Seasonal mixed layer heat balance of the southwestern tropical Indian Ocean
DRS at CSIR-National Institute of Oceanography
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Title |
Seasonal mixed layer heat balance of the southwestern tropical Indian Ocean
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Creator |
Foltz, G.R.
Vialard, J. PraveenKumar, B. McPhaden, M.J. |
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Subject |
Sea surface temperature
global climate surface heat fluxes Indian Ocean |
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Description |
Sea surface temperature (SST) in the southwestern tropical Indian Ocean exerts a significant influence on global climate through its influence on the Indian summer monsoon and Northern Hemisphere atmospheric circulation. In this study, measurements from a long-term moored buoy are used in conjunction with satellite, in situ, and atmospheric reanalysis datasets to analyze the seasonal mixed layer heat balance in the thermocline ridge region of the southwestern tropical Indian Ocean. This region is characterized by a shallow mean thermocline (90 m, as measured by the 20 degrees C isotherm) and pronounced seasonal cycles of Ekman pumping and SST (seasonal ranges of -0.1 to 0.6 m day sup(-1) and 26 degrees-29.5 degrees C, respectively). It is found that surface heat fluxes and horizontal heat advection contribute significantly to the seasonal cycle of mixed layer heat storage. The net surface heat flux tends to warm the mixed layer throughout the year and is strongest during boreal fall and winter, when surface shortwave radiation is highest and latent heat loss is weakest. Horizontal heat advection provides warming during boreal summer and fall, when southwestward surface currents and horizontal SST gradients are strongest, and is close to zero during the remainder of the year. Vertical turbulent mixing, estimated as a residual in the heat balance, also undergoes a significant seasonal cycle. Cooling from this term is strongest in boreal summer, when surface wind and buoyancy forcing are strongest, the thermocline ridge is shallow (
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Date |
2010-03-09T11:43:08Z
2010-03-09T11:43:08Z 2010 |
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Type |
Journal Article
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Identifier |
Journal of Climate, vol.23(4); 947-965.
http://drs.nio.org/drs/handle/2264/3563 |
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Language |
en
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Rights |
An edited version of this paper was published by American Meteorological Society. Copyright [2010] American Meteorological Society
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Publisher |
American Meteorological Society
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