Configuration parameters

Every parameter corresponds to a command-line option; some options map to a combination of parameters.

There are five kinds of options and parameters:

  1. Strings (mostly file names),

  2. Scalars (a number representing a physical quantify, usually with units),

  3. Integers (an integer number, usually corresponding to a count),

  4. Flags (True/False, on/off, yes/no),

  5. Keywords (one of a given set of strings).

Each parameter can be set using the command-line option consisting of a dash followed by the parameter name. For example,

-constants.standard_gravity 10

sets the acceleration due to gravity (parameter constants­.standard_gravity) to \(10\). Options listed below are shortcuts, added for convenience.

The following are equivalent and choose the temperature-based (as opposed to enthalpy-based) energy balance model:

-energy.temperature_based
-energy.temperature_based on
-energy.temperature_based yes
-energy.temperature_based true
-energy.temperature_based True

The following are also equivalent: they disable updating geometry by performing a step of the mass-continuity equation:

-geometry.update.enabled off
-geometry.update.enabled no
-geometry.update.enabled false
-geometry.update.enabled False
-no_geometry.update.enabled

The -no_ prefix is still supported for compatibility with older scripts, but will be removed in a later PISM version.

  1. age.enabled

    Solve age equation (advection equation for ice age).

    Type
    flag
    Default value

    no

    Option

    -age

  2. age.initial_value

    Initial age of ice

    Type
    number
    Default value

    0 (years)

  3. atmosphere.anomaly.file

    Name of the file containing climate forcing fields.

    Type
    string
    Default value

    empty

    Option

    -atmosphere_anomaly_file

  4. atmosphere.anomaly.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  5. atmosphere.delta_P.file

    Name of the file containing scalar precipitation offsets.

    Type
    string
    Default value

    empty

    Option

    -atmosphere_delta_P_file

  6. atmosphere.delta_P.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  7. atmosphere.delta_T.file

    Name of the file containing temperature offsets.

    Type
    string
    Default value

    empty

    Option

    -atmosphere_delta_T_file

  8. atmosphere.delta_T.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  9. atmosphere.elevation_change.file

    Name of the file containing the reference surface elevation field (variable usurf).

    Type
    string
    Default value

    empty

    Option

    -atmosphere_lapse_rate_file

  10. atmosphere.elevation_change.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  11. atmosphere.elevation_change.precipitation.lapse_rate

    Elevation lapse rate for the precipitation

    Type
    number
    Default value

    0 ((kg m-2 / year) / km)

    Option

    -precip_lapse_rate

  12. atmosphere.elevation_change.precipitation.method

    Choose the precipitation adjustment method. scale: use temperature-change-dependent scaling factor. shift: use the precipitation lapse rate.

    Type
    keyword
    Default value

    shift

    Choices

    scale, shift

    Option

    -precip_adjustment

  13. atmosphere.elevation_change.precipitation.temp_lapse_rate

    Elevation lapse rate for the surface temperature used to compute \(\Delta T\) in the precipitation scaling factor \(\exp(C \cdot \Delta T)\)

    Type
    number
    Default value

    0 (Kelvin / km)

    Option

    -precip_temp_lapse_rate

  14. atmosphere.elevation_change.temperature_lapse_rate

    Elevation lapse rate for the surface temperature

    Type
    number
    Default value

    0 (Kelvin / km)

    Option

    -temp_lapse_rate

  15. atmosphere.fausto_air_temp.c_ma

    latitude-dependence coefficient for formula (1) in [1]

    Type
    number
    Default value

    -0.7189 (Kelvin / degree_north)

  16. atmosphere.fausto_air_temp.c_mj

    latitude-dependence coefficient for formula (2) in [1]

    Type
    number
    Default value

    -0.1585 (Kelvin / degree_north)

  17. atmosphere.fausto_air_temp.d_ma

    41.83+273.15; base temperature for formula (1) in [1]

    Type
    number
    Default value

    314.98 (Kelvin)

  18. atmosphere.fausto_air_temp.d_mj

    = 14.70+273.15; base temperature for formula (2) in [1]

    Type
    number
    Default value

    287.85 (Kelvin)

  19. atmosphere.fausto_air_temp.gamma_ma

    = -6.309 / 1km; mean slope lapse rate for formula (1) in [1]

    Type
    number
    Default value

    -0.006309 (Kelvin / meter)

  20. atmosphere.fausto_air_temp.gamma_mj

    = -5.426 / 1km; mean slope lapse rate for formula (2) in [1]

    Type
    number
    Default value

    -0.005426 (Kelvin / meter)

  21. atmosphere.fausto_air_temp.kappa_ma

    longitude-dependence coefficient for formula (1) in [1]

    Type
    number
    Default value

    0.0672 (Kelvin / degree_west)

  22. atmosphere.fausto_air_temp.kappa_mj

    longitude-dependence coefficient for formula (2) in [1]

    Type
    number
    Default value

    0.0518 (Kelvin / degree_west)

  23. atmosphere.fausto_air_temp.summer_peak_day

    day of year for July 15; used in corrected formula (4) in [1]

    Type
    integer
    Default value

    196 (ordinal day number)

  24. atmosphere.frac_P.file

    Name of the file containing scalar precipitation scaling.

    Type
    string
    Default value

    empty

    Option

    -atmosphere_frac_P_file

  25. atmosphere.frac_P.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  26. atmosphere.given.file

    Name of the file containing climate forcing fields.

    Type
    string
    Default value

    empty

    Option

    -atmosphere_given_file

  27. atmosphere.given.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  28. atmosphere.models

    Comma-separated list of atmosphere melt models and modifiers.

    Type
    string
    Default value

    given

    Option

    -atmosphere

  29. atmosphere.one_station.file

    Specifies a file containing scalar time-series precipitation and air_temp.

    Type
    string
    Default value

    empty

    Option

    -atmosphere_one_station_file

  30. atmosphere.orographic_precipitation.background_precip_post

    Background precipitation \(P_{\mathrm{post}}\) added after the truncation.

