23 rd gist meeting offenbach1 cm-saf surface radiation deutscher wetterdienst 23 rd gist meeting in...
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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 productsTRANSCRIPT
23rd GIST meeting Offenbach 1
CM-SAF surface radiation
Deutscher Wetterdienst
23rd GIST meeting in Offenbach
29.04.2005
R. Hollmann, R.W. Mueller, H.D. Behr, P. Albert, A. Gratzki,
MeteoSwiss
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Outline of talk
Introduction
CM-SAF Surface radiation budget Algorithms used
results with MSG
cloud mask validation
Conclusion
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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
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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 01.01.2005● MSG based products are currently pre-operational (~available for
public Aug/Sep 2005 (tbc))
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I2004
I2007
I2008
I2005
I2006
I2009
Initial Operations Phase
Full Operations Phase
V2
V3
Area ExtensionEPSMerging
MSG(rad & clouds)HCP(ATOVS & MSG)
V1NOAA(rad & clouds)
CM-SAF: Schedule & Versioning
CM-SAF Surface Radiation Budget:
23rd GIST
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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
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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
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Overview SIS Algorithm
cloudmask
Cloud-free ?
Clear-skyAtmospheric state
Ozon, H2O, Aerosole
CLOUD-LUT Relation G-TOA for
clear-sky atmospheric states(9SZW) and 10 CODs
CLEAR-SKY: MLB-LUTG for clear-sky
atmospheric states
TOAflux
G G
SAT
ADM
AVHRRGERB/SEVIRI
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Example MSG productsMonthly mean 2004,07: top SDL, SOL; bottom SIS, SAL
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Example productsMonthly mean 2004,07: top SNL; bottom SNS
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Example productsMonthly 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
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Overview Longwave
SOL: Based on Plancks radiation law for black bodies.
Surface temperature from GME analysisSDL: Adaption of Gupta algorithm
T and H2O from GME analysis
Cloudmask and –height retrieved from AVHRR or MSG with nowcasting-SAF algorithms (SMHI, MeteoFrance)
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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.
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CARPENTRAS
0
50
100
150
200
250
300
350
400
July 2004 October 2004 July 2004 October 2004
SIS SDL
W/m
2 in_situ W/m2
sat W/m2
Overview Validation
Mean absolute bias of monthly means over all stations and months (4 stations, 2 month) .
2.759.5SDL
2.52.9SIS
27.6SOL
BIAS in %BIAS in W/m²
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Overview Validation
First validation of MMDC: July 2004, Carpentras-Station
Green: surface obsblack: MSG derived
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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
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Validation of MSG cloud fraction
● Comparison of MSG cloud fraction with Synop observations● April, May, October 2004
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MSG SYNOP
rel. differencedifference
Validation of MSG cloud fraction
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● Better agreement over land than over sea
● Day / night dependence?● Best agreement where
number of SYNOP observations is highest
Validation of MSG cloud fraction
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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).
CM-SAF Surface Radiation Budget: Conclusion & outlook
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Clear-sky MLB-LUT
MLB-LUT: G for 2 SZA different AOD, ssa, gg
USS-stand. profile, surf. albedo 0.2
G interpolatedAerosol-space
GADS/OPAC or MPI Hamburg
Aerosol climatology
LAT,LON
AODssa, gg
GME H2OO3 profile correction absorb
constituents H2O,O3
Surface albedoFMI or background
H2O, O3
Albedo correction of effect surface albedo
G
MLB: modified Lambert Beer relationship (Mueller et al. 2004)
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Cloudy-sky ‘traditional’ LUT
LUT: TOA flux – G ratiofor 9 SZA, 10 COD, 5 H2O,
7 Albedo, 3 O3, 5 atm. profile
G interpolated, no aerosols
LAT,LON
AODssa, gg
GME H2OO3 profile
Correction for Aerosols
surfacealbedo FMIor background-alb
H2O, O3
Albedo
G
GADS/OPAC or MPI Hamburg
Aerosol Climatology
TOAflux
SATADM