近49年来淮河流域降水异常及其环流特征

PRECIPITATION ANOMALIES AND THE FEATURES OF ATMOSPHERIC CIRCULATION IN THE HUAIHE RIVER BASIN

本文在对淮河流域降水气候特征分析的基础上 ,侧重研究了淮河流域夏季降水异常的周期性特征、年代际和年际变化特征 ,以及淮河流域多、少雨年的流场特征。研究发现 ,淮河流域夏季降水 70年代中期以前偏多 ,70年代中期以后偏少 ;在周期性特征上有 2 .3年左右的主周期和 8年左右的次周期 ;淮河流域夏季降水异常与印度西南季风。

Based on analyses of climatic characteristics of precipitation in the Huaihe River Basin,the interannual,the interdecadal and the periodic variations of summer precipitation anomalies and the circulation features in both more precipitation years and less precipitation years are focally investigated in the Basin.It is found that the summer precipitation before the middle of 1970′ is more than normal while that is less than normal after then.There are a principal period of about 2.3 years and secondary period of 8 years of so.The precipitation anomalies in summer in the Basin are closely related to the anomalies of the Indian southwesterly Monsoon,the East Asian subtropical Monsoon and the activity of the cold air mass.