    Type
    number
    Default value

    0 (mm/hr)

    Option

    -background_precip_post

  31. atmosphere.orographic_precipitation.background_precip_pre

    Background precipitation \(P_{\mathrm{pre}}\) added before the truncation.

    Type
    number
    Default value

    0 (mm/hr)

    Option

    -background_precip_pre

  32. atmosphere.orographic_precipitation.conversion_time

    Cloud conversion time \(\tau_c\)

    Type
    number
    Default value

    1000 (s)

    Option

    -conversion_time

  33. atmosphere.orographic_precipitation.coriolis_latitude

    Latitude used to compute Coriolis force

    Type
    number
    Default value

    0 (degrees_N)

    Option

    -coriolis_latitude

  34. atmosphere.orographic_precipitation.fallout_time

    Fallout time \(\tau_f\)

    Type
    number
    Default value

    1000 (s)

    Option

    -fallout_time

  35. atmosphere.orographic_precipitation.grid_size_factor

    The size of the extended grid is (Z*(grid.Mx - 1) + 1, Z*(grid.My - 1) + 1) where Z is given by this parameter.

    Type
    integer
    Default value

    2 (count)

  36. atmosphere.orographic_precipitation.lapse_rate

    Lapse rate \(\gamma\)

    Type
    number
    Default value

    -5.8 (K / km)

    Option

    -lapse_rate

  37. atmosphere.orographic_precipitation.moist_adiabatic_lapse_rate

    Moist adiabatic lapse rate \(\Gamma_m\)

    Type
    number
    Default value

    -6.5 (K / km)

    Option

    -moist_adiabatic_lapse_rate

  38. atmosphere.orographic_precipitation.moist_stability_frequency

    Moist stability frequency \(N_m\)

    Type
    number
    Default value

    0.05 (1/s)

    Option

    -moist_stability_frequency

  39. atmosphere.orographic_precipitation.reference_density

    Reference density \(\rho_{S_{\text{ref}}}\)

    Type
    number
    Default value

    0.0074 (kg m-3)

    Option

    -reference_density

  40. atmosphere.orographic_precipitation.scale_factor

    Precipitation scaling factor \(S\).

    Type
    number
    Default value

    1 (1)

    Option

    -scale_factor

  41. atmosphere.orographic_precipitation.smoothing_standard_deviation

    Standard deviation of the Gaussian filter used to smooth surface elevation or zero if disabled

    Type
    number
    Default value

    0 (m)

  42. atmosphere.orographic_precipitation.truncate

    Truncate precipitation at 0, disallowing negative precipitation values.

    Type
    flag
    Default value

    true

    Option

    -truncate

  43. atmosphere.orographic_precipitation.water_vapor_scale_height

    Water vapor scale height \(H_w\)

    Type
    number
    Default value

    2500 (m)

    Option

    -water_vapor_scale_height

  44. atmosphere.orographic_precipitation.wind_direction

    The direction the wind is coming from

    Type
    number
    Default value

    270 (degrees)

    Option

    -wind_direction

  45. atmosphere.orographic_precipitation.wind_speed

    The wind speed.

    Type
    number
    Default value

    10 (m/s)

    Option

    -wind_speed

  46. atmosphere.pik.file

    Name of the file containing the reference surface elevation field (variable usurf).

    Type
    string
    Default value

    empty

    Option

    -atmosphere_pik_file

  47. atmosphere.pik.parameterization

    Selects parameterizations of mean annual and mean summer near-surface air temperatures.

    Type
    keyword
    Default value

    martin

    Choices

    martin, huybrechts_dewolde, martin_huybrechts_dewolde, era_interim, era_interim_sin, era_interim_lon

    Option

    -atmosphere_pik

  48. atmosphere.precip_exponential_factor_for_temperature

    = 0.169/2.4; in SeaRISE-Greenland formula for precipitation correction using air temperature offsets relative to present; a 7.3% change of precipitation rate for every one degC of temperature change [2]

    Type
    number
    Default value

    0.0704167 (Kelvin-1)

  49. atmosphere.precip_scaling.file

    Name of the file containing temperature offsets to use for a precipitation correction.

    Type
    string
    Default value

    empty

    Option

    -atmosphere_precip_scaling_file

  50. atmosphere.precip_scaling.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  51. atmosphere.searise_greenland.file

    Name of the file containing a precipitation field.

    Type
    string
    Default value

    empty

    Option

    -atmosphere_searise_greenland_file

  52. atmosphere.uniform.precipitation

    Precipitation used by the uniform atmosphere model.

    Type
    number
    Default value

    1000 (kg m-2 year-1)

  53. atmosphere.uniform.temperature

    Air temperature used by the uniform atmosphere model.

    Type
    number
    Default value

    273.15 (Kelvin)

  54. atmosphere.yearly_cycle.file

    Name of the file containing mean annual and mean July temperatures (air_temp_mean_annual and air_temp_mean_summer) and the precipitation field.

    Type
    string
    Default value

    empty

    Option

    -atmosphere_yearly_cycle_file

  55. atmosphere.yearly_cycle.scaling.file

    Name of the file containing amplitude scaling (amplitude_scaling) for the near-surface air temperature.

    Type
    string
    Default value

    empty

    Option

    -atmosphere_yearly_cycle_scaling_file

  56. atmosphere.yearly_cycle.scaling.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  57. basal_resistance.beta_ice_free_bedrock

    value is for ice stream E from [117]; thus sliding velocity, but we hope it doesn’t matter much; at 100 m/year the linear sliding law gives 57040 Pa basal shear stress

    Type
    number
    Default value

    1.8e+09 (Pascal second meter-1)

  58. basal_resistance.beta_lateral_margin

    high value of \(\beta\) used to simulate drag at lateral ice margins (fjord walls, etc); the default value is chosen to disable flow in the direction along a margin

    Type
    number
    Default value

    1e+19 (Pascal second meter-1)

  59. basal_resistance.plastic.regularization

    Set the value of \(\epsilon\) regularization of plastic till; this is the second \(\epsilon\) in formula (4.1) in [45]

    Type
    number
    Default value

    0.01 (meter / year)

    Option

    -plastic_reg

  60. basal_resistance.pseudo_plastic.enabled

    Use the pseudo-plastic till model (basal sliding law).

