2000年以来夏季长江流域降水异常研究  

Research of JJA Precipitation Anomaly in Yangtze River Basin Since 2000

作　　者：柳艳香[1] 赵振国[1] 朱艳峰[1] 王建平[2] 陈丽华[3] 

机构地区：[1]中国气象局气候研究开放实验室 [2]唐山市气象局,河北唐山063000 [3]总参气象水文中心,北京100081

出　　处：《高原气象》2008年第4期807-813,共7页Plateau Meteorology

基　　金：国家自然科学基金项目(40675038,40505014);中国科学院创新团队国际合作伙伴计划项目“气候系统模式研发及应用研究”共同资助

摘　　要：根据1880年以来中国夏季的雨型、1890年以来长江中下游梅雨以及1951年以来北半球大气环流等资料,利用物理统计分析的方法,研究了2000年以来夏季长江流域降水异常特征及东亚大气环流背景。结果表明,20世纪50年代至70年代后期我国夏季主要多雨带位置偏北,黄河流域、华北一带降水偏多,长江流域降水偏少,长江中下游梅雨偏弱;70年代后期到90年代末我国夏季主要多雨带南移,长江流域进入多雨期,长江中下游梅雨偏强,黄河流域、华北地区则转入少雨期;但是2000年以来的夏季,在黄河流域、华北地区仍维持少雨的背景下,主要多雨带却徘徊在黄河与长江之间及华南、江南长江流域降水显著偏少,梅雨异常偏弱,空梅频繁出现,长江流域、黄河流域及华北地区同处在持续少雨位相和干旱频发阶段,这种同步振荡的异常现象历史上极为少见。夏季东亚环流型的特殊配置是2000年以来夏季长江流域持续少雨的主要原因之一,这与2000年以前长江流域夏季少雨的环流背景不一样。Based on JJA rain pattern since 1880, the Meiyu and the JJA rain anomaly features in the mid-and lower- reaches of Yangtze River after 1890 and the circulation background a,t 500 hPa in NH after 1951 are researched by physical statistical methods. The results show that, in summer from 1950＇s to 1970＇s, the main rain belts were located in Yellow River basin and North China and Yangtze River basin were dry, or the Meiyu in the mid-and lower- reaches 1970＇s to end of 1990＇s, the JJA rain wet belts were of Yangtze River were poor. Then, during the end of moved southwards to Yangtze River basin, and had good Meiyu, but in Yellow River basin and North China were dry. Again then, since 2000, in Yellow River basin and North China were still dry, main rain belts moved back and forth between Huaihe River basin, South China. Obviously the dry climate appeared Yangtze River basin and had frequently poor Meiyu. The synchronized abnormal phenomenon was quite rare in history, which keep the frequent drought in Yangtze River and Yellow River basin and North China. The special configuration of summer circulation in East Asia, was one of main causes keeping the dry climate in Yangtze River basin, it was difference from circulation before 2000.

关 键 词：长江流域 夏季降水 梅雨 异常特征 环流成因 

分 类 号：P426.6[天文地球—大气科学及气象学]