CM-SAF surface radiation R Hollmann R W Mueller

CM-SAF surface radiation R. Hollmann, R. W. Mueller, H. D. Behr, P. Albert, A. Gratzki, Deutscher Wetterdienst 23 rd GIST meeting in Offenbach 29. 04. 2005 Meteo Swiss 3/19/2018 23 rd GIST meeting Offenbach 1

Outline of talk Introduction CM-SAF Surface radiation budget Algorithms used results with MSG cloud mask validation Conclusion 3/19/2018 23 rd GIST meeting Offenbach 2

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 3/19/2018 23 rd GIST meeting Offenbach 3

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) 15 x 15 km sinusoidal projection. – ● ● 3/19/2018 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 01. 2005 MSG based products are currently pre-operational (~available for public Aug/Sep 2005 (tbc)) 23 rd GIST meeting Offenbach 4

CM-SAF Surface Radiation Budget: CM-SAF: Schedule & Versioning Full Operations Phase Initial Operations Phase V 3 V 2 V 1 MSG NOAA (rad & clouds) HCP Area Extension EPS Merging (ATOVS & MSG) I 2004 3/19/2018 I 2005 23 rd GIST I 2006 I 2007 23 rd GIST meeting Offenbach I 2008 I 2009 5

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 http: \www. cmsaf. dwd. de 3/19/2018 23 rd GIST meeting Offenbach 6

Overview SIS Algorithm RTM library lib. Radtran 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. 3/19/2018 23 rd GIST meeting Offenbach 7

Overview SIS Algorithm cloudmask SAT TOA flux AVHRR GERB/SEVIRI ADM Cloud-free ? CLEAR-SKY: MLB-LUT G for clear-sky atmospheric states G 3/19/2018 CLOUD-LUT Relation G-TOA for clear-sky atmospheric states (9 SZW) and 10 CODs Clear-sky Atmospheric state Ozon, H 2 O, Aerosole 23 rd GIST meeting Offenbach G 8

Example MSG products Monthly mean 2004, 07: top SDL, SOL; bottom SIS, SAL 3/19/2018 23 rd GIST meeting Offenbach 9

Example products Monthly mean 2004, 07: top SNL; bottom SNS 3/19/2018 23 rd GIST meeting Offenbach 11

Example products Monthly mean diurnal cycle of SIS for April 2005 3/19/2018 Rem. : at the moment no GERB-data are available -> the SIS-Algorithm is run with the 23 GIST meeting Offenbach 12 SEVIRI only based TOA albedo rd

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, Meteo. France) 3/19/2018 23 rd GIST meeting Offenbach 13

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. 3/19/2018 23 rd GIST meeting Offenbach 14

Overview Validation Mean absolute bias of monthly means over all stations and months (4 stations, 2 month). 7. 6 2 SDL 9. 5 2. 75 SIS 23 rd GIST meeting Offenbach BIAS in % SOL 3/19/2018 BIAS in W/m² 2. 9 2. 5 15

Overview Validation First validation of MMDC: July 2004, Carpentras-Station Green: surface obs black: MSG derived 3/19/2018 23 rd GIST meeting Offenbach 16

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 Meteo. Swiss. Planned: Routine (Automatized) quality check with reference data set. Validation for more stations and month. Acknow. : For providing data for validation to Meteo. Swiss, Meteo. France, KNMI, DWD, AWI 3/19/2018 23 rd GIST meeting Offenbach 17

Validation of MSG cloud fraction ● ● 3/19/2018 Comparison of MSG cloud fraction with Synop observations April, May, October 2004 23 rd GIST meeting Offenbach 18

Validation of MSG cloud fraction SYNOP MSG difference 3/19/2018 23 rd GIST meeting Offenbach rel. difference 19

Validation of MSG cloud fraction ● ● ● 3/19/2018 Better agreement over land than over sea Day / night dependence? Best agreement where number of SYNOP observations is highest 23 rd GIST meeting Offenbach 20

CM-SAF Surface Radiation Budget: Conclusion & outlook 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 29 -31. August 2005 in Nuremberg (Germany). 3/19/2018 23 rd GIST meeting Offenbach 21

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Clear-sky MLB-LUT MLB: modified Lambert Beer relationship (Mueller et al. 2004) LAT, LON GADS/OPAC or MPI Hamburg Aerosol climatology MLB-LUT: G for 2 SZA different AOD, ssa, gg USS-stand. profile, surf. albedo 0. 2 AOD ssa, gg G interpolated Aerosol-space GME H 2 O O 3 profile correction absorb constituents H 2 O, O 3 Surface albedo FMI or background 3/19/2018 H 2 O, O 3 Albedo correction of effect surface albedo G 23 rd GIST meeting Offenbach 23

Cloudy-sky ‘traditional’ LUT ADM LAT, LON SAT TOA flux GME H 2 O O 3 profile H 2 O, O 3 surfacealbedo FMI or background-alb Albedo LUT: TOA flux – G ratio for 9 SZA, 10 COD, 5 H 2 O, 7 Albedo, 3 O 3, 5 atm. profile G interpolated, no aerosols GADS/OPAC or MPI Hamburg Aerosol Climatology 3/19/2018 AOD ssa, gg 23 rd GIST meeting Offenbach Correction for Aerosols G 24