TheCommonLandModel(CoLM)Technical&UserGuideYongjiuDai&DuoyingJiSchoolofGeographyBeijingNormalUniversityBeijing100875ChinaE-mail:yongjiudai@bnu.edu.cnduoyingji@gmail.comJuly7,200812Contents1.Introduction2.CreatingandRunningtheExecutable2.1Specificationofscriptenvironmentvariablesandheaderfile2.2Surfacedatamaking2.3Initialdatamaking2.4Time-loopcalculation3.CoLMSurfaceDataset4.CoLMAtmosphericForcingDataset4.1GSWP2forcingdataset4.2PRINCETONforcingdataset4.3Temporalinterpolationoftheforcingdata5.CoLMModelStructureandParallelImplementation5.1CoLMModelStructure5.2CoLMMPIParallelDesign5.3CoLMMPIParallelImplementation5.4CoLMSourceCodeandSubroutinesOutline6.CoLMParameterandVariables6.1ModelParameters6.2Timeinvariantmodelvariables6.3TUNABLEconstants6.4Time-varyingstatevariables6.5Forcing6.6Fluxes7.Examples7.1SinglePointOfflineExperiment7.2GlobalOfflineExperimentwithGSWP2DatasetTable1:ModeldirectorystructureTable2:define.hCPPtokensTable3:NamelistvariablesforinitialdatamakingTable4:NamelistvariablesforTime-loopcalculationTable5:ThelistofrawdataavailableTable6:Descriptionof24-category(USGS)vegetationcategoriesTable7:Descriptionof17-categorysoilcategoriesTable8:Therelativeamountsofsand,soil,andclayTable9:netCDFFileInformationoftheProcessedAtmosphericForcingDataTable10:SourcecodeandSubroutinesOutline3Table11:DimensionofmodelarrayTable12:ControlvariablestodetermineupdatingontimestepsTable13:ModeltimeinvariantvariablesTable14:ModelTUNABLEconstantsTable15:RuncalendarTable16:Time-varyingVariablesforrestartrunTable17:AtmosphericForcingTable18:ModeloutputinxyGridFormFigure1:FlowchartofthesurfacedatamakingFigure2:FlowchartoftheinitialdatamakingFigure3:Flowchartofthetime-loopingcalculationFigure4:DiagramofthedomainpartitionatsurfacedatamakingFigure5:Diagramofthedomainpartitionattime-loopingcalculationFigure6:Diagramofthepatchesandgridsmappingrelationship41.IntroductionThisuser’sguideprovidetheuserwiththecodingimplementation,andoperatinginstructionsfortheCommonLandModel(CoLM)whichisthelandsurfaceparameterizationusedinofflinemodeorwiththeglobalclimatemodelsandregionalclimatemodels.ThedevelopmentoftheCommonLandModel(hereafterwecallCLMinitialversion)canbedescribedastheworkofacommunityeffort.Initialsoftwarespecificationsanddevelopmentfocusedonevaluatingthebestfeaturesofexistinglandmodels.ThemodelperformancehasbeenvalidatedinveryextensivefielddataincludedsitesadoptedbytheProjectforIntercomparisonofLand-surfaceParameterizationSchemes(Cabauw,Valdai,Red-Arkansasriverbasin)andothers[FIFE,BOREAS,HAPEX-MOBILHY,ABRACOS,SonoranDesert,GSWP,LDAS].ThemodelhasbeencoupledwiththeNCARCommunityClimateModel(CCM3).DocumentationfortheCLMinitialversionisprovidedbyDaietal.(2001)whilethecouplingwithCCM3isdescribedinZengetal.(2002).ThemodelwasintroducedtothemodelingcommunityinDaietal.(2003).TheCLMinitialversionwasadoptedastheCommunityLandModel(CLM2.0)forusewiththeCommunityAtmosphereModel(CAM2.0)andversion2oftheCommunityClimateSystemModel(CCSM2.0).ThecurrentversionofCommunityLandModel,CLM3.0,wasreleasedinJune2004aspartoftheCCSM3.0release(http://www.ccsm.ucar.edu/models/ccsm3.0/clm3/).TheCommunityLandModel(CLM3.0)isradicallydifferentfromCLMinitialversion,particularlyfromasoftwareengineeringperspective,andthegreatadvancementsintheareasofcarboncycling,vegetationdynamics,andriverrouting.ThemajordifferencesbetweenCLM2.0andCLMi...