These variables MAY BE CHANGED ANYTIME during a run. Additional machine speific variables that can be changed during a run are contained in the env_mach_specific file Note1: users SHOULD NOT modify BUILD_COMPETE in env_build.xml this is done automatically by the scripts.

char Extra copies of the component log files will be saved here. char case description char The directory where the executable will be run. By default this is set to EXEROOT/../run. RUNDIR allows you to keep the run directory separate from the build directory char startup,hybrid,branch Determines the model run initialization type. This setting is only important for the initial run of a production run when the CONTINUE_RUN variable is set to FALSE. After the initial run, the CONTINUE_RUN variable is set to TRUE, and the model restarts exactly using input files in a case, date, and bit-for-bit continuous fashion. Default: startup. -- In a startup run (the default), all components are initialized using baseline states. These baseline states are set independently by each component and can include the use of restart files, initial files, external observed data files, or internal initialization (i.e., a cold start). In a startup run, the coupler sends the start date to the components at initialization. In addition, the coupler does not need an input data file. In a startup initialization, the ocean model does not start until the second ocean coupling (normally the second day). -- In a branch run, all components are initialized using a consistent set of restart files from a previous run (determined by the RUN_REFCASE and RUN_REFDATE variables in env_run.xml). The case name is generally changed for a branch run, although it does not have to be. In a branch run, setting RUN_STARTDATE is ignored because the model components obtain the start date from their restart datasets. Therefore, the start date cannot be changed for a branch run. This is the same mechanism that is used for performing a restart run (where CONTINUE_RUN is set to TRUE in the env_run.xml) Branch runs are typically used when sensitivity or parameter studies are required, or when settings for history file output streams need to be modified while still maintaining bit-for-bit reproducibility. Under this scenario, the new case is able to produce an exact bit-for-bit restart in the same manner as a continuation run IF no source code or component namelist inputs are modified. All models use restart files to perform this type of run. RUN_REFCASE and RUN_REFDATE are required for branch runs. To set up a branch run, locate the restart tar file or restart directory for RUN_REFCASE and RUN_REFDATE from a previous run, then place those files in the RUNDIR directory. --- In a hybrid run the model is initialized as a startup, BUT uses initialization datasets FROM A PREVIOUS case. This is somewhat analogous to a branch run with relaxed restart constraints. A hybrid run allows users to bring together combinations of initial/restart files from a previous case (specified by RUN_REFCASE) at a given model output date (specified by RUN_REFDATE). Unlike a branch run, the starting date of a hybrid run (specified by RUN_STARTDATE) can be modified relative to the reference case. In a hybrid run, the model does not continue in a bit-for-bit fashion with respect to the reference case. The resulting climate, however, should be continuous provided that no model source code or namelists are changed in the hybrid run. In a hybrid initialization, the ocean model does not start until the second ocean coupling (normally the second day), and the coupler does a cold start without a restart file. char Reference directory containing RUN_REFCASE data - used for hybrid or branch runs char Reference case for hybrid or branch runs char Reference date for hybrid or branch runs (yyyy-mm-dd) char Reference time of day (seconds) for hybrid or branch runs (sssss) logical TRUE,FALSE Flag for automatically prestaging the refcase restart dataset. If TRUE, then the refcase data is prestaged into the executable directory char Run start date (yyyy-mm-dd). Only used for startup or hybrid runs. integer Run start time-of-day char none,never,nsteps,nstep,nseconds,nsecond,nminutes,nminute,nhours,nhour,ndays,nday,nmonths,nmonth,nyears,nyear,date,ifdays0,end Sets the run length along with STOP_N and STOP_DATE integer Provides a numerical count for $STOP_OPTION. integer Alternative date yyyymmdd date option, sets the run length with STOP_OPTION and STOP_N negative value implies off char