湖南省雨季一次MCS的中尺度数值模拟  

Numerical Simulation on Mesoscale Convective System in Hunan Monsoon

作　　者：李细生 张华 罗慧妮 吴萍 曾欣 

机构地区：[1]湖南省株洲市气象局,株洲412003

出　　处：《暴雨灾害》2007年第3期223-229,共7页Torrential Rain and Disasters

摘　　要：MCS(中尺度对流系统)是造成湖南暴雨等灾害性天气的主要影响系统,它与暴雨的落区、强度、持续时间密切相关。以2005年5月31至6月1日的湖南特大暴雨洪涝过程为例,利用中尺度数值模式MM5对MCS的雨量、动力热力特征、三维结构以及发展变化进行了模拟分析和研究,指出本次MCS发展的触发因子是近地层冷锋,维持机制是近地层不稳定能量的积蓄、中低层辐合和高层辐散的结构,大尺度系统是其发展或消亡的主导因素,并分析了水汽对暴雨强度和落区的影响,旨在为预报和防御同类灾害性天气提供参考依据。Mesoscale convective systems （MCSs） are major contributors to such severe weather like torrential rain in the Hunan province, which closely relate to the rainstorm districts, intensity and duration. By using mesoscale numerical model MMS, the precipitation amount, the dynamic and thermal characteristics, the three-dimensional structures and the evolution of the MCS in the flood-causing torrential rain taking place from 31 May to 1 June, 2005 in Hunan province are analyzed. The result shows that the strata cold front is the trigger factor of the MCS＇s generation, the instable energy savings at the strata, the convergence at the middle and lower layers and the divergence at the upper layer are the maintaining mechanism of the MCS. The large-scale system was the dominant factor of the MCS＇s development or demise. The impact of vapor on the rainstorm intensity and districts is also analyzed in order to provide the reference for forecasting the similar severe weather.

关 键 词：暴雨 MM5 冷锋 不稳定能量 水汽 数值模拟 

分 类 号：P456.7[天文地球—大气科学及气象学]