    Type
    flag
    Default value

    no

    Option

    -pseudo_plastic

  61. basal_resistance.pseudo_plastic.q

    The exponent of the pseudo-plastic basal resistance model

    Type
    number
    Default value

    0.25 (pure number)

    Option

    -pseudo_plastic_q

  62. basal_resistance.pseudo_plastic.sliding_scale_factor

    divides pseudo-plastic tauc (yield stress) by given factor; this would increase sliding by given factor in absence of membrane stresses; not used if negative or zero; not used by default

    Type
    number
    Default value

    -1 (1)

    Option

    -sliding_scale_factor_reduces_tauc

  63. basal_resistance.pseudo_plastic.u_threshold

    threshold velocity of the pseudo-plastic sliding law

    Type
    number
    Default value

    100 (meter / year)

    Option

    -pseudo_plastic_uthreshold

  64. basal_resistance.regularized_coulomb.enabled

    Use the regularized Coulomb till friction model (basal sliding law) as in equation (3) in [106]

    Type
    flag
    Default value

    no

    Option

    -regularized_coulomb

  65. basal_yield_stress.add_transportable_water

    If “yes” then the water amount in the transport system is added to tillwat in determining tauc (in the Mohr-Coulomb relation). Normally only the water in the till is used.

    Type
    flag
    Default value

    no

    Option

    -tauc_add_transportable_water

  66. basal_yield_stress.constant.value

    fill value for yield stress for basal till (plastic or pseudo-plastic model); note \(2 \times 10^5\) Pa = 2 bar is quite strong and little sliding should occur

    Type
    number
    Default value

    200000 (Pascal)

    Option

    -tauc

  67. basal_yield_stress.ice_free_bedrock

    the “high” yield stress value used in grounded ice-free areas.

    Type
    number
    Default value

    1e+06 (Pascal)

    Option

    -high_tauc

  68. basal_yield_stress.model

    The basal yield stress model to use when sliding is active.

    Type
    keyword
    Default value

    mohr_coulomb

    Choices

    constant, mohr_coulomb, tillphi_opt

    Option

    -yield_stress

  69. basal_yield_stress.mohr_coulomb.delta.file

    Name of the file containing space- and time-dependent variable mohr_coulomb_delta to use instead of basal_yield_stress­.mohr_coulomb­.till_effective_fraction_overburden.

    Type
    string
    Default value

    empty

    Option

    -mohr_coulomb_delta_file

  70. basal_yield_stress.mohr_coulomb.delta.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  71. basal_yield_stress.mohr_coulomb.tauc_to_phi.file

    File containing the basal yield stress field that should be used to recover the till friction angle distribution.

    Type
    string
    Default value

    empty

    Option

    -tauc_to_phi

  72. basal_yield_stress.mohr_coulomb.till_cohesion

    cohesion of till; = \(c_0\) in most references; note Schoof uses zero but Paterson pp 168–169 gives range 0–40 kPa; but Paterson notes that “… all the pairs \(c_0\) and \(\phi\) in the table would give a yield stress for Ice Stream B that exceeds the basal shear stress there…”

    Type
    number
    Default value

    0 (Pascal)

    Option

    -till_cohesion

  73. basal_yield_stress.mohr_coulomb.till_compressibility_coefficient

    coefficient of compressiblity of till; value from [109]

    Type
    number
    Default value

    0.12 (pure number)

    Option

    -till_compressibility_coefficient

  74. basal_yield_stress.mohr_coulomb.till_effective_fraction_overburden

    \(\delta\) in notes; \(N_0 = \delta P_o\) where \(P_o\) is overburden pressure; \(N_0\) is reference (low) value of effective pressure (i.e. normal stress); \(N_0\) scales with overburden pressure unlike [109]; default value from Greenland and Antarctic model runs

    Type
    number
    Default value

    0.02 (pure number)

    Option

    -till_effective_fraction_overburden

  75. basal_yield_stress.mohr_coulomb.till_log_factor_transportable_water

    If basal_yield_stress­.add_transportable_water is set then the water amount in the transport system is added to tillwat in determining tauc. Normally only the water in the till is used. This factor multiplies the logarithm in that formula.

    Type
    number
    Default value

    0.1 (meters)

    Option

    -till_log_factor_transportable_water

  76. basal_yield_stress.mohr_coulomb.till_phi_default

    fill value for till friction angle

    Type
    number
    Default value

    30 (degrees)

    Option

    -plastic_phi

  77. basal_yield_stress.mohr_coulomb.till_reference_effective_pressure

    reference effective pressure \(N_0\); value from [109]

    Type
    number
    Default value

    1000 (Pascal)

  78. basal_yield_stress.mohr_coulomb.till_reference_void_ratio

    void ratio at reference effective pressure \(N_0\); value from [109]

    Type
    number
    Default value

    0.69 (pure number)

    Option

    -till_reference_void_ratio

  79. basal_yield_stress.mohr_coulomb.tillphi_opt.dhdt_min

    rate of change in the surface elevation mismatch \(D\) used as a convergence criterion

    Type
    number
    Default value

    0.001 (meters year-1)

    Option

    -tillphi_opt_dhdt_min

  80. basal_yield_stress.mohr_coulomb.tillphi_opt.dphi_max

    maximum till friction angle adjustment \(\dphimax\)

    Type
    number
    Default value

    1 (degrees)

    Option

    -tillphi_opt_dphi_max

  81. basal_yield_stress.mohr_coulomb.tillphi_opt.dphi_scale

    scaling factor \(C\) used to compute the \(\Delta \phi\) adjustment, \(C\) degrees per meter of surface elevation mismatch