none,never,nsteps,nstep,nseconds,nsecond,nminutes,nminute,nhours,nhour,ndays,nday,nmonths,nmonth,nyears,nyear,date,ifdays0,end sets frequency of model restart writes (same options as STOP_OPTION) integer sets model restart writes with REST_OPTION and REST_DATE char Alternative date in yyyymmdd format sets model restart write date with REST_OPTION and REST_N char none,never,nsteps,nstep,nseconds,nsecond,nminutes,nminute,nhours,nhour,ndays,nday,nmonths,nmonth,nyears,nyear Sets the pause frequency along with PAUSE_N integer Provides a numerical count for $PAUSE_OPTION. logical TRUE,FALSE Pause the model at times specified by PAUSE_OPTION and PAUSE_N. Components 'pause' by writing a restart file. FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE char Sets periodic model barriers with BARRIER_OPTION and BARRIER_DATE for synchronization char Alternative date in yyyymmdd format sets periodic model barriers with BARRIER_OPTION and BARRIER_N for synchronization logical TRUE,FALSE ESP component runs after driver 'pause cycle' If any component 'pauses' (see PAUSE_OPTION, PAUSE_N and PAUSE_ACTIVE_XXX XML variables), the ESP component (if present) will be run to process the component 'pause' (restart) files and set any required 'resume' signals. If true, esp_cpl_dt and esp_cpl_offset settings are ignored. default: false logical TRUE,FALSE A setting of TRUE implies a continuation run When you first begin a branch, hybrid or startup run, CONTINUE_RUN must be set to FALSE. When you successfully run and get a restart file, you will need to change CONTINUE_RUN to TRUE for the remainder of your run. This variable determines if the run is a restart run. Set to FALSE when initializing a startup, branch or hybrid case. Set to TRUE when continuing a run. integer If RESUBMIT is greater than 0, then case will automatically resubmit Enables the model to automatically resubmit a new run. To get multiple runs, set RESUBMIT greater than 0, then RESUBMIT will be decremented and the case will be resubmitted. The case will stop automatically resubmitting when the RESUBMIT value reaches 0. Long runs can easily outstrip supercomputer queue time limits. For this reason, a case is usually run as a series of jobs, each restarting where the previous finished. logical This flag controls whether the RESUBMIT flag causes CONTINUE_RUN to toggle from FALSE to TRUE. The default is TRUE. This flag might be used in conjunction with COMP_RUN_BARRIERS for timing tests. char List of job ids for most recent case.submit char none,never,nsteps,nstep,nseconds,nsecond,nminutes,nminute,nhours,nhour,ndays,nday,nmonths,nmonth,nyears,nyear,date,ifdays0,end sets frequency of full model barrier (same options as STOP_OPTION) for synchronization with BARRIER_N and BARRIER_DATE logical TRUE,FALSE Logical to turn on short term archiving. If TRUE, short term archiving will be turned on. integer system workload snapshot frequency (in seconds, if greater than 0; disabled otherwise) logical TRUE,FALSE Logical to archive all interim restart files, not just those at eor If TRUE, perform short term archiving on all interim restart files, not just those at the end of the run. By default, this value is TRUE. The restart files are saved under the specific component directory ($DOUT_S_ROOT/$CASE/$COMPONENT/rest rather than the top-level $DOUT_S_ROOT/$CASE/rest directory). Interim restart files are created using the REST_N and REST_OPTION variables. This is for expert users ONLY and requires expert knowledge. We will not document this further in this guide. char GNU make command integer Number of processors for gmake logical TRUE,FALSE logical to diagnose model timing at the end of the run logical TRUE,FALSE Enables the papi hardware counters in gptl The papi library must be included in the build step for this to work. char ESMF_LOGKIND_SINGLE,ESMF_LOGKIND_MULTI,ESMF_LOGKIND_NONE Determines what ESMF log files (if any) are generated when USE_ESMF_LIB is TRUE. ESMF_LOGKIND_SINGLE: Use a single log file, combining messages from all of the PETs. Not supported on some platforms. ESMF_LOGKIND_MULTI: Use multiple log files -- one per PET. ESMF_LOGKIND_NONE: Do not issue messages to a log file. By default, no ESMF log files are generated. logical TRUE,FALSE Turns on component barriers for component timing. This variable is for testing and debugging only and should never be set for a production run. integer 0,1,2,3,4,5,6 Coupler decomposition option. integer 0,1,2,3 level of debug output, 0=minimum, 1=normal, 2=more, 3=too much logical