Satellite observation of upwelling along the western coast of the South China Sea

We observed the evolution of upwelling along the western east of the South China Sea (SCS). The data we used are NOAA (National Oceanic and Atmospheri c Administration) satellite AVHRR (Advanced Very High Resolution Radiometer ) IR (infrared) images taken In 1996 and 1997 summer at the HRPT (High Reso lution Picture Transmission) receiving station built on Tai-Ping Island, wh ich is located in the central SCS. An upwelling intensity, defined by the t otal heat loss in the upwelling cold water region, is used to determine the relationship between coastal upwelling and the wind stress derived from th e ERS-2 (European Remote Sensing Satellite) data. The results show that the upwelling intensity has a good linens relationship with the total alongsho re wind stress while it has a fore: correlation with the cross-shore compon ent of wind stress. These results imply that the alongshore wind stress is the main factor to pump the cold water up to the sea surfacer layer. Meanwh ile, the satellite infrared images also indicate that the centroid of cold water moved southward from 15 degreesN to 11 degreesN during the observatio n period. The size of upwelling area changed as well, and finally evolved i nto a cold jet stretching offshore along 11 degreesN-12 degreesN in the mid -August 1997. Satellite infrared and altimeteric data short; that the evolu tion of upwelling region is closely associated with the development of two anticyclonic circulations in the western SCS. (C) Elsevier Science Inc., 20 00.