中国汛期月降水量年际异常型的相关性分析

CONNECTIONS OF MONTHLY PRECIPITATION ANOMALOUS PATTERNS IN RAINY SEASONS IN CHINA

关键词:  汛期降水量  年际变化  异常分布型  相关性

Key words:  rainfall in rainy season  interannual variation  anomalous patterns  correlation

摘要:

用1958～2000年中国160站月降水量通过经验正交函数分解方法研究了中国汛期4～9月相邻及相隔月份降水量年际变化异常型的相关性。结果表明,就相邻月份而言,当5月份中国东南部地区降水偏多(少),则6月份长江中下游至江南地区的降水也偏多(少);7月长江流域的降水量异常与8月长江和黄河之间地区的降水量异常有很好的同号性;8月沿江西-湖南-广西一带的降水偏多(少),则9月在华南中、东部的降水也偏多(少)。另外,对相隔月份,6月南方的降水量与8月广西北部-湖南-江西一带的降水量有显著的反相关系;而7月广西北部-湖南-江西一带的降水量则与9月华南中东部降水量有显著反相关。

Abstract:

The connections between the monthly rainfall anomalous patterns in rainy seasons on the interannual-scale are analyzed by using the Empirical Orthogonal Function analysis and monthly precipitation data at 160 stations in China from 1958 to 2000.It is found that there exist the following correlated pair-anomalous patterns.In the case of neighboring months,the patterns of abundant(deficient) rainfall in the southeastern part of China in May were often followed by the patterns of abundant(deficient) rainfall in the middle and lower reaches of the Yangtze River and neighboring areas to its south in June;the precipitation anomalies in August in the region between the Yangtze River and the Yellow River varied well in phase with those in July in the Yangtze River basin;the patterns of abundant(deficient) rainfalls in August in a belt-shaped area from the northern part of Guangxi northeastward to Jiangxi were well correlated with the patterns of abundant(deficient) rainfalls in September in the central and eastern areas of Southern China.In the case of separated months,the rainfall anomalies in June in the southern part of China were negatively correlated with those in August in a belt-shaped area from the northern part of Guangxi northeastward to Jiangxi on the interannual-scale,while the rainfall anomalies in July in a belt-shaped area from the northern part of Guangxi northeastward to Jiangxi were negatively correlated with those in September in the central and eastern areas of Southern China.