data product user guide for s-npp sounder sips chart and ... · sounder sips s-npp chart and...

Sounder SIPS S-NPP CHART and CLIMCAPS Level-2 Products User Guide

Goddard Earth Sciences Data and Information Services Center (GES DISC) http://disc.gsfc.nasa.gov NASA Goddard Space Flight Center Code 610.2 Greenbelt, MD 20771 USA © 2019. All rights reserved.

DataProductUserGuideforS-NPPSounderSIPSCHARTandCLIMCAPS

CrISandATMSLevel-2Products

September2019

ProductVersion1.0

NationalAeronauticsandSpaceAdministrationGoddardEarthScienceDataInformationandServicesCenter(GESDISC)


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Preparedby:

_______________________________________

RuthMonarrez,ProjectElementManagerS-NPPSounderSIPSJetPropulsionLaboratoryCaliforniaInstituteofTechnologyPasadena,CA

Reviewedby:

_______________________________________

ThomasHearty,GESDISCScienceDataSupport GSFCCode610.2

Contributors:Level2ScienceTeamChrisBarnet-PI CLIMCAPS ScienceandTechnologyCorp.(STC)NadiaSmith ScienceandTechnologyCorp.(STC)JoelSusskind-PI CHART GoddardSpaceFlightCenter(GSFC)ATMSLevel2SoftwareTeamEvanManning JPLPaulSpringer JPLGESDISCScienceDataSupportLenaIredell GSFC


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RevisionHistory

RevisionDate Changes Author

2019-09-09 InitialRelease EvanManning


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TableofContents.........................................................................................................................................i

1.0Introduction................................................................................................................................11.1OverviewofSounderSIPS.................................................................................................................11.2MissionDescription............................................................................................................................11.3CrISInstrumentDescription............................................................................................................21.4ATMSInstrumentDescription.........................................................................................................31.5DataDisclaimer...................................................................................................................................31.6 Where to find the Product....................................................................................................................31.7ContactInformation...........................................................................................................................31.8References.............................................................................................................................................3

2.0Level-2ProductOverview.......................................................................................................52.1ProductGranulationandIdentification........................................................................................52.2AlgorithmBackground......................................................................................................................62.3DataOrganization...............................................................................................................................72.4FileFormatandStructure.................................................................................................................72.5Metadata................................................................................................................................................72.6FileNamingConvention....................................................................................................................72.7TimeRepresentation..........................................................................................................................92.8DataHoldings.....................................................................................................................................10

3.0DataContent.............................................................................................................................113.1Dimensions.........................................................................................................................................113.2GlobalAttributes(metadata).........................................................................................................113.3VariableAttributes...........................................................................................................................133.4GroupStructure.................................................................................................................................143.5Geolocation.........................................................................................................................................143.6ScienceDataVariables.....................................................................................................................173.7QualityInformation..........................................................................................................................193.8MissingData/FillValues................................................................................................................203.9Keysupportinginformationvariablesforprofiles..................................................................203.10Verticalprofilerepresentationofgases...................................................................................213.11Knownissues...................................................................................................................................23

4.0OptionsforReadingtheData..............................................................................................245.0DataServices............................................................................................................................25

AppendixA:DifferencesbetweenCLIMCAPSandCHARTalgorithms............................27

A.1Firstguess.................................................................................................................................27A.2Iteration....................................................................................................................................27

A.3Errorestimationapproach..................................................................................................27

A.4QualityControlapproach.....................................................................................................27A.5Retrievedquantities..............................................................................................................27

AppendixB:Sampleimages........................................................................................................28


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AppendixC:Detailedfileformats.............................................................................................31C.1CLIMCAPSRetrievalproduct...............................................................................................32

SNPPL2CLIMCAPSCRIMSSInterfaceSpecification.............................................................32GlobalGroups............................................................................................................................................32GlobalDimensions...................................................................................................................................32GlobalAttributes......................................................................................................................................33GlobalVariables.......................................................................................................................................40auxVariables.............................................................................................................................................46mol_layVariables.....................................................................................................................................48mwVariables.............................................................................................................................................49

C.2CHARTRetrievalproduct.....................................................................................................50SNPPL2CHARTCRIMSSInterfaceSpecification...................................................................50GlobalGroups............................................................................................................................................50GlobalDimensions...................................................................................................................................50GlobalAttributes......................................................................................................................................50GlobalVariables.......................................................................................................................................58auxVariables.............................................................................................................................................64mol_layVariables.....................................................................................................................................66mwVariables.............................................................................................................................................66

C.3CLIMCAPSCloud-ClearedRadianceproduct...................................................................68

SNPPL2CLIMCAPSCRIMSSCCNSRInterfaceSpecification...............................................68GlobalGroups............................................................................................................................................68GlobalDimensions...................................................................................................................................68GlobalAttributes......................................................................................................................................68GlobalVariables.......................................................................................................................................76aux_l2Variables........................................................................................................................................79

C.4CHARTCloud-ClearedRadianceproduct.........................................................................81SNPPL2CHARTCRIMSSCCNSRInterfaceSpecification.....................................................81GlobalGroups............................................................................................................................................81GlobalDimensions...................................................................................................................................81GlobalAttributes......................................................................................................................................81GlobalVariables.......................................................................................................................................88aux_l2Variables........................................................................................................................................92


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1.0IntroductionThisdocumentprovidesbasicinformationforusingVersion1Level-2productsfromtheCross-track Infrared and Microwave Sounding Suite(CrIMSS)instrumentsontheSuomi-NPPspacecraft.TheCrIMSSinstrumentsuiteconsistsoftheCross-trackInfraredSounder(CrIS)infraredsounderandtheAdvancedTechnologyMicrowaveSounder(ATMS)microwavesounder.Theproductstheresultfromtworetrievalalgorithms:ClimateHeritageAIRSRetrievalTechnique(CHART)andCommunityLong-termInfraredMicrowaveCoupledAtmosphericProductSystem(CLIMCAPS).ThedifferentapproachesofthesetwoalgorithmsarebrieflydescribedinSection2.2andAppendixA.ThemainLevel-2retrievalproductfromeachalgorithmcontainsavarietyofgeophysicalparametersderivedfromtheCrIMSSdata,includingtemperatureprofiles,watervapor,constituents,clouds,andsurfacepropertiesforsixminutesofobservations.Anadditionalcloud-clearedradianceproductcontainsestimatedradiancesthatwouldhavebeenobservedintheabsenceofclouds.Thesefilescanbevaluablebecausetheretrievalalgorithmsutilizecloudclearedradiances.Theseproductshavebeenannotatedwithbothfileandvariablelevelattributestofullydescribetheircontents.1.1 OverviewofSounderSIPSTheSuomi-NationalPolar-OrbitingPartnership(S-NPP)SounderSIPS,isoneofsixSIPSsformedbyNASAtoprovidetheprocessingoflevel0datathroughlevel1,level2andlevel3fromtheSuomiNPP(previouslyknownasNPP)satellite.TheSuomi-NPPsatelliteismanagedbytheNationalPolar-orbitingPartnership(NPP)whichincludeselementsfromNASA,NOAAandDoD.DetailsabouttheS-NPPMissioncanbefoundat:https://www.jpss.noaa.gov/.TheS-NPPSounderSIPSisateammadeupoftheJetPropulsionLaboratory(JPL)andtheGoddardEarthSciencesDataandInformationServicesCenter(GESDISC).JPLprovidestheoverallprojectmanagement,sciencealgorithmsoftwareintegration,testandvalidationsupport.TheGESDISCperformslevel0dataacquisitionandroutinedataprocessingoperations.TheGESDISC/DistributedActiveArchiveCenteranddistributionofthedataproductsandassociateddocumentation.1.2MissionDescriptionTheS-NPPsatellitewaslaunchedonOctober28,2011fromVandenburgAirForceBaseinCaliforniaintoanorbitwithanaltitudeof824kmabovetheEarthsurface,aninclinationangleof98.7deganda13:30localtimeascendingnode[Reference3].SNPPisthefirstinaseriesofnextgenerationU.S.weathersatellitesoftheJointPolarSatelliteSystem(JPSS).


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CrIMSS(CrISandATMS)aretwoofthefiveinstrumentsonboardtheS-NPPsatellite.Theotherinstrumentsare:CloudsandtheEarth'sRadiantEnergySystem(CERES),OzoneMappingandProfilerSuite(OMPS)andVisibleInfraredImagingRadiometerSuite(VIIRS).Table1.2.1containsasummaryofplatformparameters.

Table1.2.1ApproximateS-NPPorbitalparameters.

Platform Alt Orbit Incl. (°)

Equator X Time

Period Repeat Orbits

Repeat Days

Launch

S-NPP 824 98.7 13:30* 101 228 16 28 Oct 2011 CrIS and ATMS are designed to be used together as CrIMSS, the Cross-track Infrared and Microwave Sounding Suite. Both algorithms used here combine infrared (IR) data from CrIS with microwave (MW) data from ATMS in a single IR+MW retrieval. 1.3CrISInstrumentDescriptionThe Cross-track Infrared Sounder (CrIS) is a Fourier Transform Spectrometer (FTS) which measures interferograms in three Infrared (IR) bands simultaneously. The CrIS interferometer includes a beamsplitter, a stationary and moving mirror, and a laser sampling system. The scene radiance entering the interferometer is split by the beamsplitter into two beams along two separate paths. One beam travels towards the moving mirror; the other to a stationary mirror. The two beams are reflected from the corresponding mirrors and recombine before converging on the detector. The optical path difference (OPD) traveled by the two beams is twice the physical path difference between the two mirrors. As the moving mirror sweeps from one side of the zero path difference (ZPD) to the other, a time-varying interference pattern known as the interferogram is recorded. A convolution of the interferogram with a Finite Impulse Response (FIR) numerical filter is applied in real-time on the spacecraft to reduce the internal data rate to meet telemetry requirements. This results in a complex-valued interferogram of a fixed number of sample points which is included in the downlinked data packets. During a single scene scan mirror dwell period, one interferogram is recorded for each of 27 detectors simultaneously (3 focal planes (LW, MW, SW) each containing 9 bore-sighted detectors in a 3x3 pattern). The CrIS uses a 45-degree scene scan mirror to provide sequential views of an internal blackbody (ICT), a deep space view (DS), and 30 Earth views in the cross-track direction in a repeating pattern as the spacecraft moves along-track. The interferograms associated with the ICT and DS views and a measurement of ICT temperature are used in the ground processing software to calibrate the Earth views to produce radiance spectra. Prior to calibration, a correction is applied to account for measured signal nonlinearity of selected detectors. Corrections are also applied in the ground processing software to remove FTS self-apodization effects and to resample the spectra to a predefined user spectral grid. These products were produced using version 1 of the CrIS Level-1B product in Normal Spectral Resolution (NSR).


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1.4ATMSInstrumentDescriptionATMSisa22-channelcross-trackscanningmicrowavesounderprovidingbothtemperatureandhumiditysoundings.Table1.4.1containsasummaryoftheATMSinstrumentparameters.TheATMSinstrument’sScanDriveMechanismonS-NPPhasbeenexperiencingadditionalwearonthebearings.Toextendthelifeoftheinstrument,adecisionwasmadetoperformscanreversalsforthepurposeof‘re-wetting’thebearings.Thescanreversalsarenowoccurringtwiceperorbit,startingAug9,2016.Theendresultofthismaneuverisaslightlossofdata.ThislossofdataisrepresentedbytheuseofFillValues.

Table1.4.1ATMSinstrumentparameters.

Platform Instrument Instrument Type

Scan Rate (s)

Scan Range (°)

Scan Pattern

FOR Diameter

(km, nadir)

Spectral Channels

S-NPP ATMS Microwave (MW)

8/3 ±53 96 16-75 22

1.5DataDisclaimerVersion 1.0 CrIMSS Level-2 data are released to the public as is. Every effort has been made to properly represent the data which this document describes. 1.6 Where to find the Product The CrIMSS Level-2 products can be found at and downloaded from the Goddard Distributed Active Archive Center (GDAAC). There you will find additional information and documentation about this product and other products of interest. Search “Suomi-NPP CrIMSS” (with quotes) under Data Collections.

https://disc.gsfc.nasa.gov

1.7ContactInformationForinformation,questionsorconcernswiththisCrIMSSLevel-2dataset,pleasesendto:[email protected].

1.8ReferencesIflinksdonotresolve,copytheurltoabrowser.


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1.NASASNPPCrossTrackInfraredSounder(CrIS)Level1BProductUsers’Guide2.NASASNPPCrossTrackInfraredSounder(CrIS)Level1BQualityFlagsDescriptionDocument3.DataProductUserGuideforSuomi-NationalPolar-OrbitingPartnership(S-NPP)SounderScienceInvestigator-ledProcessingSystem(SIPS)AdvancedTechnologyMicrowaveSounder(ATMS)Level1BProducts4.CHARTLevel-2ATBDhttps://docserver.gesdisc.eosdis.nasa.gov/public/project/SNPP/SNPP_limited_edition/SNPP.CrIMSS.CHART_V1.ATBD.pdf5.CLIMCAPSLevel-2ATBDhttps://docserver.gesdisc.eosdis.nasa.gov/public/project/SNPP/SNPP_limited_edition/SNPP.CrIMSS.CLIMCAPS_V1.ATBD.pdf 6.NetCDFClimateandForecast(CF)MetadataConventions,Version1.7,http://cfconventions.org/Data/cf-conventions/cf-conventions-1.7/cf-conventions.html 7.MERRA-2https://gmao.gsfc.nasa.gov/reanalysis/MERRA-2/


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2.0Level-2ProductOverview Level-2productsarecreatedfromCrISandATMSLevel-1Bobservationsusingtwoalgorithms:CHARTandCLIMCAPS.Eachofthesealgorithmscreatesamainretrievalproductwithgeophysicalparametersandanadditionalcloud-clearedradianceproduct,sofourproductfiletypesaredescribedinthisdocument:1) Level-2CHARTRetrievalproduct(L2_CHART_RET)2) Level-2CLIMCAPSRetrievalproduct(L2_CLIMCAPS_RET)3) Level-2CHARTCloud-ClearedRadiances(L2_CHART_CCR)4) Level-2CLIMCAPSCloud-ClearedRadiances(L2_CLIMCAPS_CCR)

2.1ProductGranulationandIdentificationTheLevel-2productsaredividedintoaseriesof6-minutesegmentsorgranuleswitheachgranulemakinguponefileand240granulesperday.Eachfilecontainsallobservationsforagiventypemadeduringaperiodofexactly6minutes.Foreachday,each240filesareidentifiedbygranulenumberinthefilename.Forexample,g156forgranule156outof240.Thenominalstarttimeofgranule1isdefinedtobe00:00:00.BecausebothCrISandATMSinstrumentsaresyncedtoTAI93,thestarttimeofthefirst8-secondscansetofadaycanbeanywhereupto8secondslater.Itmoves1secondwitheachleapsecond.Ifthefirstscansetstarts8secondsafterthenominalstarttime,thenthedatacanextendupto8secondspastthenominalendtime.TheabilitytouniquelyidentifyagranuleisbuiltintotheLevel-1BandLevel-2products.Thisisextremelyusefulwhenpublishinganalysisresults.Thenominaltimecoverage,representedasastring:yyyymmddThhmm,isusedtoconstructauniquegranuleidentifiercalled“gran_id”.gran_idisstoredasaglobalattributethatisalsousedinthefilename,seesection2.6FileNamingConvention.Inaddition,thereisanobservationidentifiervariablecalled“obs_id”thatcanfurtheruniquelyidentifyanobservationwithinthegranule.Theobs_idisformattedasthegran_idwithobservationinformationappendedtoit.Becauseofthedifferentviewinggeometry,ATMSandCrISobs_idsdiffer.Level-2CHARTandCLIMCAPSobs_idsfollowtheCrISpatternbecausetheirretrievedinformationcorrespondstoCrISgeometry.TheformatofATMSobs_idis:yyyymmddThhmm.aaaExxwhere‘aaa’isthe3-digitalong-trackindex(001–135)andxxisthecross-trackindex(01–96).The“E”indicatesearthview.Forexample:


