长江中游地区暴雨过程的气候背景分析

Background of climatic anomalies about heavy rain in middle reaches of the Yangtze River in China

通过用气候信号场研究长江中游地区暴雨发生的气候异常环境,提出了关于信号场的合成图的检验方法,应用到暴雨规律分析中。分析表明,暴雨与500hPa信号场中异常信号显著区的出现在我国东部上空,分布形势呈‘+-+’的波列是暴雨发生的重要征兆。

The background of climatic anomalies relating to heavy rainfalls over the middle reaches of the Yangtze River in China are studies in this paper. A f-test for composite signal field is performed. The case studies of heavy rainfall show that the distribution of significant anomaly in the 500 hPa signal field is an important precursory signal of heavy rainfall. The pattern of the signal anomaly with '+ - +' in the composite signal field in the cases is found. It occurs in the area over eastern part of China.