Variation characteristics of precipitable water vapor retrieved by CORS in China Southern Power Grid during heavy rainfall

Precipitable water vapor (PWV) mirrors the dynamic changes of atmospheric water vapor and can be accurately retrieved by the Global Navigation Satellite System (GNSS). Aiming at exploring the potential of the Continuously Operating Reference System (CORS) of China Southern Power Grid to contribute to meteorology, this paper first establishes a Weighted Mean Temperature (Tm) model that is more applicable in Guangzhou. Subsequently, the PWV sequence and variation characteristics during the period of heavy rainfall from June 30 to July 5, 2022, are inversed and analyzed based on the observation data of CORS in 15 reference stations around Guangzhou. The results indicate that PWV variations bear a close relationship with the actual rainfall events. The PWV increases remarkably before heavy rainfall, remains at a high level during rainfall, and gradually returns to a stable state after rainfall stops, revealing that PWV changes can serve as an indicator for heavy rainfall monitoring. Therefore, meteorological services in the CORS of Southern Power Grid can be further enhanced in the future.