First TOA fluxes from the Geostationary Earth Radiation Budget (GERB) instrument

Abstract

On 29th January 2004 the first Meteosat Second Generation satellite MSG-1, renamed Meteosat-8 (MS-8), commenced routine operations. MS-8 carries the new Spinning Enhanced Visible and Infra Red Imager (SEVIRI) and a Geostationary Earth Radiation Budget (GERB) radiometer. GERB provides valuable short- and long wave broadband measurements of the Earth in order to estimate the top-of-atmosphere radiation budget accurately. The unique feature of GERB in comparison with previous measurements of the Earth's radiation budget is its very fast temporal sampling (15 minutes) afforded by geostationary orbit. On the other hand, the GERB instrument only accounts for a crude spatial resolution (about 50 km at the sub-satellite point). Taking advantage of the synergy between the data from GERB and SEVIRI, we propose at the Royal Meteorological Institute of Belgium to merge the two data streams to produce near real-time estimates of the radiation budget for limited geographical regions at a 3x3 SEVIRI pixel resolution (the SEVIRI resolution is 3 km at satellite sub-point). Such fluxes aim to be used by the climate and numerical weather prediction (NWP) scientific communities through climate studies and validation/evaluation of the performance of NWP models over the region covered by MS-8.