CISM Component Model Namelist Variables

Space-delimited list of variables output to history file

Default: 'acab artm thk usurf topg uvel vvel uflx vflx temp bmlt bwat'

Determines whether extra diagnostics are printed in the cism log file

Default: false

Input file

Default: For startup runs or hybrid runs with CISM_OBSERVED_IC=TRUE, a resolution-dependent
         initial conditions file (e.g., gland10.input.nc).
         For branch/hybrid runs with CISM_OBSERVED_IC=FALSE, a restart file name
         built based on RUN_REFCASE and RUN_REFDATE.

Name of top-level configuration file for Glimmer Glacier model
(Determined by scripts -- cannot be set by user)

Variable name for fraction

Default: LANDFRAC

Filename of file to specify horizontal grid resolution

Default: resolution-dependent (e.g., grid file for 0.9x1.25 deg)

How grid is being specified: from file or internally
Currently, only 'file' is supported

Default: file

Variable name for mask

Default: LANDMASK

Whether leap years are enabled in the GLC time manager.
CAUTION: Leap years don't work correctly with GLC time steps longer than a few months.

Default: .false.

Character to separate date values

Default: '-'

Time step, in units given by dt_option
This generally should not be changed

Default: set based on NCPL_BASE_PERIOD and GLC_NCPL in env_run.xml,
so that there is one GLC time step per coupling period

GLC time-step units
This generally should not be changed
Valid values: steps_per_year, steps_per_day, seconds, hours

Default: set based on NCPL_BASE_PERIOD and GLC_NCPL in env_run.xml,
so that there is one GLC time step per coupling period

Starting day number in month

Default: comes from RUN_STARTDATE or RUN_REFDATE

Starting hour of the day

Default: 0

Starting minute of the day

Default: 0

Starting month number

Default: comes from RUN_STARTDATE or RUN_REFDATE

Starting second of the minute

Default: 0

Starting year number

Default: comes from RUN_STARTDATE or RUN_REFDATE

Simulation identifier (ie case name)

Default: case name set by create_newcase

Stop option -- always let the coupler stop the model so use 'never'.

Default: 'never'

Node spacing in x-direction (m)

Default: resolution-dependent

Node spacing in y-direction (m)

Default: resolution-dependent

Number of nodes in x-direction

Default: resolution-dependent

Number of nodes in y-direction

Default: resolution-dependent

Number of nodes in z-direction

Default: 11

List of sigma levels, in ascending order, separated by spaces
These run between 0.0 (at top surface) and 1.0 (at lower surface)
Only relevant if sigma = 2

Default: 0.00 0.15 0.30 0.45 0.60 0.75 0.83 0.90 0.95 0.98 1.00

Mass-balance model to use.
In the CESM context, this should be set to 0 (receive surface mass balance from climate model)

Default: 0

0: Do not let the ice sheet evolve (hold ice state fixed at initial condition)
1: Let the ice sheet evolve

Default: 1

Ice time-step multiplier: allows asynchronous climate-ice coupling

Default: 1

Flag to control if mean-preserving interpolation is used
0: Do not use mean-preserving interpolation
1: Use mean-preserving interpolation

Default: 0

Method of precipitation downscaling:
1: Use large-scale precipitation rate
2: Use parameterization of Roe and Lindzen

Default: 1

Central latitude (degrees north)

Default: 90.0

Central longitude (degrees east)

Default: 321.0

False easting (m)

Default: 800000.0

False northing (m)

Default: 3400000.0

Scale factor; only relevant for the Stereographic projection

Default: 0.0

Location of standard parallel(s) (degrees north)
Up to two standard parallels may be specified (depending on the projection)

Default: 71.0

String specifying the map projection type
Valid values: LAEA, AEA, LCC, STERE

Default: STERE

0: not in continuity equation
1: in continuity equation

Default: 1

Determines the treatment of basal water
0: Set to zero everywhere
1: Calculated from local water balance
2: Compute the basal water flux, then find depth via calculation
3: Set to constant everywhere (10m)
4: Calculated from till water content, in the basal processes module

Default: 0

Which dycore to use
0: glide dycore (SIA, serial only)
1: glam dycore (HO, FDM, serial or parallel)
2: glissade dycore (HO, FEM, serial or parallel)