TRUE,FALSE Turns on component varying thread control in the driver. Used to set the driver namelist variable "drv_threading". logical TRUE,FALSE logical to save timing files in rundir char Where to auto archive timing data char A comma-separated list of projects that are allowed to auto archive timing data in SAVE_TIMING_DIR integer timer output depth integer timer output depth integer timer detail FIXME - add documentation logical TRUE,FALSE turns on coupler bit-for-bit reproducibility with varying pe counts logical TRUE,FALSE Turn on the passing of water isotope fields through the coupler logical TRUE,FALSE Operate on only a single point of the global grid - DO NOT EDIT (for experts only) real Latitude to find nearest points for points mode (only used if PTS_MODE is TRUE) real Longitude to find nearest points for points mode (only used if PTS_MODE is TRUE) char atm domain file char path of atm domain file char lnd domain file char path of lnd domain file char rof domain file char path of rof domain file char wav domain file char path of wav domain file char ice domain file char path of ice domain file char ocn domain file char path of ocn domain file char glc domain file char path of glc domain file char atm2ocn flux mapping file char X,Y atm2ocn flux mapping file decomp type char atm2ocn state mapping file char X,Y atm2ocn state mapping file decomp type char atm2ocn vector mapping file char X,Y atm2ocn vector mapping file decomp type char atm2lnd flux mapping file char X,Y atm2lnd flux mapping file decomp type char atm2lnd state mapping file char X,Y atm2lnd state mapping file decomp type char atm2wav state mapping file char X,Y atm2wav state mapping file decomp type char ocn2atm flux mapping file char X,Y ocn2atm flux mapping file decomp type char ocn2atm state mapping file char X,Y ocn2atm state mapping file decomp type char lnd2atm flux mapping file char X,Y lnd2atm flux mapping file decomp type char lnd2atm state mapping file char X,Y lnd2atm state mapping file decomp type char lnd2glc flux mapping file char X,Y lnd2glc flux mapping file decomp type char lnd2glc state mapping file char X,Y lnd2glc state mapping file decomp type char lnd2rof flux mapping file char X,Y lnd2rof flux mapping file decomp type char rof2lnd flux mapping file char X,Y rof2lnd flux mapping file decomp type char rof2ocn flux mapping file char X,Y rof2ocn flux mapping file decomp type char rof2ocn runoff mapping file char X,Y rof2ocn runoff mapping file decomp type char rof2ocn runoff mapping file char X,Y rof2ocn runoff mapping file decomp type char glc2lnd flux mapping file char X,Y glc2lnd flux mapping file decomp type char glc2lnd state mapping file char X,Y glc2lnd state mapping file decomp type char glc2ice runoff mapping file char X,Y glc2ice runoff mapping file decomp type char glc2ocn runoff mapping file for liquid runoff char X,Y glc2ocn runoff mapping file decomp type for liquid runoff char glc2ocn runoff mapping file for ice runoff char X,Y glc2ocn runoff mapping file decomp type for ice runoff char ocn2wav state mapping file char X,Y ocn2wav state mapping file decomp type char ice2wav state mapping file char X,Y ice2wav state mapping file decomp type char wav2ocn state mapping file char X,Y wav2ocn state mapping file decomp type char none,npfix,cart3d,cart3d_diag,cart3d_uvw,cart3d_uvw_diag vector mapping option char Error tolerance for differences in fractions in domain checking real Error tolerance for differences in atm/land areas in domain checking real Error tolerance for differences in atm/land masks in domain checking real Error tolerance for differences in atm/land lat/lon in domain checking real Error tolerance for differences in ocean/ice lon/lat in domain checking real Error tolerance for differences in ocean/ice lon/lat in domain checking real Error tolerance for differences in ocean/ice lon/lat in domain checking char ocn2glc flux mapping file char X,Y ocn2glc flux mapping file decomp type char ocn2glc state mapping file char X,Y ocn2glc state mapping file decomp type char glc2ocn flux mapping file char X,Y glc2ocn flux mapping file decomp type char glc2ocn state mapping file char X,Y glc2ocn state mapping file decomp type char A regular expression to match machine node names to ACME machine. char A regular expression to search for an indication that a run failure was caused by a node failure and should therefore be re-attempted. char Proxy (if any) setting for http_proxy to allow web access on this machine. logical Indicates to case.submit that this is a test