Sea surface wind and cold tongue over the winter South China Sea

Taking advantage of new satellite observations, we have investigated the spatial distributions and interannual variations in sea surface wind (SSW) and sea surface temperature (SST) in boreal winter over the South China Sea (SCS) during 2000-2004. The northeast monsoon prevails in the winter SCS, because orographic forcing by mountains on Taiwan and Luzon, the Ekman pumping in the southeastern half of the basin and the two dipole of SSW curls form with relatively weak winds in southwest of Taiwan and Luzon Islands. This SSW spins up a cyclonic basin scale Gyre over the SCS and three or two eddies with sub-basin scale, with a southward western boundary current (WBC) on the coast of South Vietnam and the continental slope east of the Sunda Shelf. This southward WBC forms a distinct cold tongue along the Sunda Slope. When positive SSW curl is stronger, so is the cold tongue in 2000 and 2004. The opposite is true in 2001 and 2003.