“7·22”长江中游暴雨中尺度系统的数值模拟与分析  

Numerical Simulation and Analysis of “7·22” Heavy Rainfall in the Middle Valleys of the Changjiang River

作　　者：赵玉春[1] 王叶红[2] 

机构地区：[1]武汉中心气象台,430074 [2]中国气象局武汉暴雨研究所

出　　处：《气象》2005年第1期13-18,共6页Meteorological Monthly

基　　金：湖北省科技攻关计划项目资助

摘　　要：利用中尺度暴雨模式较成功地模拟了 2 0 0 2年 7月 2 2～ 2 3日发生在长江中游的暴雨中尺度天气系统 ,结合地面加密和常规观测资料对暴雨中尺度天气系统进行了较为详细的分析。结果表明 :( 1 )大别山西侧的暴雨由中α尺度切变线上中β尺度低涡造成 ,湘鄂交界地带的暴雨由切变线上气旋性扰动造成。 ( 2 )高空槽前的正涡度平流为暴雨中尺度系统形成提供了启动机制 :在正涡度平流的作用下 ,对流层中低层降压产生变压风辐合造成上升运动 ,低层暖湿气流抬升促使对流不稳定能量爆发形成局地对流产生暴雨。The meso-scale synoptic system is successfully simulated with a meso-scale heavy rain numerical model, that leads to heavy rain in the middle valleys of the Changjiang River on 22, July in 2003. Combining surface intensive observations, conventional data and model output products, the meso-scale synoptic system is analyzed particularly. Results show as follows. The heavy rain taking place in the west side of Dabie Mountain is caused by β-scale cyclone on α-scale shear, and the heavy rain near the boundary area between Hunan and Hubei provinces is caused by cyclonic wind perturbation. The positive vortex advection in the foreside of upper trough provides triggering mechanism for the formation of meso-scale heavy rain system. The pressure in the middle-lower troposphere drops under the effect of the positive vortex advection, which generates allobaric wind convergence and then leads to ascending motion. The lift-up of warm and humid air current in the lower troposphere triggers the bursting-out of instable convective energy, which leads to form local convection and heavy rain.

关 键 词：暴雨 中尺度系统 中尺度天气系统 切变线 不稳定能量 暖湿气流 辐合 降压 爆发 流产 

分 类 号：P458[天文地球—大气科学及气象学] P457