2009年10月海南岛一次秋季强降水过程分析

利用NCEP 1°×1°全球再分析资料和常规气象观测、多普勒雷达、中尺度数值模拟等资料,综合分析了2009年10月海南岛一次秋季暴雨过程,并对其物理量场进行诊断。结果表明,此次暴雨的发生、维持和消失主要与南海低压活动及其与冷空气相互作用密切相关。对流单体回波对降水量估测和降水落区有较好的指示意义,由于回波在海南岛东半部地区移动速度缓慢,产生"列车效应",导致海南岛东半部地区雨强增大,雨量增幅明显。暴雨带近地面流场中存在多个次级环流中心,为这次暴雨提供了增幅作用。暴雨过程中水汽通量、上升运动、不稳定能量和涡度等各物理量分布对暴雨落区均具有很好的指示意义。

ANALYSIS OF AN AUTUMN RAINSTORM IN HAINAN ISLAND

Using 1°×1° NCEP reanalysis data,conventional meteorological observation data,auto station data and Doppler radar echo data,the influences of circulation background on an Autumn rainstorm in Hainan Island in 2009 are synthetically analyzed,and the physical characteristics are also diagnosed.The results show that：1） The occurrence,maintenance and disappearance of the rainstorm are closely related to South China Sea depression and its interaction with cold air.2） The convective echo has significance to the estimation of precipitation both on quantity and area.Slow movement of convective echo over eastern Hainan Island leads to increased rainfall.3） The rainstorm is directly produced by the mesoscale convective system（MCS）.4） The distribution of vertical motion,vorticity,water vapor flux divergence and instability energy has a good indication to the rainstorm.