    Type
    number
    Default value

    0.002 (degree / meters)

    Option

    -tillphi_opt_dphi_scale

  82. basal_yield_stress.mohr_coulomb.tillphi_opt.dt

    time step \(\dt_{\phi}\) for optimization of till friction angle

    Type
    number
    Default value

    250 (365days)

    Option

    -tillphi_opt_dt

  83. basal_yield_stress.mohr_coulomb.tillphi_opt.file

    Name of the file containing the time-independent variable usurf used as target surface elevation

    Type
    string
    Default value

    empty

    Option

    -tillphi_opt_file

  84. basal_yield_stress.mohr_coulomb.tillphi_opt.phi0_max

    maximum value of the lower bound of the till friction angle, \(\phi_{0,\mathrm{max}}\)

    Type
    number
    Default value

    5 (degrees)

    Option

    -tillphi_opt_phi0_max

  85. basal_yield_stress.mohr_coulomb.tillphi_opt.phi0_min

    minimum value of the lower bound of the till friction angle, \(\phi_{0,\mathrm{min}}\)

    Type
    number
    Default value

    2 (degrees)

    Option

    -tillphi_opt_phi0_min

  86. basal_yield_stress.mohr_coulomb.tillphi_opt.phi_max

    upper bound of the till friction angle \(\phimax\)

    Type
    number
    Default value

    70 (degrees)

    Option

    -tillphi_opt_phi_max

  87. basal_yield_stress.mohr_coulomb.tillphi_opt.topg_max

    the bed elevation \(\bmax\) above which basal_yield_stress­.mohr_coulomb­.tillphi_opt­.phi0_max is used

    Type
    number
    Default value

    700 (meters)

    Option

    -tillphi_opt_topg_max

  88. basal_yield_stress.mohr_coulomb.tillphi_opt.topg_min

    the bed elevation \(\bmin\) below which basal_yield_stress­.mohr_coulomb­.tillphi_opt­.phi0_min is used

    Type
    number
    Default value

    -300 (meters)

    Option

    -tillphi_opt_topg_min

  89. basal_yield_stress.mohr_coulomb.topg_to_phi.enabled

    If the option -topg_to_phi is set then this will be set to “yes”, and then MohrCoulombYieldStress will initialize the tillphi field using a piece-wise linear function of depth described by four parameters.

    Type
    flag
    Default value

    no

  90. basal_yield_stress.mohr_coulomb.topg_to_phi.phi_max

    upper value of the till friction angle; see the implementation of MohrCoulombYieldStress

    Type
    number
    Default value

    15 (degrees)

  91. basal_yield_stress.mohr_coulomb.topg_to_phi.phi_min

    lower value of the till friction angle; see the implementation of MohrCoulombYieldStress

    Type
    number
    Default value

    5 (degrees)

  92. basal_yield_stress.mohr_coulomb.topg_to_phi.topg_max

    the elevation at which the upper value of the till friction angle is used; see the implementation of MohrCoulombYieldStress

    Type
    number
    Default value

    1000 (meters)

  93. basal_yield_stress.mohr_coulomb.topg_to_phi.topg_min

    the elevation at which the lower value of the till friction angle is used; see the implementation of MohrCoulombYieldStress

    Type
    number
    Default value

    -1000 (meters)

  94. basal_yield_stress.slippery_grounding_lines

    If yes, at icy grounded locations with bed elevations below sea level, within one cell of floating ice or ice-free ocean, make tauc as low as possible from the Mohr-Coulomb relation. Specifically, at such locations replace the normally-computed tauc from the Mohr-Coulomb relation, which uses the effective pressure from the modeled amount of water in the till, by the minimum value of tauc from Mohr-Coulomb, i.e. by using the effective pressure corresponding to the maximum amount of till-stored water. Does not alter the modeled or reported amount of till water, nor does this mechanism affect water conservation.

    Type
    flag
    Default value

    no

    Option

    -tauc_slippery_grounding_lines

  95. bed_deformation.bed_topography_delta_file

    The name of the file to read the topg_delta from. This field is added to the bed topography during initialization.

    Type
    string
    Default value

    empty

    Option

    -topg_delta_file

  96. bed_deformation.bed_uplift_file

    The name of the file to read the uplift (dbdt) from. Leave empty to read it from an input file or a regridding file.

    Type
    string
    Default value

    empty

    Option

    -uplift_file

  97. bed_deformation.given.file

    Name of the file containing time-dependent topg_delta.

    Type
    string
    Default value

    empty

    Option

    -topg_delta_file

  98. bed_deformation.given.reference_file

    Name of the file containing the reference bed topography topg.

    Type
    string
    Default value

    empty

    Option

    -topg_reference_file

  99. bed_deformation.lc.elastic_model

    Use the elastic part of the Lingle-Clark bed deformation model.

    Type
    flag
    Default value

    yes

    Option

    -bed_def_lc_elastic_model

  100. bed_deformation.lc.grid_size_factor

    The spectral grid size is (Z*(grid.Mx - 1) + 1, Z*(grid.My - 1) + 1) where Z is given by this parameter. See [112], [27].

    Type
    integer
    Default value

    4 (count)

  101. bed_deformation.lc.update_interval

    Interval between updates of the Lingle-Clark model

    Type
    number
    Default value

    10 (365days)

  102. bed_deformation.lithosphere_flexural_rigidity

    lithosphere flexural rigidity used by the bed deformation model. See [112], [27]

    Type
    number
    Default value

    5e+24 (Newton meter)

  103. bed_deformation.mantle_density

    half-space (mantle) density used by the bed deformation model. See [112], [27]

    Type
    number
    Default value

    3300 (kg meter-3)

  104. bed_deformation.mantle_viscosity

    half-space (mantle) viscosity used by the bed deformation model. See [112], [27]

    Type
    number
    Default value

    1e+21 (Pascal second)

  105. bed_deformation.model

    Selects a bed deformation model to use. iso is point-wise isostasy, lc is the Lingle-Clark model (see [112], requires FFTW), given uses prescribed bed topography changes read from a file.

