Evaluation of the atmospheric precipitable water at local scale during extreme weather using groundbased CGPS measurements

Global Positioning System (GPS) has demonstrated its ability to monitor the atmospheric water vapour content with an accuracy comparable to other techniques and means of measurements (e.g. radio soundings, microwave radiometers), even with good time resolution and under all meteorological conditions. The nowadays extensive use of permanent GPS stations, operating for geodetic purposes, offers a tool for a dense and reliable remote sensing of atmospheric water vapor. Here the tropospheric delay observed on some continuous GPS (CGPS) stations of the Italian GPS network (RING) is analyzed and its time evolution is discussed. We focus mainly on the study of the wet component of the atmospheric delay of the GPS signals and the computation of the precipitable water by using co-located GPS and meteorological stations. The results are described and discussed in comparison with different meteorological observations collected during extreme weather conditions impacting the Campania region.