“05．9．20”陕西中部大暴雨分析  

Analysis of heavy rainfall "Sept.20" in Shaanxi

作　　者：孟妙志 刘勇[2] 王仲文[1] 张雅斌[2] 

机构地区：[1]宝鸡市气象局,陕西宝鸡721006 [2]陕西省气象台,西安710016

出　　处：《气象科学》2008年第4期462-467,共6页Journal of the Meteorological Sciences

基　　金：陕西省气象局多普勒宫达技术开发应用研究和科技创新基金计划项目(2006M-22)

摘　　要：利用天气图、自动站加密雨量、FY-2C卫星、西安多普勒雷达等资料,对陕西2005-09-20大暴雨(下称"9.20大暴雨")天气成因及中尺度系统特征进行分析,结果表明:地面冷锋触发不稳定能量释放;在高、低空急流耦合的有利配置下,生命史为8 h以上的中尺度对流系统(MCS)导致大暴雨的产生,强散度柱与强涡度柱互相耦合提供了MCS强烈发展的动力机制;大暴雨出现地点与地面"Ω"型中尺度能量场、中尺度切变线密切相关;雷达图上,回波强度≥40 dbz对应强降水,回波强度和强回波发展高度与地面降水强度呈正相关。With observation from synoptic chart, meteorological autostation, FY-2C satellite and Xian WSR-88D radar, the cause and mesosacale characteristics of the heavy rainfall in Shaanxi province on 20 September 2005 have been analyzed. The result showed that cold front triggered unstable energy release and under the advantageous configuration between the upper jet stream and low-level jet stream the MCS lasting more than 8h resulted in the heavy rainfall, meanwhile, coupling between intensive disvergence and vorticity provided dynamical mechanism to MCS evolution. Heavy rainstorm location had high correlation with mesosacale energy of ＂Ω＂ form and wind shear distribution. Heavy rainfall areas corre- sponded to radar echoes bigger than 40 dBz and rain tensity had positive correlationship to echo intensity and developing height.

关 键 词：大暴雨 中尺度对流系统 物理量场 中尺度特征 

分 类 号：P426.62[天文地球—大气科学及气象学]