case. char The root directory of all CIME and component input data for the selected machine. This is usually a shared disk area. Default values for the target machine are in the $CIMEROOT/machines/config_machines.xml char CLM-specific root directory for CLM type input forcing data This directory will only be used for I (CLM/DATM) compsets and only for datm forcing data that is NOT checked into the svn repository (datasets other than the Qian or single-point forcing). This is usually a shared disk area. Default values for the target machine are in the $CIMEROOT/machines/config_machines.xml char Root directory for short term archiving. This directory must be visible to compute nodes. char override the mpi run command, do not include model executable logical TRUE,FALSE TRUE implies perform asynchronous i/o char p2p,coll,default pio rearranger communication type char 2denable,io2comp,comp2io,disable,default pio rearranger communication flow control direction integer pio rearranger communication max pending requests (comp2io) : 0 implies that CIME internally calculates the value ( = max(64, 2 * PIO_NUMTASKS) ), -1 implies no bound on max pending requests logical TRUE,FALSE pio rearranger communiation options (comp2io) : TRUE implies enable handshake logical TRUE,FALSE pio rearranger communiation options (comp2io) : TRUE implies enable isend integer pio rearranger communication max pending requests (io2comp) : -1 implies no bound on max pending requests logical TRUE,FALSE pio rearranger communiation options (io2comp) : TRUE implies enable handshake logical TRUE,FALSE pio rearranger communiation options (io2comp) : TRUE implies enable isend integer pio debug level integer pio blocksize for box decompositions integer pio buffer size limit for pnetcdf output char netcdf pio io type netcdf netcdf netcdf netcdf netcdf netcdf netcdf netcdf netcdf char classic,64bit_offset,64bit_data pio netcdf format (ignored for netcdf4p and netcdf4c) https://www.unidata.ucar.edu/software/netcdf/docs/data_type.html 64bit_offset 64bit_offset 64bit_offset 64bit_offset 64bit_offset 64bit_offset 64bit_offset 64bit_offset 64bit_offset integer stride in compute comm of io tasks for each component, if this value is -99 it will be computed based on PIO_NUMTASKS and number of compute tasks $MAX_MPITASKS_PER_NODE $MAX_MPITASKS_PER_NODE $MAX_MPITASKS_PER_NODE $MAX_MPITASKS_PER_NODE $MAX_MPITASKS_PER_NODE $MAX_MPITASKS_PER_NODE $MAX_MPITASKS_PER_NODE $MAX_MPITASKS_PER_NODE $MAX_MPITASKS_PER_NODE integer 1,2 pio rearranger choice box=1, subset=2 $PIO_VERSION $PIO_VERSION $PIO_VERSION $PIO_VERSION $PIO_VERSION $PIO_VERSION $PIO_VERSION $PIO_VERSION 1 $PIO_VERSION integer pio root processor relative to component root 0 0 0 0 0 0 0 0 0 integer pio number of io tasks, if this value is -99 it will be computed based on PIO_STRIDE and number of tasks -99 -99 -99 -99 -99 -99 -99 -99 -99 logical TRUE,FALSE determine if per ice thickness category fields are passed from ice to ocean - DO NOT EDIT (set by POP build-namelist) char CESM1_ORIG,CESM1_ORIG_TIGHT,CESM1_MOD,CESM1_MOD_TIGHT,RASM_OPTION1,RASM_OPTION2 Coupler sequencing option. This is used to set the driver namelist variable cpl_seq_option. CESM1_ORIG is the cesm1.1 implementation. CESM1_MOD includes a cesm1.3 mod that swaps ocean merging and atm/ocn flux computation. RASM_OPTION1 runs prep ocean before the ocean coupling reducing most of the lags and field inconsistency but still allowing the ocean to run concurrently with the ice and atmosphere. RASM_OPTION2 is similar to RASM_OPTION1 but sequences the ice model, prep ocean and ocean model in that order. The ocean model loses some of the concurrency with the ice model. CESM1_ORIG_TIGHT and CESM1_MOD_TIGHT are consistent with the old variables ocean_tight_coupling = true in the driver. That namelist is gone and the cpl_seq_option flags take it's place. TIGHT coupling makes no sense with the OPTION5 and OPTION6 flags. char none,CO2A,CO2A_OI,CO2B,CO2C,CO2_DMSA Activates additional CO2-related fields to be exchanged between components. Possible values are: CO2A: sets the driver namelist variable flds_co2a = .true.; this adds prognostic CO2 and diagnostic CO2 at the lowest model level to be sent from the atmosphere to the land and ocean. CO2A_OI: sets the driver namelist variable flds_co2a = .true.; this adds prognostic CO2 and diagnostic CO2 at the lowest model level to be sent from the atmosphere to the land and ocean. Also sets the driver namelist variable flds_bgc_oi = .true.; this turns on the transfer