影响南海夏季风爆发因子的诊断研究

摘要

通过南海夏季风爆发偏早年和偏晚年前期冬春季东亚地区的环流、积雪及海温等要素特征的诊断分析，揭示了南海夏季风爆发时间早晚与前期冬季东亚大气环流、热带对流、热源及热带太平洋海温的异常分布有密切联系，南海夏季风爆发偏早年的前期有冬季风偏强，高原积雪偏少，海洋大陆地区的对流活跃、热源增强及La Nina型海温分布等主要特征；南海夏季风爆发偏晚年的前期特征则基本相反。根据1997～1998年冬春环流、积雪及海温等的特征作了1998年南海夏季风爆发时间的预测，其结果与1998年的实况基本一致。%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.