23 rd GIST meeting Offenbach1 CM-SAF surface radiation Deutscher Wetterdienst 23 rd GIST meeting in Offenbach R. Hollmann, R.W. Mueller, H.D. Behr, P. Albert, A. Gratzki, Meteo Swiss

23 rd GIST meeting Offenbach2 Outline of talk Introduction CM-SAF Surface radiation budget Algorithms used results with MSG cloud mask validation Conclusion

23 rd GIST meeting Offenbach3 Motivation Mandate of CM-SAF: ● support climate monitoring at regional scale ● the generation of a thematic climate data record in an operational off - line environment ● the generation of long-term validated, homogeneous and consistent data sets Beside the mandate of CM-SAF the Solar-Energy Community benefits from the CM-SAF radiation products

23 rd GIST meeting Offenbach4 Surface Radiation budget products ● Products: – SOL: surface outgoing longwave – SDL: surface downwelling longwave – SIS: surface incoming shortwave – SAL: surface albedo – SRB: surface radiation budget (SNL/SNS) ● 15x15 km sinusoidal projection. ● Monthly and daily mean (AVHRR, MSG), mean diurnal cycle (only MSG) ● Covered area: 30° N to 80° N, 60° W to 60° E ● Operational processing and delivery of NOAA-AVHRR based products has been started ● MSG based products are currently pre-operational (~available for public Aug/Sep 2005 (tbc))

23 rd GIST meeting Offenbach5 I 2004 I 2007 I 2008 I 2005 I 2006 I 2009 Initial Operations Phase Full Operations Phase V2 V3 Area Extension EPS Merging MSG (rad & clouds) HCP (ATOVS & MSG) V1 NOAA (rad & clouds) CM-SAF: Schedule & Versioning CM-SAF Surface Radiation Budget: 23 rd GIST

23 rd GIST meeting Offenbach6 Beta-user?! Passive House Institute, (J. Schnieders), Darmstadt, Germany Fraunhofer Institute for Solar Energy Systems (Chr. Reise), Freiburg, Germany DWD, Regional Office Hamburg, solar energy specific radiation maps Scientific User‘s (tbc): RADAGAST (within AMMA framework), A. Slingo, Reading, UK DLR (M. Schrödter-Homscheidt), Oberpfaffenhofen, Germany Spain Met. Service (J. L. Camacho, Guerrero) Looking for more beta-user!!! -> -> have a look at

23 rd GIST meeting Offenbach7 RTM library libRadtran for MLB-LUTs Bernhard Mayer (DLR) and Arve Kylling (NILU) SHDOM for cloud LUTs Frank Evans AVHHR TOA-flux with ERBE ADM (DWD), cloud products, nowcasting SAF (SMHI). TOA-flux for GERB/SEVIRI is calculated by RMIB. Overview SIS Algorithm

23 rd GIST meeting Offenbach8 Overview SIS Algorithm cloudmask Cloud-free ? Clear-sky Atmospheric state Ozon, H2O, Aerosole CLOUD-LUT Relation G-TOA for clear-sky atmospheric states (9SZW) and 10 CODs CLEAR-SKY: MLB-LUT G for clear-sky atmospheric states TOA flux G G SAT ADM AVHRR GERB/SEVIRI

23 rd GIST meeting Offenbach9 Example MSG products Monthly mean 2004,07: top SDL, SOL; bottom SIS, SAL

23 rd GIST meeting Offenbach10 Example products Monthly means 2004,07: top SDL, SOL; bottom SIS, SAL

23 rd GIST meeting Offenbach11 Example products Monthly mean 2004,07: top SNL; bottom SNS

23 rd GIST meeting Offenbach12 Example products Monthly mean diurnal cycle of SIS for April 2005 Rem.: at the moment no GERB-data are available -> the SIS-Algorithm is run with the SEVIRI only based TOA albedo

23 rd GIST meeting Offenbach13 Overview Longwave SOL: Based on Plancks radiation law for black bodies. Surface temperature from GME analysis SDL: Adaption of Gupta algorithm T and H 2 O from GME analysis Cloudmask and –height retrieved from AVHRR or MSG with nowcasting-SAF algorithms (SMHI, MeteoFrance)

23 rd GIST meeting Offenbach14 Overview Validation 4-5 stations: Payerne, Carpentras, Lindenberg, Cabauw (Ny-Alesund). Ongoing validation of the operational products Validation of reference months. Base for Initial operations phase. To analyse comparable results with the goal to improve the algorithm. To track the effect of changes in the algorithm.

23 rd GIST meeting Offenbach15 Overview Validation Mean absolute bias of monthly means over all stations and months (4 stations, 2 month) SDL SIS 27.6SOL BIAS in % BIAS in W/m²

23 rd GIST meeting Offenbach16 Overview Validation First validation of MMDC: July 2004, Carpentras-Station Green: surface obs black: MSG derived

23 rd GIST meeting Offenbach17 Conclusion Validation 10 W/m² „target accuracy“ für monthly means (SIS,SOL,SDL) are in general achieved. Problems in the Alpine region, especially for the longwave radiation. Support for heterogeneous terrain by MeteoSwiss. Planned: Routine (Automatized) quality check with reference data set. Validation for more stations and month. Acknow.: For providing data for validation to MeteoSwiss, MeteoFrance, KNMI, DWD, AWI

23 rd GIST meeting Offenbach18 Validation of MSG cloud fraction ● Comparison of MSG cloud fraction with Synop observations ● April, May, October 2004

23 rd GIST meeting Offenbach19 MSG SYNOP rel. difference difference Validation of MSG cloud fraction

23 rd GIST meeting Offenbach20 ● Better agreement over land than over sea ● Day / night dependence? ● Best agreement where number of SYNOP observations is highest Validation of MSG cloud fraction

23 rd GIST meeting Offenbach21 Outlook: Operational production based on NOAA-AVHRR since Jan 2005 Operational production based on MSG will start Aug/Sep 2005 (tbc) Surface Radiation Processing; mean differences for SIS ~ 10 W/m² mean differences for SDL ~ 10 W/m² Ongoing validation; selected reference target stations with quick data availability TOA albedo comparison MSG/GERB vs. AVHRR improvement of LUT-approach new background maps for aerosol properties merging of both data set User Workshop August 2005 in Nuremberg (Germany). CM-SAF Surface Radiation Budget: Conclusion & outlook

23 rd GIST meeting Offenbach22

23 rd GIST meeting Offenbach23 Clear-sky MLB-LUT MLB-LUT: G for 2 SZA different AOD, ssa, gg USS-stand. profile, surf. albedo 0.2 G interpolated Aerosol-space GADS/OPAC or MPI Hamburg Aerosol climatology LAT,LON AOD ssa, gg GME H2O O 3 profile correction absorb constituents H 2 O,O 3 Surface albedo FMI or background H2O, O3 Albedo correction of effect surface albedo G MLB: modified Lambert Beer relationship (Mueller et al. 2004)

23 rd GIST meeting Offenbach24 Cloudy-sky ‘traditional’ LUT LUT: TOA flux – G ratio for 9 SZA, 10 COD, 5 H2O, 7 Albedo, 3 O 3, 5 atm. profile G interpolated, no aerosols LAT,LON AOD ssa, gg GME H2O O 3 profile Correction for Aerosols surfacealbedo FMI or background-alb H2O, O3 Albedo G GADS/OPAC or MPI Hamburg Aerosol Climatology TOA flux SAT ADM