of bgc fields between the ocean and seaice components via the coupler. CO2B: sets the driver namelist variable flds_co2b = .true.; this adds prognostic CO2 and diagnostic CO2 at the lowest model level to be sent from the atmosphere just to the land, and the surface upward flux of CO2 to be sent from the land back to the atmosphere CO2C: sets the driver namelist variable flds_co2c = .true.; this adds prognostic CO2 and diagnostic CO2 at the lowest model level to be sent from the atmosphere to the land and ocean, and the surface upward flux of CO2 to be sent from the land and the open ocean back to the atmosphere. CO2_DMSA: sets the driver namelist variable flds_co2_dmsa = .true. The namelist variables flds_co2a, flds_co2b, flds_co2c and flds_co2_dmsa are in the namelist group cpl_flds_inparm. char hour,day,year,decade Base period associated with NCPL coupling frequency. This xml variable is only used to set the driver namelist variables, atm_cpl_dt, lnd_cpl_dt, ocn_cpl_dt, ice_cpl_dt, glc_cpl_dt, rof_cpl_dt, wav_cpl_dt, and esp_dt. integer Number of atm coupling intervals per NCPL_BASE_PERIOD. This is used to set the driver namelist atm_cpl_dt, equal to basedt/ATM_NCPL, where basedt is equal to NCPL_BASE_PERIOD in seconds. integer Number of land coupling intervals per NCPL_BASE_PERIOD. This is used to set the driver namelist atm_cpl_dt, equal to basedt/LND_NCPL, where basedt is equal to NCPL_BASE_PERIOD in seconds. integer Number of ice coupling intervals per NCPL_BASE_PERIOD. This is used to set the driver namelist ice_cpl_dt, equal to basedt/ICE_NCPL where basedt is equal to NCPL_BASE_PERIOD in seconds. integer Number of ocn coupling intervals per NCPL_BASE_PERIOD. Thisn is used to set the driver namelist ocn_cpl_dt, equal to basedt/OCN_NCPL where basedt is equal to NCPL_BASE_PERIOD in seconds. integer Number of glc coupling intervals per NCPL_BASE_PERIOD. char glc_coupling_period,yearly Period at which coupler averages fields sent to GLC. This supports doing the averaging to GLC less frequently than GLC is called (i.e., separating the averaging frequency from the calling frequency). This is useful because there are benefits to only averaging the GLC inputs as frequently as they are really needed (yearly for CISM), but GLC needs to still be called more frequently than that in order to support mid-year restarts. Setting GLC_AVG_PERIOD to 'glc_coupling_period' means that the averaging is done exactly when the GLC is called (governed by GLC_NCPL). integer Number of rof coupling intervals per NCPL_BASE_PERIOD. This is used to set the driver namelist rof_cpl_dt, equal to basedt/ROF_NCPL where basedt is equal to NCPL_BASE_PERIOD in seconds. integer Number of wav coupling intervals per NCPL_BASE_PERIOD. This is used to set the driver namelist wav_cpl_dt, equal to basedt/WAV_NCPL where basedt is equal to NCPL_BASE_PERIOD in seconds. char none,never,nsteps,nstep,nseconds,nsecond,nminutes,nminute,nhours,nhour,ndays,nday,nmonths,nmonth,nyears,nyear,date,ifdays0,end Sets driver snapshot history file frequency (like REST_OPTION) integer Sets driver snapshot history file frequency (like REST_N) integer yyyymmdd format, sets coupler snapshot history date (like REST_DATE) char none,never,nsteps,nstep,nseconds,nsecond,nminutes,nminute,nhours,nhour,ndays,nday,nmonths,nmonth,nyears,nyear,date,ifdays0,end Sets driver average history file frequency (like REST_OPTION) char Sets driver average history file frequency (like REST_N) integer yyyymmdd format, sets driver average history date (like REST_DATE) char External script to be run before model completion char External script to be run after model completion logical TRUE,FALSE Run the external tool pointed to by DATA_ASSIMILATION_SCRIPT after the model run completes FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE integer Number of model run - data assimilation steps to complete char External script to be run after model completion char minus1p8,linear_salt,mushy Freezing point calculation for salt water. logical TRUE,FALSE Only used for compsets with DATM and POP (currently C, G and J): If true, compute albedos to work with daily avg SW down If false (default), albedos are computed with the assumption that downward solar radiation from the atm component has a diurnal cycle and zenith-angle dependence. This is normally the case when using an active atm component If true, albedos are computed with the assumption that downward solar radiation from the atm component is a daily average quantity and does not have a zenith-angle