New methods to Use GNSS Vapor Estimates for Meteorology of Portugal
In cooperation with IPMA , SEGAL is using their expertise with GNSS, to help predict the weather.
Water vapor is difficult to measure, but is of great importance for accurate modeling of the dynamics of the atmosphere, both for weather prediction and for climate applications.
Nowadays, the use of information about the atmospheric water vapor content above each receiving GNSS antenna is already obtained routinely from accurate geodetic data analysis. In this respect, the application of GNSS (Global Navigation Satellite System) observations for use in very short range weather forecasting (nowcasting) has improved considerably in the last few years due to:
a) improved GNSS raw data timeliness (hourly uploads and/or real-time data streaming);
b) improved coverage (the number of ground-based stations of the GNSS networks has increased enormously in the last 5 years);
c) increased temporal resolution of tropospheric estimates.
Both atmospheric and geodetic communities will join efforts in order to operationalize the inclusion of GNSS-PWV estimates for nowcasting in Portugal, namely for the preparation of warnings of severe weather.
The main reason for this has been the cost of ensuring receipt and response. To achieve such goal, the NUVEM project is divided in two major components:
a) development and implementation of methods to compute accurate estimates of PWV (Precipitable Water Vapor) in NRT (Near Real-Time);
b) integration of these estimations in the nowcasting operations done at IPMA (Portuguese Meteo Office).