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20160125T1300.001E18CrIS/Level-2obs_id:Eachfieldofregard(FOR),definedasasetof9simultaneouslyobservedfieldsofview,hasagloballyuniqueIDstoredinthevariable“obs_id”.TheobservationIDiscreatedfromthegranuleID,withinformationappendedtoidentifytheFORobservationwithinthegranule.Thedimensionsofthisvariable(atrack=45,xtrack=30)correspondtothefirsttwodimensionsofthesciencedatavariables,suchasradiances.AnobservationIDcanbeassociatedwithdatabyapplyingthesameindicesintothesecommondimensions.TheformatoftheCrIS/Level-2observationIDstringis“yyyymmddThhmm.aaExx”,where“aa”isthe2-digitalong-trackindex(01-45),and“xx”isthe2-digitcross-trackindex(01-30).The“E”indicatesthatitisanearthview.Forexample:

20160125T1300.01E18FOVObservationID:Atthefinestlevelofgranularity,eachfieldofview(FOV)withinaFORobservationhasagloballyuniqueIDthatisstoredinavariablecalled“fov_obs_id”.TheFOVobservationIDiscreatedfromtheobservationID,withextrainformationappendedtoidentifytheFOVwithintheFORobservation.Thedimensionsofthisvariable(atrack=45,xtrack=30,fov=9)correspondtothefirstthreedimensionsofthesciencedatavariables,suchasradiances.AFOVobservationIDcanbeassociatedwithdatabyapplyingthesameindicesintothesecommondimensions.TheformatoftheFOVobservationIDstringis“yyyymmddThhmm.aaExx.f”where“f”isthe1-digitFOVnumber(1-9).Forexample:

20160125T1300.01E18.6

2.2AlgorithmBackgroundTheSounderSIPSLevel-2dataproductsareaproductofprocessingNASALevel0datathroughLevel1A,Level1B,andLevel-2.ForadefinitionoftheNASADataProcessingLevelsgoto:https://earthdata.nasa.gov/earth-science-data-systems-program/policies/data-information-policy/data-levelsBothCHARTandCLIMCAPSarebasedontheAIRSLevel-2teamalgorithm[https://disc.gsfc.nasa.gov/information/documents?title=AIRS%20Documentation].CHARTv6.46remainsveryclosetotheAIRSv6algorithm,withchangesconsistentwithchangestowardstheAIRSv7algorithm[


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https://airs.jpl.nasa.gov/system/presentations/files/321_Susskind_AIRS_CrIS_Retrieval.pdf].CLIMCAPSv1.01isbasedonanearlierAIRSteamalgorithm.ItreplacestheSCCNNneuralnetfirstguesswithMERRA2(seeSection3.11,GFSwasaccidentallyusedasthefirstguess),streamlinesthealgorithmflowtouseasinglepass,andusesoptimalestimationintheindividualspeciesretrievalsteps[https://airs.jpl.nasa.gov/system/presentations/files/381_StatusBarnet.pdf]. TechnicaldetailsoftheLevel-2processingstepsandcalibrationscanbefoundintheAlgorithmTheoreticalBasisDocuments(ATBDs).Seereferences.

2.3DataOrganizationTheLevel-2productsaredividedintoaseriesof6-minutesegmentswithonesegmentperfile.Eachfilecontainsallobservationsofagiventypemadeduringaperiodofexactly6minutes.Foreachdaythereare240files(alsoknownasgranules),identifiedbygranulenumberinthefilename.Forgranulestarttimedetails,refertosection2.1.2.4FileFormatandStructureThefilesareinNetworkCommonDataForm,version4(netCDF4/HDF5)format.TheproductformattakesadvantageofthenetCDF4datamodelandmakesuseofgroups,dimensions,variablesandattributestofullydescribethesciencedata. 2.5MetadataEveryefforthasbeenmadetoensurethatmetadataconformstotheClimateandForecasting(CF),Version1.6,andAttributeConventionsforDataDiscovery(ACDD),Version1.3,guidelines.SeethefullproductspecificationsinAppendixC. FormoreinformationonCF,referto: http://cfconventions.org/FormoreinformationonACDD,referto:

http://wiki.esipfed.org/index.php?title=Category:Attribute_Conventions_Dataset_Discovery2.6FileNamingConventionFilenamingforSounderSIPSproductswillbeuniqueandincludethefollowingtokensseparatedbythedelimiter‘.’Foreachtokenthatmakesupthefilename,therewillbeanattributeinthedataproductthatitmapsto(seeTable2.6.1Filenaming).


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<Sounder_SIPS_ID>.<platform>.<inst_ID>.<granuleID>.<product_granularity>.<granule_number>.<product_type>.<variant>.<version>.<production_location>.<prod_timestamp>.<extension>Where:

o Sounder_SIPS_IDasaprojectidentifier<product_name_project>=SNDRo platform<product_name_platform>=SNPPo inst_ID<product_name_instr>=CRIMSSo granuleID(yyyymmddThhmm)<gran_id>nominalstarttimewhere:

§ yyyy=year§ mm=monthofyear(01-12)§ dd=dayofmonth(01-31)§ hh=hour(00-24)§ mm=minute(00-59)

o product_granularity<product_name_duration>=m06(6minute)o granule_number<granule_number>=g###o product_typewithanoptionalidentifierfortesting<product_type_name_id>

§ L2_CHART_RET_NSRforCHARTgeophysicalretrievedproductsderivedfromCrISNSRspectralresolution.

§ L2_CLIMCAPS_RET_NSRforCLIMCAPSgeophysicalretrievedproductsderivedfromCrISNSRspectralresolution.

§ L2_CHART_CCR_NSRforCHARTcloud-clearedradiancesatNSRspectralresolution.

§ L2_CLIMCAPS_CCR_NSRforCLIMCAPScloud-clearedradiancesatNSRspectralresolution.

o variant<product_name_variant>=stdo versionvmm_mm<product_name_version>-eg.v01_25

§ VersioningwillbesynchronizedacrossSounderSIPSproducts§ Version1Level-2productsarederivedfromversion1Level-1B

productso production_location<product_name_producer>-J=SIPSatJPL,

G=Operations,T=Test,W=CrISTeamatUnivofWisco prod_timestampsoeachproducthasauniquename(yymmddhhmmss)

<product_name_timestamp>-150407123456o Extension(.nc)

Table2.6.1ProductFilenamingFilenametoken AttributenameinCDF

(mapping)Format Value(s) Notes

Sounder_SIPS_ID product_name_project SNDR

platform product_name_platform SNPP


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inst_ID product_name_instr CRIMSS CRIMSS=CrIS+ATMS

granuleID gran_id yyyymmddThhmm Nominalstarttime

product_granularity product_name_duration m06 6minutes

granule_number granule_number g### g001–g240 Onlyfor6-minutegranuleLeve-1andLevel-2products

product_type product_name_type_id+optionalidentifierforuniqueness

L2_<alg>_<prod>_NSR L2_CHART_RET_NSR

L2_CHART_CCR_NSR

L2_CLIMCAPS_RET_NSR

L2_CLIMCAPS_CCR_NSR

<alg>isCHARTorCLIMCAPS

<prod>isRETorCCR

_NSRisalwayspresentinthev1releasebecausev1Level-1BCrISisonlyNSR

Version product_name_version v01_##;v01_##_## e.g.v01_05;(v01_05_00whenproducedatJPL)

variant product_name_variant Freeformtext.Nowhitespaceoranypunctuationexceptunderscore.

std Usedtoidentifyspecialruns.Thedefaultis:std=standard.

production_location product_name_producer J:JPLG:GSFCT:Test

prod_timestamp product_name_timestamp yymmddhhmmss

ExampleFilename:6-minuteCrIMSSLevel-2granule

SNDR.SNPP.CRIMSS.yyyymmddThhmm.m06.g101.L2_CLIMCAPS_RET_NSR.std.vmm_mm.G.yymmddhhmmss.nc

SNDR.SNPP.CRIMSS.20160114T1000.m06.g101.L2_CLIMCAPS_RET_NSR.std.v02_04.G.180110183539.nc2.7TimeRepresentation


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TimesintheLevel-2productsaregenerallyrepresentedasUTC.However,observationtimesareprovidedinbothUTCandTAI93representationsasaconveniencetousers.CoordinatedUniversalTime(UTC)istheinternationalstandardforrepresentationoftime.UTCtimesareexpressedinhuman-readableform,asasetofvaluesindicatingyear,month,day,hourandsoon.Inthedatastreamreceivedfromthesatellite,observationtimesarerepresentedasUTC.TimestampsinproductfilenamesandattributesarerepresentedasUTCandformattedaccordingtothe“ISO8601:2004”standard.Forexample,thetimeJanuary25,2016at13:00mayberepresentedaseitherofthefollowing:

2016-01-25T13:00Z20160125T1300

Thelongerformisusedinattributes,andthemorecompactformisusedinfilenames.Thecharacter“Z”indicates“Zulutime”,orUTC.InternationalAtomicTime(TAI)isexpressedasnumberofsecondselapsedonthesurfaceoftheEarthsincesomereferenceUTCtime.Theterm“TAI93”indicatesthatthereferencetimeisthebeginningoftheyear1993,or1993-01-01T00:00:00Z.Thisreferencetimewaschosentobeconsistentwithdataproductsfromotherinstruments,andtoallowforpreciserepresentationoftimesspanningtheexpectedmissionlength.

2.8DataHoldingsFortheinitialreleaseofv1CHART&CLIMCAPS,atestdatasetof8monthsofdataisprovided.Thisdatacoversthemonthsof{January,April,July,October}oftheyears2013&2015.ThissetisdesignedtoallowresearchandcomparisonsoverafullseasonalcycleandcomparisonsofdifferentphasesoftheENSOcycle.


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3.0DataContentTheLevel-2dataproductsarewritteninnetCDF4formatandthereforemakesuseofgroups,dimensions,variablesandattributes(global&variable).EverynetCDF4filecontains,ataminimum,onerootgroupwhichisunnamed.Attentionshouldbegiventoqualityflagsandcheckedforfillvaluesbeforebeingusedforanyanalysisorhigherprocessingoftheproduct.AfullprofileofthecontentsofthefilesisincludedinAppendixC.

Selectedfieldsarehighlightedinthissection.

3.1Dimensions KeydimensionsforCHARTandCLIMCAPSLevel-2RETandCCRproducts.

Table3.1KeyRETDimensions

Name Size Description atrack 45 along-track spatial dimension xtrack 30 cross-track spatial dimension fov 9 Field-of-view dimension air_pres 100 Fine atmospheric pressure levels for temperature and most gases air_pres_h2o 66 Fine atmospheric pressure levels for water-vapor variables

Table3.2KeyCCRDimensions

Name Size Description atrack 45 along-track spatial dimension xtrack 30 cross-track spatial dimension wnum_lw 717 longwave IR channel number wnum_mw 437 midwave IR channel number wnum_sw 163 shortwave IR channel number

3.2GlobalAttributes(metadata)Therearetwotypesofattributes:global&variable.Inthissectionwewilltalkaboutglobalattributes.Globalattributes,sometimesreferredtoas‘file-levelattributes’,provideinformationabouttheentirefileor6-minutegranule.Thisincludesobservationtimes,publisherandcreatorinformation,dataprovenance,andlocationinformation.ManyattributesarerequiredtoconformtotheCF&ACDDstandardswhileotherattributesarewrittenforconsistencywithlegacyproducts.


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AfulldefinitionoftheglobalattributescanbefoundinAppendixC.

Table3.2.2KeyGlobalAttributes

Name Description date_created The date on which this version of the data was created geospatial_lat_min The southernmost latitude covered by the dataset geospatial_lat_max The northernmost latitude covered by the dataset geospatial_lon_min The westernmost longitude covered by the dataset. See also

geospatial_lon_max. geospatial_lon_max The easternmost longitude covered by the dataset. Cases where

geospatial_lon_min is greater than geospatial_lon_max indicate the bounding box extends from geospatial_lon_max, through the longitude range discontinuity at the antimeridian, to geospatial_lon_min; for example, geospatial_lon_min=170 and geospatial_lon_max=-175 incorporates 15 degrees of longitude (ranges 170 to 180 and -180 to -175).

geospatial_lat_mid granule center latitude geospatial_lon_mid granule center longitude geospatial_bounds Describes the data's 2D or 3D geospatial extent in OGC's Well-Known

Text (WKT) Geometry format. Longitude values are limited to the (-180, 180) range. Example: 'POLYGON ((40.26 -111.29, 41.26 -111.29, 41.26 -110.29, 40.26 -110.29, 40.26 -111.29))'.

product_name_granule_number zero-padded string for granule number of day (g001-g240) gran_id Unique granule identifier yyyymmddThhmm of granule start, including

year, month, day, hour, and minute of granule start time identifier_product_doi digital signature (DOI) AutomaticQualityFlag "Passed": the granule contains a non-degraded retrieved value for at least

one value in a geolocated FOV; "Suspect": the granule does not qualify as "Passed" but contains a (possibly degraded) retrieved value (possibly without associated geolocation); "Failed": the granule contains no retrieved values.

qa_no_data A simple indicator of whether this is an "empty" granule with no data from the instrument. "TRUE" or "FALSE".


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3.3VariableAttributesEachvariablehasitsownassociatedattributes.VariableattributesareaCFstandardandareusedtodescribethevariableinmoredetailtoproperlyinterpretitsvalue.

Table3.3:VariableAttributesAttribute Description

units units, for variables that represent physical quantities _FillValue a single sentinel value indicating the data point contains fill instead of

valid data standard_name standard name from the CF standard name table, if one exists for the

quantity being represented long_name a longer name describing the quantity being represented, suitable for a plot

title description a longer description of the quantity being represented valid_range a pair of values indicating the minimum and maximum values to be

considered valid coordinates a space-separated list of the names of other variables that are coordinates

for this variable coverage_content_type ACDD/ISO field categorizing types of data:

• image • thematicClassification • physicalMeasurement • auxillaryInformation • coordinate • modelResult • qualityInformation • referenceInformation

https://geo-ide.noaa.gov/wiki/index.php?title=ISO_19115_and_19115-2_CodeList_Dictionaries#MD_CoverageContentTypeCode

ancillary_variables a space-separated list of the names of other variables that contain information about this variable

bounds defines the extent, for cell variables cell_methods describes statistical methods used to derive data, for cell variables flag_values These attributes collectively tell how to interpret flag variables. See the

CF standard for details. In these Level-2 products, these attributes are mostly used in association with the *_qc QC ancillary variables.

flag_meanings flag_masks


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3.4GroupStructure

OnefeaturewhichwasaddedtonetCDF4istheabilitytostructurefileswith“groups”,whicharesimilartoadirectoryhierarchy.SounderCDFfilesaredesignedsothatallofthemostcommonlyneededinformationiscontainedin“/”,therootgroup.Subgroupscontainmorespecializedinformation.Thesearethegroupsforretrievalfiles:Group Purpose/(root) Maingroup,withtemperatureandwatervaporprofiles,alongwith

supportinglocationandqualityinformation/mw ResultsfromtheMicrowave-Onlyretrievalstep/mol_lay Retrievedvaluesofwatervaporandothergasesinunitsofmoleculesper

squaremeterperlayer--theSIequivalentofthe“columndensity”usedintheSARTAforwardmodel

/aux Supportinginformationprimarilyforthealgorithmdevelopers/ave_kern Averagingkernels(notincludedinthev1release)

Thesearethegroupsforcloud-clearedradiancefiles:Group Purpose/(root) Maingroup,withcloud-clearedspectra,alongwithsupportinglocation

andqualityinformation/aux_l2 SupportinginformationabouttheLevel-2retrievalprimarilyforthe

algorithmdevelopers/aux_l1b_cris Supportinginstrumentcharacterizationinformationpropagatedfrom

Level-1(notincludedinthev1release)3.5GeolocationGeolocationparametersareusedfordetermininglocationofeachobservationonEarthandassociatedinformationaboutthatlocation.Geolocationvariablesarelocatedinthefileattherootlevel.Theseincludelatitudesandlongitudesassociatedwitheachobservation,aswellassatelliteandsolargeometryinformation,spacecraftpositionandorbitalcharacteristics,surfaceinformationandrelatedmetadata.Theseproductscomefromretrievalalgorithmsthatdoacloud-clearingonaField-of-Regard(FOR)madeupof9Fields-of-View(FOVs).InthisretrievalitisassumedthatmostgeophysicalparametersareconstantovertheareaofaFOR,andtheseareprovidedatFORspatialresolution(45x30).Forsomevariables,includingsomecloudquantities,informationisavailableatFOVspatialresolution(45x30x9).Theproductcontainstwo


15

setsoflocationinformation:{lat,lon,land_frac,...}provideinformationaboutthelargerFORwhile{fov_lat,fov_lon,fov_land_frac,…}provideinformationaboutthesmallerFOV.The“coordinates”variableattributeattachedtoeachgeophysicalfieldspecifieswhichsetoflatitudeandlongitudeisappropriate.

