中文摘要：

利用华南地区逐日降水量资料以及美国NCEP/NCAR逐日再分析资料,对2008年5—6月华南连续强降水过程的大尺度环流、水汽输送及其与南半球相联系的环流背景进行分析。结果表明：（1）强降水期间西太平洋副高偏强,位置偏西偏南;鄂霍次克海地区多有阻高出现,形成一脊两槽的经向环流形势,有利于冷空气分裂南下与西南暖湿气流交汇。（2）4次强降水期间索马里急流的水汽输送均异常偏强,孟加拉湾及南海的水汽输送亦偏强;4次降水过程的水汽输送特征又有所差异。（3）4次强降水过程的发生与越赤道气流及南半球马斯克林高压、澳大利亚高压的加强密切相关,索马里越赤道气流的特别强劲是华南发生暴雨的主要原因之一。前期马斯克林高压、澳大利亚高压以及索马里、西太平洋越赤道气流的异常活动,对于华南强降水过程具有预报指示意义。

英文摘要：

The large-scale circulation,vapor transport and closed relation circulation background of the Southern Hemisphere about continuous heavy rainfall processes over South China from May to June in 2008 are studied by using the rainfall data and the NCEP/NCAR reanalysis data.Results show that：（1） The Western Pacific Ocean subtropical High is stronger and shifts both to south and to west during heavy rainfall periods.Sea of Okhotsk appears the blocking high,forming a longitudinal circulation of ＂trough-ridge-trough＂,which advantages southward movement of cold air and joins with warm and moisture air current from southwest.（2） Vapor transportation of the Somali jet,the Bay of Bengal and the South China Sea are all stronger and vapor characteristics are different during the four heavy rainfall processes.（3） The four heavy rainfall processes have closed relationship with the intensities of cross-equatorial flows and the Australian and the Mascarene high in Southern Hemisphere.Anomalous convection enhancement of the Somali jet is one of the main reasons for the formation of lasting-several-day heavy rainfall.So anomalously active of the prior Australian and Mascarene high and prior cross-equatorial flows are premonitory for heavy rainfall.