Model Establishment of Atmospheric Weighted Mean Temperature in Chongming Eco-Island and Its Application During Typhoon Lekima

Chongming Eco-Island is the largest estuarine alluvial island in the world, which is very important to Shanghai and the Yangtze River Delta economic belt. Due to the special geographical location of Chongming, it is affected by typhoons almost every year, which have caused serious damage to the ecological environment and economic development. A typhoon often brings a large amount of water vapor. Thus, studying characteristics of water vaper during a typhoon is very important for the typhoon’s understanding. The ground-based GNSS can be used to invert the atmospheric precipitable water vapor (GNSS/PWV), with many advantages, such as flexible, real-time, less interference with weather conditions and so on. Atmosphere weighted mean temperature (\(T_{m}\)) plays a very important role in the progress of GNSS/PWV. In this study, a \(T_{m}\) model in Chongming Island has been established, named as CMTM. The result indicates that the mean bias (\(\overline{bias}\)) and the root-mean-square error (\(RMS\)) of CMTM are 1.97 k and 2.59 k, respectively, both of them are superior to the Bevis model. Based on the consecutive observation data of 4 GNSS stations in Chongming Eco-Island from 2019/8/7 to 2019/8/13 (UTC time) and CMTM, we analyze the variation characteristics of GNSS/PWV during Typhoon Lekima. The result suggests that GNSS/PWV data can well reflect the dynamic change process of water vapor during the typhoon, and have a good correspondence with precipitation.