    Type
    keyword
    Default value

    none

    Choices

    none, iso, lc, given

    Option

    -bed_def

  106. bootstrapping.defaults.bed

    bed elevation value to use if topg (bedrock_altitude) variable is absent in bootstrapping file

    Type
    number
    Default value

    1 (meters)

  107. bootstrapping.defaults.bmelt

    basal melt rate value to use if variable bmelt is absent in bootstrapping file

    Type
    number
    Default value

    0 (meter / second)

  108. bootstrapping.defaults.bwat

    till water thickness value to use if variable tillwat is absent in bootstrapping file

    Type
    number
    Default value

    0 (meters)

  109. bootstrapping.defaults.bwp

    basal water pressure value to use if variable bwp is absent in bootstrapping file; most hydrology models do not use this value because bwp is diagnostic

    Type
    number
    Default value

    0 (Pascal)

  110. bootstrapping.defaults.enwat

    effective englacial water thickness value to use if variable enwat is absent in bootstrapping file

    Type
    number
    Default value

    0 (meters)

  111. bootstrapping.defaults.geothermal_flux

    geothermal flux value to use if bheatflx variable is absent in bootstrapping file

    Type
    number
    Default value

    0.042 (Watt meter-2)

  112. bootstrapping.defaults.ice_thickness

    thickness value to use if thk (land_ice_thickness) variable is absent in bootstrapping file

    Type
    number
    Default value

    0 (meters)

  113. bootstrapping.defaults.tillwat

    till water thickness value to use if variable tillwat is absent in bootstrapping file

    Type
    number
    Default value

    0 (meters)

  114. bootstrapping.defaults.uplift

    uplift value to use if dbdt variable is absent in bootstrapping file

    Type
    number
    Default value

    0 (meter / second)

  115. bootstrapping.temperature_heuristic

    The heuristic to use to initialize ice temperature during bootstrapping: smb uses the surface mass balance, surface temperature, and the geothermal flux, quartic_guess uses the surface temperature and the geothermal flux.

    Type
    keyword
    Default value

    smb

    Choices

    smb, quartic_guess

    Option

    -boot_temperature_heuristic

  116. calving.eigen_calving.K

    Set proportionality constant to determine calving rate from strain rates. Note references [89], [3] use K in range \(10^{9}\) to \(3 \times 10^{11}\) m a, that is, \(3 \times 10^{16}\) to \(10^{19}\) m s.

    Type
    number
    Default value

    0 (meter second)

    Option

    -eigen_calving_K

  117. calving.float_kill.calve_near_grounding_line

    Calve floating ice near the grounding line.

    Type
    flag
    Default value

    yes

    Option

    -float_kill_calve_near_grounding_line

  118. calving.float_kill.margin_only

    Apply float_kill at ice margin cells only.

    Type
    flag
    Default value

    no

    Option

    -float_kill_margin_only

  119. calving.hayhurst_calving.B_tilde

    Effective damage rate [91]

    Type
    number
    Default value

    65 ((MPa)^r / year)

  120. calving.hayhurst_calving.exponent_r

    Damage law exponent [91]

    Type
    number
    Default value

    0.43 (1)

  121. calving.hayhurst_calving.sigma_threshold

    Damage threshold stress [91]

    Type
    number
    Default value

    0.17 (MPa)

  122. calving.methods

    comma-separated list of calving methods; one or more of eigen_calving, float_kill, thickness_calving

    Type
    string
    Default value

    empty

    Option

    -calving

  123. calving.rate_scaling.file

    File containing the scaling factor applied to calving rates from eigen_calving, vonmises_calving, and hayhurst_calving (variable name: frac_calving_rate)

    Type
    string
    Default value

    empty

  124. calving.rate_scaling.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  125. calving.thickness_calving.file

    Name of the file containing the spatially-variable thickness calving threshold.

    Type
    string
    Default value

    empty

    Option

    -thickness_calving_file

  126. calving.thickness_calving.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  127. calving.thickness_calving.threshold

    When terminal ice thickness of floating ice shelf is less than this threshold, it will be calved off.

    Type
    number
    Default value

    50 (meters)

    Option

    -thickness_calving_threshold

  128. calving.vonmises_calving.Glen_exponent

    Glen exponent in ice flow law for von Mises calving

    Type
    number
    Default value

    3 (pure number)

    Option

    -vonmises_calving_n

  129. calving.vonmises_calving.flow_law

    The custom flow law for the von Mises stress computation

    Type
    keyword
    Default value

    gpbld

    Choices

    arr, arrwarm, gpbld, hooke, isothermal_glen, pb

  130. calving.vonmises_calving.sigma_max

    Set maximum tensile stress. Note references [90] use 1.0e6 Pa.

    Type
    number
    Default value

    1e+06 (Pa)

    Option

    -vonmises_calving_calving_sigma_max

  131. calving.vonmises_calving.threshold_file

    Name of the file containing the spatially-variable vonmises_calving_threshold.