Table3.5.1GeolocationDimensions

Dimensionname Size Meaning

atrack 45 Along-trackFORhorizontaldimension

xtrack 30 Cross-trackFORhorizontaldimension

fov 9 CrISFOVdimensionwithinFOR

fov_poly 8 latitude/longitude points defining the polygon bounding an fov (anticlockwise as viewed from above)

Figure1.geolocationhorizontaldimensions


16

Thekeygeolocationvariablesare:

Table3.5.2KeyFORGeolocationVariablesGeolocationVariable

Dimensions Meaning

lat atrack,xtrack latitudeofFORcenter

lon atrack,xtrack longitudeofFORcenter

lat_bnds atrack,xtrack,fov_poly

latitudeofFORboundingpolygon

lon_bnds atrack,xtrack,fov_poly

longitudeofFORboundingpolygon

land_frac atrack,xtrack LandfractionovertheFOR

surf_alt atrack,xtrack meansurfacealtitudeWRTEarthmodeloverFOR

obs_time_tai93 atrack,xtrack earthviewobservationmidtimeforeachfovinunitsofsecondssince1993-01-01T00:00:00

obs_time_utc atrack,xtrack,utc_tuple

UTCearthviewobservationtimeasanarrayofintegers:year,month,day,hour,minute,second,millisecond,microsecond

Correspondingvariablesfov_lat,fov_lon,fov_lat_bnds,fov_lon_bnds,fov_land_frac,fov_surf_altprovideinformationattheFOVspatialresolution.

Fullgeolocationincludesinformationaboutsolargeometry(sol_zen,sol_azi,sun_glint_dist),viewinggeometry(sat_zen,sat_azi,view_ang,sat_range,subsat_lat,…)andorbitalparameters.SeeAppendixCforfullspecification.

Onekeyfeatureisboundaries.EachFORandFOVhasabounding8-pointpolygoninvariables{lat_bnds,lon_bnds}and{fov_lat_bnds,fov_lon_bnds}.Thismakesiteasytoplacevaluesinappropriateregionsonamap,includingthedistortedshapesofFOVsandFORsattheedgesoftheswath.


17

Figure2.SampleplotofretrievedCrISNH3usingboundingpolygons.Credit:KarenCady-Pereira.

3.6ScienceDataVariablesTheseretrievalsprovideinformationonawidevarietyofgeophysicalparameters,includingtemperature,watervapor,constituents,clouds,andsurfaceparameters.Thisresultsinalargenumberofsciencedatavariables.

Manyvariableshaveassociatedqualitycontrolanderrorestimateinformation.Thesearecontainedinvariableswiththesamenamebutwith“_qc”and“_err”appended.Forexampletheairtemperatureprofileiscontainedinavariablenamed“air_temp”;itserrorestimateisin“air_temp_err”anditsqualitycontrolis“air_temp_qc”.The“ancillary_variables”variableattributeofair_templists“air_temp_qc,air_temp_err”.Inthetablesbelowtheancillaryvariablesarenotlistedexplicitly.Theyareindicatedinthe“ancillaryvariables”column.


18

Keysciencedatafieldsaredefinedbelow.Seetheappendixesforafulllisting.

Table3.6.1KeyRETScienceDataVariablesName Dimensions Description Units Ancillary

Variables air_temp atrack, xtrack,

air_pres air temperature profile Kelvin err, qc

surf_air_temp atrack, xtrack near-surface air temperature (~2 meters above surface)

Kelvin err, qc

h2o_vap_tot atrack, xtrack total precipitable water vapor kg / m2 err, qc spec_hum atrack, xtrack,

air_pres_h2o mass fraction of water vapor in moist air

unitless err, qc

surf_spec_hum atrack, xtrack Near-surface mass fraction of water vapor in moist air

unitless err, qc

rel_hum atrack, xtrack, air_pres_h2o

relative humidity over equilibrium phase

unitless err, qc

surf_rel_hum atrack, xtrack relative humidity near the surface over equilibrium phase

unitless err, qc

gp_hgt atrack, xtrack, air_pres

Geopotential is the sum of the specific gravitational potential energy relative to the geoid and the specific centripetal potential energy. Geopotential height is the geopotential divided by the standard acceleration due to gravity.

m err, qc

surf_gp_hgt atrack, xtrack geopotential height at the surface

m err, qc

o3_tot atrack, xtrack Total column ozone. (Multiply by 4.670e5 to convert to Dobson Units from kg m^-2)

kg m-2 err, qc

o3_mmr atrack, xtrack, air_pres

ozone mass mixing ratio to moist air

unitless err, qc

co_mmr_midtrop atrack, xtrack Carbon monoxide mass mixing ratio to moist air at 50000 Pa, near the peak of sensitivity

unitless err, qc

ch4_mmr_midtrop atrack, xtrack Methane mass mixing ratio to moist air at 40000 Pa, near the peak of sensitivity

unitless err, qc

h2o_liq_tot atrack, xtrack total column cloud liquid water kg m-2 err, qc h2o_liq_mol_lay atrack, xtrack,

air_pres_lay cloud liquid water layer total unitless err, qc

cld_frac atrack, xtrack, fov, cld_lay

effective cloud fraction unitless err, qc

cld_top_pres atrack, xtrack, fov, cld_lay

cloud top pressure in order of increasing pressure

Pa err, qc


19

cld_top_temp atrack, xtrack, fov, cld_lay

cloud top temperature Kelvin err, qc

num_cld atrack, xtrack, fov

Number of cloud layers with nonzero cloud fraction

unitless

tpause_gp_hgt atrack, xtrack tropopause geopotential height, where tropopause is determined according to the WMO definition

m qc

tpause_pres atrack, xtrack tropopause pressure, where tropopause is determined according to the WMO definition

Pa qc

tpause_temp atrack, xtrack tropopause temperature, where tropopause is determined according to the WMO definition

Kelvin qc

surf_freq_mw surf_freq_mw Microwave surface emissivity frequencies (hinge points)

Hz

Table3.6.2KeyCCRScienceDataVariablesName Dimensions Description Units Ancillary

Variables rad_lw atrack, xtrack,

wnum_lw longwave clear spectral radiance

mW/(m2 sr cm-1) err, qc

rad_mw atrack, xtrack, wnum_mw

midwave clear spectral radiance


rad_sw atrack, xtrack, wnum_sw

shortwave clear spectral radiance


nedn_lw fov, wnum_lw longwave noise equivalent differential radiance

mW/(m2 sr cm-1)

nedn_mw fov, wnum_mw midwave noise equivalent differential radiance

mW/(m2 sr cm-1)

nedn_sw fov, wnum_sw shortwave noise equivalent differential radiance

mW/(m2 sr cm-1)

3.7QualityInformationFor most retrieved geophysical variables, a numerical error estimate in the same physical units is provided in a corresponding ancillary_variable with a name ending in “_err”. There are also Quality Control (QC) scores of {0, 1, 2} in corresponding ancillary_variables with a name ending in “_qc”.

Table:3.7.1*_qcValues


20

Value Meaning 0 Highest quality – use without reservation 1 Good quality – suitable for most purposes

2 Do not use. In some cases a physical value is present but is not considered reliable. In other cases only fill values are present.

WhiletheCHARTandCLIMCAPSproductsbothhavethisstructure,thephilosophyofsettingindividualvaluesisdifferent.CLIMCAPSdecidesanentireFORretrievalisgoodorbadandsetsalllevelsofallvariablescollectivelyto0or2.CHARTmakesdifferentjudgementsperphysicalquantityandperpressurelevel,andusesthe“1”intermediatequalitylevel.

Inadditiontothe_qcand_errvariables,thereareotherindicatorsofquality.*_dofaredegrees-of-freedomforretrievalsofindividualquantities(air_temp_dof,h2o_vap_dof,o3_dof,….).Inthe/auxsubgrouptherearemoredetailedinternalqualityindicatorsincludingcloud-clearingnoiseamplificationfactorsandChi-squared.

3.8MissingData/FillValuesFillvaluesareusedwherethereisnovaliddata,includingprofileslevelwithpressuresgreaterthanthesurfacepressure.Thefillvalueisindicatedbytheattribute‘_FillValue’.Itisadvisedtocheckthedataforfillvaluesbeforeitisused.Thefillvaluespervariabledatatypearelistedinthetablebelow.

Table:3.8.1FillValuesVariable Type Fill Value unsigned 8-bit integer 255UB unsigned 16-bit integer 65535US

unsigned 32-bit integer 4294967295U floating point 9.96921e+36

3.9KeysupportinginformationvariablesforprofilesThese variables provide supporting information to interpret the science variables.

Name Dimensions Description Units

air_pres air_pres pressure levels Pa air_pres_h2o air_pres_h2o H2O vapor pressure levels Pa air_pres_lay air_pres_lay pressure at the middle of each layer Pa


21

air_pres_lay_bnds air_pres_lay, bnds_1d

Min and max pressure of each layer Pa

air_pres_nsurf atrack, xtrack Index in air_pres of the level at the surface. Values at levels beyond this are invalid, representing data below the Earth's surface.

unitless

air_pres_h2o_nsurf atrack, xtrack Index in air_pres_h2o of the level at the surface. Values at levels beyond this are invalid, representing data below the Earth's surface.

unitless

air_pres_lay_nsurf atrack, xtrack Index in air_pres_lay of the layer at the surface. Values for layers beyond this are invalid, representing data below the Earth's surface.

unitless

3.10VerticalprofilerepresentationofgasesBoth retrievals maintain internal vertical profiles of gases on 100 fixed-pressure layers. This information is preserved in the “mol_lay” subgroup. For the main public products in the root group, water vapor and ozone are reported on the 100 fixed-pressure levels which bound the layers. For water vapor, levels at pressures under 5153 Pa (51.53 hPa) are not reported. For gases CO and CH4, where there is less than a single degree of freedom, we report MMR only at a single pressure level near the peak of the retrieval sensitivity: 40000 Pa for CH4, and 50000 Pa for CO. Pressure levels below the surface are always filled with fill values. Level concentrations of gases are estimated from the layer gas amounts using different approaches, based on different philosophies. For CHART, we use a smoothing spline fit to represent the limits of the vertical information that is present in the input CrIMSS data by removing sharper features which may be artifacts from SCCNN. For CLIMCAPS, a more direct interpolation preserves information from MERRA2 (seeSection3.11,GFSwasaccidentallyusedasthefirstguess) along with the information from the retrieval.


22

Figure3.WatervaporlevelconcentrationforCLIMCAPSandCHART.


23

For CLIMCAPS, level concentrations of gases are estimated from layer-amounts using the mean-value theorem and assuming that layers with boundaries at

𝑃bnd = 𝑃' −𝑃')*

ln𝑃' − ln𝑃')*, have mean values which estimate the profile at the levels Pi. Layer-mean mixing ratios are uniquely specified by the layer amounts, the temperature profile and pressure differences through the hydrostatic and hypsometric equations [Wallace and Hobbs, 1977, pgs. 53-54]. Figure 3a illustrates the procedure. A true radiosonde profile of water vapor mixing ratio is converted to layer amounts as would be produced by the CLIMCAPS algorithm. These are shown in the figure as mean mass mixing ratio, which is obtained by dividing the layer water vapor amount by the layer dry air amount. The amounts in each layer are summed from top to bottom to produce a piecewise linear profile of top-to-level integrated amount. The integrated amount is then interpolated to a new set of levels, Pbnd, and differenced to produce a new set of layer amount. Similarly, the dry-air top-to-level integrated amounts are interpolated to the new levels, and mean mixing ratios (ratio of gas amount to dry-air amount) are assumed to be the mixing ratio at the levels Pi. Values at the end points are linearly extrapolated from the profile at interior points. The reported profiles have errors from the interpolations and use of the mean value theorem1. The algorithm uses linear interpolation in log pressure and top-to-level amount which introduces larger errors when top-to-level amount second derivative is large; these errors are not included in mixing ratio error estimates. Error estimates for the level mixing ratios are interpolated from the fractional layer-amount errors. Fractional error is assumed to be fully correlated and linearly interpolated in log pressure from the arithmetic mean pressures of each level (uncorrelated error involves linearly interpolating variance). CHART level concentrations are estimated from the layer amounts by least squares fitting a profile to the CHART output layer amounts. The mixing ratio profile is represented as a sum of 4th-order bsplines:

𝑋(𝑃) = ∑ 𝐴'𝑏'(𝑃)' , the fitting solves for the coefficients Ai, subject to the layer column amounts, a climatological smoothness a priori, and constrained to match the column total. Figure 3b shows the same profile as in the previous figure, and shows the bspline functions, the fitted profile, and the error profile error estimates. This algorithm adds some smoothness to the output profile and performs comparably to the mean-value-theorem method, when the fitting functions are representative of the structure contained in the input layer quantities.

3.11Knownissuesa) The MERRA-2 first guess profile was accidentally overwritten by the GFS forecast file,

so that in this 8-month sample run the apriori and all the "fg" variables are actually the

1Themeanvaluetheoremsaysthatsomepointintheintervalhasthemeanvalue,butnotwherethepointislocated.


24

GFS forecast interpolated to the time and location of the observation. For the purpose of evaluation of the behavior of CLIMCAPS versus CHART the use of GFS forecasts should not be significantly different than MERRA-2.

b) CLIMCAPS surf_emis_mw is wrong. c) Reported error estimates are all fill values for

i. [surf_]spec_hum_sat_[ice|liq]_err ii. [surf_]gp_hgt_err

iii. h2o_liq_mol_lay_err iv. mw_[surf_]air_temp_err v. mw_surf_temp_err

vi. CLIMCAPS surf_ir_emis_err, cld_frac_err, cld_top_pres_err, for_cld_frac_tot_err, for_cld_top_pres_tot_err, for_cld_frac_2lay_err, for_cld_top_pres_2lay_err, h2o_liq_tot_err

vii. CLIMCAPS cloud-cleared radiances, rad_*w_err d) CLIMCAPS co2_mol_lay is all fill values, but retrieved CO2 info is available in VMR

units in aux/co2_vmr. e) Even though the description of o3_mmr and co_mmr_midtrop says they are MMR to

moist air, the values are calculated as MMR to dry air. The differences are very small.

4.0OptionsforReadingtheDataTheproductfilesarewritteninnetCDF4/HDF5.BecausenetCDF4buildsupontheclassicnetCDFdatamodelusingHDF5asthestoragelayer,auserofthedataproductcantakefulladvantageoftoolsandlibrariesreadilyavailabletoaccessthedata.EverynetCDF4fileisconsideredanHDF5file,however,noteveryHDF5fileisnecessarilyanetCDF4file.AlimitedsubsetoftheHDF5datamodelandfileformatfeaturesareusedinnetCDF4files.ConformancetotheearliermentionedCF&ACDDstandardsallowsforuserstotakeadvantageofmostnetCDFinterfaces.ToolsandlibrariesforreadingnetCDF4aswellasanetCDFUsers’GuidearewrittenandmaintainedbyUnidataandcanbefoundonlineat:

http://www.unidata.ucar.edu/software/netcdf/

Panoplyisagoodtoolforvisualizingthesefiles.https://www.giss.nasa.gov/tools/panoply/ThereareanumberofinterfacesavailableforreadingnetCDFfordifferentprogramminglanguagesincluding:C/C++,Fortran,Matlab,IDL,PythonandPerl.ThefilescanalsobeaccessedwithHDF5toolsandlibrariesavailableat:

https://www.hdfgroup.org/products/hdf5_tools/


25

5.0DataServices

TheproductsareavailabletotheusercommunityviatheGoddardDistributedActiveArchiveCenter(GDAAC).https://disc.gsfc.nasa.gov/ InadditiontothenetCDFdatafiles,thereyoucanalsogetdailygranulemaps,showingthelocationofeachgranuleofeachday.

