clouds and the earth's radiant energy system (ceres
TRANSCRIPT
Clouds and the Earth'sRadiant Energy System(CERES) Clouds andRadiation Swath (CRS)Data Set Abstract
Table of Contents:
Data Set DescriptionSummary of ChangesReferencesContact InformationAcknowledgement
Data Set Description:
The Clouds and Radiative Swath (CRS) product contains one hour of instantaneous Clouds and the Earth's Radiant Energy System (CERES)data for a single scanner instrument. The CRS contains all of the CERES SSF product data. For each CERES FOV on the SSF, the CRS alsocontains vertical flux profiles evaluated at five levels in the atmosphere: the surface, 500 hPa, 200 hPa, 70 hPa, and TOA. These through-the-atmosphere fluxes are computed by making two passes through a radiative transfer model. After an initial pass through the model, themodeled TOA results are compared against the CERES TOA results produced by the CERES inversion process and contained on the SSF.Inputs to the model are adjusted accordingly, and a second pass is made through the model. The results of the second, or constrained, passare more consistent with the CERES TOA values.
The CRS contains the following constrained vertical flux profiles for both clear sky and total sky conditions evaluated at the surface, 500 hPa,200 hPa, 70 hPa, and TOA, along with pristine and aerosol-free total sky fluxes evaluated at the surface and the TOA. (Please note that theaerosol-free total sky flux data are not available on the TRMM CRS granules.) Pristine denotes a theoretical sky condition that is free of bothaerosols and clouds. Aerosol-free total sky denotes a theoretical sky condition that includes clouds but is free of aerosols.
Longwave upward and downward.Shortwave upward and downward.Window channel upward and downward.
The initial flux profiles are not contained on the CRS; however, the adjustments between the constrained and initial profiles for the followingare included for clear sky, total sky, pristine, and aerosol-free total sky conditions:
Longwave upward at the surface and TOA, and downward at the surface.Shortwave upward at the surface and TOA, and downward at the surface.Window channel upward at the surface and TOA, and downward at the surface.
The adjustments to the radiative transfer model input parameters between the initial and the constrained passes are also contained on theCRS. These parameters include:
Surface albedo and skin temperature.Total column precipitable water and upper tropospheric relative humidity.Aerosol optical depth.Cloud optical depth, fractional area, and effective temperature.
Additional information about the format and content of the CRS can be found in the CERES Data Products Catalog. The CRS QualitySummary briefly describes the algorithms used for radiative transfer and constrainment (tuning), as well as the data inputs.
Summary of Changes:
The CERES Data Management Team and the Atmospheric Science Data Center (ASDC) at Langley use a Sampling Strategy, a ProductionStrategy, and a Configuration Code (CCode) to track versions of CERES primary data products. In general, minor reprocessing changes aretracked by increasing the Configuration Code while major reprocessing changes result in a new Production Strategy. The Sampling Strategyidentifies the satellite and instruments which aquired the data in the product.
A summary of changes made to the CERES CRS product is shown in the following tables.
Modification History for: Aqua | Terra | TRMM
Modification History of the CERES Aqua CRS Archival ProductAlso see Modification History for CERES SSF Aqua FM3 and FM4
Sampling Strategy andProduction Strategy
CCode Availableat ASDC
Impact on Aqua CRS Product
Aqua-FM3-MODIS_Edition2C (4)
Aqua-FM4-MODIS_Edition2C (4)021033 September 2008 No changes to the CERES
SARB software.Switched MODIS inputfiles for CRS processingfrom collection 004 tocollection 005.See corresponding SSFdocumentation and CRSData Quality Summary forimpacts of switch ofMODIS inputs fromCollection 004 toCollection 005.
Aqua-FM3-MODIS_Edition2B (4)
Aqua-FM4-MODIS_Edition2B (4)021031 March 2008 A new ancillary data file
was added for Aquaprocessing whicheliminates the use of themonthly MODIS aerosolmap. This solvedinfrequent problemscaused by treatment ofdefault data in MODISfiles.
