冬季南海海表温度异常、欧亚波列和北半球大气环流

WINTERTIME SSTA IN THE SOUTH CHINA SEA, EURASIAN WAVE TRAINS AND THE NORTHERN HEMISPHERE CIRCULATION

本文讨论了冬季南海海表温度异常(SSTA)对北半球大气环流的影响。结果发现南海SST暖异常和冷异常对北半球大气环流的影响是相反的,异常环流具有相当正压结构。当南海暖异常时,亚州冷高压较弱,中心偏北;冷异常时,冷高压较强,其前锋可达中国南海。欧亚上空存在着生命史为20天左右的波列。冬季南海异常的海表温度可能通过该波列发生异常来影响大气环流,这种影响至少可持续到南海海表温度异常月的下一月。

In this study the influence of wintertime SSTA in the SouthChina Sea on the northern hemisphere circulation is examined. It isfound that the influence of warm SSTA is opposite to that of cold SSTAand that the circulation anomaly thus caused has the equivalent barotropicstructure. When wintertime SSTA is warm in the South China Sea, theanticyclone over Asia is rather weak with its center lying a little north;when it is cold, the anticyclone is strong with its front reaching as faras to the South China Sea.It is probable that wintertime SSTA in the South China Sea modifies thecirculation by its effect on the Eurasian wave trains which usually persistfor about twenty days. And this effect can at least last till the monthafter the one when SSTA in the South China Sea becomes anomalous.