华南前汛期一次暴雨过程中的中尺度对流系统

Multi-MCSs(Mesoscale Convective Systems) over the Heavy Rainfall Region During 23-24 May 1998 in South China

通过对卫星云图观测到的MCS云团生消过程和实测降水资料的分析 ,发现 1998年 5月 2 3 - 2 4日发生在华南的一次前汛期暴雨过程主要是由多个相继生消的MCS造成的。利用MM5模式成功地模拟出了其中两个主要MCS的发生发展。对模拟结果进行分析发现这两个MCS的发生发展是冷暖空气交汇的结果 ,MCS生成于暖空气而消亡于冷空气中。两个MCS的上升运动都非常强 ,最大辐散位于 40 0hPa左右 ,垂直方向上表现为气旋性的涡柱 ,右侧低层有中尺度的低空急流 ,高空有强的西南风区。

Multi-MCSs(mesoscale convective systems) associated with a heavy rainf all during 23-24 May 1998 in South China have been examined by using s atellite images and precipitation data. It is found that the development of thes e MCSs was associated with the initiation and evolution of several cloud cluster s during this period. Using numerical modeling system MM5, the successive development of two MCSs was simulated.