BASIC CLIMATOLOGICAL FEATURES OF AIR-SEA HEAT EXCHANGES IN THE SOUTH CHINA SEA (SCS) REGION AND THEIR RELATIONS WITH THE SCS MONSOONS

By using the NCEP reanalysis data set in 1979-1995, the fluxes of the latent heat, the sensible heat and the net long-wave radiation in the South China Sea (SCS) are expanded by means of EOF in order to discuss the basic climatological features in the SCS. The detailed analysis shows that the air-sea heat exchanges in different SCS regions have different seasonal variations. The middle and the north of the SCS are the high value regions of the air-sea heat exchanges during the winter and the summer monsoon periods, respectively, the seasonal variations of air-sea heat exchanges in the south of the SCS are small. In addition, the proportions of different components in the total air-sea heat exchanges have different seasonal variations in different regions. The results show that the SCS monsoon and the air-sea heat exchanges in the SCS region are the accompaniments of each other, the great difference of the sensible heat flux between the Indochina Peninsula and the SCS before the SCS summer monsoon onset may be one of the triggers of the latter. There maintains a high value center of the sensible heat flux before the 13th dekad, its disappearing time consists with that of the summer monsoon onset. It means that as far as the SCS local conditions are concerned, the northwest of the Indochina Peninsula is probably a sensitive region to the SCS summer monsoon onset and the land may play a leading role in the SCS summer monsoon onset.