海气系统年际异常中欧亚环流的作用及其与华南沿海降水的关系

THE ROLE OF EURASIAN CIRCULATION IN INTERANNUAL ANOMALIES OF AIR-SEA INTERACTION AND ITS ASSOCIATION WITH PRECIPITATION OVER COASTAL SOUTH CHINA

摘要:

本文利用通过周期分析提取主要信息的方法,分析了赤道东太平洋海温、欧亚西风环流经向指数、西太平洋副高面积指数和广州降水量之间的关系。发现它们之间有着密切的联系。主要表现为:欧亚西风环流经向度的变化早于赤道东太平洋的海温;赤道东太平洋的海温变化先于西太平洋副高;副高的变化又先于降水;同时,还有副高的变化先于欧亚环流的迹象。此外,本文进一步证实了欧亚环流对El Nino事件的作用,并且这种作用有可能是低纬普遍存在的准2年振荡的原因。最后,本文还指出了利用环流、海温等的变化进行El Nino预报和华南沿海降水预报

Abstract:

Subtracting main information from periodicity analyses,relationship among sea surface temperature over the equatorial Pacific Ocean (SSTep),meridional index for the westerly circulation over Europe-Asia (Mlea),area index for the subtropical high over the West Pacific (AIwp),and rainfall in Guangzhou (Rg) are investigated in the paper. They interact so closely that the Mlea fluctuates prior to SSTep,which again prior to AIwp,which yet again prior to Rg. There is also evidence for prior changes in AIwp to those in MIea.Furthermore.the role of Mlea in El Nino processes,which may contribute to a quasi-2-year oscillation popular for low latitudes,is comfirmed. Finally,the possibility is shown for predicting El Nino and coastal precipitation for South China using the variations of circulation and SST.