海南岛秋季暴雨天气的环流特征和形成机制初探  

Preliminary Study on Circulation Characteristics and Mechanism of Rainstorm in Autumn of Hainan Island

作　　者：赵付竹[1] 王凡[1] 冯文[1] 

机构地区：[1]海南省气象台,海南海口570203

出　　处：《热带农业科学》2011年第5期50-57,共8页Chinese Journal of Tropical Agriculture

基　　金：2011年中国气象局预报员专项项目基金";海南重点科技项目"海南省江河流域面雨量预报系统建设"(20080222)和"基于客观天气分型重建动力释用系统

摘　　要：对海南岛2000年和2008年两次秋季暴雨的特性和影响系统的分析发现:暴雨的发生、维持和消失主要与大陆冷高、南海低值系统、热带云团活动密切相关,暴雨一般与华南沿海的低空偏东风急流相伴。对流层中层正差动涡度平流和副高南侧的暖平流破坏了海南岛及邻近区域的准地转平衡,动力强迫和热力强迫共同作用激发了次级环流,导致暴雨区上空的垂直运动的发展,促使暴雨增强。对流层中层干冷空气的侵入,正的差动假相当位温平流加剧了大气层结的不稳定,强的风垂直切变更促使对流上升运动的发展,这对暴雨局地的再增强起到了重要作用。可以综合提出海南岛秋季暴雨天气的预报着眼点,为海南岛秋季暴雨天气潜势预报和临近预报提供线索。By comprehensive analysis the climate characteristics and the influencing systems on rainstorm in Autumn of Hainan Island,it＇s found that： storm rainfall out-breaking,maintaining and weakening has something to do with the continental cold high,low system above the South China Sea and tropical cloud clusters.Storm rainfall is often accompanied with low-level easterly jet at the coastal South China.In the middle troposphere,the positive vertically differential vorticity advection and the warm advection to the south of the Western Pacific Sub-tropical High destroy the quasi-geostrophic balance in the Hainan Island and its neighborhood.The secondary circulation is present by the interaction of dynamical and thermal forcing,result in vertical motion and heavy rain.The unstable stratification is intensified by the dry cold air intrusion in the middle troposphere and the advection of positive differential pseudo-equivalent potential temperature.The strong vertical shear of wind also enhanced the development of convective ascending motion further,and is in favor of the intensification of storm rainfall.These characters can be summarized to form ideas for forecasting the NON-Typhoon storm rainfall in Autumn,so as to serve the potential and nowcasting forecasts of strong convective weathers in Hainan Island.

关 键 词：秋季暴雨 天气分析 能量锋 湿有效位能 差动 平流 

分 类 号：P458.121.1[天文地球—大气科学及气象学]