太平洋区域海温跃变及其与东亚夏季风的关系

SST INTERDECADAL CHANGE OVER PACIFIC AREA AND ITS RELATION TO EAST ASIAN SUMMER MONSOON

本文利用英国气象局提供的全球ＳＳＴ月平均资料和 ＮＣＡＲ／ＮＣＥＰ提供的５００百帕高度场资料，分析了全球ＳＳＴＡ的年际和年代际变化，发现夏季全球ＳＳＴ在７０年代发生了一次跃变，尤其北太平洋区域ＳＳＴ在１９７６年前后，由正距平变为负距平；并且跃变前后东亚夏季风也发生了显著变化，我国汛期降水异常形势成相反分布；海温对东亚夏季风的影响途径和机制也发生了改变，１９７６年以前北太平洋区域海温起主要作用，跃变后，北太平洋区域海温异常与东亚夏季风关系变得不明显，而赤道中东太平洋海温的作用变得异常重要。

This paper analyses interannual and decadel variations of global summer SST based on SST monthly data from England Royal Meteorology Bureau and 40 years reanalysis data. The results show that global SST go through a abrupt change in 70's,especial SST changes from positive anomaly to negative anomaly over northern Pacific region. East Asian summer monsoon varies remarkably, precipitation distribution pattern is conversely; the mechanism and approaches of SST acting on east Asian summer monsoon have changed. The northern Pacific effect is important before 1976,but the equatorial east-middle Pacific SST is more important.