A numerical study of the effects of South China Sea SST anomalies on the climate in south China

Serious floods occurred in the central, southern and southwestern Guangdong province in May 1998. With the mesoscale model (MM5) of the U.S.A., the work was successful in simulating the climate in southern China for the month and through sensitivity experiments studies the effects of anomalous SST warming in the South China Sea on the weather and climate in southern China. The result shows that the warming changes the energy exchanges between the sea surface and the planetary boundary layer. It adds in effect latent and sensible heat transmitting upward from sea surface to increase the monthly mean air temperature in the lower troposphere over the sea and adjacent regions and the instability of air columns. It also results in an additional differential cyclonic (anti-cyclonic) circulation in the lower (upper) parts of the troposphere. The changes in the atmospheric circulation structure have important effect on the floods in the above-mentioned regions of the province in May 1998.