东北夏季降水年代际、年际变化的区域差别

采用REOF方法对我国东北夏季降水异常进行了区划,并通过周期分析等方法分析了各分区降水年代际、年际变化特征。结果表明:东北夏季降水异常可划分为南部、中部、东部、西南部、西北部和北部6个区域,东南部(包括前3个区域)的年代际变化高于西北部(后3个区域)。50 a来东北全区夏季降水没有明显变干或变湿的倾向,但存在明显的年代际变化。其中,南部与全区旱涝在两种时间尺度上(特别在年代际尺度上)的相关均较高;东部与全区的相关也主要表现在年代际尺度上,而中部、西南部主要表现在年际尺度上。

REGIONAL DIFFERENCES OF SUMMER RAINFALL INTERDECADAL AND INTERANNUAL VARIATIONS IN THE NORTHEAST CHINA

The compartments of the Summer Precipitation Anomaly in the Northeast China(NESPA) are made,and their interdecadal and interannual variations are discussed by means of REOF and harmonic analysis.The results show that NESPA is divided into 6 regions,which are south,middle,east,southwest,northwest and north parts,and interdecadal variations is more significant in southeast(including the former three regions) than in northwest area(including the rest three parts).In the recent 50 years,wetting or drying trend isn't obvious in the total region,but exists significant interdecadal variation.There is higher relation between the south part and the total region at the two time-scales(especially in the interdecadal scale),and the relationship between the east part and the total region is also displayed mainly at the interdecadal scale,but that of the middle or west part is mainly showed at the interannual scale.