天津地区雨季降水异常年大气环流特征分析  

Analyses of the Atmospheric Circulation Characteristics over Tianjin Area in the Years of Anomalous Precipitation in Rainy Season

作　　者：汪靖[1] 吕江津[2] 

机构地区：[1]天津市气象台,天津300074 [2]天津市气象局,天津300074

出　　处：《气象》2011年第8期950-955,共6页Meteorological Monthly

基　　金：天津市科技计划项目(07ZCGYSF03300)资助

摘　　要：利用1958—2009年天津地区和中国160站月总降水资料以及NCEP/NCAR月平均再分析数据资料集,采用相关分析和合成分析,分别研究了天津地区雨季降水的变化特征以及异常年同期(7—8月)和前期(前一年1 2月至当年6月)大气环流的特征。结果表明:天津地区的降水大部分集中于雨季且雨季降水存在着年际变化和年代际变化。天津地区雨季降水偏多年同期,西太平洋副热带高压主体偏北,天津地区西北部有低值系统发展,对流层低层有正涡度发展,辐合上升运动较强,南亚高压和高空副热带西风急流偏北,西南暖湿气流输送较强;雨季降水偏少年同期情况正好相反。此外,天津地区雨季降水与前期夏季6月SAM(南半球环状模)存在显著的反相关关系,这为天津地区雨季降水的短期气候预测提供了有参考意义的前兆信号。Based on the 1958—2009 monthly total precipitation data of 4 stations over Tianjin area,160 stations over China and the NCEP/NCAR reanalysis data set,the variation characteristics of precipitation over Tianjin area and atmospheric circulation features in the same term of July to August as well as in the previous months from the preceding December through June for the anomalous years are investigated respectively by employing the simple correlation and composite analysis.The results show that the precipitation over Tianjin area is mainly concentrated in the rainy season.There exist interannual and interdecadal variations about the rainfall in rainy season.During the simultaneous term of the more precipitation years, the western Pacific subtropical high lies more northward,the low value systems develop on the northwest side of Tianjin area.Positive vorticity develops in the lower troposphere and the convergence ascending movement is more intense accordingly.The South Asia high and the subtropical upper westerly jet lie more northward.Meanwhile,warm and wet flow coming from southwest is stronger.For the less precipitation years the situations are just opposite.Additionally,there is a significant negative correlation between the precipitation and SAM（Southern Hemisphere Annular Mode） in the preceding June,which provides meaningful references for the short-term climate prediction of precipitation over Tianjin area.

关 键 词：雨季降水 大气环流异常 SAM 短期气候预测 

分 类 号：P461.2[天文地球—大气科学及气象学]