Figure4.Granulemapfornighttimedata2016-01-14.Granule101isusedinApp

DataattheGDAACisorganizedbyuniqueshortnamesandversionnumbers.

Table5.1Shortnamesshortname.version Description

CHART+CLIMCAPSLevel-2productsdescribedinthisdocumentSNDRSNIML2CCPRETN.1 CLIMCAPSLevel-2retrievedproductSNDRSNIML2CCPCCRN.1 CLIMCAPSLevel-2Cloud-clearedradiancesSNDRSNIML2CHTRETN.1 CHARTLevel-2retrievedproductSNDRSNIML2CHTCCRN.1 CHARTLevel-2Cloud-clearedradiances

RelateddatasetsatGDAACN/A (on demand) SNPPgranulemapsSNPPCrISL1BNSR.1 SNPPCrISLevel1BNormalSpectralResolutionV1

7

8

9

10

11

12

24

25

26

27

28

29

41

42

43

44

45

46

58

59

60

61

62

63

75

76

77

78

79

80

92

93

94

95

96

97

109

110

111

112

113

114

126

127

128

129

130

131

143

144

145

146

147

148

160

161

162

163

164

165

177

178

179

180

181

182

194

195

196

197

198

199

210

211

212

213

214

215

227

228

229

230

231

232

Ascending Data

SNPPCrIS Files: 240

14 Jan 2016DoY 14

SNPP Day 1539

1

2

3

4

16

17

18

19

20

21

33

34

35

36

37

38

50

51

52

53

54

55

67

68

69

70

71

72

84

85

86

87

88

89

101

102

103

104

105

106

117

118

119

120

121

122

134

135

136

137

138

139

151

152

153

154

155

156

168

169

170

171

172

173

185

186

187

188

189

190

202

203

204

205

206

207

219

220

221

222

223

224

236

237

238

239

240

Descending Data

Legend: CrIS Available Created on 2018-04-19 16:16:15 PDT by [email protected]


26

usedasinputfortheseretrievalsSNPPATMSL1B.1 SNPPATMSLevel1BBrightnessTemperatureV1

usedasinputfortheseretrievalsSNDRSNIML3DCCPN.1 CLIMCAPSLevel-31-dayretrievedproductSNDRSNIML3MCCPN.1 CLIMCAPSLevel-3monthlyretrievedproductSNDRSNIML3DCHTN.1 CHARTLevel-31-dayretrievedproductSNDRSNIML3MCHTN.1 CHARTLevel-3monthlyretrievedproduct


27

AppendixA:DifferencesbetweenCLIMCAPSandCHARTalgorithmsAlthoughCHARTandCLIMCAPSshareacommonheritage,therearesignificantdifferencesinimplementation.Theyusedifferentchannelsandverticalbasisfunctionsamongotherchanges.PleaseseetheirrespectiveATBDdocumentsforfulldetails.Hereareafewkeydifferences.A.1Firstguess

CLIMCAPSstartsfromabackgroundgeophysicalstatederivedfromMERRA2(seeSection3.11,GFSwasaccidentallyusedasthefirstguess).CHARTstartsfromtheresultsofaneuralnetusingCrIMSSdata,andtrainedusingECMWFforecasts.ThisneuralnetisStochasticCloudClearingNeuralNet(SCCNN),andisprovidedbyAdamMilsteinofMIT.A.2Iteration

CHARTconvergesthroughseveraliterationsofcloudclearingandrefininggeophysicalstate;CLIMCAPSdoesonlyasinglecloudclearing. A.3Errorestimationapproach

CLIMCAPSerrorestimatesareproducedaspartoftheSVDretrieval.CHARTusesaregressiontrainedonECMWFdatatopredictlikelyerrors.A.4QualityControlapproach

Bothproductsincludevariableswithnamesendingin“_qc”tellingwhichvaluesaresafetouse(0:bestquality;1:goodquality,2:donotuse)butthevaluesarederiveddifferently.CLIMCAPSdeclareseachretrievalassuccessfulornotbasedonwhetherallstepsoftheretrievalwereabletoexecutesuccessfully,sothevaluesforalmostallquantitiesandlevelsareidentical.CHARTusesthresholdsbasedonthepredictederrorlevels,appliedindividuallytodifferentretrievedparametersandatmosphericlevels.

A.5Retrievedquantities

Afterthecoreretrievaloftemperature,watervapor,clouds,andozone,CHARTandCLIMCAPSadddifferentadditionalretrievals.

CHARThasvariousOutgoingLongwaveRadiation(OLR),independentper-FOVcloudpressure,andaninfrared-basedprecipitationestimate.

CLIMCAPSretrievestheseadditionalgases:HNO3,SO2,N2O,andCO2.Forthev1release,theyareconsideredpreliminaryandonlyprovidedinthemol_layorauxsubgroups.


28

AppendixB:SampleimagesTheseimagesfor2016-01-14granule101(gran_id=20160114T1005)weregeneratedwithPanoply.WeshowCLIMCAPSair_tempforlevel87,whichis75400Pa(=754hPa).ThisgranulecoversthewesternpartoftheUSandtheadjacentpartofthePacificOceanatnight.Someofthetallermountainsbringthesurfacepressurebelow75400hPa,sonodataispresentfortheseFORs.

Nextwelookatthislevelofair_tempinasimplerectangulargridofatrackxxtrack.ThePacificOceanisnowatthetopofeachimageandtheRockyMountainsnearthebottom.Thismeanswe’reactuallylookingoutfrominsidetheEarth.ThetableshowsCLIMCAPSandCHARTimagesforthislevel,withassociatederrorestimatesandQC.


29

CLIMCAPS CHARTair_temp

air_temp_err

air_temp_qc


30

Lookingatthecloud-clearedradianceproduct,LWchannel401,898.75cm-1.

CLIMCAPS CHARTrad_lw

rad_lw_err

N/A(allfiller)

rad_lw_qc


31

AppendixC:DetailedfileformatsThese tables show all of the dimensions, global attributes, and variables in the four product types. For clarity, some variable attributes are omitted, including long_name, standard_name, coverage_content_type, axis, valid_range, coordinates, and _FillValue. Ancillary variables are also omitted. The presence of “bnds” in the ancillary_variables column for “lat” means that there is also a variable named “lat_bnds”. To get a complete listing including all variable attributes, apply “ncdump -h” to any netCDF4 product file.


32

C.1CLIMCAPSRetrievalproduct

SNPPL2CLIMCAPSCRIMSSInterfaceSpecificationInterfaceSpecificationVersion02.00.28

04-10-2019GlobalGroups

Path Description

/ Mainsciencedata

/mw MW-Onlydata

/mol_lay Layermoleculeamounts

/aux Internalproductteamdata

GlobalDimensions

Name Size Description

spatial 3 directions:x,y,z forsatellitepositionandvelocity

fov_poly 8 latitude/longitudepointsdefiningthepolygonboundinganFOV(anticlockwiseasviewedfromabove)

utc_tuple 8 partsofUTCtime:year,month,day,hour,minute,second,millisec,microsec

attitude 3 roll,pitch,yaw

fov 9 Field-of-viewdimension

atrack 45 along-trackhorizontaldimension

xtrack 30 cross-trackhorizontaldimension

air_pres 100 Fineatmosphericpressurelevelsstartingfromthetop

air_pres_h2o 66 Fineatmosphericpressurelevelsstartingfromthetop

air_pres_lay 100 Fineatmosphericpressurelayersstartingfromthetop

surf_wnum_ir 100 IRsurfaceemissivityhingepoints

surf_freq_mw 7 MWsurfaceemissivityhingepoints

cld_lay 2 Measuredcloudlayers:top,bottom

bnds_1d 2 Boundariesfor1-dfieldslikeair_pres_lay:min,max


33

GlobalAttributes

Name Type Size Value Description

keywords string 1

ATMOSPHERE>ATMOSPHERICTEMPERATURE>UPPERAIRTEMPERATURE\,ATMOSPHERE>ATMOSPHERICWATERVAPOR>WATERVAPOR

Acomma-separatedlistofkeywordsand/orphrases.Keywordsmaybecommonwordsorphrases,termsfromacontrolledvocabulary(GCMDisoftenused),orURIsfortermsfromacontrolledvocabulary(seealso"keywords_vocabulary"attribute).

Conventions string 1 CF-1.6\,ACDD-1.3 Acomma-separatedlistoftheconventionsthatarefollowedbythedataset.

history string 1

Providesanaudittrailformodificationstotheoriginaldata.ThisattributeisalsointheNetCDFUsersGuide:'Thisisacharacterarraywithalineforeachinvocationofaprogramthathasmodifiedthedataset.Well-behavedgenericnetCDFapplicationsshouldappendalinecontaining:date,timeofday,username,programnameandcommandarguments.'ToincludeamorecompletedescriptionyoucanappendareferencetoanISOLineageentity;seeNOAAEDMISOLineageguidance.

source string 1 CrISandATMSinstrumenttelemetry

Themethodofproductionoftheoriginaldata.Ifitwasmodel-generated,sourceshouldnamethemodelanditsversion.Ifitisobservational,sourceshouldcharacterizeit.ThisattributeisdefinedintheCFConventions.Examples:'temperaturefromCTD#1234';'worldmodelv.0.1'.

processing_level string 1 2 Atextualdescriptionoftheprocessing(orqualitycontrol)levelofthedata.

product_name_type_id string 1 L2_CLIMCAPS_RET_NSR Productnameasitappearsinproduct_name(L1A,L1B,L2,SNO_AIRS_CrIS)

comment string 1 Miscellaneousinformationaboutthedataormethodsusedtoproduceit.Canbeempty.

acknowledgment string 1 SupportforthisresearchwasprovidedbyNASA.

Aplacetoacknowledgevarioustypesofsupportfortheprojectthatproducedthisdata.

license string 1 LimitedtoSounderSIPSaffiliates

ProvidetheURLtoastandardorspecificlicense,enter"FreelyDistributed"or"None",ordescribeanyrestrictionstodataaccessanddistributioninfreetext.

standard_name_vocabulary string 1 CFStandardNameTablev28

Thenameandversionofthecontrolledvocabularyfromwhichvariablestandardnamesaretaken.(Valuesforanystandard_nameattributemustcomefromtheCFStandardNamesvocabularyforthedatafileorproducttocomplywithCF.)Example:'CFStandardNameTablev27'.

date_created string 1 Unassigned

Thedateonwhichthisversionofthedatawascreated.(Modificationofvaluesimpliesanewversion,hencethiswouldbeassignedthedateofthemostrecentvaluesmodification.)


34


Metadatachangesarenotconsideredwhenassigningthedate_created.TheISO8601:2004extendeddateformatisrecommended,asdescribedintheAttributeContentGuidancesection.

creator_name string 1 UnassignedThenameoftheperson(orothercreatortypespecifiedbythecreator_typeattribute)principallyresponsibleforcreatingthisdata.

creator_email string 1 Unassigned

Theemailaddressoftheperson(orothercreatortypespecifiedbythecreator_typeattribute)principallyresponsibleforcreatingthisdata.

creator_url string 1 UnassignedTheURLoftheperson(orothercreatortypespecifiedbythecreator_typeattribute)principallyresponsibleforcreatingthisdata.

institution string 1 Unassigned Processingfacilitythatproducedthisfile

project string 1 SounderSIPS

Thenameoftheproject(s)principallyresponsiblefororiginatingthisdata.Multipleprojectscanbeseparatedbycommas,asdescribedunderAttributeContentGuidelines.Examples:'PATMOS-X','ExtendedContinentalShelfProject'.

product_name_project string 1 SNDRThenameoftheprojectasitappearsinthefilename.'SNDR'forallSounderSIPSproducts,evenAIRSproducts.

publisher_name string 1 Unassigned

Thenameoftheperson(orotherentityspecifiedbythepublisher_typeattribute)responsibleforpublishingthedatafileorproducttousers,withitscurrentmetadataandformat.

publisher_email string 1 Unassigned

Theemailaddressoftheperson(orotherentityspecifiedbythepublisher_typeattribute)responsibleforpublishingthedatafileorproducttousers,withitscurrentmetadataandformat.

publisher_url string 1 Unassigned

TheURLoftheperson(orotherentityspecifiedbythepublisher_typeattribute)responsibleforpublishingthedatafileorproducttousers,withitscurrentmetadataandformat.

geospatial_bounds string 1

Describesthedata's2Dor3DgeospatialextentinOGC'sWell-KnownText(WKT)Geometryformat(referencetheOGCSimpleFeatureAccess(SFA)specification).Themeaningandorderofvaluesforeachpoint'scoordinatesdependsonthecoordinatereferencesystem(CRS).TheACDDdefaultis2DgeometryintheEPSG:4326coordinatereferencesystem.Thedefaultmaybeoverriddenwithgeospatial_bounds_crsandgeospatial_bounds_vertical_crs(seethoseattributes).EPSG:4326coordinatevaluesarelatitude(decimaldegrees_north)andlongitude


35


(decimaldegrees_east),inthatorder.Longitudevaluesinthedefaultcasearelimitedtothe-180,180)range.Example:'POLYGON((40.26-111.29,41.26-111.29,41.26-110.29,40.26-110.29,40.26-111.29))'.

geospatial_bounds_crs string 1 EPSG:4326

Thecoordinatereferencesystem(CRS)ofthepointcoordinatesinthegeospatial_boundsattribute.ThisCRSmaybe2-dimensionalor3-dimensional,buttogetherwithgeospatial_bounds_vertical_crs,ifthatattributeissupplied,mustmatchthedimensionality,order,andmeaningofpointcoordinatevaluesinthegeospatial_boundsattribute.Ifgeospatial_bounds_vertical_crsisalsopresentthenthisattributemustonlyspecifya2DCRS.EPSGCRSsarestronglyrecommended.Ifthisattributeisnotspecified,theCRSisassumedtobeEPSG:4326.Examples:'EPSG:4979'(the3DWGS84CRS),'EPSG:4047'.

geospatial_lat_min float 1 9.9692099683868690e+36f

Describesasimplelowerlatitudelimit;maybepartofa2-or3-dimensionalboundingregion.Geospatial_lat_minspecifiesthesouthernmostlatitudecoveredbythedataset.

geospatial_lat_max float 1 9.9692099683868690e+36f

Describesasimpleupperlatitudelimit;maybepartofa2-or3-dimensionalboundingregion.Geospatial_lat_maxspecifiesthenorthernmostlatitudecoveredbythedataset.

geospatial_lon_min float 1 9.9692099683868690e+36f

Describesasimplelongitudelimit;maybepartofa2-or3-dimensionalboundingregion.geospatial_lon_minspecifiesthewesternmostlongitudecoveredbythedataset.Seealsogeospatial_lon_max.

geospatial_lon_max float 1 9.9692099683868690e+36f

Describesasimplelongitudelimit;maybepartofa2-or3-dimensionalboundingregion.geospatial_lon_maxspecifiestheeasternmostlongitudecoveredbythedataset.Caseswheregeospatial_lon_minisgreaterthangeospatial_lon_maxindicatetheboundingboxextendsfromgeospatial_lon_max,throughthelongituderangediscontinuitymeridian(eithertheantimeridianfor-180:180values,orPrimeMeridianfor0:360values),togeospatial_lon_min;forexample,geospatial_lon_min=170andgeospatial_lon_max=-175incorporates15degreesoflongitude(ranges170to180and-180to-175).

time_coverage_start string 1

Nominalstarttime.Describesthetimeofthefirstdatapointinthedataset.UsetheISO8601:2004dateformat,preferablytheextendedformatasrecommendedintheAttributeContentGuidancesection.

time_of_first_valid_obs string 1 Describesthetimeofthefirstvaliddatapointinthedataset.UsetheISO8601:2004dateextendedformat.


