山西一次低涡暴雨过程的成因分析  

Formation Mechanism of a Low Vortex Heavy Rain in Shanxi Province

作　　者：崔粉娥 王咏青[2] 狄利华 

机构地区：[1]河北省秦皇岛市气象局,秦皇岛066000 [2]南京信息工程大学,南京210044 [3]浙江省衢州市气象局,衢州324000

出　　处：《暴雨灾害》2009年第3期241-245,共5页Torrential Rain and Disasters

基　　金：国家自然科学基金项目(40405009);江苏省科技厅社会发展项目(BS2005055)共同资助

摘　　要：采用地面、高空常规观测资料和NCEP全球再分析资料(空间分辨率1°×1°),对2005年7月1日20时至2日20时(北京时)发生在山西的一次低涡暴雨过程从环流形势、物理量场方面进行了初步的分析,发现这次暴雨过程是受5OOhPa高空槽、副热带高压以及中尺度低涡等天气系统共同作用产生的。利用数值模拟输出的高时空分辨率资料探讨了此次暴雨过程的发生发展特征和机理,指出中低层中尺度涡旋是造成这次过程的主要天气系统,低涡的时空演变与暴雨中心的移动和雨强的变化有着较好的对应关系。湿位涡诊断表明:强降水发生时,暴雨区上空低层是不稳定区,湿位涡负中心出现在暴雨中心附近,且对流不稳定性远大于湿斜压性。地形的敏感试验进一步揭示了地形对暴雨的增幅作用。Based on the conventional surface observations and the NCEP reanalysis data（spatial precision 1°×1°）,the synoptic situation and the physics quantity fields of the low vortex heavy rain process occurred on 1-2 July 2005 in Shanxi Provence are analyzed.The heavy rainfall occurred in a well weather situation with the high-level trough,the subtropical high at 500 hPa and the meso-scale low vortex.Using the model output with the high spatial and the temporal resolution,we study the characteristics and formation mechanism of the rainfall in more detail.It is found that the main weather system brought the heavy rain is a meso-scale vortex at low-mid levels,whose evolution is accorded with the variations in shift and intensity of the rainfall center.The diagnosis of moist potential vorticity（MPV） shows that the negative MPV area is instability,and its center located at the center of heavy rainfall.when heavy rainfall happening.Moreover,｜MPV1｜≥｜MPV2｜ are the favorable condition for the heavy rainfall generating.Moreover,the sensitivity experiments further reveal the impact of terrain on the heavy rain.

关 键 词：低涡暴雨 数值模拟 形成机制 

分 类 号：P458.121.1[天文地球—大气科学及气象学]