Cloud scene accuracy by radiance and flux measurements from GERB and SEVIRI

The first Meteosat Second Generation (MSG) satellite with an Earth radiation budget instrument (GERB) and a multi-channel instrument (SEVIRI) aboard is planned to be launched in late 2000. MSG will be the first satellite carrying both a multichannel narrowband and a broadband instrument in a geostationary orbit which allows a high temporal resolution. Every 15 minutes a complete dataset of total and solar spectral band and 12 narrowbands is obtained for the whole area visible from geostationary orbit. This unique opportunity will allow to investigate the diurnal cycle of the Earth radiation budget and its dependence on different atmospheric scenes. In this pre-launch study, measurements are simulated with a radiation transfer model (STREAMER). Vertical profiles of radiation divergence are derived from these simulated measurements of both MSG instruments, in synergy with other, polar orbiting satellites. The main focus is on cloud and radiation interaction.