一次极端短时强降水过程中FY-3微波湿度计观测特征分析

Analysis of observation characteristic of FY-3 microwave hygrometer during an extreme short-term heavy precipitation process

利用FY-3微波湿度计资料和常规观测资料,对2016年贵州至湖北一次强降水事件中极端短时强降水站点、一般性短时强降水站点上空对流云的微波观测特征进行了对比分析。结果表明:(1)极端短时强降水站点上空150 GHz附近窗区探测通道亮温低于一般性短时降水站点。(2)极端短时强降水站点上空水汽通道亮温垂直分布呈现漏斗状,对干侵入有一定指示作用,亮温最低值出现在183.31±7 GHz附近,主要为暖云降水;一般性短时强降水站点上空水汽通道亮温垂直分布则呈竖条形,亮温最低值出现在183.31±3 GHz和183.31±7 GHz探测通道附近,为冷云暖云混合降水。(3)极端短时强降水站点上空未出现冲顶对流,但低层对流发展旺盛;一般性短时强降水站点上空出现冲顶对流,但低层对流发展强度偏弱。

Based on data of FY-3 satellite microwave hygrometer and conventional observation,microwave observational characteristics of convective clouds during a heavy precipitation event from Giuzhou to Hubei province in 2016 were analyzed.The results show that(1)The brightness temperature at the window channel near 150 GHz over an extreme short-term heavy rainfall station is lower than that of the non-extreme short-term heavy rainfall station.(2)The brightness temperature vertical distribution at water vapor absorption channel is fun⁃nel-shaped over the extreme short-term heavy rainfall station,which is a certain indication of dry invasion.The lowest brightness tempera⁃ture occurs near 183.31±7 GHz,indicating warm cloud precipitation.However,the brightness temperature vertical distribution at water va⁃por absorption channel is vertical-bar shaped over the non-extreme short-term heavy rainfall station.The lowest brightness temperature oc⁃curs near 183.31±3 GHz and 183.31±7 GHz,indicating precipitation of mixed cold and warm clouds.(3)There is no topping convection over extreme short-term heavy rainfall stations,but the low-level convection develops vigorously.Top-rushing convection appears over non-extreme short-term heavy rainfall stations,but the intensity of low-level convection is weak.