中尺度模式积云参数化方案的改进及其在暴雨模拟中的应用

A modified cumulus parameterization scheme and its applications in simulation of heavy rainfall

本文针对中国暴雨发生发展天气特征,改进和发展了一种适合于描述东亚暴雨的中尺度积云参数化方案.首先基于近年来(1990—2010)江淮流域汛期降水合成分析的基础上,诊断出组织化对流降水环境的动力参数;其次利用该动力参数作为动力控制条件,改进了Kain-Fritsch Eta中尺度积云对流参数化方案;最后利用改进的中尺度积云参数化方案对梅雨期暴雨、华南前汛期暴雨过程进行了数值模拟,结果表明:改进后的中尺度积云参数化方案对上述两次暴雨过程的落区及强度的模拟,均有明显改进.

A cumulus parameterization scheme has been developed and modified according to the local weather features of East Asia,which can be used to simulate the heavy rainfall on the mesoscale model.Firstly,on the basis of synthetic analysis of organized convective precipitation located in Yangtze and Huaihe River basins during flood seasons from 1990 to 2010,the dynamic parameters that could reflect the environment of organized convective precipitation are diagnosed.Secondly,the dynamic parameters are used to control conditions in order to develop and improve the Kain-Fritsch Eta cumulus scheme.Finally,the rainstorms occurring over the Yangtze River valley and South China have been simulated with the Kain-Fritsch Eta cumulus scheme and the modified cumulus scheme,respectively.The comparison of simulation results shows that the modified cumulus parameterization scheme could obviously improve the simulated precipitationboth in locations and intensity.