摘要
利用欧洲中心１９８０～１９８９年逐日２００ｈＰａ、８５０ｈＰａ风场及日本气象研究所提供的ＧＭＳ观测的ＴＢＢ逐日资料，探讨了夏季东亚热带、副热带季风的强弱对中国东部夏季降水的影响．指出东亚夏季风系统中的两条辐合带热带辐合带（热带季风槽）和副热带辐合带（副热带梅雨锋）的强度的变化呈相反趋势，即热带季风槽偏弱时（弱季风），副热带梅雨锋偏强；反之热带季风槽偏强时（强季风），副热带梅雨锋偏弱．江淮流域的降水与热带季风槽、副热带梅雨锋的强度密切相关，即热带季风槽偏弱（弱季风），梅雨锋偏强时，江淮流域的降水偏多；热带季风槽偏强（强季风），梅雨锋偏弱时，江淮流域的降水偏少．研究表明：热带季风槽和副热带梅雨锋的强度与偏西气流的加强密切相关．当赤道东太平洋海温偏高，赤道西太平洋海温偏低，黑潮地区的海温偏高时，赤道东西太平洋上空的Ｗａｌｋｅｒ环流和西太平洋中纬度Ｈａｄｌｅｙ环流的下沉支气流减弱，东亚季风槽较弱（弱季风），梅雨锋较强；当赤道东太平洋海温偏低、西太平洋海温偏高，黑潮地区的海温偏低时，赤道东西太平洋上空的Ｗａｌｋｅｒ环流和西太平洋中纬度Ｈａｄｌｅｙ环流的下沉支气流加强，东亚季风槽较强（强季风），梅雨锋较弱．
ased on ECMWF daily wind data during 1980～1989 at 200 hPa and 850 hPa and black body temperature (TBB) of JMA Geostationary Meteorological Satellite (GMS), the different features between tropical monsoon trough and subtropical Meiyu front over East Asia and their influencing on the rainfall over eastern China in summer were studied. The main results were obtained as follows: (1) There was an opposite variation trend for the intensity of East Asian tropical monsoon trough from subtropical Meiyu front. The intensity of subtropical Meiyu front weakened (strengthened) while the intensity of East Asian tropical monsoon trough strengthened (weakened). (2) The rainfall over the Changjiang River valley decreased (increased) when the convection of East Asian tropical monsoon trough strengthened(weakened) and when the intensity of East Asian subtropical Meiyu front weakened (strengthened). (3) The intensity of East Asian tropical monsoon trough or subtropical Meiyu front strengthened when the westerly wind occupied over East Asian tropical monsoon trough or subtropical Meiyu front. (4) The intensity of East Asian subtropical Meiyu front strengthened (weakened) when Hadley circulation over the West Pacific weakened(strengthened). The intensity of East Asian tropical monsoon trough strengthened(weakened) when Walker circulation over the East and West Pacific strengthened(weakened).
出处
《应用气象学报》
CSCD
北大核心
1998年第S1期17-,19+21+23+18+20+22,共8页
Journal of Applied Meteorological Science
基金
国家"九五"重中之重科技项目
关键词
热带季风槽
副热带梅雨锋
江淮流域降水
Tropical monsoon trough Subtropical Meiyu front Rainfall of the ChangjiangHuaihe River valley
