冬季太平洋海温变化对中国5月降水的影响

THE INFLUENCING OF WINTER PACIFIC SST UPON MAY PRECIPITATION OF CHINA

本文采用EOF—CCA方法研究了12—2月份北太平洋海温场与中国5月降水指数之间的相关关系。研究结果表明,12月海温与中国5月降水有较好的相关关系。赤道东太平洋和日本以东洋面的海温与中国东部地区的降水正相关,与中国华南、云南和西部地区的降水负相关。相反,东北太平洋、菲律宾以东洋面和墨西哥以西洋面的海温与中国东部地区的降水负相关,与中国华南、云南和西部地区的降水正相关。上述5个海区的太平洋前期海温对中国5月降水有影响的海温关键区。前期海温异常将影响到5月中高纬度的西风带波动和低纬西太平洋副热带高压的强度、位置。

The correlation between SST field in Pacific and May rainfall index of China is studied with EOF-CCA method in this paper. The results show that there is fine correlation between December SST and May precipitation of China. The SST in eastern equatorial Pacific and eastward ocean of Japan are positive correlation with precipitation of East China, but they are negative correlation with rainfall of South China, Yunnan and West China. On the other hand,the correlation between the precipitation of China and SST in northeastern Pacific,eastward ocean of Philippines and westward ocean of Mexico is reverse. These five o-cean areas are SST key regions which play important role in precipitation of China. The anomaly of previous Pacific SST will influence the wave motion of westerly belt in middle and high latitude and the intensity and location of West Pacific subtropical high in May. It leads to the anomalous distribution of precipitation over China in May finally.