2012年8月19～21日西藏持续性强降水的中尺度分析  

Meso-Scale Analysis on the Continuous Heavy Rainfall over Tibet during April 19 to 21 2012

作　　者：余燕群 

机构地区：[1]西藏自治区气象台,西藏拉萨850000

出　　处：《成都信息工程学院学报》2013年第5期549-556,共8页Journal of Chengdu University of Information Technology

基　　金：国家自然科学基金资助项目(41175060)

摘　　要：对2012年8月19~21日西藏持续性强降水天气过程的成因进行分析。利用加密地面观测资料、FY-2C卫星TBB资料、常规观测资料和NCEP 1°×1°再分析资料,对2012年8月19~21日西藏持续性强降水天气过程进行诊断和中尺度特征分析。此次强降水天气过程是在稳定的径向型环流背景下产生的,巴尔喀什湖附近东移南下的短波槽和500hPa低涡切变是造成此次降水过程的主要影响系统,西太平洋副热带高压边缘的西南暖湿气流为降水过程提供了有利的水汽条件;β中尺度对流云团的先后影响,为强对流发展提供了必要的热力、动力条件;而中层冷空气的侵入和强的垂直风切变加剧了大气层结的不稳定,为降水天气提供了有利的条件。该研究为西藏夏季降水的相关预报预测提供科学依据。Using surface intensive observation data, TBB data of FY-2C satellite, conventional observation data and NCEP l^x l^reanalysis data, the continuous heavy rainfall process over Tibet during April 19 to 21 2012 and its meso-scale character have been diagnosed and analyzed . The results show that the weather process occurred in the background of a stable meridional circulation, and the short-wave trough moving eastward and southward from Balkhash Lake and the low vortex with shear line in 500 hPa are the mainly influence systems. The warm and humid southeastward flow from the western Pacific subtropical high offering ample moisture, the^- meso-scale convective cloud influenced repeatedly providing the essential thermal and motive condition, and the cold air invasion in the mid- dle level and the vertical wind shear making the air stratification to be more unstable, were propitious to the rainfall. All these results provide scientific basis to the rainfall forecast in the summer over Tibet.

关 键 词：气象学 诊断分析 强降水 低涡切变 中尺度分析 

分 类 号：P458.121.1[天文地球—大气科学及气象学]