Aqua-FM3-MODIS_Edition2A (4)
Aqua-FM4-MODIS_Edition2A (4)021028 August 2006 Photosynthetically active
radiation over surfacevalues were modified toinclude spectral weightingfactors that convert thespectral band 7-10 (557.5- 689.6nm) output to 400 -700nm (CRS SDS 161).Surface albedo retrievalswere corrected forinstances where theassociated MATCH valueis less than 0.0001 toavoid division by zero.The definition of surfacealbedo over cloudy-skycoast was modified to usethe SAH cloudy landalbedo value from themonthly SSF-basedsurface albedo historymap for ocean coverage ofless than 1% to correctunrealistically largesurface albedo values forcloudy-sky coastal FOVs.The definition of surfacealbedo for clear-sky coastwas modified to useZhonghai Jin's ocean look-up table value to correctthe resulting modeled TOAalbedo that was largerthan the CERES value forclear-sky coast.Cloudy sky over snow
surface albedo retrievalswere modified to include amore complex look-uptable to account for theinfluence of more availableinput parameters. Sulfateaerosol optical depth isused for the retrievalmodel. Ocean surfacealbedo is assumed for out-of-range low retrieval andSnow is assumed for out-of-range high retrieval.The spectral shape in theUV region was modified toinclude revised values forthe closed shrubs, woodysavanna, savanna,grassland, cropland, cropmosaic, and tundra IGBPscene types.The direct/diffusedefinition for ice cloudswas corrected to improvethe handling of the icecloud forward scatteringpeak for the 2-streamsolver.Time varying trace gasconcentrations for CO2,CH4, and N2O wereincluded to account fortrace gas increases thathave been observed.The water percentagethresholds to 20:99% weretreated as coast forsurface albedo logic.FOVs that are mostly land(1:20%) are better servedby using the monthly SSF-based surface albedohistory map than a waterpercent weighted IGBPdefault surface albedo.
Aqua-FM3-MODIS_Beta1 (4)
Aqua-FM4-MODIS_Beta1 (4)020027 July 2005 The Aqua Beta1 CRS data
set was the first CRS dataset produced from Aquadata. This data set wasproduced using the samesoftware and ancillaryinput data sets as theTerra Edition2B CRS dataset.For FOVs where theMATCH data is the solesource of aerosol opticaldepth information, theMATCH 0.55 mm datainstead of the MATCH0.63 mm data will beapplied in the Fu-Lioumodel. Using the wrongwavelength causesconstituents with extinctiondecreasing withwavelength (sulfate, watersoluble, soot) to have areduced effect, and
causes constituents thathave extinction increasingwith wavelength (mineraldust, insoluble) to have anincreased effect.The Langley Fu-Lioumodel was updated to addnew Lacis dust aerosoldata for the aerosol scenetype indexes 19-23 for0.5mm, 1.0mm, 2.0mm,4.0mm, and 8.0mm dust,respectively. The FLSAtable was also modifiedaccordingly. The new dustproperties are lessabsorbing than the earlier(1996) version.Aerosols are now allowedin the stratosphere above15km, which allows for fulluse of the MATCH aerosolprofile data which isprovided up to 1 hPa or~50Km.Modified interpretation ofthe ADMgeo parameter totake advantage of newinformation added by theADM group for the TerraEdition2B SSF delivery.Default values are nowclearer and new non-default data providedinformation regarding thelocation of the centroid ofthe FOV in relation to themicrowave imagerretrievals.CRS Parameters Affected:Terra CRS 161-163,172-183, 193-235
Availability: (1) not available; (2) restricted to CERES analysts; (3) restricted to CERES Science Team and analysts; (4) public
Modification History for: Aqua | Terra | TRMM
Modification History of the CERES Terra CRS Archival ProductAlso see Modification History for CERES SSF Terra FM1 and FM2
Sampling Strategy andProduction Strategy
CCode Availableat ASDC
Impact on Terra CRS Product
Terra-FM1-MODIS_Edition2G (4) 029034 August 2010 No changes to the CERESSARB software.Continued with MODISinput files for CRSprocessing from collection005 (as Ed2F).Switched input files fromGEOS-4 (Ed2B and Ed2F)to GEOS-5 (Ed2G).See corresponding SSFdocumentation and CRSData Quality Summary forimpacts of switch toGEOS-5.
