摘要
选取NCEP再分析高度场和风场资料、地面长波辐射(OLR)资料以及中国160个测站的降水资料,利用相关分析和合成分析方法,从资料分析入手来研究东亚冬季风异常变化及其对中国夏季降水的影响。研究表明:东亚冬季风有明显的年际和年代际变化特征,1950年代～1980年代中期为强冬季风时段,1980年代中期以后,季风明显减弱,为弱冬季风期。冬季风异常对中国大部分地区,特别对中国长江中下游地区的降水影响较大。分析进一步揭示了强弱东亚冬季风年后期海温分布和夏季流场明显不同的变化特征,并结合以前的许多研究对长江中下游地区降水异常形成的可能原因作了解释,指出正是由于这种不同的海温分布以及夏季环流的异常变化使得中国长江中下游地区在强(弱)冬季风年的夏季降水偏少(偏多)。
Based on the data of NCEP, OLR and rainfall of China, we studied the influences of the East Asian winter monsoon activities on the precipitation during the raining season over China by correlation analysis and composite analysis. The result shows that annual and interdecadal change of East Asian winter monsoon is distinct. It is stronger from 1950s to the middle of 1980s but weaker after the middle of 1980s. The effect of abnormal winter monsoon on the precipitation during raining season is significant over lower-middle reaches of the Yangtze River basin. It is revealed that the precipitation will increase when preceding winter monsoon is weaker but decrease when preceding winter monsoon is stronger. In this paper, some appropriate reasons are given to explain the abnormal rainfall by analyzing the distribution of SSTA and the variation of summer circulation. It is pointed out definitely that the variation of SSTA and summer circulation is a primary cause of abnormal rainfall over lower-middle reaches of the Yangtze River.
出处
《热带气象学报》
CSCD
北大核心
2003年第4期367-376,共10页
Journal of Tropical Meteorology
基金
云南省科学基金课题"东亚冬季风与云南夏季旱涝及其年代际异常"
云南省基金课题(97D022G)资助
关键词
东亚冬季风
东亚副热带夏季风
长江中下游夏季降水
East Asian winter monsoon
East Asian subtropical summer monsoon
summer precipitation over lower-middle reaches area of the Yangtze River
