%0 Journal Article %T Atmospheric Water Monitoring by Using Ground-Based GPS during Heavy Rains Produced by TPV and SWV %A Guoping Li %A Jia Deng %J Advances in Meteorology %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/793957 %X The time series of precipitable water (PW) in 30£żmin intervals has been determined through experimentation and operational application of a ground-based global positioning system (GPS) network in Chengdu Plain, which is used for precise and reliable meteorological research. This study is the first to apply PW to the southwest vortex (SWV) and heavy rain events by using the data from an intensive SWV experiment conducted in summer 2010. The PW derived from the local ground-based GPS network was used in the monitoring and analysis of heavy rain caused by the SWV and the Tibetan Plateau vortex (TPV). Results indicate that an increase in GPS precipitable water (GPS-PW) occurs prior to the development of the TPV and SWV; rainfall occurs mainly during high levels of GPS-PW. The evolution features of GPS-PW in rainfall process caused by different weather systems over the Tibetan Plateau (TP) also differ. These results indicate the reference values for operational applications of GPS-PW data in short-term forecasting and nowcasting of high-impact weather in addition to further investigation of heavy rain caused by the TPV, SWV, and other severe weather systems over the TP. 1. Introduction Atmospheric water is a key factor in precipitation forecasting. The spatial and temporal distribution of this water and the latent heat generated by its phase transition play important roles in atmospheric water transport, energy conversion, and the evolution of weather by affecting atmospheric stability and the structure and changes of weather systems. Such factors are important in the formation of heavy rainfall events including vortices and storms. The three states of water liquid, solid, and gas influence global positioning system (GPS) signals, which are used to determine the total atmospheric water content. Technology developed in the 1990s that uses GPS precipitable water (GPS-PW) to detect the atmospheric water content has high potential and practical value [1]. This method is used to determine water data for an entire day with high precision and temporal resolution, which is not possible by using conventional meteorological observations. Thus, the GPS-PW method is a practical improvement in the monitoring and forecasting capability of water vapor and precipitation [2, 3]. In recent years, local meteorological agencies in China, in conjunction with the departments of astronomy, earthquakes, surveying and mapping, investigation, and design, have developed numerous ground-based GPS meteorological networks based on various GPS meteorology and GPS-PW methods for data %U http://www.hindawi.com/journals/amete/2013/793957/