Default: 0 for cism1, 1 for cism2

0: pseudo-diffusion
1: ADI scheme [CANNOT BE USED: RESTARTS ARE NOT EXACT]
2: diffusion
3: remap thickness
4: 1st order upwind
5: no thickness evolution

Default: 0 for cism1, 3 for cism2

0: constant value, taken from default_flwa
1: uniform value equal to the Paterson-Budd value at -10 deg C
2: Paterson-Budd temperature-dependent relationship

Default: 2

0: prescribed uniform geothermal heat flux
1: read 2D geothermal flux field from input file (if present)
2: calculate geothermal flux using 3d diffusion

Default: 0

Hotstart (restart) the model if set to 1. 
This allows for exact restarts from previous initial conditions

Default: 0 for startup or hybrid with CISM_OBSERVED_IC=TRUE, 1 for hybrid/branch with CISM_OBSERVED_IC=FALSE

0: no isostasy
1: compute isostasy

Default: 0

0: ignore marine margin
1: set thickness to zero if floating
2: lose a specified fraction of floating ice
3: set thickness to zero if relaxed bedrock is below a given depth (marine_limit)
4: set thickness to zero if current bedrock is below a given depth (marine_limit)
5: Huybrechts grounding line scheme for Greenland initialization

Default: 1

0: no periodic EW boundary conditions
1: periodic EW boundary conditions
(This is a Glimmer serial option. The parallel code enforces periodic
EW and NS boundary conditions by default.)

Default: 0

How to determine sigma values
0: compute standard Glimmer sigma coordinates
1: sigma coordinates are given in external file [NOT ALLOWED WHEN RUNNING CISM IN CESM]
2: read sigma coordinates from config file (from sigma_levels)
3: evenly spaced levels, as required for glam dycore
4: compute Pattyn sigma coordinates

Default: 0

Basal traction parameter
0: no basal sliding
1: constant basal traction coefficient
2: constant coefficient where basal water is present, else no sliding
3: constant coefficient where the basal temperature is at the pressure melting point, else no sliding
4: coefficient is proportional to basal melt rate
5: coefficient is a linear function of basal water depth

Default: 0

Temperature initialization method
0: Initialize temperature to 0 C
1: Initialize temperature to surface air temperature
2: Initialize temperature with a linear profile in each column

Default: 2

Determines the temperature solution method
0: isothermal: set column to surface air temperature
1: full prognostic temperature solution
2: do NOTHING: hold temperatures steady at initial value

Default: 1

0: relaxed topography is read from a separate variable
1: first time slice of input topography is assumed to be relaxed
2: first time slice of input topography is assumed to be in isostatic equilibrium with ice thickness

Default: 0

Method of integration used to obtain vertical velocity
0: standard vertical integration
1: vertical integration constrained to obey an upper kinematic boundary condition

Default: 0

Ice sheet timestep (years)
Must translate into an integer number of hours

Default: Depends on resolution and physics option

Diagnostic frequency (years)
Set to 0 for no diagnostic output; set to dt for diagnostic output every time step

Default: 1

x coordinate of point for diagnostic output

Default: resolution-dependent

y coordinate of point for diagnostic output

Default: resolution-dependent

Multiplier of ice sheet timestep, dt
(in theory, can be real-valued, but values less than 1 are not handled properly, so restricted to being an integer)

Default: 1

Multiplier of ice sheet timestep, dt
(in theory, can be real-valued, but values less than 1 are not handled properly, so restricted to being an integer)

Default: 1

Profile period (number of time steps between profiles)

Default: 100

Subcycling for glissade

Default: 1

(m yr-1 Pa-1)

Default: 1.e-4

(m yr-1 Pa-1)
(Only used for slip_coeff = BTRC_LINEAR_BMLT)

Default: (use hard-coded default)

(Pa-1)
(Only used for slip_coeff = BTRC_LINEAR_BMLT)

Default: (use hard-coded default)

5-element list of values
(Only used for slip_coeff = BTRC_TANH_BWAT)

Default: (use hard-coded default)

Fraction of ice lost to calving

Default: (use hard-coded default)

Glen's A to use in isothermal case

Default: (use hard-coded default)

The flow law is enhanced with this factor.
The greater the value, the lower the viscosity and the faster the ice will flow.

