一次江淮暴雨过程中中尺度气旋的数值模拟及分析

本文利用PSU／NCAR中尺度数值模式MM5，并利用鄂、豫、皖、苏四省的加密地面气象要素场资料做检验，对1991年7月6日江淮地区发生的一次暴雨过程进行了分析。结果表明：江淮暴雨过程中的中尺度气旋在发生、发展、变化过程中其结构具有不对称性，因而进一步造成了局地降水强度和分布的不均匀性。而中尺度气旋的结构不对称性又与其地面及高空的流场、涡度场及散度场等的中尺度特征有直接的联系。

A MESOSCALE CYCLONE NUMERICAL SIMULATION AND ANALYSIS OF A HEAVY RAIN PROCESS IN THE CHANGJIANG-HUAIHE RIVER BASIN

A heaVy rain process occurring over the Jianghuai Basin on July 6, 1991 is simulated by using PSU /NCAR mesoscale numerical model MMS and the dense surface observation.The results show that its structure is asymmetric,as the mesoscale cyclone occurs,develops and evolves. Thus it results in nonuniform on density and distribution of local precipitation. Moreover,the asymmetric structure of the meso-scale cyclone is closely related to the mesoscale characteristics of its wind,vorticity,divergence and so on.