初夏东亚-太平洋大气热源与长江流域及邻近地区7、8月降水异常的关系  

The Relationship of the Atmospheric Heat Sources in Early Summer over East Asia-Pacific to the Abnormality of Precipitation in the Yangtze River Basin and Its Vicinity in July and August

作　　者：简茂球[1] 乔云亭[1] 罗会邦[1] 陈文[2] 

机构地区：[1]中山大学季风与环境研究中心大气科学系,广州510275 [2]中国科学院大气物理研究所,北京100080

出　　处：《大气科学》2007年第4期735-746,共12页Chinese Journal of Atmospheric Sciences

基　　金：国家重点基础研究发展规划项目2004CB418303;国家自然科学基金资助项目40175018

摘　　要：用1958-2000年NCEP/NCAR再分析资料、中国160站降水量及1958-1998年月平均海温资料分析了中国夏季相邻月份降水异常型的相关特征,及其与大气热源的关系和相关物理过程。结果表明,7月长江流域的降水异常与8月长江和黄河之间地区的降水异常有很好的同号性。7、8月长江流域及附近地区持续性偏旱（涝）与太平洋洋盆尺度的大气热源异常有关,并与前期5、6月热带中、东太平洋大范围的热源异常、青藏高原热源异常也有密切的联系,即当5、6月赤道东太平洋的大气热源正异常,而赤道中太平洋北侧的热源负异常,则中国7月长江中下游偏涝,8月长江中上游与江淮流域和内蒙古东部偏涝,华南偏旱;反之亦然。前期热带中、东太平洋上空的热源异常中心和与之联系的异常垂直运动中心的西扩和西移,以及青藏高原东部的热源异常中心是影响我国7、8月持续偏旱（涝）的重要环流异常特征。另外,南海-西太平洋海温在前期也已经具有我国夏季长江流域发生旱涝对应的同期海温异常分布型的特征。The relationship of the atmospheric heat source over East Asia - Pacific region to the summer precipitation anomalies in the Yangtze River basin and its vicinity is studied on the interannual scale together with the exploration of associated physical processes using the 1958 - 2000 NCEP/NCAR reanalysis data, the 1958 - 2000 precipitation data in China, and the 1958 - 1998 reconstructed monthly sea surface temperature data from NOAA. It is found that there exists a very good inphase relation between the July precipitation anomalies in the Yangtze River basin and the August precipitation anomalies in the region between the Yangtze River and the Yellow River. These precipitation abnormalities are closely related to not only the summer atmospheric heat source anomalies over the North Pacific ocean and the eastern Tibetan Plateau, but also the May - June atmospheric heat source anomalies over the central and eastern tropical Pacific. That is, if there are positive （negative） heat source anomalies over the central and eastern equatorial Pacific, and negative （positive） anomalies over the tropical region north of the central equatorial Pacific during May-June, then positive （negative） precipitation anomalies occur in the middle and lower reaches of the Yangtze River basin in July and in the region between the Yangtze River and the Yellow River in August, but negative （positive） precipitation anomalies in southern China. The westward movement and extension of the anomalous heat source centers and the related anomalous vertical motion centers in the tropical central and eastern Pacific are the important physical processes responsible for the persistent abnormality of rainfall in July and August in central and eastern China. In addition, as a pre-signal, the favorable anomalous patterns of the sea surface temperature over the South China Sea and the western Pacific already show up in May and June for the abnormality of summer rainfall around the Yangtze River basin.

关 键 词：长江流域 降水异常 大气热源 

分 类 号：P461[天文地球—大气科学及气象学]