西太平洋暖池海温异常与中国夏季降水的关系

RELATIONSHIP OF THE WESTERN PACIFIC WARM POOL SST ANOMALY AND SUMMER PRECIPITATION IN CHINA

利用1951—2007年NOAA延长重构的海温资料、NCEP/NCAR再分析资料和中国160站降水资料,研究了夏季西太平洋暖池海温的年际变化特征及其与中国夏季降水的关系。结果表明,夏季西太平洋暖池海温异常具有明显的年际变化特征;夏季西太平洋暖池海温异常偏高(低)时,亚洲热低压减弱(加强),西太平洋副热带高压加强(减弱)、位置偏西(偏东),850 hPa风场上中国东部地区为偏北(南)风距平,使得东亚夏季风减弱(增强),导致长江中下游地区夏季降水偏多(少)。

Using the NOAA extended reconstruction sea surface temperature（SST）,NCEP/NCAR reanalysis data and 160 stations precipitation in China from 1951 to 2007,the interannual variation of the SST anomaly of the western Pacific Warm Pool（PWP） in summer and its relationship with summer precipitation in China are discussed.Results show that the SST anomaly of PWP presents obvious interannual features.When the summer SST anomaly of PWP is high（low）,the warm Asia low pressure is weakened（strengthened）,the western Pacific subtropical high is strengthened（weaken） and moves westward（eastward）,and there is north（south） wind anomaly at 850 hPa over the eastern China.Therefore,the East Asian Summer Monsoon becomes weak（strong） in the high（low） SST anomaly years,which results in more（less） precipitation in the mid-lower valleys of Yangtze River.