Updated CM SAF Top-Of-Atmosphere Radiation GERB/SEVIRI Climate Data Record available

Illustration 1: daily mean TOA Reflected Solar fluxes in all-sky (left) and clear sky Source: CM SAF

The data record provides estimates of the Top-Of-Atmosphere broadband radiative fluxes derived from the Geostationary Earth Radiation Budget (GERB) and the Spinning Enhance Visible and InfraRed Imager (SEVIRI) sensors onboard the Meteosat Second Generation satellites. The fluxes are reported as TOA Reflected Solar (TRS aka shortwave flux) and TOA Emitted Thermal (TET aka longwave flux or outgoing longwave radiation). In addition to the all-sky fluxes, their clear-sky counterparts are also provided, allowing for instance the estimation of the cloud radiative effect or a better evaluation of the radiative schemes in climate/NWP models. The TOA incoming flux is also provided and can be used to estimate the “net” radiation budget.

The original GERB level 2.0 High Resolution (HR) and SEVIRI level 1.5 observations have been processed to estimate solar and thermal fluxes in hourly boxes on the GERB HR grid. From the hourly values, the daily mean, the monthly mean and the monthly mean diurnal cycle are estimated. Finally, the data is regridded on a regular latitude-longitude grid covering 70°N-70° and 70°W-70°E, with a spatial resolution of 0.1°.

Being based on 15' geostationary observations, the data record is very well suited to study the diurnal cycle of atmospheric radiation, e.g. the effect of convection on the OLR. The spatial resolution of the data, 0.1°, allows to study the effect on the radiation budget of processes taking place at fine spatial scale, e.g. valley fog. Combining the all-sky and clear-sky allows quantifying the cloud radiative effects at high spatial and temporal resolution.

A special effort has been put on the estimation of the accuracies of the fluxes which are reported at the pixel level in the daily and monthly mean products.

The data record can be ordered via the Web User Interface.

Technical specifications

NC / Sept2017