【摘要】 本文对中国异常季风降水与太平洋海表温度距平之间的关系进行了研究,特别注意到1951—1975年夏季北半球月平均年际变化. 赤道东太平洋海温距平经验正交函数(EOF)第一特征向量的时间序列与长江流域季风降水及太平洋副高指数之间的相互关系存在着相当明确的遥相关,发现长江流域旱(涝)与赤道东太平洋暖(冷)、西太平洋冷(暖)以及太平洋海温距平的二种行星型相符合.存在两种异常季风环流型,其一种型式相似于Horel和Wallace1982年提出的赤道增暖事件冬季的波列,另一种型式在相同位置其距平中心符号相反,只是强度较前一种情况弱. 东太平洋海温异常改变着西太平洋副高的强度及位置,从而影响印度尼西亚地区的跨赤道气流和中国东部低层的东南季风及长江流域的降水. 在赤道中太平洋和西太平洋(或东亚)之间表面温度对比的基础上,提出了三维行星对流环流,并以此来解释异常的季风环流.更多还原

【Abstract】 The relation between the abnormal monsoon rainfall over China and the Pacific sea surface temperature (SST) departures is examined. This paper is specifically concerned with the interannual variability of monthly means for the Northern Hemisphere during the summers of 1951-1975.The correlations between the time series of the first empirical orthogonal function (EOF) of the Eastern Equatorial Pacific SST departures and the monsoon rainfall over the Yangtze River and the Pacific subtropical high index exhibit a well-defined teleconnection pattern. It is found that the drought (flood) over the Yangtze River corresponds to the warming (cooling) in the Eastern Equatorial Pacific and the cooling (warming) in the Western Pacific. Corresponding to these two planetary patterns of Pacific SST departures, there are two abnormal monsoon circulation patterns: one is similar to the wavetrains shown by Horel and Wallace (1982) in the winter during an equatorial warm episode, the other has opposite signs of departure centers in similar locations, but the intensity is weaker than the former case. The SST departures in the Eastern Pacific change the intensity and location of the Western Pacific subtropical high, with subsequent effects on the cross-equatorial flow over the Indonesia area, the low level southeast monsoon over the eastern China and the rainfall over the Yangtze River.A three-dimensional planetary convective cell is proposed to interpret the global abnormal monsoon circulation, based on the surface temperature contrast between the middle Equatorial Pacific and the Western Pacific (or the Eastern Asia).更多还原