冬春海温异常对东亚初夏季风环流的影响

Numerical Study on Effects of SST Anomaly in Tropical Western Pacific during Winter and Spring on the Early Summer Monsoon in East Asia

用ＯＳＵ的两层大气环流模式进行了热带西太平洋冬春海温异常对东亚初夏（５月）季风环流影响的数值试验．结果表明：①海温的负距平引起西太平洋副热带高压脊南落和西伸，东亚热带季风环流减弱，我国西南和华南地区的降水增加；②海温的正距平引起西太平洋副热带高压明显减弱，西太平洋的赤道西风加强。

In order to study the effects of SST anomaly in tropical western Pacific during winter and spring on the early summer monsoon in East Asia, a set of numerical experiments is conducted using OSU AGCM. It is shown that the early summer monsoon in East Asia responds significantly to the SST anomaly. The negative SST anomaly results in the extending westward of the western Pacific subtropical high with the ridge line shifted by south, the weakening of the tropical monsoon over East Asia, as well as the rainfall increasing over southwest China and south China. The positive SST anomaly results in the weakening of the western Pacific subtropical high, the strenthening of equatorial westerlies in the lower troposphere over the tropical western Pacific, as well as the rainfall decreasing over southwest China and south China.