ENSO对我国江南及印度降水影响的比较

Comparison of the impact of ENSO on the rainfall over Southern China and India

根据近百年找国江南和印度的降水资料，对比分析了其各季降水与ENSO的关系。统计表明，E1Nino发生时印度夏季和秋季降水的减少最显著，分别比多年平均减少4．5％和6．0％，LaNina时则分别增加66％和8.1％。对我国江南降水影响最显著的是冬季，在E1Nino事件时降水比多年平均偏多18.5％，LaNina时则偏低了17.7％。降水的年代际变化可以影，响ENSO与降水的关系。90年代江南处于多雨或，加上E1Nino现象接连发生，因此造成90年代以来我国南方频频发生严重的洪涝灾害。80年代以来，ENSO与印度和我国江南降水的关系发生了显著的变化，与印度降水的关系减弱，而与我国江南降水的关系则在加强，ENSO本身特性的变化及全球变暖可能是造成这种变化的重要原因。

The relationships between ENSO and seasonal rainfall over Sopth China and Indiaare exandned using the data available from 1900 to 1998. lt shows that there are significantdecreases of Indian rainfall in surrunr and autumn during El Nino years. In average theprecipitation is 4.5% and 6.0% below normal in sununr and autumn respectively. On theother hand, 6.6% and 8.1 % over normal can be expected in La Nina sununr and autunm. InSouth China the considerable impect occurs in winter and the precipitation is 18.5% more thanand 17.7% less than nonnal in El Nino and La Nina events respectively.It is probable thatthe decadal climate variability of rainfall changes the relationship between rainfall and ENSO.South China is in epoch of the above-normal since late 1980s, in the same time and there isa succession of El Nino events. Thus, South China experienced many severe floods in this peri-od. Since 1980s the relations between ENSO and rainfall over South China and India havechanged strikingly. The interdecadal variability of rainfall itself and the global warming maybe responsible for the recent changes in the relationships between ENSO and rainfall overSouth China and India.