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time_coverage_mid string 1

Describesthemidpointbetweenthenominalstartandendtimes.UsetheISO8601:2004dateformat,preferablytheextendedformatasrecommendedintheAttributeContentGuidancesection.

time_coverage_end string 1

Nominalendtime.Describesthetimeofthelastdatapointinthedataset.UseISO8601:2004dateformat,preferablytheextendedformatasrecommendedintheAttributeContentGuidancesection.

time_of_last_valid_obs string 1 Describesthetimeofthelastvaliddatapointinthedataset.UsetheISO8601:2004dateextendedformat.

time_coverage_duration string 1 P0000-00-00T00:06:00

Describesthedurationofthedataset.UseISO8601:2004durationformat,preferablytheextendedformatasrecommendedintheAttributeContentGuidancesection.

product_name_duration string 1 m06 Productdurationasitappearsinproduct_name(m06meanssixminutes)

creator_type string 1 institution

Specifiestypeofcreatorwithoneofthefollowing:'person','group','institution',or'position'.Ifthisattributeisnotspecified,thecreatorisassumedtobeaperson.

creator_institution string 1JetPropulsionLaboratory--CaliforniaInstituteofTechnology

Theinstitutionofthecreator;shoulduniquelyidentifythecreator'sinstitution.Thisattribute'svalueshouldbespecifiedevenifitmatchesthevalueofpublisher_institution,orifcreator_typeisinstitution.

product_version string 1 v01.00.00

Versionidentifierofthedatafileorproductasassignedbythedatacreator.Forexample,anewalgorithmormethodologycouldresultinanewproduct_version.

keywords_vocabulary string 1 GCMD:GCMDKeywords

Ifyouareusingacontrolledvocabularyforthewords/phrasesinyour"keywords"attribute,thisistheuniquenameoridentifierofthevocabularyfromwhichkeywordsaretaken.Ifmorethanonekeywordvocabularyisused,eachmaybepresentedwithaprefixandafollowingcomma,sothatkeywordsmayoptionallybeprefixedwiththecontrolledvocabularykey.Example:'GCMD:GCMDKeywords,CF:NetCDFCOARDSClimateandForecastStandardNames'.

platform string 1SUOMI-NPP>SuomiNationalPolar-orbitingPartnership

Nameoftheplatform(s)thatsupportedthesensordatausedtocreatethisdatasetorproduct.Platformscanbeofanytype,includingsatellite,ship,station,aircraftorother.Indicatecontrolledvocabularyusedinplatform_vocabulary.

platform_vocabulary string 1 GCMD:GCMDKeywords Controlledvocabularyforthenamesusedinthe"platform"attribute.

product_name_platform string 1 SNPP Platformnameasitappearsinproduct_name


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instrument string 1

CRIMSS>Cross-trackInfraredandAdvancedTechnologyMicrowaveSounders\,CrIS>Cross-trackInfraredSounder\,ATMS>AdvancedTechnologyMicrowaveSounder

Nameofthecontributinginstrument(s)orsensor(s)usedtocreatethisdatasetorproduct.Indicatecontrolledvocabularyusedininstrument_vocabulary.

instrument_vocabulary string 1 GCMD:GCMDKeywords Controlledvocabularyforthenamesusedinthe"instrument"attribute.

product_name_instr string 1 CRIMSS Instrumentnameasitappearsinproduct_name

product_name string 1 Canonicalfullyqualifiedproductname(officialfilename)

product_name_variant string 1 std

Processingvariantidentifierasitappearsinproduct_name.'std'(shorthandfor'standard')istobethedefaultandshouldbewhatisseeninallpublicproducts.

product_name_version string 1 vxx_xx_xx Versionnumberasitappearsinproduct_name(v01_00_00)

product_name_producer string 1 TProductionfacilityasitappearsinproduct_name(singlecharacter)'T'isthedefault,forunofficiallocaltestproducts

product_name_timestamp string 1 yymmddhhmmss Processingtimestampasitappearsinproduct_name(yymmddhhmmss)

product_name_extension string 1 nc Fileextensionasitappearsinproduct_name(typicallync)

granule_number ushort 1 granulenumberofday(1-240)

product_name_granule_number string 1 g000 zero-paddedstringforgranulenumberofday(g001-g240)

gran_id string 1 yyyymmddThhmmUniquegranuleidentifieryyyymmddThhmmofgranulestart,includingyear,month,day,hour,andminuteofgranulestarttime

geospatial_lat_mid float 1 9.9692099683868690e+36f granulecenterlatitude

geospatial_lon_mid float 1 9.9692099683868690e+36f granulecenterlongitude

featureType string 1 point structureofdatainfile

data_structure string 1 swath

acharacterstringindicatingtheinternalorganizationofthedatawithcurrentlyallowedvaluesof'grid','station','trajectory',or'swath'.The'structure'heregenerallydescribesthehorizontalstructureandinallcasesdatamayalsobefunctions,forexample,ofaverticalcoordinateand/ortime.(IfusingCMORpassthisinacalltocmor_set_cur_dataset_attribute.)


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cdm_data_type string 1 Swath

Thedatatype,asderivedfromUnidata'sCommonDataModelScientificDatatypesandunderstoodbyTHREDDS.(ThisisaTHREDDS"dataType",andisdifferentfromtheCFNetCDFattribute'featureType',whichindicatesaDiscreteSamplingGeometryfileinCF.)

id string 1 Unassigned

Anidentifierforthedataset,providedbyanduniquewithinitsnamingauthority.Thecombinationofthe"namingauthority"andthe"id"shouldbegloballyunique,buttheidcanbegloballyuniquebyitselfalso.IDscanbeURLs,URNs,DOIs,meaningfultextstrings,alocalkey,oranyotheruniquestringofcharacters.Theidshouldnotincludewhitespacecharacters.

naming_authority string 1 Unassigned

Theorganizationthatprovidestheinitialid(seeabove)forthedataset.Thenamingauthorityshouldbeuniquelyspecifiedbythisattribute.Werecommendusingreverse-DNSnamingforthenamingauthority;URIsarealsoacceptable.Example:'edu.ucar.unidata'.

identifier_product_doi string 1 Unassigned digitalsignature

identifier_product_doi_authority string 1 Unassigned digitalsignaturesource

algorithm_version string 1

Theversionofthealgorithminwhateverformatisselectedbythedevelopers.Afterthemainalgorithmnameandversion,versionsfrommultiplesub-algorithmsmaybeconcatenatedwithsemicolonseparators.(ex:'CCAST4.2;BBemisfromMIT2016-04-01')Mustbeupdatedwitheverydeliverythatchangesnumericalresults.

production_host string 1 Identifyinginformationaboutthehostcomputerforthisrun.(Outputoflinux"uname-a"command.)

format_version string 1 v02.00.29 Formatversion.

input_file_names string 1 Semicolon-separatedlistofnamesoruniqueidentifiersoffilesthatwereusedtomakethisproduct.Therewillalwaysbeonespaceaftereachsemicolon.Thereisnofinalsemicolon.

input_file_types string 1 Semicolon-separatedlistoftagsgivingtheroleofeachinputfileininput_file_names.Therewillalwaysbeonespaceaftereachsemicolon.Thereisnofinalsemicolon.

input_file_dates string 1 Semicolon-separatedlistofcreationdatesforeachinputfileininput_file_names.Therewillalwaysbeonespaceaftereachsemicolon.Thereisnofinalsemicolon.

orbitDirection string 1 Orbitisascendingand/ordescending.Valuesare"Ascending"or"Descending"iftheentiregranulefitsthatdescription."NorthPole"and"SouthPole"areusedforpolar-crossing


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granules."NA"isusedwhenadeterminationcannotbemade.

day_night_flag string 1

Dataisdayornight."Day"meanssubsatellitepointforallvalidscanshassolarzenithanglelessthan90degrees."Night"meanssubsatellitepointforallvalidscanshassolarzenithanglegreaterthan90degrees."Both"meansthedatasetcontainsvalidobservationswithsolarzenithangleaboveandbelow90degrees."NA"meansavaluecouldnotbedetermined.

AutomaticQualityFlag string 1 Missing

"Passed":thegranulecontainsanon-degradedcalibratedbrightnesstemperature,radiance,orretrievedvalueforatleastonevalueinageolocatedFOV;"Suspect":thegranuledoesnotqualifyas"Passed"butcontainsa(possiblydegraded)calibratedorretrievedvalue(possiblywithoutassociatedgeolocation);"Failed":thegranulecontainsnocalibratedorretrievedvalues.

qa_pct_data_missing float 1 Percentageofexpectedobservationsthataremissing.

qa_pct_data_geo float 1 Percentageofexpectedobservationsthataresuccessfullygeolocated.

qa_pct_data_sci_mode float 1 Percentageofexpectedobservationsthatweretakenwhiletheinstrumentwasinsciencemodeandaresuccessfullygeolocated.

qa_no_data string 1 TRUEAsimpleindicatorofwhetherthisisan"empty"granulewithnodatafromtheinstrument."TRUE"or"FALSE".

title string 1 Level-2CLIMCAPSSNPPCrIMSS

asuccinctdescriptionofwhatisinthedataset.(=ECSlongname)

summary string 1

TheLevel-2CLIMCAPSproductincludesatmosphericstateretrievalproductsfromtheCLIMCAPSalgorithmforonesix-minuteinterval.Theseincludetemperatureandwatervaporprofilesaswellascloudandsurfaceproductsandminorgases.

Aparagraphdescribingthedataset,analogoustoanabstractforapaper.

shortname string 1 SNDRSNIML2CCPRETN ECSShortName

product_group string 1 l2_crimssThegroupnametobeusedforthisproductwhenitiscollectedinamulti-groupfiletype,likeSNOorcalsub.

metadata_link string 1 UnassignedAURLthatgivesthelocationofmorecompletemetadata.ApersistentURLisrecommendedforthisattribute.

references string 1 ATDBanddesigndocumentsdescribingprocessingalgorithms.Canbeempty.


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contributor_name string 1

ChristopherD.Barnet\,STC;L.LarrabeeStrow\,UMBC;PhilipW.Rosenkranz\,MIT

Thenamesofanyindividualsorinstitutionsthatcontributedtothecreationofthisdata.

contributor_role string 1 RetrievalPI;ForwardModelPI;MicrowavePI

Therolesofanyindividualsorinstitutionsthatcontributedtothecreationofthisdata.

GlobalVariables

Name Type Dimensions Description Units

AncillaryVariables

obs_id string atrack,xtrack

uniqueearthviewobservationidentifier:yyyymmddThhmm.aaExx.Includesgran_idplus2-digitalong-trackindex(01-45)and2-digitcross-trackindex(01-30).

fov_obs_id string atrack,xtrack,fov

uniqueearthviewobservationidentifierforFOV:yyyymmddThhmm.aaExx.f.Includesgran_idplus2-digitalong-trackindex(01-45),2-digitcross-trackindex(01-30),and1-digitFOVnumber(1-9).

obs_time_tai93 double

atrack,xtrack earthviewobservationmidtimeforeachFOV

secondssince1993-01-0100:00

bnds

obs_time_utc uint16

atrack,xtrack,utc_tuple

UTCearthviewobservationtimeasanarrayofintegers:year,month,day,hour,minute,second,millisec,microsec

lat float atrack,xtrack latitudeofFORcenter degrees_nor

th bnds

lat_geoid float atrack,xtrack

latitudeofFORcenteronthegeoid(withoutterraincorrection)

degrees_north

fov_lat float atrack,xtrack,fov latitudeofFOVcenter degrees_nor

th bnds

lon float atrack,xtrack longitudeofFORcenter degrees_eas

t bnds

lon_geoid float atrack,xtrack

longitudeofFORcenteronthegeoid(withoutterraincorrection)

degrees_east

fov_lon float atrack,xtrack,fov longitudeofFOVcenter degrees_eas

t bnds

land_frac float atrack,xtrack landfractionovertheFOR unitless

fov_land_frac float atrack,xtrack,fov landfractionovertheFOV unitless

surf_alt float atrack,xtrack meansurfacealtitudewrtearthmodelovertheFOR m


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AncillaryVariables

fov_surf_alt float atrack,xtrack,fov meansurfacealtitudewrtearthmodelovertheFOV m

surf_alt_sdev float atrack,xtrack standarddeviationofsurfacealtitudewithintheFOR m

fov_surf_alt_sdev float atrack,xtrack,fov standarddeviationofsurfacealtitudewithintheFOV m

sun_glint_lat float atrack sunglintspotlatitudeatscan_mid_time.Fillfornightobservations.

degrees_north

sun_glint_lon float atrack sunglintspotlongitudeatscan_mid_time.Fillfornightobservations.

degrees_east

sol_zen float atrack,xtrack solarzenithangleatthecenterofthespot degree

sol_azi float atrack,xtrack

solarazimuthangleatthecenterofthespot(clockwisefromNorth) degree

sun_glint_dist float atrack,xtrack

distanceofsunglintspottothecenterofthespot.Fillfornightobservations. m

view_ang float atrack,xtrack offnadirpointingangle degree

sat_zen float atrack,xtrack satellitezenithangleatthecenterofthespot degree

sat_azi float atrack,xtrack

satelliteazimuthangleatthecenterofthespot(clockwisefromNorth) degree

sat_range float atrack,xtrack

lineofsightdistancebetweensatelliteandspotcenter m

asc_flag ubyte atrack ascendingorbitflag:1ifascending,0descending

subsat_lat float atrack sub-satellitelatitudeatscan_mid_time degrees_north

subsat_lon float atrack sub-satellitelongitudeatscan_mid_time degrees_east

scan_mid_time double atrack TAI93atmiddleofearthscenescans


sat_alt float atrack satellitealtitudewithrespecttoearthmodelatscan_mid_time m

sat_pos float atrack,spatial satelliteECRpositionatscan_mid_time m

sat_vel float atrack,spatial satelliteECRvelocityatscan_mid_time ms-1


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AncillaryVariables

sat_att float atrack,attitude

satelliteattitudeatscan_mid_time.Anorthogonaltriad.Firstelementisangleaboutthe+x(roll)ORBaxis.+xaxisispositivelyorientedinthedirectionoforbitalflight.Secondelementisangleabout+y(pitch)ORBaxis.+yaxisisorientednormaltotheorbitplanewiththepositivesenseoppositetothatoftheorbit'sangularmomentumvectorH.Thirdelementisangleabout+z(yaw)axis.+zaxisispositivelyorientedEarthwardparalleltothesatelliteradiusvectorRfromthespacecraftcenterofmasstothecenteroftheEarth.

degree

local_solar_time float atrack,xtrack localapparentsolartimeinhoursfrommidnight hours

mean_anom_wrt_equat float atrack spacecraftmeananomalymeasuredwithrespectto

theascendingnode degree

sat_sol_zen float atrack solarzenithangleatthesatellite degree

sat_sol_azi float atrack solarazimuthangleatthesatellite(clockwisefromNorth) degree

asc_node_lon float Longitudeofthelastascendingnodeofspacecraftorbitbeforetime_coverage_end.

degrees_east

asc_node_tai93 double

TAI93timeofthelastascendingnodeofspacecraftorbitbeforetime_coverage_end.


asc_node_local_solar_time float localapparentsolartimeatthelastascendingnode

beforetime_coverage_endinhoursfrommidnight hours

solar_beta_angle float Betaangleforthespacecraftorbit,determiningthepercentageoftheorbitthatthespacecraftisindirectsunlight.

degree

attitude_lbl string attitude listofrotationaldirections(roll,pitch,yaw)

spatial_lbl string spatial listofspatialdirections(X,Y,Z)

utc_tuple_lbl string utc_tuple

namesoftheelementsofUTCwhenitisexpressedasanarrayofintegersyear,month,day,hour,minute,second,millisecond,microsecond

air_temp float32

atrack,xtrack,air_pres

airtemperatureprofile Kelvin err,qc

surf_air_temp float32

atrack,xtrack

near-surfaceairtemperature(~2metersabovesurface) Kelvin err,qc

air_temp_dof float32

atrack,xtrack

Thetraceoftheaveragingkernelmatrixasameasureofthenumberofpiecesofinformationabouttheairtemperatureprofileprovidedbythephysicalretrievalstep.

unitless


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AncillaryVariables

h2o_vap_tot float32

atrack,xtrack totalprecipitablewatervapor kg/m2 err,qc

spec_hum float32

atrack,xtrack,air_pres_h2o

massfractionofwatervaporinmoistair unitless err,qc

surf_spec_hum float32

atrack,xtrack

Near-surfacemassfractionofwatervaporinmoistair unitless err,qc

h2o_vap_dof float32

atrack,xtrack

Thetraceoftheaveragingkernelmatrixasameasureofthenumberofpiecesofinformationaboutthewatervaporprofileprovidedbythephysicalretrievalstep.

