低层锋生型暴雨特征合成分析  

Composite analysis on features of low-level frontogenesis rainstorm

作　　者：李银娥[1] 王艳杰[1] 李武阶[1] 柳草[1] 郭英莲[1] 

机构地区：[1]武汉中心气象台,武汉430074

出　　处：《气象科学》2015年第2期223-229,共7页Journal of the Meteorological Sciences

基　　金：中国气象局预报员专项(CMAYB2014-042)

摘　　要：应用湖北省县级以上84个气象观测站点24 h降水资料,统计分析了2008—2011年5—8月低层锋生类型10场暴雨的雨量特征,对天气系统和各种物理量特征进行合成分析。结果发现:低层锋生型暴雨主要是由于低层锋生强迫触发不稳定能量的释放,同时形成跨锋面的次级正环流,其上升支与高层次级反环流的上升支在暴雨区上空叠加,形成深厚的上升运动区,触发位势不稳定能量的释放。在中层槽前正涡度平流、低层西南急流风速辐合以及锋面倾斜导致倾斜涡度发展等共同作用下,中尺度低涡发生发展。中尺度低涡中心区域和低涡移向的右前方动力水汽辐合最强烈,是暴雨发生的主要区域。By using 24 h rainfall data from 84 meteorological observation sites in Hubei province, the features of rainfall amount in ten low-level frontogenesis rainstorm processes from May to August dur- ing 2008-2011 were statistically analyzed, moreover, the weather systems and various physical character- istics were also composite analyzed. Results showed that the low-level frontogenesis rainstorm occurred when the low-level frontogenesis forced to trigger the releasing of unstable energy and form the secondary positive circulation, the overlapping of updrafts of the above circulation and a high-level senior secondary reverse circulation over the heavy rain areas formed a deep upward movement area, which triggered the release of the potential unstable energy. Furthermore, the combined effects of the middle-level positive vorticity advection, low-level southwest jet convergence and slantwise vorticity development promoted the development of mesoscale vortex. The stronger moisture convergence at the center and on right-front side of its moving direction contributed to the heavv rain.

关 键 词：暴雨 锋生 倾斜涡度 中尺度低涡 

分 类 号：P458.121.1[天文地球—大气科学及气象学]