基于地基GNSS资料的青海省典型强降水过程水汽特征OA

An empirical atmospheric weighted average temperature(Tm)model for Qinghai was estab-lished based on data from 7 radiosonde stations in Qinghai from 2019 to 2022.This model was then used to retrieve precipitable water vapor(PWV)from 42 GNSS stations in the province for analyzing the spatiotemporal characteristics of water vapor during multiple heavy rainfall processes in August 2022.The results show that:1)The newly established Tm model has a mean bias of 0.4 K and a root mean square error(RMSE)of 3.41 K,indicating its accuracy is significantly superior to the Bevis model and China-regional models,while being comparable to that of the single-station models.2)The GNSS PWV retrieved based on the localized Tm model highly agrees with radiosonde results(correla-tion coefficient of 0.98).3)Before heavy rainfall occurs,PWV exhibits a rapid increase sustained for several hours,and its 3-hour variation(PWV*)remains positive,whereas before weak rainfall,PWV shows fluctuating changes.4)Short-term heavy rainfall is likely to occur when the regional PWV value exceeds 34 mm and PWV* is positive;conversely,rainfall intensity is lower.