Nino C区秋季海温异常对东亚冬季大气环流的影响

POSSIBLE IMPACTS OF NINO C SSTA ON WINTER ATMOSPHERIC GENERAL CIRCULATION OVER EAST ASIA

关键词:  海温异常  东亚冬季大气环流  WP遥相关型  东亚冬季风

Key words:  SSTA(sea surface temperature anomaly)  winter atmospheric general circulation East Asian winter monsoon  WP teleconnection pattern

摘要:

研究了秋季赤道中东太平洋(Nino C区:0～10°S,180～90°W)的SST异常对东亚冬季大气环流的可能影响。在揭示二者联系的基础上,通过分析海温异常所引起的500hPa高度、经向风及纬向风的异常特征,探讨了秋季海温异常影响东亚冬季大气环流的可能途径。研究发现,Nino C区秋季SST异常,能够对东亚及西太平洋地区的大气环流及风场产生显著影响,进而影响东亚冬季风活动:秋季SST正(负)异常,引起西太平洋地区出现类似负(正)WP遥相关型的环流异常,中纬度纬向西风加强(减弱),东亚及沿海地区出现异常南(北)风分量,经向风减弱(加强),最终导致偏弱(强)的东亚冬季风活动。这是海温异常影响东亚冬季大气环流的一种可能途径。

Abstract:

In this paper, possible impacts of equatorial east-central Pacific (Nino C) SSTA on winter atmospheric general circulation over East Asia are investigated. The relationship between them is disclosed and the possible mechanism of SSTA influencing winter atmospheric general circulation is discussed by investigations on the anomalous features of 500 hPa circulation, zonal and longitudinal winds induced by SSTA. Results show that Nino C SSTA has significant impacts on atmospheric general circulation and winds over East Asia and West Pacific, that is, positive SST anomaly in Autumn can lead to atmospheric circulation anomalies that are similar to negative WP pattern over the Western Pacific, in such a way that the mid-latitude zonal westerly intensify and meridional wind anomalies appear over East Asia and its adjoining sea decrease with anomalous south wind component, and the activities of East Asian winter monsoon weaken. It is a possible mechanism by which SSTA affects winter atmospheric general circulation.