1999年夏季长江及以南地区洪涝的大尺度环流成因初探  

Preliminary Study on Circulation Cause of Abnormal Rich Precipitation in and to the South of Yangtze River in Summer of 1999

作　　者：张培群[1] 何敏[1] 许力[1] 

机构地区：[1]国家气候中心,北京100081

出　　处：《高原气象》2002年第3期243-250,共8页Plateau Meteorology

基　　金："1998年长江;嫩江流域特大暴雨的成因及预报应用研究"项目 ( 0 2 )专题;国家"九五"重中之重科技项目 ( 96 90 8 0 4 0 4 )专题的共同资助

摘　　要：通过对比分析 ,探讨了 1 999年夏季长江及以南地区洪涝灾害的环流成因。指出 1 999年处在LaNi na年 ,西太平洋副热带高压偏弱、偏北且异常偏东 ;南海夏季风前期偏强 ,后期偏弱 ;热带对流层上部南亚高压脊和洋中槽位置偏南 ;对流层下部长江下游至江南受气旋性异常环流影响 ,形成异常加强的水汽输送圈 ;夏季亚洲中纬度地区大陆高压维持 。Circulation characteristics associated with abnormal rich precipitation in and to the south of Yangtze River basin in summer of 1999 were discussed. The following circulation characteristicswere noticed: During the sustained stage of La Nia period, the intensity of WestPacific subtropical high (WPSH) was belownormal with its position more moving northward and eastward. The tropical monsoon over South China Sea was stronger in earliersummer, butweaker later. In upper troposphere, South Asia anticyclone ridge and TUTT located something south. Meanwhile, in lower troposphere,the enhanced transportation of water vapor was formed by the cyclonic abnormal circulation over mid to low reach of Yangtze River and to the south of Yangtze river valley. In the summer, the continental high persisted in the mid latitude region of Asia. Mid and low latitude circulation anomalies syntheticallycause the flooding around and to the south of Yangtze river basin.

关 键 词：1999年 夏季 长江 洪涝灾害 环流成因 

分 类 号：P426.616[天文地球—大气科学及气象学]