    Type
    string
    Default value

    empty

    Option

    -vonmises_calving_threshold_file

  132. calving.vonmises_calving.use_custom_flow_law

    Use custom flow law in the von Mises stress computation

    Type
    flag
    Default value

    no

    Option

    -vonmises_calving_use_custom_flow_law

  133. constants.fresh_water.density

    density of fresh water

    Type
    number
    Default value

    1000 (kg meter-3)

  134. constants.fresh_water.latent_heat_of_fusion

    latent heat of fusion for water [75]

    Type
    number
    Default value

    334000 (Joule / kg)

  135. constants.fresh_water.melting_point_temperature

    melting point of pure water

    Type
    number
    Default value

    273.15 (Kelvin)

  136. constants.fresh_water.specific_heat_capacity

    at melting point T_0 [75]

    Type
    number
    Default value

    4170 (Joule / (kg Kelvin))

  137. constants.global_ocean_area

    area of the global ocean [118]

    Type
    number
    Default value

    3.625e+14 (meter2)

  138. constants.ice.beta_Clausius_Clapeyron

    Clausius-Clapeyron constant relating melting temperature and pressure: \(\beta = dT / dP\) [24]

    Type
    number
    Default value

    7.9e-08 (Kelvin / Pascal)

  139. constants.ice.density

    \(\rho_i\); density of ice in ice sheet

    Type
    number
    Default value

    910 (kg meter-3)

  140. constants.ice.grain_size

    Default constant ice grain size to use with the Goldsby-Kohlstedt [25] flow law

    Type
    number
    Default value

    1 (mm)

    Option

    -ice_grain_size

  141. constants.ice.specific_heat_capacity

    specific heat capacity of pure ice at melting point T_0

    Type
    number
    Default value

    2009 (Joule / (kg Kelvin))

  142. constants.ice.thermal_conductivity

    = W m-1 K-1; thermal conductivity of pure ice

    Type
    number
    Default value

    2.1 (Joule / (meter Kelvin second))

  143. constants.ideal_gas_constant

    ideal gas constant

    Type
    number
    Default value

    8.31441 (Joule / (mol Kelvin))

  144. constants.sea_water.density

    density of sea water

    Type
    number
    Default value

    1028 (kg meter-3)

  145. constants.sea_water.salinity

    salinity of sea water

    Type
    number
    Default value

    35 (g / kg)

  146. constants.sea_water.specific_heat_capacity

    at 35 psu, value taken from Kaye and Laby, section 2.7.9

    Type
    number
    Default value

    3985 (Joule / (kg Kelvin))

  147. constants.standard_gravity

    acceleration due to gravity on Earth geoid

    Type
    number
    Default value

    9.81 (meter second-2)

  148. energy.allow_temperature_above_melting

    If set to “yes”, allow temperatures above the pressure-malting point in the cold mode temperature code. Used by some verifiaction tests.

    Type
    flag
    Default value

    no

  149. energy.basal_melt.use_grounded_cell_fraction

    If geometry.grounded_cell_fraction is set, use the fractional floatation mask to interpolate the basal melt rate at the grounding line between grounded and floating values.

    Type
    flag
    Default value

    true

    Option

    -subgl_basal_melt

  150. energy.bedrock_thermal.conductivity

    = W m-1 K-1; for bedrock used in thermal model [7]

    Type
    number
    Default value

    3 (Joule / (meter Kelvin second))

  151. energy.bedrock_thermal.density

    for bedrock used in thermal model

    Type
    number
    Default value

    3300 (kg meter-3)

  152. energy.bedrock_thermal.file

    Name of the file containing the geothermal flux field bheatflx. Leave empty to read it from the input­.file.

    Type
    string
    Default value

    empty

  153. energy.bedrock_thermal.specific_heat_capacity

    for bedrock used in thermal model [7]

    Type
    number
    Default value

    1000 (Joule / (kg Kelvin))

  154. energy.ch_warming.average_channel_spacing

    Average spacing between elements of the cryo-hydrologic system (controls the rate of heat transfer from the CH system into the ice).

    Type
    number
    Default value

    20 (meters)

  155. energy.ch_warming.enabled

    Enable the cryo-hydrologic warming model

    Type
    flag
    Default value

    no

  156. energy.ch_warming.residual_water_fraction

    residual water fraction in the cryo-hydrologic system at the end of a melt season

    Type
    number
    Default value

    0.005 (pure number)

  157. energy.ch_warming.temperate_ice_thermal_conductivity_ratio

    ratio of thermal conductivities of temperate and cold ice in the cryo-hydrologic system

    Type
    number
    Default value

    1 (pure number)

  158. energy.drainage_maximum_rate

    0.05 year-1; maximum rate at which liquid water fraction in temperate ice could possibly drain; see [35]

    Type
    number
    Default value

    1.58444e-09 (second-1)

  159. energy.drainage_target_water_fraction

    liquid water fraction (omega) above which drainage occurs, but below which there is no drainage; see [35]

    Type
    number
    Default value

    0.01 (1)

  160. energy.enabled

    Solve energy conservation equations.

    Type
    flag
    Default value

    yes

  161. energy.enthalpy.cold_bulge_max

    = (2009 J kg-1 K-1) * (30 K); maximum amount by which advection can reduce the enthalpy of a column of ice below its surface enthalpy value

    Type
    number
    Default value

    60270 (Joule / kg)

  162. energy.enthalpy.temperate_ice_thermal_conductivity_ratio

    K in cold ice is multiplied by this fraction to give K0 in [35]

    Type
    number
    Default value

    0.1 (pure number)

  163. energy.margin_exclude_horizontal_advection

    Exclude horizontal advection of energy at grid points near ice margins. See energy­.margin_ice_thickness_limit.

    Type
    flag
    Default value

    yes

  164. energy.margin_exclude_strain_heating

    Exclude strain heating at grid points near ice margins. See energy­.margin_ice_thickness_limit.

    Type
    flag
    Default value

    yes

  165. energy.margin_exclude_vertical_advection

    Exclude vertical advection of energy at grid points near ice margins. See energy­.margin_ice_thickness_limit.

    Type
    flag
    Default value

    yes

  166. energy.margin_ice_thickness_limit

    use special margin treatment at grid points with a neighbor with the thickness below this limit.

    Type
    number
    Default value

    100 (meters)

  167. energy.max_low_temperature_count

    Maximum number of grid points with ice temperature below energy.minimum_allowed_temperature.

    Type
    integer
    Default value

    10 (count)

    Option

    -max_low_temps

  168. energy.minimum_allowed_temperature

    Minimum allowed ice temperature

    Type
    number
    Default value

    200 (Kelvin)

    Option

    -low_temp

  169. energy.temperature_based

    Use cold ice (i.e. not polythermal) methods.

