The Study on the Interannual Variation and the Mechanism of the South China Sea Monsoon

By using the USA NCAR / NCEP reanalysis data, the characteristics of climatic elements and the temporal and spatial structures of precipitation in the strong and weak years of the SCS monsoon are analyzed,the mechanism of the interannual variation of the SCS monsoon is discussed. It is found that the climatic elements in SCS have great differences, and there are great differences in the spatial and temporal structuresof the precipitation anomalies between the strong and weak monsoon years. The variation of climatic elements in the south of Indochina Peninsula in April is a good index of the strength of the SCS monsoon.There is a good connection between the SCS monsoon and the sea surface temperature. The SCS monsoon isweak in the EL Nino years, and strong in the La Nina years. The strength of the SCS monsoon depends onthe local heating differences between the eastern continent of China and the western Pacific. It depends onthe intensity and the position of the western Pacific Subtropical High. The western Pacific Subtropical Highis weak and eastward in the strong monsoon years, and the case is reversed in the weak monsoon years.