Terra-FM1-MODIS_Edition2F (4)
Terra-FM2-MODIS_Edition2F (4)020030 September 2008 No changes to the CERES
SARB software.Switched MODIS input
files for CRS processingfrom collection 004 tocollection 005.See corresponding SSFdocumentation and CRSData Quality Summary forimpacts of switch ofMODIS inputs fromCollection 004 toCollection 005.
Terra-FM1-MODIS_Edition2B (4)
Terra-FM2-MODIS_Edition2B (4)021028 September 2006 No science impact.
Terra-FM1-MODIS_Edition2B (4)
Terra-FM2-MODIS_Edition2B (4)018024 May 2005 For FOVs where the
MATCH data is the solesource of aerosol opticaldepth information, theMATCH 0.55 mm datainstead of the MATCH0.63 mm data will beapplied in the Fu-Lioumodel. Using the wrongwavelength causesconstituents with extinctiondecreasing withwavelength (sulfate, watersoluble, soot) to have areduced effect, andcauses constituents thathave extinction increasingwith wavelength (mineraldust, insoluble) to have anincreased effect.The Langley Fu-Lioumodel was updated to addnew Lacis dust aerosoldata for the aerosol scenetype indexes 19-23 for0.5mm, 1.0mm, 2.0mm,4.0mm, and 8.0mm dust,respectively. The FLSAtable was also modifiedaccordingly. The new dustproperties are lessabsorbing than the earlier(1996) version.Aerosols are now allowedin the stratosphere above15km, which allows for fulluse of the MATCH aerosolprofile data which isprovided up to 1 hPa or~50Km.Modified interpretation ofthe ADMgeo parameter totake advantage of newinformation added by theADM group for the TerraEdition2B SSF delivery.Default values are nowclearer and new non-default data providedinformation regarding thelocation of the centroid ofthe FOV in relation to themicrowave imagerretrievals.CRS Parameters Affected:Terra CRS 161-163,172-183, 193-235
Terra-FM1-MODIS_Edition2A (4)
Terra-FM2-MODIS_Edition2A (4)016020 October 2004 The use of the Gridded
Daily MODIS landangstrom exponent withthe 0.55µm AOT wasincorporated to produce aspectral AOT for desertscene types. Theangstrom exponentpreviously derived fromthe fit to the threewavelengths for land givenby the MOD08_d3 productproduced large negative(physically unrealistic)angstrom exponents inmany locations.A new version of Fu-Liouradiative transfer modelthat includes a GammaWeighted Two-StreamAlgorithm (GWTSA) SWcode that deals withinhomogeneous cloudswas incorporated. Thenew model configuration isa more efficient, one timecomputation of cloud andaerosol optical properties,necessary for the morecomplex GWTSA solver.The SW downwardspectral weights for anadjustment of the initialspectral albedo to matchthe retrieved TOA-basedbroadband surface albedowas modified to includetables for desert and snowsurfaces where spectralinsolation weights aredifferent from those for lowalbedo surfaces. Thiscorrected for significantdifferences at low sunangles.The definition for out ofrange cloudy sky TOA-based retrievals wasupdated to default to thebroadband surface albedoand spectral shape of thesea ice. The previousapproach of defaulting tothe ocean broadbandsurface albedo andspectral shape wasincorrect.The surface propertiesalgorithm was updated totreat sea ice coverageover the range of 0 to 100percent. Previously, theocean albedo algorithmwas only called when theocean area coverage wasgreater than 50 percent.The spectral emissivity fordesert and open shrubscene types for the10-11µm and 11-12µm Fu-
