GNSS/MET观测的台风“烟花”对上海地区PWV的影响

The Impact of Typhoon“In-Fa”on PWV in Shanghai Basedon GNSS/MET Observations

利用上海5个GNSS/MET站2021-07-21~08-08的观测数据,使用GAMIT软件反演大气可降水量(PWV),研究台风“烟花”期间上海地区PWV与降雨量之间的关系及PWV的空间分布特征。结果表明,GNSS PWV与探空PWV之间相关系数大于0.9。降水生成前,PWV经历了3次波动性上升过程,降水生成时间比台风登陆时间早约60 h;降水持续期间,PWV剧烈变化时会造成降水量急升或急降;降水结束后,PWV逐渐下降至40 mm以下。台风登陆前,PWV基本在75 mm以上,PWV大于80 mm的区域主要分布于上海南部和中部;台风登陆后,PWV在80 mm以上,高值区可达90 mm;台风远离后,PWV下降至85 mm以下。PWV高值区向西北方向的扩大、推移与台风路径基本吻合。

We use observation data from 5 GNSS/MET stations in Shanghai from July 21 to August 8,2021 to invert atmospheric precipitable water vapor(PWV)by GAMIT software,and study the relationship between PWV and rainfall in Shanghai and the spatial distribution characteristics of PWV during typhoon“In-Fa”.The results show that the correlation between GNSS PWV and sounding PWV is above 0.9.Before the formation of precipitation,PWV undergoes three obvious rise processes and the precipitation generation time is about 60 h ahead of typhoon landfall.PWV sharp change will cause a sharp rise or fall in precipitation.After the precipitation,PWV gradually drops below 40 mm.Before typhoon landfall,PWV is basically above 75 mm;PWV above 80 mm is mainly distributed in southern and central areas of Shanghai.After typhoon landfall,PWV is above 80 mm,and higher value areas can reach 90 mm.After the typhoon moved away,the PWV value dropped below 85 mm.The expansion and progression of the high-value area to the northwest is basically consistent with the typhoon path.