Diagnosis of Factors of Influence on Onset over the South China Sea Summer Monsoon
影响南海夏季风爆发因子的诊断研究

The diagnosis of circulations, snow depths, SST, and many other factors over the eastern Asia and the tropics during the winters and springs of the years when the summer monsoon over the South China Sea burst earlier or later show a good relationship between the anomalous onset time of summer monsoon and the previous patterns of circulations anomalies. In the years when the summer monsoon bursts early, the previous patterns are characterized by stronger East Asian winter monsoon, reduced snow over the Tibetan Plateau, more active convections and enhanced heat sources over the Maritime Continent, La Nina-like SSTA, and vice versa when the summer monsoon bursts late. Thus, the onset trend of summer monsoon in 1998 is predicted by using the previous data of the factor as mentioned above. And the results is consistent with the observations.