    Type
    flag
    Default value

    no

  170. energy.temperature_dependent_thermal_conductivity

    If yes, use varkenthSystemCtx class in the energy step. It is base on formula (4.37) in [56]. Otherwise use enthSystemCtx, which has temperature-independent thermal conductivity set by constant ice.thermal_conductivity.

    Type
    flag
    Default value

    no

    Option

    -vark

  171. enthalpy_converter.T_reference

    = T_0 in enthalpy formulas in [35]

    Type
    number
    Default value

    223.15 (Kelvin)

  172. enthalpy_converter.relaxed_is_temperate_tolerance

    Tolerance within which ice is treated as temperate (cold-ice mode and diagnostics).

    Type
    number
    Default value

    0.001 (Kelvin)

  173. flow_law.Hooke.A

    \(A_{\text{Hooke}} = (1/B_0)^n\) where n=3 and \(B_0\) = 1.928 \(a^{1/3}\) Pa. See [79]

    Type
    number
    Default value

    4.42165e-09 (Pascal-3 second-1)

  174. flow_law.Hooke.C

    See [79]

    Type
    number
    Default value

    0.16612 (Kelvin^k)

  175. flow_law.Hooke.Q

    Activation energy, see [79]

    Type
    number
    Default value

    78800 (Joule / mol)

  176. flow_law.Hooke.Tr

    See [79]

    Type
    number
    Default value

    273.39 (Kelvin)

  177. flow_law.Hooke.k

    See [79]

    Type
    number
    Default value

    1.17 (pure number)

  178. flow_law.Paterson_Budd.A_cold

    Paterson-Budd \(A_\text{cold}\), see [76]

    Type
    number
    Default value

    3.61e-13 (Pascal-3 / second)

  179. flow_law.Paterson_Budd.A_warm

    Paterson-Budd \(A_\text{warm}\), see [76]

    Type
    number
    Default value

    1730 (Pascal-3 / second)

  180. flow_law.Paterson_Budd.Q_cold

    Paterson-Budd \(Q_\text{cold}\), see [76]

    Type
    number
    Default value

    60000 (Joule / mol)

  181. flow_law.Paterson_Budd.Q_warm

    Paterson-Budd \(Q_\text{warm}\), see [76]

    Type
    number
    Default value

    139000 (Joule / mol)

  182. flow_law.Paterson_Budd.T_critical

    Paterson-Budd critical temperature, see [76]

    Type
    number
    Default value

    263.15 (Kelvin)

  183. flow_law.Schoof_regularizing_length

    Regularizing length (Schoof definition)

    Type
    number
    Default value

    1000 (km)

  184. flow_law.Schoof_regularizing_velocity

    Regularizing velocity (Schoof definition)

    Type
    number
    Default value

    1 (meter / year)

  185. flow_law.gpbld.water_frac_coeff

    coefficient in Glen-Paterson-Budd flow law for extra dependence of softness on liquid water fraction (omega) [56], [77]

    Type
    number
    Default value

    181.25 (pure number)

  186. flow_law.gpbld.water_frac_observed_limit

    maximum value of liquid water fraction omega for which softness values are parameterized by [77]; used in Glen-Paterson-Budd-Lliboutry-Duval flow law; compare [35]

    Type
    number
    Default value

    0.01 (1)

  187. flow_law.isothermal_Glen.ice_softness

    ice softness used by the isothermal Glen flow law [34]

    Type
    number
    Default value

    3.1689e-24 (Pascal-3 second-1)

  188. fracture_density.borstad_limit

    Model fracture growth according to the constitutive law in [96] (Eq. 4), ignoring fracture_density­.gamma.

    Type
    flag
    Default value

    no

    Option

    -constitutive_stress_limit

  189. fracture_density.constant_fd

    Keep fracture density fields constant in time but include its softening effect.

    Type
    flag
    Default value

    no

    Option

    -constant_fd

  190. fracture_density.constant_healing

    Use a constant healing rate \(-\gamma_h \dot{\epsilon}_h\) independent of the local strain rate.

    Type
    flag
    Default value

    no

    Option

    -constant_healing

  191. fracture_density.enabled

    Model the fracture density using computed to stresses and strain rates.

    Type
    flag
    Default value

    no

    Option

    -fractures

  192. fracture_density.fd2d_scheme

    Use an alternative transport scheme to reduce numerical diffusion (Eq. 10 in [95])

    Type
    flag
    Default value

    no

    Option

    -scheme_fd2d

  193. fracture_density.fracture_weighted_healing

    Multiply the healing rate by \(1 - D\), i.e. assume that highly damaged ice heals slower. This mechanism can be combined with fracture_density­.constant_healing.

    Type
    flag
    Default value

    no

    Option

    -fracture_weighted_healing

  194. fracture_density.gamma

    fracture growth constant \(\gamma\)

    Type
    number
    Default value

    1 (1)

    Option

    -fracture_gamma

  195. fracture_density.gamma_h

    fracture healing constant \(\gamma_{h}\)

    Type
    number
    Default value

    0 (1)

    Option

    -fracture_gamma_h

  196. fracture_density.healing_threshold

    fracture healing strain rate threshold \(\dot \epsilon_{h}\)

    Type
    number
    Default value

    2e-10 (1/s)

    Option

    -fracture_healing_threshold

  197. fracture_density.include_grounded_ice

    Model fracture density in grounded areas (e.g. along ice stream shear zones) in addition to ice shelves

    Type
    flag
    Default value

    no

    Option

    -do_frac_on_grounded

  198. fracture_density.initiation_threshold

    fracture initiation stress threshold \(\sigma_{\text{cr}}\)

    Type
    number
    Default value

    70000 (Pa)

    Option

    -fracture_initiation_threshold

  199. fracture_density.lefm

    Use the mixed-mode fracture toughness stress criterion based on Linear Elastic Fracture Mechanics, Eqs. 8-9 in [95]

    Type
    flag
    Default value

    no

    Option

    -lefm

  200. fracture_density.max_shear_stress

    Use the maximum shear stress criterion for fracture formation (Tresca or Guest criterion in literature), which is more stringent than the default von Mises criterion, see Eq. 7 in [95]

    Type
    flag
    Default value

    no

    Option

    -max_shear

  201. fracture_density.phi0

    Fracture density value used at grid points where ice velocity is prescribed. This assumes that all ice entering a shelf at bc_mask locations has the same fracture density.

