Global Navigation Satellite System-Based Retrieval of Precipitable Water Vapor and Its Relationship with Rainfall and Drought in Qinghai, China

Qinghai Province is situated deep in inland China, on the Qinghai-Tibet plateau, and it has unique climate change characteristics. Therefore, understanding temporal spatial distributions of water vapor this region can be great significance. The present study applied global navigation satellite system (GNSS) technology to retrieve precipitable (PWV) analyzed its relationship with rainfall drought. Firstly, radiosonde (RS) data used verify precision surface pressure (P) temperature (T) from fifth-generation atmosphere reanalysis set (ERA5) European Centre for Medium-Range Weather Forecasts (ECMWF), as well zenith troposphere delay (ZTD), calculated based continuously operating reference stations (CORS) Qinghai. Secondly, a regional atmospheric weighted mean (Tm) (QH-Tm) model was developed P, T, relative humidity, consideration influence seasonal changes Tm. Finally, PWV each CORS using GNSS-derived ZTD ERA5-derived meteorological data, drought evaluated. results show that P T have high precision, their average root square (RMS), absolute error (MAE) bias were 1.06/0.85/0.01 hPa 2.98/2.42/0.03 K, respectively. RMS, MAE 13.2 mm, 10.3 mm −1.8 theoretical 1.98 mm; compared RS- PWV, actual 2.69 2.16 In addition, changing trend consistent events, closely negatively correlated standardized precipitation evapotranspiration index. retrieved GNSS offers good feasibility practical applications; thus, serve crucial tool investigating distribution