dependence. This is often the case when using a data atm component. Only used for compsets with DATM and POP (currently C, G and J). NOTE: This should really depend on the datm forcing and not the compset per se. So, for example, whether it is set in a J compset should depend on what datm forcing is used. char off,ocn Only used for compsets with DATM and POP (currently C, G and J): If ocn, ocn provides EP balance factor for precipitation. Provides EP balance factor for precip for POP. A factor computed by POP is applied to precipitation so that precipitation balances evaporation and ocn global salinity does not drift. This is intended for use when coupling POP to a DATM. Only used for C, G and J compsets. Default is off logical TRUE,FALSE logical that turns on diagnostic budgets for driver real This set the namelist values of CO2 ppmv for CAM and CLM. This variables is introduced to coordinate this value among multiple components. integer 0,1,3,5,10,36 Glacier model number of elevation classes, 0 implies no glacier land unit in clm Used by both CLM and CISM (even if CISM is not running, and only SGLC is used). logical TRUE,FALSE Whether the glacier component feeds back to the rest of the system This affects: (1) Whether CLM updates its areas based on glacier areas sent from GLC (2) Whether GLC sends fluxes (e.g., calving fluxes) to the coupler Note that this is set to TRUE by default for TG compsets - even though there are no feedbacks for TG compsets, this enables extra coupler diagnostics for these compsets. char CAM namelist use_case. Provides the use_case option for the CAM build-namelist utility (which is called from $CASEROOT/Buildconf/cam.buildnml). The CAM build-namelist leverages groups of namelist options (use cases) that are often paired with the CAM configure options. These use cases are xml files located in $CIMEROOT/../components/atm/cam/bld/namelist_files/use_cases. In general, this variable should not be modified for supported component sets (compsets). Recommendation: If you want to modify this value for your experiment, use your own user-defined component sets. char CAM specific namelist settings for -namelist option Provides options to the -namelist argument for the CAM build-namelist utility. This should be reserved for component set specification. Users should modify CAM namelists only via the $CASEROOT/user_nl_cam file. char CLM namelist use_case. Determines the use-case that will be sent to the CLM build-namelist utility. This is normally set by the component set. This is an advanced flag and should only be used by expert users. char CLM build-namelist options char constant,diagnostic,prognostic Determines how CLM will determine where CO2 is set. If value is constant, it will be set to CCSM_CO2_PPMV, if value is either diagnostic or prognostic, the atmosphere model MUST send it to CLM. CLM_CO2_TYPE is normally set by the specific compset, since it HAS to be coordinated with settings for the atmospheric model. Do not modify this variable. If you want to modify for your experiment, use your own user-defined component set This is an advanced flag and should only be used by expert users. char CLM-specific namelist settings for -namelist option in the CLM build-namelist. CLM_NAMELIST_OPTS is normally set as a compset variable and in general should not be modified for supported compsets. It is recommended that if you want to modify this value for your experiment, you should use your own user-defined component sets via using create_newcase with a compset_file argument. This is an advanced flag and should only be used by expert users. char on,off Turn on any settings for accellerating the model spinup. char Dataset name for user-created datasets. This is used as the argument in Buildconf/clm.buildnml to build-namelist -clm_usr_name. An example of such a dataset would be 1x1pt_boulderCO_c090722. The default value is UNSET. This is an advanced flag and should only be used by expert users. char on,off Flag to the CLM build-namelist command to force CLM to do a cold start (finidat will be set to blanks). A value of on forces the model to spin up from a cold-start (arbitrary initial conditions). Setting this value in the xml file will take precedence over any settings for finidat in the $CASEROOT/user_clm_clm file. char CICE specific namelist settings for -namelist option char prescribed,sst_aquap1,sst_aquap2,sst_aquap3,sst_aquap4,sst_aquap5,sst_aquap6,sst_aquap7,sst_aquap8,sst_aquap9,sst_aquap10,sst_aquapfile,som,som_aquap,interannual,null DOCN