2003年淮河流域致洪暴雨过程的环流背景及其前兆信号  

Large scale circulation background of heavy rainstorm processes in the Huai River Valley in summer of 2003 and lts precursor signal

作　　者：程华琼[1] 陈菊英[1] 

机构地区：[1]中国气象科学研究院,北京100081

出　　处：《地球物理学进展》2004年第2期465-473,共9页Progress in Geophysics

基　　金：本文由国家自然科学基金项目(10373017)资助.

摘　　要：　分析研究了2003年夏季淮河流域致洪暴雨过程的时空分布特征及其前期和同期欧亚地区环流背景的逐日变化特征,重点分析了致洪暴雨过程发生前后乌山地区阻塞高压强度指数(UBHII)逐日变化特征及其对淮河流域致洪暴雨过程的影响.结果表明:2003年淮河流域持续性强暴雨过程均发生在乌山阻塞高压强高峰后的减弱期,即在淮河流域发生持续性强暴雨过程之前乌山阻塞高压就发生了突变;同时发现西太平洋副热带高压加强并登陆后的,其北界的位置变化对淮河流域致洪暴雨过程的发生和持续也有十分重要的作用.因此,乌拉尔山阻塞高压异常加强后的突然减弱和西太平洋副热带高压的加强并西进登陆,是淮河流域地区发生持续性暴雨过程的两个重要前兆.The space\|time distributing features of heavy rainstorm processes in Huai River valley in summer of 2003 and the day\|to\|day changes of large\|scale circulation background in Eurasian continent in the same term are analyzed. We mainly analyzed the daily change features of UBHII before and after the heavy rain in the Huai River Valley and the changes' influence on heavy rain system in the Huai River Valley. We find that the persistent heavy rainstorm processes in the Huai River Valley in 2003 occurred usually in the descending periods of the daily UBHII, and that after the Western Pacific subtropical High intensification and landing, the changes of its northern boundary have an important impact on producing and persisting of heavy rainstorm. The results shows that the abrupt turning of UBH changing from developing period into weaken period and the developing and westward landing of Western Pacific subtropical High are precursor signals of producing heavy rainstorm in the Huai River Valley. 

关 键 词：淮河流域 致洪暴雨 阻高指数 西太平洋副高指数 环流背景 

分 类 号：P46[天文地球—大气科学及气象学]