unitless

rel_hum float32


relativehumidityoverequilibriumphase unitless err,qc

surf_rel_hum float32

atrack,xtrack

relativehumiditynearthesurfaceoverequilibriumphase unitless err,qc

spec_hum_sat_ice float32


saturationspecifichumidityinequilibriumwithice unitless err,qc

surf_spec_hum_sat_ice float32

atrack,xtrack

Near-surfacesaturationspecifichumidityinequilibriumwithice unitless err,qc

spec_hum_sat_liq float32


saturationspecifichumidityinequilibriumwithliquidwater unitless err,qc

surf_spec_hum_sat_liq float32

atrack,xtrack

Near-surfacesaturationspecifichumidityinequilibriumwithliquidwater unitless err,qc

gp_hgt float32


Geopotentialisthesumofthespecificgravitationalpotentialenergyrelativetothegeoidandthespecificcentripetalpotentialenergy.Geopotentialheightisthegeopotentialdividedbythestandardaccelerationduetogravity.

m err,qc

surf_gp_hgt float32

atrack,xtrack geopotentialheightatthesurface m err,qc

o3_tot float32

atrack,xtrack

Totalcolumnozone.(Multiplyby4.670e5toconverttoDobsonUnitsfromkgm^-2) kgm-2 err,qc

o3_mmr float32


ozonemassmixingratiotomoistair unitless err,qc

o3_dof float32

atrack,xtrack

Thetraceoftheaveragingkernelmatrixasameasureofthenumberofpiecesofinformationabouttheozoneprofileprovidedbythephysicalretrievalstep.

unitless


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AncillaryVariables

co_mmr_midtrop float32

atrack,xtrack

Carbonmonoxidemassmixingratiotomoistairat50000Pa,nearthepeakofsensitivity unitless err,qc

co_dof float32

atrack,xtrack

Thetraceoftheaveragingkernelmatrixasameasureofthenumberofpiecesofinformationaboutthecarbonmonoxideprofileprovidedbythephysicalretrievalstep.

unitless

ch4_mmr_midtrop float32

atrack,xtrack

Methanemassmixingratiotomoistairat40000Pa,nearthepeakofsensitivity unitless err,qc

ch4_dof float32

atrack,xtrack

Thetraceoftheaveragingkernelmatrixasameasureofthenumberofpiecesofinformationaboutthemethaneprofileprovidedbythephysicalretrievalstep.

unitless

co2_dof float32

atrack,xtrack

Thetraceoftheaveragingkernelmatrixasameasureofthenumberofpiecesofinformationaboutthecarbondioxideprofileprovidedbythephysicalretrievalstep.

unitless

n2o_dof float32

atrack,xtrack

Thetraceoftheaveragingkernelmatrixasameasureofthenumberofpiecesofinformationaboutthenitrousoxideprofileprovidedbythephysicalretrievalstep.

unitless

hno3_dof float32

atrack,xtrack

Thetraceoftheaveragingkernelmatrixasameasureofthenumberofpiecesofinformationaboutthenitricacidprofileprovidedbythephysicalretrievalstep.

unitless

so2_dof float32

atrack,xtrack

Thetraceoftheaveragingkernelmatrixasameasureofthenumberofpiecesofinformationaboutthesulfurdioxideprofileprovidedbythephysicalretrievalstep.

unitless

mw_cld_phase int16atrack,xtrack,air_pres_lay

CloudIce/Waterflagfrommicrowave.0forliquidcloudsornoclouds;1foriceclouds.

h2o_liq_tot float32

atrack,xtrack totalcolumncloudliquidwater kgm-2 err,qc

h2o_liq_mol_lay float32

atrack,xtrack,air_pres_lay

cloudliquidwaterlayertotal unitless err,qc

surf_temp float32

atrack,xtrack radiativetemperatureofthesurface Kelvin err,qc

surf_temp_dof float32

atrack,xtrack

Thetraceoftheaveragingkernelmatrixasameasureofthenumberofpiecesofinformationaboutthesurfaceskintemperatureprovidedbythephysicalretrievalstep.

unitless

surf_ir_emis float32

atrack,xtrack,surf_wnum_ir

infraredsurfaceemissivity unitless err,qc


45


AncillaryVariables

surf_ir_refl float32


infraredsurfacereflectivity unitless qc

surf_ir_wnum_cnt int16 atrack,xtrack Numberofinfraredsurfaceemissivityfrequencies unitless

surf_ir_wnum float32


Surfaceinfraredemissivityfrequencies(hingepoints) cm-1

surf_mw_emis float32

atrack,xtrack,surf_freq_mw

Microwavesurfaceemissivity unitless err,qc

cld_frac float32

atrack,xtrack,fov,cld_lay

effectivecloudfraction unitless err,qc

cld_top_pres float32


cloudtoppressureinorderofincreasingpressure Pa err,qc

cld_top_temp float32


cloudtoptemperature Kelvin err,qc

num_cld byte atrack,xtrack,fov Numberofcloudlayerswithnonzerocloudfraction unitless

tpause_gp_hgt float32

atrack,xtrack

tropopausegeopotentialheight,wheretropopauseisdeterminedaccordingtotheWMOdefinition m qc

tpause_pres float32

atrack,xtrack

tropopausepressure,wheretropopauseisdeterminedaccordingtotheWMOdefinition Pa qc

tpause_temp float32

atrack,xtrack

tropopausetemperature,wheretropopauseisdeterminedaccordingtotheWMOdefinition Kelvin qc

air_pres_nsurf int16 atrack,xtrack

Indexinair_presofthelevelatthesurface.Valuesatlevelsbeyondthisareinvalid,representingdatabelowtheEarth'ssurface.

unitless

air_pres_h2o_nsurf int16 atrack,xtrack

Indexinair_pres_h2oofthelevelatthesurface.Valuesatlevelsbeyondthisareinvalid,representingdatabelowtheEarth'ssurface.

unitless

air_pres_lay_nsurf int16 atrack,xtrack

Indexinair_pres_layofthelayeratthesurface.Valuesforlayersbeyondthisareinvalid,representingdatabelowtheEarth'ssurface.

unitless

air_pres float32 air_pres pressurelevels Pa

air_pres_h2o float32

air_pres_h2o H2Ovaporpressurelevels Pa


46


AncillaryVariables

air_pres_lay float32 air_pres_lay pressureatthemiddleofeachlayer Pa bnds

cld_lay_lbl string cld_lay Cloudlayer{top,bottom}

mw_surf_class int16 atrack,xtrack

Microwavespectralsurfaceclass.0forcoastline;1forland;2forocean;3forfirst-yearsea-ice;4formulti-yearsea-ice;5forsnow(higher-freqscattering);6forglacier/snow(verylow-freqscattering);7forsnow(lower-freqscattering);

surf_freq_mw float32

surf_freq_mw

Microwavesurfaceemissivityfrequencies(hingepoints) Hz

auxVariables

Name Type Dimensions Description Units AncillaryVariables

co2_vmr float32atrack,xtrack,air_pres

carbondioxidevolumemixingratio unitless err,qc

for_cld_frac_tot float32 atrack,xtrack Field-Of-Regardeffectivecloudfractionsummedoverallcloudlayers unitless err,qc

for_cld_top_pres_tot float32 atrack,xtrack Field-Of-Regardweightedcloudtoppressure Pa err,qc

for_cld_frac_2lay float32atrack,xtrack,cld_lay

Effectivecloudfractionassuming2commoncloudlayersoverthewholeField-Of-Regard unitless err,qc

for_cld_top_pres_2lay float32atrack,xtrack,cld_lay

Cloudtoppressureassuming2commoncloudlayersoverthewholeField-of-Regard Pa err,qc

clim_o3_mol_lay float32atrack,xtrack,air_pres_lay

Ozonecolumndensityon100layersfromtheclimatologyfirstguess

molecules/m2

clim_surf_ir_emis float32atrack,xtrack,surf_wnum_ir

Infraredsurfaceemissivityfromtheclimatologyfirstguess unitless

clim_surf_ir_refl float32atrack,xtrack,surf_wnum_ir

infraredsurfacereflectivityfromtheclimatologyfirstguess unitless

clim_surf_ir_wnum_cnt int16 atrack,xtrack Numberofinfraredsurfaceemissivityfrequenciesfortheclimatologyfirstguess unitless

clim_surf_ir_wnum float32atrack,xtrack,surf_wnum_ir

Surfaceinfraredemissivityfrequencies(hingepoints)fortheclimatologyfirstguess cm-1

clim_co2_mmr float32 atrack,xtrack Assumedcarbondioxideconcentration unitless

prior_surf_pres float32 atrack,xtrack surfacepressurefromforecast Pa


47


prior_sea_lev_pres float32 atrack,xtrack sealevelsurfacepressurefromforecast Pa

idprof string atrack,xtrack profileID

etarej float32 atrack,xtrack cloudclearingresidualusedf/rejatiteration=ieta_rej unitless

cldfrc_tot float32 atrack,xtrack TotalcloudfractionoverFOR unitless

cldfrc_500 float32 atrack,xtrack TotalcloudfractionoverFORbelow500hPa unitless

ampl_eta float32 atrack,xtrack cloudclearingnoiseamplificationfactor unitless

ir_x float32 atrack,xtrack RMS(rad(IR.ret)-radobs())forAMSUchannels unitless

bt2 float32 atrack,xtrack RMS(T(p)f/IR.ret-T(p)f/AMSU.ret) unitless

qualsurf float32 atrack,xtrack qualsurf

qualtemp float32 atrack,xtrack qualtemp

softcode float32 atrack,xtrack softwarerejectioncode

aeff_1 float32 atrack,xtrack A_eff(1stetastep) unitless

aeff_end float32 atrack,xtrack A_eff(lastetastep) unitless

a0_cloud float32 atrack,xtrack interceptofalpha(1)=f(alpha(2))fitting unitless

totliqwat float32 atrack,xtrack totalliquidwater(MW) unitless

fg_air_temp float32atrack,xtrack,air_pres

airtemperatureprofilefromtheMERRA2(seeSection3.11,GFSwasaccidentallyusedasthefirstguess)firstguess

Kelvin

fg_h2o_vap_mol_lay float32atrack,xtrack,air_pres_lay

watervaporlayertotalsfromtheMERRA2(seeSection3.11,GFSwasaccidentallyusedasthefirstguess)firstguess

molecules/m2

fg_surf_air_temp float32 atrack,xtracknear-surfaceairtemperature(~2metersabovesurface)fromtheMERRA2(seeSection3.11,GFSwasaccidentallyusedasthefirstguess)firstguess

Kelvin

fg_surf_temp float32 atrack,xtrackradiativetemperatureofthesurfacefromtheMERRA2(seeSection3.11,GFSwasaccidentallyusedasthefirstguess)firstguess

Kelvin

chi2_temp float32 atrack,xtrack Temperatureprofilechi^2ofalpha(1)=f(alpha(2))fitting unitless

chi2_h2o float32 atrack,xtrack Watervaporchi^2ofalpha(1)=f(alpha(2))fitting unitless

chi2_o3 float32 atrack,xtrack Ozonechi^2ofalpha(1)=f(alpha(2))fitting unitless

chi2_ch4 float32 atrack,xtrack Methanechi^2ofalpha(1)=f(alpha(2))fitting unitless

chi2_co float32 atrack,xtrack Carbonmonoxidechi^2ofalpha(1)=f(alpha(2))fitting unitless


48


chi2_co2 float32 atrack,xtrack Carbondioxidechi^2ofalpha(1)=f(alpha(2))fitting unitless

chi2_n2o float32 atrack,xtrack Nitrousoxidechi^2ofalpha(1)=f(alpha(2))fitting unitless

chi2_hno3 float32 atrack,xtrack Nitricacidchi^2ofalpha(1)=f(alpha(2))fitting unitless

chi2_so2 float32 atrack,xtrack Sulfurdioxidechi^2ofalpha(1)=f(alpha(2))fitting unitless

ispare_2 ushort atrack,xtrack bitflagsforrejectionofretrievalsteps.Detailsarealgorithm-specific.

bad_phys_ret ubyte atrack,xtrack Flagforbadphysicalretrieval.

bad_mw_ret ubyte atrack,xtrack Flagforbadmicrowaveretrieval.

bad_reg_ret ubyte atrack,xtrack Flagforbadregressionretrieval.

pbest float32 atrack,xtrack MaximumvalueofpressureforwhichtemperatureisQuality=0 Pa

pgood float32 atrack,xtrack MaximumvalueofpressureforwhichtemperatureisQuality=0or1 Pa

nbest int16 atrack,xtracklevelindexofhighestpressure(i.e.lowestaltitude)forwhichQuality=0.Avalueof0indicatesthatnopartoftheprofilepassesthetest.

unitless

ngood int16 atrack,xtracklevelindexofhighestpressure(i.e.lowestaltitude)forwhichQuality=0or1.Avalueof0indicatesthatnopartoftheprofilepassesthetest.

unitless

mol_layVariables


h2o_vap_mol_lay float32 atrack,xtrack,air_pres_lay Watervaporlayertotalon100layers molecules/

m2 err,qc

o3_mol_lay float32 atrack,xtrack,air_pres_lay Ozonelayertotalon100layers molecules/

m2 err,qc

co_mol_lay float32 atrack,xtrack,air_pres_lay

Carbonmonoxidelayertotalon100layers

molecules/m2 err,qc

ch4_mol_lay float32 atrack,xtrack,air_pres_lay Methanelayertotalon100layers molecules/

m2 err,qc

co2_mol_lay float32 atrack,xtrack,air_pres_lay

carbondioxidelayertotalon100layers

molecules/m2 err,qc

n2o_mol_lay float32 atrack,xtrack,air_pres_lay nitrousoxidelayertotalon100layers molecules/

m2 err,qc

hno3_mol_lay float32 atrack,xtrack,air_pres_lay nitricacidlayertotalon100layers molecules/

m2 err,qc

so2_mol_lay float32 atrack,xtrack,air_pres_lay

sulfurdioxidelayertotalon100layers

molecules/m2 err,qc


49

mwVariables


mw_air_temp float32 atrack,xtrack,air_pres airtemperatureprofilefromtheMW-onlystep Kelvin err,qc

mw_surf_air_temp float32 atrack,xtrack Near-surfaceairtemperature(~2metersabovesurface)fromtheMW-onlystep Kelvin err,qc

mw_surf_temp float32 atrack,xtrack RadiativetemperatureofthesurfacefromtheMW-onlystep Kelvin err,qc

mw_h2o_vap_tot float32 atrack,xtrack TotalprecipitablewatervaporfromtheMW-onlystep kg/m2 err,qc

mw_h2o_vap_mol_lay float32 atrack,xtrack,air_pres_lay WatervaporlayertotalfromtheMW-onlystep molecules

/m2 err,qc

mw_spec_hum float32 atrack,xtrack,air_pres_h2o

massfractionofwatervaporinmoistairfromtheMW-Onlystep unitless err,qc

mw_surf_spec_hum float32 atrack,xtrack Near-surfacemassfractionofwatervaporinmoistairfromtheMW-Onlystep unitless err,qc


50

C.2CHARTRetrievalproduct

SNPPL2CHARTCRIMSSInterfaceSpecificationInterfaceSpecificationVersion02.00.28

04-10-2019

GlobalGroups

Path Description

/ Mainsciencedata

/mw MW-Onlydata

/mol_lay Layermoleculeamounts

/aux Internalproductteamdata

GlobalDimensions


spatial 3 directions:x,y,zforsatellitepositionandvelocity







air_pres 100 Fineatmosphericpressurelevelsstartingfromthetop

air_pres_h2o 66 Fineatmosphericpressurelevelsstartingfromthetop

air_pres_lay 100 Fineatmosphericpressurelayersstartingfromthetop

surf_wnum_ir 100 IRsurfaceemissivityhingepoints

surf_freq_mw 7 MWsurfaceemissivityhingepoints

olr_wnum 16 frequencybandsforspectrallydecomposedoutgoinglongwaveradiation

cld_lay 2 Measuredcloudlayers:top,bottom

bnds_1d 2 Boundariesfor1-dfieldslikeair_pres_lay:min,max

GlobalAttributes


keywords string 1ATMOSPHERE>ATMOSPHERICTEMPERATURE>UPPER

Acomma-separatedlistofkeywordsand/orphrases.Keywordsmaybecommonwordsorphrases,termsfromacontrolledvocabulary


51


AIRTEMPERATURE\,ATMOSPHERE>ATMOSPHERICWATERVAPOR>WATERVAPOR

(GCMDisoftenused),orURIsfortermsfromacontrolledvocabulary(seealso"keywords_vocabulary"attribute).


history string 1





product_name_type_id string 1 L2_CHART_RET_NSR Productnameasitappearsinproduct_name(L1A,L1B,L2,SNO_AIRS_CrIS)









Thedateonwhichthisversionofthedatawascreated.(Modificationofvaluesimpliesanewversion,hencethiswouldbeassignedthedateofthemostrecentvaluesmodification.)Metadatachangesarenotconsideredwhenassigningthedate_created.TheISO8601:2004extendeddateformatisrecommended,asdescribedintheAttributeContentGuidancesection.