Default: 3.0 for cism1, 1.0 for cism2

Constant geothermal heat flux (W m-2; sign convention is positive down)
(May be overwritten by a spatially-varying field in input file [bheatflx])

Default: -0.05

Time scale for basal water to drain (yr-1)
(Not relevant for basal_water=2)

Default: 1000.

Thickness below which ice dynamics is ignored (m)
Below this limit, ice is only accumulated

Default: 100.

Set to a value between 0 (no messages) and 6 (all messages)

Default: 6

All ice is assumed lost once water depths reach this value (for marine_margin=2 or 4) (m)
Note that water depth is negative

Default: -200.

Optional periodic offset for ismip-hom and similar tests
May be needed to ensure continuous ice geometry at the edges of the
global domain

Default: 0.

Optional periodic offset for ismip-hom and similar tests
May be needed to ensure continuous ice geometry at the edges of the
global domain

Default: 0.

Method for computing the dissipation during the temperature calculation
0: 0-order SIA approx.
1: 1st order solution (e.g., Blatter-Pattyn)
2: 1st order depth-integrated solution (SSA)

Default: 0

Basal boundary condition for Payne/Price dynamical core
0: constant value (hardcoded in, useful for debugging)
1: simple pattern (hardcoded in, useful for debugging)
2: use till yield stress (Picard-type iteration)
3: circular ice shelf
4: no slip everywhere (using stress basal bc and large value for B^2)
5: beta^2 field passed in from CISM
6: no slip everywhere (using Dirichlet, no slip basal bc)
7: use till yield stress (Newton-type iteration)

Default: 5

How effective viscosity is computed for higher-order dynamical core
0: constant value
1: multiple of flow factor
2: compute from effective strain rate

Default: 2

Method for solving the nonlinear iteration when solving the first-order momentum balance
0: use the standard Picard iteration
1: use Jacobian Free Newton Krylov (JFNK) method

Default: 1

Method for computing residual in Payne/Price dynamical core
0: maxval
1: maxval ignoring basal velocity
2: mean value
3: L2 norm of system residual, Ax-b=resid

Default: 3

Method for solving the sparse linear system that arises from the higher-order solver
0: Biconjugate gradient, incomplete LU preconditioner
1: GMRES, incomplete LU preconditioner
2: Conjugate gradient, incomplete LU preconditioner
3: Conjugate gradient, structured grid, parallel-enabled
4: standalone interface to Trilinos

Default: 4 when building with trilinos, 1 otherwise

thermal conductivity of lithosphere (W m-1 K-1)
Only relevant if gthf = 2

Default: (use hard-coded default)

Number of vertical layers
Only relevant if gthf = 2

Default: 20

1: 1D calculations
3: 3D calculations
Only relevant if gthf = 2

Default: 1

Number of time steps for spinning up GTHF calculations
Only relevant if gthf = 2

Default: 0

Density of lithosphere (kg m-3)
Only relevant if gthf = 2

Default: (use hard-coded default)

Depth below sea-level at which geothermal heat gradient is applied (m)
Only relevant if gthf = 2

Default: (use hard-coded default)

Specific heat capacity of lithosphere (J kg-1 K-1)
Only relevant if gthf = 2

Default: (use hard-coded default)

Initial surface temperature (degrees C)
Only relevant if gthf = 2

Default: (use hard-coded default)

0: fluid mantle, isostatic adjustment happens instantaneously
1: relaxing mantle, mantle is approximated by a half-space
Only relevant if isostasy = 1

Default: 0

Flexural rigidity of the lithosphere
Only relevant if 'lithosphere' is set to 1

Default: (use hard-coded default)

0: local lithosphere, equilibrium bedrock depression is found using Archimedes' principle
1: elastic lithosphere, flexural rigidity is taken into account
Only relevant if isostasy = 1

Default: 0

Characteristic time constant of relaxing mantle (years)
Only relevant if isostasy = 1

Default: (use hard-coded default)

Lithosphere update period (years)
Only relevant if isostasy = 1

Default: (use hard-coded default)