Liou bands was revised toreflect the yearly scenetype mean of the CloudWG ISCCP-basedemissivity maps toproduce more consistentresults between Cloudsand SARB.The software was modifiedto process FOVs for whichthe CERES Observed SWTOA is bad but theCERES Observed LWTOA is good through theradiative transfer model.The increased number ofprocessed FOVs providesmore LW results foranalysis.The SSF ADMgeoparameter was included inthe logic that adjusts theIGBP scene vector whenthe cloud coverage isgreater than 95 percent tobe consistent with theCloud WG retrievalassumption of cloudproperties over a snow orice surface. TheInstantaneous SARB logicuses the IGBP scenevector to decide thesurface spectral albedoand emissivity as well asthe mode of obtaining thebroadband surface albedo.The look-up table valuesfor fresh snow andpermanent snow surfacealbedo used in thecomputation of surfacealbedo were modified toinclude values for differentsnow grain sizes (50µmfor fresh snow and1000µm for permanentsnow).The diffuse angle forcloudy scenes wascorrected from 60 degreesto 53 degrees.The ocean surface albedolookup table was updated.The new table values arebased on improved oceanoptics data (sea waterabsorption data from Popeand Fry (1997) andparameterizations for theoptical properties ofPhytoplankton particlesbased on Morel andMariterena (2001)).SARB SDS 75, Sigmatable version number, wasredefined as FuLiou modelerror code. SARB SDS 75now indicates the errorstatus returned from the
radiative transferalgorithm. The new SDS isthe same type as the oldSDS. (CERES SCCR#498)Use of the GFDL aerosolclimatology was replacedwith the use of a newMATCH-based climatologythat varies with month.The MATCH-basedclimatology is only used ifthere is no daily MATCHdata. The proportion ofabsorbing aerosol over theNorthern Polar regionswas too large in the GFDLclimatology.
Terra-FM1-MODIS_Beta5 (3)
Terra-FM2-MODIS_Beta5 (3)014017014017
October 2003 No changes were made tothe SARB algorithms fromthose used for the Terra-FM1-MODIS_Beta4 dataset.
Terra-FM1-MODIS_Beta4 (1)
Terra-FM2-MODIS_Beta4 (1)013016013016
The cloudy-sky over snowalbedo retrieval algorithmswere modified to correctlyuse the snow/icepercentage flag providedon the SSF input product.Corrections were made tothe use of aerosol opticalthickness over land fromthe backup source, theMODIS MOD08-basedInterpolated Daily Maps.Previous use resulted ininvalid OLR values.Aerosol-free total sky fluxprofile data at the surfaceand the TOA were addedto the CRS product.
Terra-FM1-MODIS_Beta3 (1)
Terra-FM2-MODIS_Beta3 (1)011014 / 012015011014 / 012015
Two new sources foraerosol optical thicknessdata were incorporatedinto the CRS product. Thefirst is an instantaneousaerosol optical thicknessdata set based on theMODIS MOD03 productand the second newsource is aerosol opticalthickness over land datafrom the MODISMOD08-basedInterpolated Daily Mapproduct.Algorithms for retrievingsurface albedo over snowconditions wereincorporated.The modified version ofthe Fu-Liou model used bythe CERES SARBWorking Group wasmodified to include theHitran2000 SWabsorption.
Availability: (1) not available; (2) restricted to CERES analysts; (3) restricted to CERES Science Team and analysts; (4) public
Modification History for: Aqua | Terra | TRMM
Modification History of the CERES TRMM CRS Archival ProductAlso see Modification History for CERES SSF TRMM-PFM-VIRS
Sampling Strategy andProduction Strategy
CCode Availableat ASDC
Impact on TRMM CRS Product
TRMM-PFM-VIRS_Edition2C (4) 012015 March 2003 No changes were made tothe SARB algorithms fromthose used for the TRMM-PFM-VIRS_Edition2B dataset.Software errorsencountered whenconverting from a binaryformat to an HDF formatwere corrected. Theparameters affectedinclude the CERESObserved TOA andsurface fluxes, the numberof levels included in thevertical profiles, and theaerosol constituency flags.In the TRMM-PFM-VIRS_Edition2B data setthese parameters wereerroneously definedaccording to the CERESdefault values.
