Model Version: 3.0a
Component Tag:
cmeps1.1.48
HTML Created:
2026-07-02

Use the CASEROOT tools xmlquery to query these variables and xmlchange to change their values.

Parameter Name Default Value Data Type Group CASEROOT File Valid Values Description
MODEL_DOI_URL https://doi.org/10.5065/D67H1H0V char run_metadata env_case.xml None
run DOI
SAVE_TIMING FALSE logical run_flags env_run.xml ['TRUE', 'FALSE']
logical to save timing files in rundir
TPROF_TOTAL 0 integer run_flags env_run.xml None
Determines number of times profiler is called over the model run period.
    This sets values for tprof_option and tprof_n that determine the timing output file frequency
    
TIMER_DETAIL 2 integer run_flags env_run.xml None
    integer indicating maximum detail level to profile. This xml
    variable is used to set the namelist variable
    timing_detail_limit. This namelist variable is used by perf_mod
    (in $CIMEROOT/src/share/timing/perf_mod.F90) to turn timers off
    and on depending on calls to the routine t_adj_detailf. If in the
    code a statement appears like t_adj_detailf(+1), then the current
    timer detail level is incremented by 1 and compared to the
    time_detail_limit obtained from the namelist.  If the limit is
    exceeded then the timer is turned off.
    
TIMER_LEVEL 12 integer run_flags env_run.xml None
Maximum code stack depth of enabled timers.
DOUT_S_SAVE_INTERIM_RESTART_FILES FALSE logical run_data_archive env_run.xml ['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 FALSE.
    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.
CCSM_BGC none char run_coupling env_run.xml ['none', 'CO2A', 'CO2B', 'CO2C']
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.

    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.

    The namelist variables flds_co2a, flds_co2b and flds_co2c are in the
    namelist group cpl_flds_inparm.
    
DMS_EMIS_OCN FALSE logical run_coupling env_run.xml ['TRUE', 'FALSE']
      Activates DMS fluxes to be sent from ocn to atm.
      Currently this is only available with BLOM ocean component.
    
BRF_EMIS_OCN FALSE logical run_coupling env_run.xml ['TRUE', 'FALSE']
      Activates Bromoform fluxes to be sent from ocn to atm.
      Currently this is only available with BLOM ocean component.
    
N2O_EMIS_OCN FALSE logical run_coupling env_run.xml ['TRUE', 'FALSE']
      Activates N2O fluxes to be sent from ocn to atm.
      Currently this is only available with BLOM ocean component.
    
NH3_EMIS_OCN FALSE logical run_coupling env_run.xml ['TRUE', 'FALSE']
      Activates NH3 fluxes to be sent from ocn to atm.
      Currently this is only available with BLOM ocean component.
    
CPL_USER_MODS char run_component_cpl env_case.xml None
User mods to apply to specific compset matches. 
NCPL_BASE_PERIOD day char run_coupling env_run.xml ['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.
ATM_NCPL 48 integer run_coupling env_run.xml None
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.
LND_NCPL $ATM_NCPL integer run_coupling env_run.xml None
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.
ICE_NCPL $ATM_NCPL integer run_coupling env_run.xml None
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.
OCN_NCPL $ATM_NCPL integer run_coupling env_run.xml None
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.
GLC_NCPL 1 integer run_coupling env_run.xml None
Number of glc coupling intervals per NCPL_BASE_PERIOD.
GLC_AVG_PERIOD yearly char run_coupling env_run.xml ['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).

    IMPORTANT: In order to restart mid-year when running with CISM, you MUST specify GLC_AVG_PERIOD = 'yearly'.
    If using GLC_AVG_PERIOD = 'glc_coupling_period' with CISM, you can only restart on year boundaries.
    
ROF_NCPL 8 integer run_coupling env_run.xml None
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.
WAV_NCPL $ATM_NCPL integer run_coupling env_run.xml None
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.
CPL_ALBAV FALSE logical run_component_cpl env_run.xml ['TRUE', 'FALSE']
      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.
      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.
    
CPL_SEQ_OPTION TIGHT char run_coupling env_run.xml ['TIGHT', 'OPTION1', 'OPTION2']
      OPTION1 (like RASM_OPTION1 in CPL7) runs prep_ocn_avg,
      BEFORE the aoflux and ocnalb calculations, thereby reducing
      most of the lags and field inconsistency but still allowing the
      ocean to run concurrently with the ice and atmosphere.
      OPTION2 (like CESM1_MOD in CPL7) runs prep_ocn_avg,
      AFTER the aoflux and ocnalb calculations, thereby permitting maximum
      concurrency
      TIGHT (like CESM1_MOD_TIGHT), is a tight coupling run sequence
    
HIST_OPTION never char med_history env_run.xml ['none', 'never', 'nsteps', 'nseconds', 'nminutes', 'nhours', 'ndays', 'nmonths', 'nyears', 'date', 'end']
Sets driver snapshot history file frequency (like REST_OPTION)
HIST_N -999 integer med_history env_run.xml None
Sets driver snapshot history file frequency (like REST_N)
HIST_DATE -999 integer med_history env_run.xml None
yyyymmdd format, sets coupler snapshot history date (like REST_DATE)
BUDGETS FALSE logical run_budgets env_run.xml ['TRUE', 'FALSE']
logical that turns on diagnostic budgets for driver
CCSM_CO2_PPMV 284.7 real run_co2 env_run.xml None
      Mechanism for setting the CO2 value in ppmv for
      CLM if CLM_CO2_TYPE is constant or
      MOM6 if OCN_CO2_TYPE is constant.
    
GLC_NEC 10 integer run_glc env_run.xml ['1', '3', '5', '10', '36']
Number of glacier elevation classes used in CLM.
    Used by both CLM and the coupler (even if CISM is not running, and only SGLC is used).
GLC_TWO_WAY_COUPLING FALSE logical run_glc env_run.xml ['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.
TFREEZE_SALTWATER_OPTION mushy char run_physics env_run.xml ['minus1p8', 'linear_salt', 'mushy']
Freezing point calculation for salt water.
WATER_TRACERS char run_coupling env_run.xml None
      Colon-delimited list of water tracers enabled in this run.

      Each item in the list consists of a name and then, optionally, a '%' followed by the
      isotope species for this tracer. For standard water tracers (i.e., tracers of bulk
      water), the list item will only contain the name (without a '%'). The name can be
      anything; if an isotope species is specified, it must match one of the implemented
      water isotopes: H218O, H217O or HDO. By convention, a tracer that is the full
      quantity of a given isotope will have a name that is identical to the species (e.g.,
      H218O:H218O).

      For example, this list could be:
      MyRegularTracer:HDO%HDO:H218O%H218O:SomeOtherTracer:MyHdoTracer%HDO:YetAnotherTracer

      This specifies three standard (bulk water) tracers (MyRegularTracer, SomeOtherTracer
      and YetAnotherTracer), two isotopes (HDO and H218O), and a tracer that is a subset
      of HDO (MyHdoTracer). (Note that the ordering in the list is not important.)
   
Parameter Name Default Value Data Type Group CASEROOT File Valid Values Description