华南前汛期区域持续性暴雨的分布特征及分型

利用广东和广西两省共175个台站的日降水观测资料,采用计算机检索的方法,对1961-2005年间华南前汛期区域持续性暴雨进行了定义。对南海夏季风爆发前后区域持续性暴雨的气候分布特征的分析发现,季风爆发前持续性暴雨频数从60年代至今呈现出正态分布的年代际变化特征,而季风爆发后的区域持续性暴雨频数变化则几乎相反;广东省前汛期区域持续性暴雨降水明显比广西强。此外,通过EOF方法和相关分析得到了夏季风爆发前后出现频率较高的几种分布雨型,它们能较好地代表季风爆发前后华南降水分布的特点。

The Distribution Features and Patterns of Regional Durative Rainstorm during Pre-rainy Season over South China

The regional durative rainstorm during pre-rainy season over South China is defined and its climatic distribution features before and after the onset of South China Sea summer monsoon are studied using daily rainfall data of 175 stations in Guangdong and Guangxi provinces. The results show that the frequency of regional durative rainstorm before the onset of South China Sea summer monsoon behaves with decadal variation of normal distribution from 1960s to now, and nearly opposite behavior exists in the frequency of that after the onset of South China Sea summer monsoon. The rainfall intensity of regional durative rainstorm during pre-rainy season over Guangdong province is obviously greater than that over Guangxi province. In addition, four rainfall patterns with higher frequency of occurrence before and after the onset of South China Sea summer monsoon are obtained using EOF and correlation methods. They can figure the distribution features of rainfall after and before the onset of South China Sea summer monsoon over south China.