TRMM-PFM-VIRS_Edition2B (4) 010011 September 2002 The limit for the allowablesunglint percentage perFOV was increased fromzero to 90%, allowingmore FOVs to beprocessed through theSARB algorithms.The SARB Constrainmentalgorithm was modified to"freeze" cloud parametersfor skies that are less than5% cloudy.New water spectralsurface albedo look uptable values wereincorporated.
TRMM-PFM-VIRS_Beta3 (1) 009009 A new ocean spectralsurface albedo look uptable, the result of adiscrete ordinate modelwith coupled ocean andatmosphere optics, wasincorporated.To improve accuracy ofthe Outgoing LongwaveRadiation (OLR) resultsover hot surfaces, theradiative transfer modelwas modified to includetwo bands in the thermalIR/Solar transition regionto cover wavelengths 2200to 2850 cm-1.The water vaporcontinuumparameterization wasupdated from CKD 2.1 to
CKD 2.4. CKD2.4 is moretransparent in the 400 to1000 cm-1 wavelengthrange, leading toincreased OLR byapproximately 1 Wm-2.A bug in previous CRSresults for ice clouds wascorrected. The ice particlediameter is now convertedfrom the mean effectivediameter (De) obtainedfrom the input SSFproduct to a generalizedeffective diameter (Dge)that is required by the Fu-Liou radiative transfermodel.An inconsistency betweencloud height andtemperature between theinitial and constrainedpasses was corrected byconstraining to the cloudtop temperature instead ofto the cloud effectivetemperature.Scene-dependent spectralcurves for wavelengthsgreater than 1.5 micronswere modified forconsistency with resultsfrom MODIS, whichshowed a lower surfacereflectance than that whichSARB had been using.Instead of calculatingvertical flux profile valuesfor the TOA at 1.0 hPa,modeled TOA fluxes arenow calculated at 0.1 hPa.
TRMM-PFM-VIRS_Beta2 (1) 008008 Due to the advances in theTRMM ADMs that yieldmore accurateinstantaneous CERESTOA flux values, thesigma values used in theconstrainment processwere modified so that themodeled TOA fluxes aremore tightly constrained tothe Total flux provided onthe SSF product, and lesstightly to the radiancesand window channel fluxalso provided as input onthe SSF.
TRMM-PFM-VIRS_Beta1 (1) 008007 Corrected aerosolconstituency scale heightsand default value
TRMM-PFM-VIRS_Subset-ValR4 (1)
007006 May 2001 Use of a monthly surfacealbedo history product wasadded.Access to a climatology forthe total aerosol opticaldepth whenever such datawere unavailable from theSSF input product wasadded. The aerosol data
provided by either the SSFor the climatology weredivided into multipleaerosol scene-dependentconstituencies, withconstituency scale heightsand percent ratiosobtained through theclimatology.The archived vertical fluxprofiles for clear and totalsky conditions wereexpanded to include a fifthlevel at 200 hPa.Pristine fluxes at thesurface and TOA wereadded.
TRMM-PFM-VIRS_ValidationR3 (1)
006004 April 1999 One month (January1998) of data onlyFirst software delivery toproduce CRS data atASDC
Availability: (1) not available; (2) restricted to CERES analysts; (3) restricted to CERES Science Team and analysts; (4) public
References:
1. Charlock, T. P., and T. L. Alberta, 1996: The CERES/ARM/GEWEX Experiment (CAGEX) for the retrieval of radiative fluxes withsatellite data. Bull. Amer. Meteor. Soc., 77, 2673-2683.
2. Clouds and the Earth's Radiant Energy System (CERES) Algorithm Theoretical Basis Document, Compute Surface and AtmosphericFluxes (System 5.0), Release 2.2, June 2, 1997.
3. Clouds and the Earth's Radiant Energy System (CERES) Data Management System Data Products Catalog Release 3, Version 2,August 2001.
