1. 1st Progress meeting ELDAS The ELDORADO surface radiation system Bart vd Hurk & Dirk Meetschen et al (see ELDAS web-page)

2. 1st Progress meeting ELDAS Principle Generating 3-hrly LW & SW surface downward radiative fluxes ELDAS grid resolution Combining METEOSAT data and RT calculations from the ECMWF model Simplified data assimilation technique Brief verification using routine SW stations in The Netherlands

3. 1st Progress meeting ELDAS ELDORADO steps (1) 1.Create initial field of cloud cover & liquid water profile Continuous simulation using LAM version of ECMWF model at 0.5 , started daily from interpolated ECMWF analysis Interpolate cloud fields at 3hrly intervals to ELDAS 0.2  grid 2.Create METEOSAT-derived cloud cover field at ELDAS grid METCLOCK cloud mask product Cloud cover = average mask of 5  3 METEOSAT pixels surrounding target location

4. 1st Progress meeting ELDAS ELDORADO steps (2) 3.Create METEOSAT net TOA SW radiation at ELDAS resolution Sensor irradiance  net TOA flux Extra time/space/month-dependent calibration factor, derived from monthly averaged clear sky TOA SW flux generated by LAM 6UTC9UTC12UTC

5. 1st Progress meeting ELDAS ELDORADO steps (3) 4.Reshuffle model columns for relocation of cloudy/cloud-free atmospheric columns For each target location, select model column with the smallest value of: J = a distance + b  albedo + c  SWnet TOA 5.Adjust total cloud cover to METCLOCK value by scaling cloud cover profile Cumulative cloud cover MetClock obs First guess Scaled scaling factor height

6. 1st Progress meeting ELDAS ELDORADO steps (4) 6.Adjust liquid water content similarly in order to match SWnet TOA Non-linear relation: 2 iterations applied Only applied to cloudy model gridpoints 7.Store and interpolate resulting downward LW and SW surface fluxes as best estimate When either METCLOCK or SW-obs are absent: use first guess Archived METEOSAT/METCLOCK data covers only part of the ELDAS domain

7. 1st Progress meeting ELDAS Total cloud cover

8. 1st Progress meeting ELDAS TOA SWnet

9. 1st Progress meeting ELDAS Surface verification  30 Routine stations in Netherlands Only downward shortwave Daily totals First guess affected by erroneous daily reset to cloudfree conditions at 0 UTC: probably little cloud spin-up in morning hours

10. 1st Progress meeting ELDAS Statistics April/May 2000 this dataset: first guess: 37 W/m2 ELDORADO: 12 W/m2 Bias of ERA40 over SGP ARM observations (April-May 1999): clear sky: 31 W/m2 overcast: 26 W/m2 all cond.: 17 W/m2

11. 1st Progress meeting ELDAS Still to do Further validation –BSRN stations (hardly available via www-service, but Lindenberg-data are ordered) –Validation plan Cleaning the archive –Replace missing time slots by first guess –Fill area outside METEOSAT domain with first guess Interpolation to ELDAS grid