不同降水资料在我国降水变异研究中的对比

Comparison of precipitation variation mutation in China analysed by different precipitation data sets

基于中国气象站点和高分辨率地表气候变量数据集CRU中的降水数据,利用变异系数、持续时间和突变3个指标,分别表征变异性在变异量、时间结构和跳跃式的变化,研究了1982~2000年我国各月份降水的变异性变化特征。结果表明:月降水量变化幅度较大,冬季降水量变化幅度大于夏季;各月份降水均无长期持续的变化趋势,变异较显著;降水突变现象主要出现在7月和9月,11月降水突变最少,1983年因为El Nino现象是降水突变现象最多年份。2份降水数据在不同的变异指标使用中结果略有差异,站点数据在降水量的变异研究中信号清晰,而CRU数据在降水突变现象中更能体现全国范围的实际情况。

Based on the Chinese meteorological stations precipitation data and high resolution surface precipitation data in data set CRU,we used three indexes,including variation coefficient,persistence of above/below average conditions and abrupt change,to study the variation of monthly precipitation in China from 1982 to 2000. Three indicators represent variation in quantity,time structure,and jump change. The results showed that the monthly precipitation varied largely,the variation amplitude in winter was greater than that in summer. The monthly precipitation has no long-term trend and the variation was very significant.The precipitation abrupt changes mainly occurred in July and September,and the least in November. In 1983,the phenomenon of El Nino leaded to the most significant year of precipitation abrupt change. The results of two precipitation data sets are slightly different in different variation indexes. The station data is clear in the variation of precipitation,and CRU data can reflect the actual situation of the whole country in the phenomenon of abrupt changes.