52

















Describesthedata's2Dor3DgeospatialextentinOGC'sWell-KnownText(WKT)Geometryformat(referencetheOGCSimpleFeatureAccess(SFA)specification).Themeaningandorderofvaluesforeachpoint'scoordinatesdependsonthecoordinatereferencesystem(CRS).TheACDDdefaultis2DgeometryintheEPSG:4326coordinatereferencesystem.Thedefaultmaybeoverriddenwithgeospatial_bounds_crsandgeospatial_bounds_vertical_crs(seethoseattributes).EPSG:4326coordinatevaluesarelatitude(decimaldegrees_north)andlongitude(decimaldegrees_east),inthatorder.Longitudevaluesinthedefaultcasearelimitedtothe-180,180)range.Example:'POLYGON((40.26-111.29,41.26-111.29,41.26-110.29,40.26-110.29,40.26-111.29))'.


53



Thecoordinatereferencesystem(CRS)ofthepointcoordinatesinthegeospatial_boundsattribute.ThisCRSmaybe2-dimensionalor3-dimensional,buttogetherwithgeospatial_bounds_vertical_crs,ifthatattributeissupplied,mustmatchthedimensionality,order,andmeaningofpointcoordinatevaluesinthegeospatial_boundsattribute.Ifgeospatial_bounds_vertical_crsisalsopresentthenthisattributemustonlyspecifya2DCRS.EPSGCRSsarestronglyrecommended.Ifthisattributeisnotspecified,theCRSisassumedtobeEPSG:4326.Examples:'EPSG:4979'(the3DWGS84CRS),'EPSG:4047'.















54




















instrument string 1

CRIMSS>Cross-trackInfraredandAdvancedTechnologyMicrowaveSounders\,CrIS>Cross-trackInfraredSounder\,



55


ATMS>AdvancedTechnologyMicrowaveSounder



















Thedatatype,asderivedfromUnidata'sCommonDataModelScientificDatatypesandunderstoodbyTHREDDS.(ThisisaTHREDDS"dataType",andisdifferentfromtheCFNetCDFattribute'featureType',which


56


indicatesaDiscreteSamplingGeometryfileinCF.)


Anidentifierforthedataset,providedbyanduniquewithinitsnamingauthority.Thecombinationofthe"namingauthority"andthe"id"shouldbegloballyunique,buttheidcanbegloballyuniquebyitselfalso.IDscanbeURLs,URNs,DOIs,meaningfultextstrings,alocalkey,oranyotheruniquestringofcharacters.Theidshouldnotincludewhitespacecharacters.












orbitDirection string 1

Orbitisascendingand/ordescending.Valuesare"Ascending"or"Descending"iftheentiregranulefitsthatdescription."NorthPole"and"SouthPole"areusedforpolar-crossinggranules."NA"isusedwhenadeterminationcannotbemade.

day_night_flag string 1 Dataisdayornight."Day"meanssubsatellitepointforallvalidscanshassolarzenithangle


57


lessthan90degrees."Night"meanssubsatellitepointforallvalidscanshassolarzenithanglegreaterthan90degrees."Both"meansthedatasetcontainsvalidobservationswithsolarzenithangleaboveandbelow90degrees."NA"meansavaluecouldnotbedetermined.

AutomaticQualityFlag string 1 Missing

"Passed":thegranulecontainsanon-degradedcalibratedbrightnesstemperature,radiance,orretrievedvalueforatleastonevalueinageolocatedFOV;"Suspect":thegranuledoesnotqualifyas"Passed"butcontainsa(possiblydegraded)calibratedorretrievedvalue(possiblywithoutassociatedgeolocation);"Failed":thegranulecontainsnocalibratedorretrievedvalues.





title string 1 Level-2CHARTSNPPCrIMSS


summary string 1

TheLevel-2CHARTproductincludesatmosphericstateretrievalproductsfromtheCHARTalgorithmforonesix-minuteinterval.Theseincludetemperatureandwatervaporprofilesaswellascloudandsurfaceproductsandminorgases.


shortname string 1 SNDRSNIML2CHTRETN ECSShortName

product_group string 1 l2_crimssThegroupnametobeusedforthisproductwhenitiscollectedinamulti-groupfiletype,likeSNOorcalsub.




JoelSusskind\,NASAGSFC;WilliamJ.Blackwell\,MIT;L.LarrabeeStrow\,UMBC;PhilipW.Rosenkranz\,MIT



58


contributor_role string 1RetrievalPI;NeuralNetworkPI;ForwardModelPI;MicrowavePI


GlobalVariables


AncillaryVariables








bnds

obs_time_utc uint16




th bnds



degrees_north


th bnds


t bnds



degrees_east


t bnds







59


AncillaryVariables



degrees_north


degrees_east










sat_range float atrack,xtrack

lineofsightdistancebetweensatelliteandspotcenter m










satelliteattitudeatscan_mid_time.Anorthogonaltriad.Firstelementisangleaboutthe+x(roll)ORBaxis.+xaxisispositivelyorientedinthedirectionoforbitalflight.Secondelementisangleabout+y(pitch)ORBaxis.+yaxisisorientednormaltotheorbitplanewiththepositivesenseoppositetothatoftheorbit'sangularmomentumvectorH.Thirdelementisangleabout+z(yaw)axis.+zaxisis

degree


60


AncillaryVariables

positivelyorientedEarthwardparalleltothesatelliteradiusvectorRfromthespacecraftcenterofmasstothecenteroftheEarth.







degrees_east







degree





air_temp float32


airtemperatureprofile Kelvin err,qc

surf_air_temp float32

atrack,xtrack

near-surfaceairtemperature(~2metersabovesurface) Kelvin err,qc

air_temp_dof float32

atrack,xtrack

Thetraceoftheaveragingkernelmatrixasameasureofthenumberofpiecesofinformationabouttheairtemperatureprofileprovidedbythephysicalretrievalstep.

unitless

h2o_vap_tot float32

atrack,xtrack totalprecipitablewatervapor kg/m2 err,qc

spec_hum float32


massfractionofwatervaporinmoistair unitless err,qc


61


AncillaryVariables

surf_spec_hum float32

atrack,xtrack

Near-surfacemassfractionofwatervaporinmoistair unitless err,qc

h2o_vap_dof float32

atrack,xtrack

Thetraceoftheaveragingkernelmatrixasameasureofthenumberofpiecesofinformationaboutthewatervaporprofileprovidedbythephysicalretrievalstep.

unitless

rel_hum float32


relativehumidityoverequilibriumphase unitless err,qc

surf_rel_hum float32

atrack,xtrack

relativehumiditynearthesurfaceoverequilibriumphase unitless err,qc

spec_hum_sat_ice float32


saturationspecifichumidityinequilibriumwithice unitless err,qc

surf_spec_hum_sat_ice float32

atrack,xtrack

Near-surfacesaturationspecifichumidityinequilibriumwithice unitless err,qc

spec_hum_sat_liq float32


saturationspecifichumidityinequilibriumwithliquidwater unitless err,qc

surf_spec_hum_sat_liq float32

atrack,xtrack

Near-surfacesaturationspecifichumidityinequilibriumwithliquidwater unitless err,qc

gp_hgt float32


Geopotentialisthesumofthespecificgravitationalpotentialenergyrelativetothegeoidandthespecificcentripetalpotentialenergy.Geopotentialheightisthegeopotentialdividedbythestandardaccelerationduetogravity.

m err,qc

surf_gp_hgt float32

atrack,xtrack geopotentialheightatthesurface m err,qc

o3_tot float32

atrack,xtrack

Totalcolumnozone.(Multiplyby4.670e5toconverttoDobsonUnitsfromkgm^-2) kgm-2 err,qc

o3_mmr float32


ozonemassmixingratiotomoistair unitless err,qc

o3_dof float32

atrack,xtrack

Thetraceoftheaveragingkernelmatrixasameasureofthenumberofpiecesofinformationabouttheozoneprofileprovidedbythephysicalretrievalstep.

unitless

co_mmr_midtrop float32

atrack,xtrack

Carbonmonoxidemassmixingratiotomoistairat50000Pa,nearthepeakofsensitivity unitless err,qc

co_dof float32

atrack,xtrack

Thetraceoftheaveragingkernelmatrixasameasureofthenumberofpiecesofinformationaboutthecarbonmonoxideprofileprovidedbythephysicalretrievalstep.

unitless


62


AncillaryVariables

ch4_mmr_midtrop float32

atrack,xtrack

Methanemassmixingratiotomoistairat40000Pa,nearthepeakofsensitivity unitless err,qc

ch4_dof float32

atrack,xtrack

Thetraceoftheaveragingkernelmatrixasameasureofthenumberofpiecesofinformationaboutthemethaneprofileprovidedbythephysicalretrievalstep.

unitless

mw_cld_phase int16atrack,xtrack,air_pres_lay

CloudIce/Waterflagfrommicrowave.0forliquidcloudsornoclouds;1foriceclouds.

h2o_liq_tot float32

atrack,xtrack totalcolumncloudliquidwater kgm-2 err,qc

h2o_liq_mol_lay float32

atrack,xtrack,air_pres_lay

cloudliquidwaterlayertotal unitless err,qc

surf_temp float32

atrack,xtrack radiativetemperatureofthesurface Kelvin err,qc

surf_temp_dof float32

atrack,xtrack

Thetraceoftheaveragingkernelmatrixasameasureofthenumberofpiecesofinformationaboutthesurfaceskintemperatureprovidedbythephysicalretrievalstep.

unitless

surf_ir_emis float32


infraredsurfaceemissivity unitless err,qc

surf_ir_refl float32


infraredsurfacereflectivity unitless qc

surf_ir_wnum_cnt int16 atrack,xtrack Numberofinfraredsurfaceemissivityfrequencies unitless

surf_ir_wnum float32


Surfaceinfraredemissivityfrequencies(hingepoints) cm-1

surf_mw_emis float32

atrack,xtrack,surf_freq_mw

Microwavesurfaceemissivity unitless err,qc

cld_frac float32


effectivecloudfraction unitless err,qc

cld_top_pres float32


cloudtoppressureinorderofincreasingpressure Pa err,qc


63


AncillaryVariables

cld_top_temp float32


cloudtoptemperature Kelvin err,qc

num_cld byte atrack,xtrack,fov Numberofcloudlayerswithnonzerocloudfraction unitless

olr float32

atrack,xtrack,fov

outgoinglongwaveradiationfluxintegratedover2to2800cm-1 W/m2 err,qc

olr_band float32

atrack,xtrack,fov,olr_wnum

outgoinglongwaveradiationfluxperband W/m2 err,qc

olr_clr float32

atrack,xtrack

clear-skyoutgoinglongwaveradiationfluxintegratedover2to2800cm-1 W/m2 err,qc

olr_clr_band float32

atrack,xtrack,olr_wnum

clear-skyoutgoinglongwaveradiationfluxperband W/m2 err,qc

tpause_gp_hgt float32

atrack,xtrack

tropopausegeopotentialheight,wheretropopauseisdeterminedaccordingtotheWMOdefinition m qc

tpause_pres float32

atrack,xtrack

tropopausepressure,wheretropopauseisdeterminedaccordingtotheWMOdefinition Pa qc

tpause_temp float32

atrack,xtrack

tropopausetemperature,wheretropopauseisdeterminedaccordingtotheWMOdefinition Kelvin qc

ir_precip_est_24hr float32

atrack,xtrack,fov

Thethicknessofalayerofliquidwaterequivalenttotheestimtedpreciptitationover24hours. m err,qc

air_pres_nsurf int16 atrack,xtrack

Indexinair_presofthelevelatthesurface.Valuesatlevelsbeyondthisareinvalid,representingdatabelowtheEarth'ssurface.

unitless

air_pres_h2o_nsurf int16 atrack,xtrack

Indexinair_pres_h2oofthelevelatthesurface.Valuesatlevelsbeyondthisareinvalid,representingdatabelowtheEarth'ssurface.

unitless

air_pres_lay_nsurf int16 atrack,xtrack

Indexinair_pres_layofthelayeratthesurface.Valuesforlayersbeyondthisareinvalid,representingdatabelowtheEarth'ssurface.

unitless

air_pres float32 air_pres pressurelevels Pa

air_pres_h2o float32

air_pres_h2o H2Ovaporpressurelevels Pa

air_pres_lay float32 air_pres_lay pressureatthemiddleofeachlayer Pa bnds

cld_lay_lbl string cld_lay Cloudlayer{top,bottom}

olr_wnum float32 olr_wnum OLRfrequencybandcenters cm-1 bnds


64


AncillaryVariables

mw_surf_class int16 atrack,xtrack

Microwavespectralsurfaceclass.0forcoastline;1forland;2forocean;3forfirst-yearsea-ice;4formulti-yearsea-ice;5forsnow(higher-freqscattering);6forglacier/snow(verylow-freqscattering);7forsnow(lower-freqscattering);

surf_freq_mw float32

surf_freq_mw

Microwavesurfaceemissivityfrequencies(hingepoints) Hz

auxVariables


for_cld_frac_tot float32 atrack,xtrack Field-Of-Regardeffectivecloudfractionsummedoverallcloudlayers unitless err,qc

for_cld_top_pres_tot float32 atrack,xtrack Field-Of-Regardweightedcloudtoppressure Pa err,qc

for_cld_frac_2lay float32atrack,xtrack,cld_lay

Effectivecloudfractionassuming2commoncloudlayersoverthewholeField-Of-Regard unitless err,qc

for_cld_top_pres_2lay float32atrack,xtrack,cld_lay

Cloudtoppressureassuming2commoncloudlayersoverthewholeField-of-Regard Pa err,qc

clim_o3_mol_lay float32atrack,xtrack,air_pres_lay

Ozonecolumndensityon100layersfromtheclimatologyfirstguess

molecules/m2

clim_surf_ir_emis float32atrack,xtrack,surf_wnum_ir

Infraredsurfaceemissivityfromtheclimatologyfirstguess unitless

clim_surf_ir_refl float32atrack,xtrack,surf_wnum_ir

infraredsurfacereflectivityfromtheclimatologyfirstguess unitless

clim_surf_ir_wnum_cnt int16 atrack,xtrack Numberofinfraredsurfaceemissivityfrequenciesfortheclimatologyfirstguess unitless

clim_surf_ir_wnum float32atrack,xtrack,surf_wnum_ir

Surfaceinfraredemissivityfrequencies(hingepoints)fortheclimatologyfirstguess cm-1

clim_co2_mmr float32 atrack,xtrack Assumedcarbondioxideconcentration unitless

prior_surf_pres float32 atrack,xtrack surfacepressurefromforecast Pa

prior_sea_lev_pres float32 atrack,xtrack sealevelsurfacepressurefromforecast Pa





65












chi2_cloud float32 atrack,xtrack chi^2ofalpha(1)=f(alpha(2))fitting unitless

fzeta float32 atrack,xtrack fzeta_effect unitless

rzeta float32 atrack,xtrack rzeta_effect unitless

bias_ccdiff float32 atrack,xtrack BIAS(-Rccr)in800-900cm-1region unitless

lambda_max float32 atrack,xtrack lambda(2,iter_eta)=U^TS^TN^{-1}SU unitless


etarejfinal float32 atrack,xtrack etarejfinal unitless

gtest_a float32 atrack,xtrack gtest_a unitless

tsurfnoaa float32 atrack,xtrack tsurfnoaa unitless

noaadifftest float32 atrack,xtrack noaadifftest unitless

mitdifftest float32 atrack,xtrack T(p)final-T(p)startup unitless

mitsurftest float32 atrack,xtrack abs(Tsurfret-Tsurfstartup) unitless

nn_air_temp float32atrack,xtrack,air_pres

airtemperatureprofilefromtheneuralnetfirstguess Kelvin

nn_h2o_vap_mol_lay float32atrack,xtrack,air_pres_lay

watervaporlayertotalsfromtheneuralnetfirstguess

molecules/m2

nn_surf_air_temp float32 atrack,xtrack near-surfaceairtemperature(~2metersabovesurface)fromtheneuralnetfirstguess Kelvin

nn_surf_temp float32 atrack,xtrack radiativetemperatureofthesurfacefromtheneuralnetfirstguess Kelvin


66


nn_olr float32 atrack,xtrack

outgoinglongwaveradiationfluxintegratedover2to2800cm-1fromtheneuralnetfirstguess.Suspectbecausenocloudretrievalcontributed.

