热带环流异常与我国夏季降水分布的关系

本文利用经验正交函数（EOF）分解方法，给出我国夏季雨带分型的定量指标，它们分别代表三种典型雨型。文章分析了夏季不同雨型年的热带环流特征，讨论了热带风场与前三个特征向量所对应的时间系数之间的相关场分布。结果表明:夏季南方类雨型与赤道中、东太平洋地区850 hPa（200 hPa）纬向风成正（负）相关；北方类雨型与澳大利亚附近高低空纬向风密切相关；中间类雨型则对印度洋地区的环流异常响应最为敏感。

The Relationships Between Summer Rainfall in China and Tropical Circulation Anomaly

Total rainfall percentage anomaly of summer in China has been estimated by using EOF method. The first three characteristic vectors of EOF represent three typical rainfall distribution patterns, respectively. In this paper, the features of tropical circulation of three rainfall distribution patterns are analysed, and correlation analyses of the time coefficients corresponding to the three characteristic vectors are discussed. The results show that there exists positive (negative) correlation between southern rainfall pattern and 850 hPa (200 hPa) equatorial zonal wind in the middle and eastern Pacific. Northern rainfall pattern is closely associated with 850 hPa and 200 hPa zonal wind in the vicinity of Australia. Middle rainfall pattern is related to the circulation anomalies in Indian ocean