Near-real-time Maps of Integrated Water Vapour (IWV) and Zenital Total Delay (ZTD) in the Troposphere over South America for 2022

Abstract

Water vapor (WV) is a key component in the hydrological cycle. Changes in the distribution of WV and the rate of these changes influence the evolution of the climate. In addition, near-real-time (NRT) observations of WV have important applications through their assimilation into Numerical Weather Predictions (NWP). Here we present a regional NRT WV monitoring system based on GNSS observations. It relies exclusively on data produced by existing geodetic and meteorological infrastructure, and uses only GNSS and surface meteorological observations. Coverage extends from central Brazil to the Antarctic Peninsula, including Argentina and Uruguay, and produces hourly estimates of both Zenith Total Delay (ZTD) and Integrated Water Vapor (IWV).