Watts/meter2

nn_clrolr float32 atrack,xtrackclear-skyoutgoinglongwaveradiationfluxintegratedover2to2800cm-1fromtheneuralnetfirstguess

Watts/meter2

ispare_2 ushort atrack,xtrack bitflagsforrejectionofretrievalsteps.Detailsarealgorithm-specific.

bad_phys_ret ubyte atrack,xtrack Flagforbadphysicalretrieval.

bad_mw_ret ubyte atrack,xtrack Flagforbadmicrowaveretrieval.

bad_sccnn_ret ubyte atrack,xtrack FlagforbadSCCNNneuralnetretrieval.

pbest float32 atrack,xtrack MaximumvalueofpressureforwhichtemperatureisQuality=0 Pa

pgood float32 atrack,xtrack MaximumvalueofpressureforwhichtemperatureisQuality=0or1 Pa

nbest int16 atrack,xtrack

levelindexofhighestpressure(i.e.lowestaltitude)forwhichQuality=0.Avalueof0indicatesthatnopartoftheprofilepassesthetest.

unitless

ngood int16 atrack,xtrack

levelindexofhighestpressure(i.e.lowestaltitude)forwhichQuality=0or1.Avalueof0indicatesthatnopartoftheprofilepassesthetest.

unitless

mol_layVariables


h2o_vap_mol_lay float32 atrack,xtrack,air_pres_lay Watervaporlayertotalon100layers molecules/

m2 err,qc

o3_mol_lay float32 atrack,xtrack,air_pres_lay Ozonelayertotalon100layers molecules/

m2 err,qc

co_mol_lay float32 atrack,xtrack,air_pres_lay

Carbonmonoxidelayertotalon100layers

molecules/m2 err,qc

ch4_mol_lay float32 atrack,xtrack,air_pres_lay Methanelayertotalon100layers molecules/

m2 err,qc

mwVariables


mw_air_temp float32 atrack,xtrack,air_pres airtemperatureprofilefromtheMW-onlystep Kelvin err,qc


67


mw_surf_air_temp float32 atrack,xtrack Near-surfaceairtemperature(~2metersabovesurface)fromtheMW-onlystep Kelvin err,qc

mw_surf_temp float32 atrack,xtrack RadiativetemperatureofthesurfacefromtheMW-onlystep Kelvin err,qc

mw_h2o_vap_tot float32 atrack,xtrack TotalprecipitablewatervaporfromtheMW-onlystep kg/m2 err,qc

mw_h2o_vap_mol_lay float32 atrack,xtrack,air_pres_lay WatervaporlayertotalfromtheMW-onlystep molecules

/m2 err,qc

mw_spec_hum float32 atrack,xtrack,air_pres_h2o

massfractionofwatervaporinmoistairfromtheMW-Onlystep unitless err,qc

mw_surf_spec_hum float32 atrack,xtrack Near-surfacemassfractionofwatervaporinmoistairfromtheMW-Onlystep unitless err,qc


68

C.3CLIMCAPSCloud-ClearedRadianceproduct

SNPPL2CLIMCAPSCRIMSSCCNSRInterfaceSpecificationInterfaceSpecificationVersion02.00.28

04-10-2019

GlobalGroups

Path Description

/ Mainsciencedata

/aux_l2 InternalproductteamdatafromL2

GlobalDimensions


spatial 3 directions:x,y,zforsatellitepositionandvelocity







wnum_lw 717 longwaveIRchannelnumber

wnum_mw 437 midwaveIRchannelnumber

wnum_sw 163 shortwaveIRchannelnumber

GlobalAttributes


keywords string 1

EARTHSCIENCE>SPECTRAL/ENGINEERING>INFRAREDWAVELENGTHS>INFRAREDRADIANCE



history string 1 Providesanaudittrailformodificationstotheoriginaldata.Thisattributeisalsointhe


69


NetCDFUsersGuide:'Thisisacharacterarraywithalineforeachinvocationofaprogramthathasmodifiedthedataset.Well-behavedgenericnetCDFapplicationsshouldappendalinecontaining:date,timeofday,username,programnameandcommandarguments.'ToincludeamorecompletedescriptionyoucanappendareferencetoanISOLineageentity;seeNOAAEDMISOLineageguidance.




product_name_type_id string 1 L2_CLIMCAPS_CCR_NSR Productnameasitappearsinproduct_name(L1A,L1B,L2,SNO_AIRS_CrIS)














70
















Thecoordinatereferencesystem(CRS)ofthepointcoordinatesinthegeospatial_boundsattribute.ThisCRSmaybe2-dimensionalor3-dimensional,buttogetherwithgeospatial_bounds_vertical_crs,ifthatattributeissupplied,mustmatchthedimensionality,order,andmeaningofpointcoordinatevaluesinthegeospatial_boundsattribute.Ifgeospatial_bounds_vertical_crsisalsopresentthenthisattributemustonlyspecifya2DCRS.


71


EPSGCRSsarestronglyrecommended.Ifthisattributeisnotspecified,theCRSisassumedtobeEPSG:4326.Examples:'EPSG:4979'(the3DWGS84CRS),'EPSG:4047'.


















72

















instrument string 1






73




















Anidentifierforthedataset,providedbyanduniquewithinitsnamingauthority.Thecombinationofthe"namingauthority"andthe"id"shouldbegloballyunique,buttheidcanbegloballyuniquebyitselfalso.IDscanbeURLs,URNs,DOIs,meaningfultextstrings,alocalkey,oranyotheruniquestringof


74


characters.Theidshouldnotincludewhitespacecharacters.
















AutomaticQualityFlag string 1 Missing "Passed":thegranulecontainsanon-degradedcalibratedbrightnesstemperature,radiance,


75


orretrievedvalueforatleastonevalueinageolocatedFOV;"Suspect":thegranuledoesnotqualifyas"Passed"butcontainsa(possiblydegraded)calibratedorretrievedvalue(possiblywithoutassociatedgeolocation);"Failed":thegranulecontainsnocalibratedorretrievedvalues.





title string 1 Level-2CLIMCAPSSNPPCrIMSSClearRadiances


summary string 1

TheLevel-2CLIMCAPScloud-clearedproductincludesinfraredradiancesadjustedtosimulateclear-skyconditions.


shortname string 1 SNDRSNIML2CCPCCRN ECSShortName

product_group string 1 l2_crimss_ccThegroupnametobeusedforthisproductwhenitiscollectedinamulti-groupfiletype,likeSNOorcalsub.




ChristopherD.Barnet\,STC;L.LarrabeeStrow\,UMBC;PhilipW.Rosenkranz\,MIT


contributor_role string 1 RetrievalPI;ForwardModelPI;MicrowavePI



76

GlobalVariables


AncillaryVariables








bnds

obs_time_utc uint16




th bnds



degrees_north


th bnds


t bnds



degrees_east


t bnds








degrees_north


77


AncillaryVariables


degrees_east










sat_range float atrack,xtrack lineofsightdistancebetweensatelliteandspotcenter m











degree



78


AncillaryVariables






degrees_east







degree





rad_lw float32

atrack,xtrack,wnum_lw

longwaveclearspectralradiance mW/(m2srcm-1) err,qc

rad_mw float32

atrack,xtrack,wnum_mw

midwaveclearspectralradiance mW/(m2srcm-1) err,qc

rad_sw float32

atrack,xtrack,wnum_sw

shortwaveclearspectralradiance mW/(m2srcm-1) err,qc

cal_qualflag int32 atrack,xtrack,fov per-observationL1Bproductquality

cal_lw_qualflag int32 atrack,xtrack,fov per-observationL1BLWproductquality

cal_mw_qualflag int32 atrack,xtrack,fov per-observationL1BMWproductquality

cal_sw_qualflag int32 atrack,xtrack,fov per-observationL1BSWproductquality

nedn_lw float32

fov,wnum_lw longwavenoiseequivalentdifferentialradiance mW/(m2sr

cm-1)


79


AncillaryVariables

nedn_mw float32

fov,wnum_mw midwavenoiseequivalentdifferentialradiance mW/(m2sr

cm-1)

nedn_sw float32

fov,wnum_sw shortwavenoiseequivalentdifferentialradiance mW/(m2sr

cm-1)

wnum_lw float64 wnum_lw longwavewavenumber cm-1

wnum_mw float64 wnum_mw midwavewavenumber cm-1

wnum_sw float64 wnum_sw shortwavewavenumber cm-1

aux_l2Variables
















chi2_temp float32 atrack,xtrack Temperatureprofilechi^2ofalpha(1)=f(alpha(2))fitting unitless

chi2_h2o float32 atrack,xtrack Watervaporchi^2ofalpha(1)=f(alpha(2))fitting unitless

chi2_o3 float32 atrack,xtrack Ozonechi^2ofalpha(1)=f(alpha(2))fitting unitless

chi2_ch4 float32 atrack,xtrack Methanechi^2ofalpha(1)=f(alpha(2))fitting unitless


80


chi2_co float32 atrack,xtrack Carbonmonoxidechi^2ofalpha(1)=f(alpha(2))fitting unitless

chi2_co2 float32 atrack,xtrack Carbondioxidechi^2ofalpha(1)=f(alpha(2))fitting unitless

chi2_n2o float32 atrack,xtrack Nitrousoxidechi^2ofalpha(1)=f(alpha(2))fitting unitless

chi2_hno3 float32 atrack,xtrack Nitricacidchi^2ofalpha(1)=f(alpha(2))fitting unitless

chi2_so2 float32 atrack,xtrack Sulfurdioxidechi^2ofalpha(1)=f(alpha(2))fitting unitless


81

C.4CHARTCloud-ClearedRadianceproduct

SNPPL2CHARTCRIMSSCCNSRInterfaceSpecificationInterfaceSpecificationVersion02.00.28

04-10-2019

GlobalGroups

Path Description

/ Mainsciencedata

/aux_l2 InternalproductteamdatafromL2

GlobalDimensions


spatial 3 directions:x,y,z forsatellitepositionandvelocity







wnum_lw 717 longwaveIRchannelnumber

wnum_mw 437 midwaveIRchannelnumber

wnum_sw 163 shortwaveIRchannelnumber

GlobalAttributes


keywords string 1

EARTHSCIENCE>SPECTRAL/ENGINEERING>INFRAREDWAVELENGTHS>INFRAREDRADIANCE




82


history string 1





product_name_type_id string 1 L2_CHART_CCR_NSR Productnameasitappearsinproduct_name(L1A,L1B,L2,SNO_AIRS_CrIS)














83
















Thecoordinatereferencesystem(CRS)ofthepointcoordinatesinthegeospatial_boundsattribute.ThisCRSmaybe2-dimensionalor3-dimensional,buttogetherwithgeospatial_bounds_vertical_crs,ifthatattributeissupplied,mustmatchthedimensionality,order,andmeaningofpointcoordinatevaluesinthegeospatial_boundsattribute.Ifgeospatial_bounds_vertical_crsisalsopresentthenthisattributemustonlyspecifya2DCRS.


84


EPSGCRSsarestronglyrecommended.Ifthisattributeisnotspecified,theCRSisassumedtobeEPSG:4326.Examples:'EPSG:4979'(the3DWGS84CRS),'EPSG:4047'.


















85

















instrument string 1






86




















Anidentifierforthedataset,providedbyanduniquewithinitsnamingauthority.Thecombinationofthe"namingauthority"andthe"id"shouldbegloballyunique,buttheidcanbegloballyuniquebyitselfalso.IDscanbeURLs,URNs,DOIs,meaningfultextstrings,alocalkey,oranyotheruniquestringof


87


characters.Theidshouldnotincludewhitespacecharacters.
















AutomaticQualityFlag string 1 Missing "Passed":thegranulecontainsanon-degradedcalibratedbrightnesstemperature,radiance,


88


orretrievedvalueforatleastonevalueinageolocatedFOV;"Suspect":thegranuledoesnotqualifyas"Passed"butcontainsa(possiblydegraded)calibratedorretrievedvalue(possiblywithoutassociatedgeolocation);"Failed":thegranulecontainsnocalibratedorretrievedvalues.





title string 1 Level-2CHARTSNPPCrIMSSClearRadiances


summary string 1

TheLevel-2CHARTcloud-clearedproductincludesinfraredradiancesadjustedtosimulateclear-skyconditions.


shortname string 1 SNDRSNIML2CHTCCRN ECSShortName

product_group string 1 l2_crimss_ccThegroupnametobeusedforthisproductwhenitiscollectedinamulti-groupfiletype,likeSNOorcalsub.




JoelSusskind\,NASAGSFC;WilliamJ.Blackwell\,MIT;L.LarrabeeStrow\,UMBC;PhilipW.Rosenkranz\,MIT


contributor_role string 1RetrievalPI;NeuralNetworkPI;ForwardModelPI;MicrowavePI


GlobalVariables


89


AncillaryVariables








bnds

obs_time_utc uint16




th bnds



degrees_north


th bnds


t bnds



degrees_east


t bnds








degrees_north


degrees_east


90


AncillaryVariables










sat_range float atrack,xtrack lineofsightdistancebetweensatelliteandspotcenter m











degree





91


AncillaryVariables




degrees_east







degree





rad_lw float32

atrack,xtrack,wnum_lw

longwaveclearspectralradiance mW/(m2srcm-1) err,qc

rad_mw float32

atrack,xtrack,wnum_mw

midwaveclearspectralradiance mW/(m2srcm-1) err,qc

rad_sw float32

atrack,xtrack,wnum_sw

shortwaveclearspectralradiance mW/(m2srcm-1) err,qc

cal_qualflag int32 atrack,xtrack,fov per-observationL1Bproductquality

cal_lw_qualflag int32 atrack,xtrack,fov per-observationL1BLWproductquality

cal_mw_qualflag int32 atrack,xtrack,fov per-observationL1BMWproductquality

cal_sw_qualflag int32 atrack,xtrack,fov per-observationL1BSWproductquality

nedn_lw float32

fov,wnum_lw longwavenoiseequivalentdifferentialradiance mW/(m2sr

cm-1)

nedn_mw float32

fov,wnum_mw midwavenoiseequivalentdifferentialradiance mW/(m2sr

cm-1)


92


AncillaryVariables

nedn_sw float32

fov,wnum_sw shortwavenoiseequivalentdifferentialradiance mW/(m2sr

cm-1)

wnum_lw float64 wnum_lw longwavewavenumber cm-1

wnum_mw float64 wnum_mw midwavewavenumber cm-1

wnum_sw float64 wnum_sw shortwavewavenumber cm-1

aux_l2Variables















chi2_cloud float32 atrack,xtrack chi^2ofalpha(1)=f(alpha(2))fitting unitless

fzeta float32 atrack,xtrack fzeta_effect unitless

rzeta float32 atrack,xtrack rzeta_effect unitless

bias_ccdiff float32 atrack,xtrack BIAS(-Rccr)in800-900cm-1region unitless

lambda_max float32 atrack,xtrack lambda(2,iter_eta)=U^TS^TN^{-1}SU unitless


etarejfinal float32 atrack,xtrack etarejfinal unitless


93


gtest_a float32 atrack,xtrack gtest_a unitless

tsurfnoaa float32 atrack,xtrack tsurfnoaa unitless

noaadifftest float32 atrack,xtrack noaadifftest unitless

mitdifftest float32 atrack,xtrack T(p)final-T(p)startup unitless

mitsurftest float32 atrack,xtrack abs(Tsurfret-Tsurfstartup) unitless