4. Clouds and the Earth's Radiant Energy System (CERES) Validation Document, Surface and Atmospheric Radiation Budget (SARB)Validation Plan for CERES Subsystem 5.0 (Compute Surface and Atmospheric Fluxes), Release 4.0, October 2000.
5. Collins, W.D., P.J.Rasch, B.E.Eaton, B.V.Khattatov, J-F.Lamarque, and C.S.Zender, 2001: Simulating Aerosols Using a ChemicalTransport Model With Assimilation of Satellite Aerosol Retrievals: Methodology for INDOEX. Journal Geophysical Research, Volume106, 7313-7336.
6. Fu, Q. and K.N.Liou, 1993: Parameterization of the Radiative Properties of Cirrus Clouds. Journal of Atmospheric Science, 50,2000-2025.
7. HDF User's Guide, NASA Langley Atmospheric Science Data Center, Hierarchical Data Format Web Site, (from NCSA) Version 4.0,February 1996.
8. Rose, F., T. Charlock, D, Rutan, and G. L. Smith, 1997: Tests of a constrainment algorithm for the surface and atmospheric radiationbudget. Proceedings of the Ninth Conference on Atmospheric Radiation, Long Beach (Feb. 2-7, 1997), AMS, 466-469.
9. Rutan, D., and T. Charlock, 1997: Spectral reflectance, directional reflectance, and broadband albedo of the earth's surface.Proceedings of the Ninth Conference on Atmospheric Radiation, Long Beach (Feb. 2-7, 1997), AMS, 466-469.
10. Wielicki, B.A., B.R.Barkstrom, E.F.Harrison, R.B.Lee, G.L.Smith, and J.E.Cooper, 1996: Clouds aand the Earth's Radiant EnergySystem (CERES): An Earth Observing System Experiment. Bullitin American Meteorological Society, 77, 853-868.
Contact Information:
Investigator(s) Name and Title Technical Contact(s) Data Center
Norman G. LoebCERES Interdisciplinary Principal InvestigatorE-mail: [email protected]: (757) 864-5688
Dr. Thomas P. Charlock, SARB WorkingGroup ChairE-mail: [email protected]: (757) 864-5687
Atmospheric Sciences ResearchMail Stop 420NASA Langley Research CenterHampton, Virginia 23681-2199USAFAX: (757) 864-7996
User and Data Services OfficeAtmospheric Science Data CenterNASA Langley Research CenterMail Stop 157DHampton, Virginia 23681-2199USATelephone: (757) 864-8656FAX: (757) 864-8807E-mail: [email protected]: http://eosweb.larc.nasa.gov
Acknowledgement:
The requested form of acknowledgment for any publication in which these data are used is:
"These data were obtained from the NASA Langley Research Center Atmospheric Science Data Center."
The Langley Data Center requests a reprint of any published papers or reports or a brief description of other uses (e.g., posters, oralpresentations, etc.) of data that we have distributed. This will help the Data Center determine the use of data distributed, which is helpful inoptimizing product development. It also helps us to keep our product related references current.
Reference:
The CERES Team has gone to considerable trouble to remove major errors and to verify the quality and accuracy of these data. Pleaseprovide a reference to the following paper when you publish scientific results with the CERES data:
Wielicki, B. A., B. R. Barkstrom, E. F. Harrison, R. B. Lee III, G. L. Smith, and J. E. Cooper, "Clouds and the Earth's Radiant Energy System(CERES): An Earth Observing System Experiment," Bull. Amer. Meteor. Soc., 77, 853-868, 1996.
Document Information:
Document Creation Date: August 28, 2001Last Date Modified: Jan 23, 2002; Dec 3, 2003; Mar 15, 2004; Sep 21, 2004; Jul 6, 2005; Sep 19, 2006; Oct 18, 2007; Aug 28, 2008Review Date: August 2008Author: User and Data Services Office, ASDCASDC Help Desk: Phone (757) 864-8656; E-mail [email protected]
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