东亚地区夏季大气环流季节循环进程及其在区域持续性降水异常形成中的作用  

The Seasonal March of Atmospheric Circulation over East Asia in the Late Summer and Its Role in the Formation of the Regional Persistent Precipitation Anomaly

作　　者：廖清海[1] 陶诗言[1] 

机构地区：[1]中国科学院大气物理研究所,北京100029

出　　处：《大气科学》2004年第6期835-846,共12页Chinese Journal of Atmospheric Sciences

基　　金：国家杰出青年基金项目 40 1 2 5 0 1 4 (部分 );国家自然科学基金资助项目 40 1 0 5 0 1 0共同资助

摘　　要：利用 32年 ( 1 968～ 1 999年 )月平均NCAR/NCEP再分析资料 ,分析了东亚地区夏季大气环流的季节循环进程 ,并以 1 991 /1 994年为例 ,探讨了东亚地区夏季 7～ 8月对流层上层环流的季节循环提前和延迟与气候平均的季节循环的差异 ,以及在江淮流域持续性降水异常过程中的作用 ,证实东亚地区季节循环的变异对形成我国东部地区持续性降水异常 ,特别是 7月旱涝起着重要作用 ,江淮流域旱涝一般是和东亚地区大气环流季节循环的提早或推迟一个月左右相对应。通过波作用量的动力学诊断分析 ,研究了欧亚大陆沿副热带西风急流传播的异常准静止波的传播特征 ,并从以副热带西风急流为波导的准静止波(或者遥相关 )角度对东亚地区夏季 7～ 8月环流季节循环进程提前和延迟的可能机制作了分析。Based on the NCAR/NCEP monthly reanalysis dataset of 1968-1999, and the cases of 1991 and 1994,the progress of seasonal cycle of the summer atmospheric circulation in the East Asia during July-August, both advancing and delaying,and their roles in the processes of regional persistent precipitation anomalies in the Changjiang River and the Huaihe River valleys are analyzed and compared with that of climatology. The results show that the progress of seasonal cycle is advanced about a month ahead of the climatological time when floods occur in the Changjiang River and the Huaihe River valleys, while it is delayed about a month when droughts appear in the same region.Eliasson-Palm flux diagnosis confirm that the wave patterns over the Eurasian continent along the subtropical jet have important impacts on the formation of the advancing and delaying of the East Asian summer atmospheric circulation during July-August, and thus on the floods and droughts in the Changjiang River and the Huaihe River regions. However, further study is need on the origin and variation of the wave patterns and the machenism of the summer seasonal cycle in East Asia.

关 键 词：降水异常 大气环流 旱涝 江淮流域 急流 NCAR NCEP再分析资料 季节 夏季 热带 

分 类 号：P426[天文地球—大气科学及气象学] P458