2005年7月1—2日山西大暴雨中排熵指数的诊断分析  

Numercial Simulation of Forming Mechanism for a Heavy Rain in Shanxi Province during 1—2 July 2005

作　　者：崔粉娥[1] 王咏青[1] 李勋[1] 

机构地区：[1]南京信息工程大学江苏省气象灾害重点实验室

出　　处：《南京气象学院学报》2007年第6期841-848,共8页Journal of Nanjing Institute of Meteorology

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

摘　　要：利用美国新一代中尺度WRF(weather research and forecasting)模式,采用双向二重嵌套网格技术,对2005年7月1—2日山西的大暴雨天气过程进行数值模拟,并利用模式输出的高分辨率动力协调资料进行了初步诊断分析,着重分析了排熵指数与暴雨区的关系。结果表明:活跃的副高是造成此次强降水的主要影响系统,低空西南风急流为暴雨提供了充足的水汽及动力条件;大气排熵指数由高值向低值的演变有利于对流的发展,从而导致对流暴雨形成;负熵变区(IRE<0)对应着暴雨区,负熵变区的汇合反映了暴雨的落区;排熵指数与暴雨区有较好的对应关系。Based on the synoptic analysis for a heavy rain event occurred in Shanxi on 1-2 July 2005, using the new generation mesoscale model of Weather Research and Forecasting（WRF） with two-way nested grid, the numerical simulation of the rain event is performed in this paper, and high spatial and temporal resolution model outputs are used to diagnose the relation between removal entropy index and rainfall area. Diagnostic results show that the event is caused by active subtropical high;the rainfall area matches well with the mid-low level convergence and the upper-level divergence, and the the SW low-level jets provide vapor and motive terms and play an important role in the heavy rain event. Results also show that the negative entropy change （IRE 〈 0） area corresponds to the large-scale heavy rain area; the convergence of the negative entropy change indicates the location of heavy rain; and the removal entropy index match the heavy rainfall centers quite well.

关 键 词：暴雨过程 数值模拟 诊断分析 排熵指数 

分 类 号：P458.121.1[天文地球—大气科学及气象学]