张家界多个例降雹过程对比分析  

Comparative Analysis of Several Hailing Cases in Zhangjiajie

作　　者：刘兵[1,2] 戴泽军 胡振菊 李玉梅 黄俊 黄萍 

机构地区：[1]兰州大学大气科学系,730000 [2]湖南省张家界市气象局 [3]湖南省气象台 [4]湖南省常德市气象局

出　　处：《气象》2009年第7期23-32,共10页Meteorological Monthly

基　　金：湖南省气象局重点项目高分辨率数值预报释用技术研究;科技部气象公益性行业专项(GYHY(QX)2007-6-12)共同资助

摘　　要：利用NCEP再分析资料、常规资料及ECMWF数值预报产品等资料,从降雹特征、大气环流形势特征、物理量条件、风暴源地、雷达回波特征等方面入手,对2005年张家界5次降雹过程进行深入对比分析。结果表明:冰雹区具有点、线、面三种分布特征,不同冰雹灾害过程造成的直接经济损失程度与受灾面积及受灾人口在数量上存在显著的正相关关系;5次降雹过程分别发生在高空槽型和东北低涡型两种典型冰雹环流背景形势下,其中高空槽型影响范围更大,破坏更强;较好的水汽条件、对流不稳定条件和较强的垂直风切变促使冰雹等强对流天气过程发生发展;5次风暴均初生于地形高度高梯度区上空,聚集在大山周围及山地偏南区的迎风坡,说明热力及地形对风暴的生成及能否发展成为冰雹云有着极为重要的作用;降雹过程均具有典型的冰雹云雷达回波特点和形态,在风暴体VIL密度超过4g·m-3的4次降雹过程中均产生直径约2cm的大冰雹,说明VIL密度对大冰雹具有强的指示作用。Based on the characteristics of hailing, characteristics of atmospheric circulation, physical quantity conditions, storm source and characteristics of radar echo, five hailing processes in Zhangjiajie in 2005 were analyzed by using the NCEP re_analysis data, conventional data and ECMWF forecast products. The result shows that the hailing areas are distributed respectively in spots, lines and planes, and the direct economical losses caused by different ty.pes of hailingprocesses have a significant positive correlation with the disaster stricken area and disaster stricken population amount. The five hailing processes occur under the typical upper air trough and northeast vortex hailing circulation background respectively, whereas those hails occurred in the upper air trough circulation influence a larger area with greater destruction. Favorable hydromcteor conditions, convective instability conditions and strong vertical wind shear promote the generation and development of strong convection synoptic processes. All the five storms occur in the location with a large gradient of topqgraphy, and concentrate around mountains and the windward slopes in south of the mountainous area, which means that the thermodynamic effect and landform play a critical role in the generation of storms and the development into hail cloud. All the hailing processes have thc characteristics of typical hail cloud radar echo, and the large hails with a diameter of about 2era are generated during the four hailing processes with the storm body VIL density of more than 4g·m^-3, which means that VIL densitv has a significant indicating function for largehails.

关 键 词：冰雹 天气形势 对流参数 垂直风切变 雷达回波 

分 类 号：P426.64[天文地球—大气科学及气象学] P448