The ″7·20″ extremely heavy rainstorm in Henan Province caused serious urban waterlogging and several geolog-ical disasters.Precipitable water vapor(PWV)is one of the main drivers of extreme rainfall,and the analysis of the spatial and temporal variations of atmospheric water vapor during the ″7·20″ extremely heavy rainstorm can help to improve the understanding of the mechanism of rainfall and water vapor regional interaction.The PWV data with a temporal resolution of 5 min before and after the rainstorm from July 17 to July 24 were inverted using observations from eight GNSS stations in the Henan CORS network.On this basis,the integrated PWV values were compared with those of the ERA-5 reanalysis data,and the spatial and temporal distribution characteristics of water vapor during the rainstorm were analyzed in relation to the actual rainfall.The results are as follows.The deviation and root mean square error of GNSS-PWV are 0.4 and 2.3 mm,respectively.The PWV values showed a rapid increasing trend during the 3 days before the storm and reached the maximum value 3 hours before the storm,and gradually decreased to the normal range after July 22.The variation trend of GNSS-PWV is basically consistent with the actual rainfall process.The research results can provide a certain theoretical basis for real-time all-weather meteorological warning work based on GNSS observation data.
关键词
GNSS/大气水汽/再分析数据/"7·20"特大暴雨
Key words
GNSS/precipitable water vapor/reanalysis data/″7·20″ extremely heavy rainstorm
万方数据