1. RMIB involvement in the Geostationary Earth Radiation Budget (GERB) and Climate Monitoring SAF projects Nicolas Clerbaux Remote sensing from Space Division Royal Meteorological Institute of Belgium

2. The remote sensing from space division of the RMIB About 20 scientists/technicians working on the Earth radiation budget: Spaceborn measurement of the total solar irradiance (solar 'constant') – space shuttle, ISS, SOHO, picard. Processing of the GERB instrument data (MSG) Generation of TOA radiative flux products within the CM-SAF (MSG + polar sat.)

3. GERB project Science goals: Improvement of climate models by better understanding the role of clouds and water vapour in the ERB, Improvement of Numerical Weather Prediction (NWP) models by data assimilation or near real-time validation, Synergy with low orbit satellites observations: improvement of the diurnal model, Climate monitoring in the frame of the EUMETSAT Satellite Application Facility on Climate Monitoring (CM- SAF). Mission: accurate rapid broadband measurement of the reflected solar and emitted thermal radiation (first BB radiometer on the geo orbit).

4. Interest of the Meteosat Field-of-View Also: desertification, African monsoon, marine stratocumulus, volcanoes, biomass burning, … Aerosols Tropical Convection Contrails Cirrus

5. blue : cooling effect red : warming effect unit : W/m² Radiative effect of aerosols biomass burning mineral dust

6. GERB instrument WAVEBANDS Total:0.32 µm - 100.0 µm Shortwave, SW:0.32 µm - 4.0 µm Longwave, LW (by subtraction):4.0 µm - 100.0 µm RADIOMETRY SWLW Absolute Accuracy:< 1.0 %< 1.0 % Signal/Noise:1250 400 Dynamic Range:0-380 W m -2 sr -1 0-90 W m -2 sr -1 SPATIAL SAMPLING : 44.6  39.3 km (NS  EW) at nadir TEMPORAL SAMPLING: 15 minute SW and LW fluxes CYCLE TIME: Full Earth disc, both channels in 5 minutes CO-REGISTRATION Spatial:3 km wrt SEVIRI at satellite sub-point Temporal:Within 15 min of SEVIRI at each pixel INSTRUMENT MASS 25 kg POWER 35 W

7. Scanning 256 detector pixels 282 steps

8. Measured (filtered) Radiance Images shortwave [W/m²/sr]total [W/m²/sr]

9. GERB data processing Geolocation and calibration (RAL, UK) Tuning of the geolocation wrt SEVIRI Radiance unfiltering: correction for the instrument spectral response  Conversion in flux: angular modelling of the radiation field –Scene identification (surface, cloudiness,…) –Application of angular models Enhancement of the spatial resolution: 50km  10km Near real-time dissemination (FTP) Long term archiving and dissemination (RAL,UK) At the RMIB (Brussels)

10. Derived Fluxes Images (50km) Solar [W/m²]Thermal [W/m²]

11. Current Status GERB acquisition on Meteosat-8 started December 2002 and is ongoing, The instrument is operating well, is stable and the measurements have low noise Cross-calibration with other instruments (CERES) indicates good performances of the instrument Release of Edition-1 data in March 2006  NRT generation of Edition-1 data  Reprocessing of 02/2004 -> 03/2006 ongoing 10 May 2007 : switch to GERB on Meteosat-9  Validation not yet finished  GERB becomes an operational EUMETSAT service

12. TOA Radiative Products in the Climate Monitoring SAF Production of  monthly means,  daily means,  monthly means diurnal cycle of  incoming solar irradiance  reflected solar flux  emitted thermal flux  net flux from  GERB data  GERB-like data  CERES data

13. CMSAF Status Entering in the CDOP phase  Reprocessing, reprocessing, reprocessing,...  Extension of the dataset to Meteosat first generation data (GERB-like)  possibly generation of global products Thank you ! More info? http://gerb.oma.be http://cmsaf.oma.be email: gerb@oma.be