanks are also due toDr. M. Ravichandran, INCOIS for his valuable suggestions.
References
Blumberg, A.F., Mellor, G.L., 1987. A description of a three-dimensional coastalocean circulation model. In: Heaps, N. (Ed.), Three-Dimensional Coastal OceanModels coastal and Estuarine Sciences, vol. 4. , AGU, Washington 208 pp.
M. Joshi, A.D. Rao / Continental Shelf Research 32 (2012) 62–7070
Conkright, M.E., Boyer, T.P., 2002. World Ocean Atlas 2001: Objective Analyses,Data Statistics, and Figures, CD-ROM Documentation. National OceanographicData Center, Silver Spring, MD 17 pp.
Ezer, T., Mellor, G.L., 1994. Diagnostic and prognostic calculations of the North Atlanticcirculation and sea level using a sigma coordinate ocean model. Journal ofGeophysical Research 99 (C7), 14159–14171. doi:10.1029/94JC00859.
Findlater, J., 1977. Observational aspects of the low-level cross-equatorial jet stream onthe western Indian Ocean. Pure and Applied Geophysics 115, 1251–1262.
Gan, J., Allen, J.S., 2002a. A modeling study of shelf circulation off northernCalifornia in the region of the Coastal Ocean Dynamics Experiments: responseto relaxation of upwelling winds. Journal of Geophysical Research 107, 3123.doi:10.1029/2000JC000768.
Gan, J., Allen, J.S., 2002b. A modeling study of shelf circulation off northernCalifornia in the region of the Coastal Ocean Dynamics Experiment 2.Simulations and comparisons with observations. Journal of GeophysicalResearch 107, 3184. doi:10.1029/2001JC001190.
Haugen, V.E., Johannessen, O.M., Evensen, G., 2002. Mesoscale modeling study ofthe oceanographic conditions off the southwest coast of India. Proceedings ofthe Indian Academy of Science (Earth and Planetary Science) 111 (3), 321–337.
Johannessen, O.M., Subbaraju, G., Blindheim, J., 1987. Seasonal variations of theoceanographic conditions off the southwest coast of India during 1971–75.Fiskeridirektoratets skrifter, Serie Havundersøkelse 18 (5), 247–261.
Johns, B., Rao, A.D., Rao, G.S., 1992. On the occurrence of upwelling along the EastCoast of India. Esttuarine Coastal and Shelf Science 35, 75–90.
Luis, A.J., Kawamura, H., 2002a. A case study of SST cooling dynamics near theIndian tip during May 1997. Journal of Geophysical Research 107, 3171.doi:10.1029/2000JC000778.
Luis, A.J., Kawamura, H., 2002b. Dynamics and mechanism for sea surface coolingnear the Indian tip during winter monsoon. Journal of Geophysical Research107, 3187. doi:10.1029/2000JC000455.
Luis, A.J., Kawamura, H., 2003. Seasonal SST patterns along the West India shelfinferred from AVHRR. Remote Sensing of Environment 86, 206–215.
Philander, S.G.H., Yoon, J.H., 1982. Eastern boundary currents and coastal upwel-ling. Journal of Physical Oceanography 12, 862–879.
Rao, A.D., Joshi, Madhu, Babu, S.V., 2005. A three dimensional numerical model ofcoastal upwelling along the west coast of India. Mathematical and ComputerModelling 41 (1–2), 177–195.
Rao, A.D., Joshi, Madhu, Ravichandran, M., 2008. Oceanic upwelling and down-welling processes in waters off the west coast of India. Ocean Dynamics.doi:10.1007/s10236-008-0147-4.
Rao, R.R., Girish Kumar, M.S., Ravichandran, M., Samala, B.K., Sreedevi, N., 2006.Observed mini-cold pool off the southern tip of India and its intrusion into thesouth central Bay of Bengal during summer monsoon season. GeophysicalResearch Letters 33. doi:10.1029/2005GL025382.
Sanilkumar, K.V., Unni, V.K., James, V.V., 2004. Upwelling characteristics off thesouthwest coast of India during 2003. In: Proceedings of the NationalSymposium on Emerging Trends in the Fields of Meteorology and Oceano-graphy METOC—February 2004, Kochi, pp. 137–143.
Sindhu, B., Suresh, I., Unnikrishnan, A.S., Bhatkar, N.V., Neetu, S., Michael, G.S.,2007. Improved bathymetric datasets for the shallow water regions in theIndian Ocean. Journal of Earth System Science 116 (3), 261–274.
Shetye, S.R., Shenoi, S.C.C., 1988. Seasonal cycle of surface circulation in the coastalnorth Indian Ocean. Proceedings of the Indian Academy of Science (Earth andPlanetary Science) 97, 53–62.
Shetye, S.R., Gouveia, A.D., Shenoi, S.C.C., Sundar, D., Michael, G.S., Almeida, A.M.,Santanam, K., 1990. Hydrography and circulation off the west coast of Indiaduring the southwest monsoon 1987. Journal of Marine Research 48, 359–378.
Wyrtki, K., 1971. Oceanographic Atlas of the International Indian Ocean Expedi-tion. US Government of Printing Office, Washington, DC 531 pp.
![[PPT]PowerPoint Presentation - Climate Prediction viewWorldwide Monsoons in 2008-09 1. Global monsoon features • Australian monsoon • South American monsoon • North American monsoon • African monsoon • Asian monsoon 2. Northern China winter drought 3. Weak Indian](https://static.documents.pub/doc/80x56/5aba45597f8b9a441d8b6e25/pptpowerpoint-presentation-climate-prediction-viewworldwide-monsoons-in-2008-09.jpg)
