长江中游一次暴雨中尺度天气系统的观测分析  

Meso-Scale Analysis of a Heavy Rainfall over the Middle Valleys of Changjiang River

作　　者：赵玉春[1] 王仁乔[1] 郑启松[1] 彭军[1] 

机构地区：[1]武汉中心气象台,430074

出　　处：《气象》2003年第11期14-19,共6页Meteorological Monthly

摘　　要：利用多种加密观测资料 ,详细分析了长江中游一次暴雨中尺度天气系统的观测特征。结果发现 :(1 )暴雨由各种尺度的天气系统相互作用造成 ,直接造成这场暴雨的是中α尺度切变线上活动的多个并不深厚的中 β尺度对流系统 ,该对流系统在发生发展过程中一直伴有明显的中尺度雨团活动。 (2 )这次中 β尺度对流系统活动可能的物理图像为 :在切变线东北方和西南方各有一支气流在切变线上辐合抬升并汇入对流系统中 ,在暖平流的作用下 ,气流在倾斜的θse锋前上升 (或沿锋区爬升 )并随高度发生顺转 ,到 7km高度以上开始以西南气流发散 ,在离对流区 4 0 0～ 50 0km处下沉 ,并在θse锋区附近构成中尺度垂直环流圈 ,对流云团发生在该垂直环流的上升支一侧。With intensive detecting data, the observational characteristics of meso scale weather system triggering heavy rainfall over the middle valleys of Changjiang River is analyzed. The Results show that the interaction of multi scale synoptic systems leads to heavy rainfall, and several β scale convective systems moving along α scale shear directly result in heavy rainfall. Several meso scale heavy rainfall masses come into being with the forming and developing of convective system and move along the active route of the convective system. The physical image of the β scale convective system can be described as follows. Air flow in the northeast and southwest of the shear converged into the shear and ascend and joined into the convective system, then the air current rose in the foreside of (or along) the θ se front and rotated clockwise with a height under the effect of warn advection and diverge as southwest air flow at the height of 7km and subside at the range of 400～500km, and lastly a meso scale vertical circulation formed by the θ se front with convective cloud in the ascending branch of the circulation.

关 键 词：暴雨 中尺度天气分析 切变线 对流 

分 类 号：P458.2[天文地球—大气科学及气象学] P458.121.1