2013年鄂东北一次梅雨期强降雨日变化分析  

Diurnal variation analysis on a heavy rain event during Meiyu period in Northeast Hubei of 2013

作　　者：张端禹[1] 许建玉[1] 赵玉春 付志康[1] 王叶红[1] 

机构地区：[1]中国气象局武汉暴雨研究所暴雨监测预警湖北省重点实验室,武汉430205 [2]厦门市气象局,福建厦门361012

出　　处：《气象科学》2015年第6期783-790,共8页Journal of the Meteorological Sciences

基　　金：公益性行业(气象)科研专项(GYHY201106003;GYHY201206003);国家自然科学基金(41405106);国家自然科学基金青年科学基金(41105073);湖北省气象局科技发展基金面上项目(2014Y06)

摘　　要：利用FY2E卫星观测TBB、GFS0.5°×0.5°再分析资料与湖北GPS网观测PWV等资料,应用环流特征、TBB、物理量场等,诊断分析2013年7月梅雨末期鄂东北连续强降雨成因。结果表明:强降雨主要发生在5—6日,夜间超过白天,日变化明显。5日夜间鄂东北云团发展旺盛但移速较快,降雨发展。6日夜间云带在移出鄂东北的同时,其西侧又新生多个对流云单体;这些对流云单体合并后形成东移缓慢的β中尺度云团,降雨达到峰值。强降雨期间鄂东北位于200 h Pa南亚高压东伸脊北侧的较强辐散区内。5、6日两天早晨,湖南南岳一带西南风异常加大有利于暖湿气流向东北方向输送;午后鄂东北地面对流有效位能加大,大气层结非常不稳定;入夜后动力抬升机制加强,降雨明显增幅。降雨全过程鄂东北PWV夜间比白天均有所增加。By using Temperature of Black Body （ TBB ） data from FY- 2E satellite, reanalysis data with 0. 5°×0.5° resolution GFS and observed Precipitable Water Vapor （PWV）data from Hubei GPS net, a continuous heavy rainfall at the end of Meiyu period in July, 2013 of Northeast Hubei province is investigaled. Results show that the rainstorm occurred mainly in July 5-6, which was heavier at night than in the day and had obvious diurnal variations. At the night of July 5, cloud clusters developed quick- ly and moved fast over Northeast Hubei, and then the rainfall occurred there. At the night of July 6, the cloud belt moved away from Northeast Hubei, at the same time, at its west side, several newly born con- vective clouds merged to form a meso-β cloud, which moved eastward slowly and the rainfall, reached its peak. During the heavy rainfall, the Northeast Hubei was in the strongly divergent area at the north side of eastward stretching ridge of South Asia high at 200 hPa. The anomalous strong southwester in the morn- ings of July 5 and 6 at Nanyue Mountain promoted the northeast transportation of warm and wet air. Sur- face CAPE rose and stratification became unstable in the afternoons of Northeast Hubei. The dynamical lifting factors reinforced obviously at nights, which brought more rain at nights than in the day. During the whole rain events, PWV value over Northeast Hubei at nights became a little more than that in the days.

关 键 词：强降水 日变化 环流特征 云顶亮温 物理量诊断 梅雨期 鄂东北地区 

分 类 号：P458.2[天文地球—大气科学及气象学]