mode. The data ocean component (DOCN) always returns SSTs to the driver. The atmosphere/ocean fluxes are computed in the coupler. Therefore, the data ocean model does not compute fluxes like the data ice model. DOCN has two distinct modes of operation. It can run as a pure data model, reading in ocean SSTs (normally climatological) from input datasets, performing time/spatial interpolations, and passing these to the coupler. Alternatively, DOCN can compute updated SSTs by running as a slab ocean model where bottom ocean heat flux convergence and boundary layer depths are read in and used with the atmosphere/ocean and ice/ocean fluxes obtained from the driver. --- A setting of prescribed assumes the only field in the input stream is SST. It also assumes the SST is in Celsius and must be converted to Kelvin. All other fields are set to zero except for ocean salinity, which is set to a constant reference salinity value. Normally the ice fraction data is found in the same data files that provide SST data to the data ocean model. They are normally found in the same file because the SST and ice fraction data are derived from the same observational data sets and are consistent with each other. --- Settings of som (slab ocean model) or som_aquap (aquaplanet slab ocean) are prognostic modes which compute a prognostic sea surface temperature and a freeze/melt potential (surface Q-flux) used by the sea ice model. This calculation requires an external SOM forcing data file that includes ocean mixed layer depths and bottom-of-the-slab Q-fluxes. Scientifically appropriate bottom-of-the-slab Q-fluxes are normally ocean resolution dependent and are derived from the ocean model output of a fully coupled CCSM run. Note that while this mode runs out of the box, the default SOM forcing file is not scientifically appropriate and is provided for testing and development purposes only. Users must create scientifically appropriate data for their particular application. A tool is available to derive valid SOM forcing. --- A setting of sst_aquapN (where "N" is an integer index value) is a type of prescribed SST mode used specifically for an aquaplanet setup in which global SSTs correspond to an analytic form set by the index value. Currently, indices for 10 SST profiles are supported [e.g., index 3 corresponds to the “QOBS” profile of Neale and Hoskins (2001, Atmos. Sci. Lett.)]. With source code modifications, it is possible for users to create their own analytic SST distributions and match them to indices 11 or greater. char Sets SOM forcing filename. This is only used when DOCN_MODE=som. char Sets aquaplanet forcing filename instead of using an analytic form. This is only used when DOCN_MODE=sst_aquapfile. char Prescribed SST and ice coverage stream name. Sets SST and ice coverage stream name. This is only used when DOCN_MODE=prescribed. char Prescribed SST and ice coverage data file name. Sets SST and ice coverage data file name. This is only used when DOCN_MODE=prescribed. char Prescribed SST and ice coverage grid file name. Sets SST and ice coverage grid file name for prescribed runs. This is only used when DOCN_MODE=prescribed. integer The model year that corresponds to SSTICE_YEAR_START on the data file. Prescribed SST and ice coverage data will be aligned so that the first year of data corresponds to SSTICE_YEAR_ALIGN in the model. For instance, if the first year of prescribed data is the same as the first year of the model run, this should be set to the year given in RUN_STARTDATE. If SSTICE_YEAR_ALIGN is later than the model's starting year, or if the model is run after the prescribed data ends (as determined by SSTICE_YEAR_END), the default behavior is to assume that the data from SSTICE_YEAR_START to SSTICE_YEAR_END cyclically repeats. This behavior is controlled by the "taxmode" stream option; see the data model documentation for more details. This is only used when DOCN_MODE=prescribed. integer The first year of data to use from SSTICE_DATA_FILENAME. This is the first year of prescribed SST and ice coverage data to use. For example, if a data file has data for years 0-99, and SSTICE_YEAR_START is 10, years 0-9 in the file will not be used. This is only used when DOCN_MODE=prescribed. integer The last year of data to use from SSTICE_DATA_FILENAME. This is the last year of prescribed SST and ice coverage data to use. For example, if a data file has data for years 0-99, and value is 49, years 50-99 in the file will not be used. This is only used when DOCN_MODE=prescribed.