Comparison of GNSS integrated water vapor and NWM reanalysis data over Central and South America
Abstract. We compared and analyzed data of vertically Integrated Water Vapor (IWV) from two different re-analysis models (ERA-Interim from ECMWF and MERRA-2 from NASA's Global Modeling and Assimilation Office) with respect to IWV values from Global Navigation Satellite Systems (GNSS) at 53 stations of Central and South America during the 7-year period from January 2007 till December 2013. The comparison was performed taking into account the geopotential height differences between each GNSS station and the correspondent values assigned by the models. Thus, the set of GNSS stations was divided into 3 groups: Small, Large and Critical height difference stations. Moreover, the performance of the re-analysis models was also analyzed by using an additional classification of three levels according to the mean IWV (IWV) value expected at the station: IWV > 30 kg m−2, 12 kg m−2 ⩽ IWV ⩽ 30 kg m−2 and IWV