Sibylle Vey

Validation of Precipitable Water Vapor within the NCEP/DOE Reanalysis Using Global GPS Observations from One Decade

Abstract In contrast to previous studies validating numerical weather prediction (NWP) models using observations from the global positioning system (GPS), this paper focuses on the validation of seasonal and interannual variations in the water vapor. The main advantage of the performed validation is the independence of the GPS water vapor estimates compared to studies using water vapor datasets from radiosondes or satellite microwave radiometers that are already assimilated into the NWP models. Tropospheric parameters from a GPS reanalysis carried out in a common project of the Technical Universities in Munich and Dresden were converted into precipitable water (PW) using surface pressure observations from the WMO and mean atmospheric temperature data from ECMWF. PW time series were generated for 141 globally distributed GPS sites covering the time period from the beginning of 1994 to the end of 2004. The GPS-derived PW time series were carefully examined for their homogeneity. The validation of the NWP mo...

Validation of the Atmospheric Water Vapour Content from NCEP Using GPS Observations Over Antarctica

An evaluation of the precipitable water (PW) in the reanalysis of the National Center for Environmental Prediction (NCEP) over Antarctica was carried out using observations from eight coastal Antarctic GPS stations. PW time series were derived from tropospheric parameters in conjunction with meteorological observations provided by the British Antarctic Survey for the period from 1994 to 2004 with a 2h temporal resolution. The tropospheric parameters this study is based on are a product of the common GPS reprocessing from the Universities of Technology in Munic and Dresden.