【作者】 王建捷； 李泽椿；

【Author】 Wang Jianjie, Li Zechun(National Meteorological Center, Beijing 100081)

【机构】 国家气象中心；

【摘要】 <正> 1 引言1998年夏季,我国长江流域出现了历史上罕见的全流域性洪涝灾害,两度梅雨期暴雨是导致洪水发生的直接原因。陶诗言等[1-4]对1998年夏季中国暴雨洪涝灾害的气象水文特征、大尺度环流条件、影响系统、梅雨锋结构、暴雨特征等进行了较为细致的研究。本文将以1998年6月16～17日(第一阶段梅雨期间)发生在赣闽浙沿五夷山北麓地区的梅雨锋暴雨过程为例,更多还原

【Abstract】 In this paper, the characteristics of the mesoscale convective systems of a torrential rain case occurring over south Yangtz River on 16 - 17 June 1998 are investigated by using mesoscale numerical simulations and observations as well as 1998 filed-experiment’s data. It has been revealed that the torrential rain occurs associated with the generation of a mesoscale convergence line in the region to the south of a mesoscale low in lower-troposphere; under the weak vertical wind-shear condition, several meso-β clouds, the convective systems directly related the torrential rain, develop strongly in vertical like towers within a meso-β cloud; and before the occurrence (about 8 h) of the torrential rain, the maximum value of CAPE could reaches 2600 J/kg, which is gained thanks to the intensive sounding data from 1998 field experiments. On the basis of the study on torrential rain related meso-β convective systems, which develop con-comitantly with lower-troposphere mesoscale convergence line in Meiyu period, the air motion image of this kind meso-β convective systems (or say meso-β cloud towers), is sketchily given in the paper.更多还原