GPS, NCEP Data and METEOSAT Precipitable Water Comparison for Balkan Area

Integrated Precipitable Water Vapor (IPWV) studies are an important mode for the hydrological regime evaluation with respect to the vertical structure of the atmosphere. The aim of this work is to integrate different observation systems (for instance Global Positioning System and METEOSAT-8) and data sources in order to study IPWV spatial and temporal distribution for Balkans region, sparsely covered with atmospheric vertical observations, as the helpful aid in the analysis of weather and synoptic processes.Global Positioning System (GPS) represents an enormous ongoing three-dimensional atmospheric observation system since the wet component of the tropospheric delay in GPS signals is nearly proportional to the quantity of integrated precipitable water vapor (IPWV). Tropospheric solutions for Balkans GPS sites of Sarajevo, Osjek, Dubrovnik and Ohrid are studied and presented in comparison to METEOSAT-8 and NCEP data.Tropospheric humidity product derived from the two water vapor channels of meteorological satellite METEOSAT-8 provides a layer-mean relative humidity for two tropospheric layers (between about 500 and 200hPa and between 850 and 300 hPa) with the resolution of 3 km, subsequently a biased estimation of IPWV can be obtained.Daily global analysis precipitable water data since 1980 available at 2.5 degrees resolution from the National Centres for Environmental Prediction (NCEP) is a helpful climate data source to evaluate humidity observations.