    Type
    number
    Default value

    0 (1)

    Option

    -phi0

  202. fracture_density.softening_lower_limit

    Parameter controlling the strength of the feedback of damage on the ice flow. If \(1\): no feedback, if \(0\): full feedback (\(\epsilon\) in Eq. 6 in [95])

    Type
    number
    Default value

    1 (1)

    Option

    -fracture_softening

  203. frontal_melt.constant.melt_rate

    default melt rate used by the constant frontal_melt model

    Type
    number
    Default value

    1 (m / day)

    Option

    -frontal_melt_rate

  204. frontal_melt.discharge_given.file

    Name of the file containing climate forcing fields.

    Type
    string
    Default value

    empty

    Option

    -frontal_melt_discharge_given_file

  205. frontal_melt.discharge_given.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  206. frontal_melt.given.file

    Name of the file containing climate forcing fields.

    Type
    string
    Default value

    empty

    Option

    -frontal_melt_given_file

  207. frontal_melt.given.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  208. frontal_melt.include_floating_ice

    Apply frontal melt to all grid icy cells next to ocean cells

    Type
    flag
    Default value

    no

  209. frontal_melt.models

    Comma-separated list of frontal melt models and modifiers. (Leave empty to disable.)

    Type
    string
    Default value

    empty

    Option

    -frontal_melt

  210. frontal_melt.routing.file

    Name of the file containing climate forcing fields.

    Type
    string
    Default value

    empty

    Option

    -frontal_melt_routing_file

  211. frontal_melt.routing.parameter_a

    parameter A in eqn. 1 in [119]

    Type
    number
    Default value

    0.0003 (m-alpha day^(alpha-1) Celsius-beta)

  212. frontal_melt.routing.parameter_b

    parameter B in eqn. 1 in [119]

    Type
    number
    Default value

    0.15 (m day^(alpha-1) Celsius-beta)

  213. frontal_melt.routing.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  214. frontal_melt.routing.power_alpha

    exponent \(\alpha\) in eqn. 1 in [119]

    Type
    number
    Default value

    0.39 (1)

  215. frontal_melt.routing.power_beta

    exponent \(\beta\) in eqn. 1 in [119]

    Type
    number
    Default value

    1.18 (1)

  216. geometry.front_retreat.prescribed.file

    Name of the file containing the maximum ice extent mask land_ice_area_fraction_retreat

    Type
    string
    Default value

    empty

    Option

    -front_retreat_file

  217. geometry.front_retreat.prescribed.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  218. geometry.front_retreat.use_cfl

    apply CFL criterion for eigen-calving rate front retreat

    Type
    flag
    Default value

    false

    Option

    -front_retreat_cfl

  219. geometry.front_retreat.wrap_around

    If true, wrap around domain boundaries. This may be needed in some regional synthetic geometry setups.

    Type
    flag
    Default value

    false

    Option

    -front_retreat_wrap_around

  220. geometry.grounded_cell_fraction

    Linear interpolation scheme (“LI” in Gladstone et al. 2010) expanded to two dimensions is used if switched on in order to evaluate the position of the grounding line on a subgrid scale.

    Type
    flag
    Default value

    false

    Option

    -subgl

  221. geometry.ice_free_thickness_standard

    If ice is thinner than this standard then the mask is set to MASK_ICE_FREE_BEDROCK or MASK_ICE_FREE_OCEAN.

    Type
    number
    Default value

    0.01 (meters)

  222. geometry.part_grid.enabled

    apply partially filled grid cell scheme

    Type
    flag
    Default value

    no

    Option

    -part_grid

  223. geometry.part_grid.max_iterations

    maximum number of residual redistribution iterations

    Type
    integer
    Default value

    10 (count)

  224. geometry.remove_icebergs

    identify and kill detached ice-shelf areas

    Type
    flag
    Default value

    no

    Option

    -kill_icebergs

  225. geometry.update.enabled

    Solve the mass conservation equation

    Type
    flag
    Default value

    yes

    Option

    -mass

  226. geometry.update.use_basal_melt_rate

    Include basal melt rate in the continuity equation

    Type
    flag
    Default value

    yes

    Option

    -bmr_in_cont

  227. grid.Lbz

    Thickness of the thermal bedrock layer. (Inactive if grid­.Mbz < 2)

    Type
    number
    Default value

    1000 (meters)

    Option

    -Lbz

  228. grid.Lx

    Default computational box is 3000 km x 3000 km (= 2 Lx x 2 Ly) in horizontal.

    Type
    number
    Default value

    1.5e+06 (meters)

  229. grid.Ly

    Default computational box is 3000 km x 3000 km (= 2 Lx x 2 Ly) in horizontal.

    Type
    number
    Default value

    1.5e+06 (meters)

  230. grid.Lz

    Height of the computational domain.

    Type
    number
    Default value

    4000 (meters)

    Option

    -Lz

  231. grid.Mbz

    Number of thermal bedrock layers; 1 level corresponds to no bedrock.

    Type
    integer
    Default value

    1 (count)

    Option

    -Mbz

  232. grid.Mx

    Number of grid points in the x direction.

    Type
    integer
    Default value

    61 (count)

    Option

    -Mx

  233. grid.My

    Number of grid points in the y direction.

    Type
    integer
    Default value

    61 (count)

    Option

    -My

  234. grid.Mz

    Number of vertical grid levels in the ice.

    Type
    integer
    Default value

    31 (count)

    Option

    -Mz

  235. grid.allow_extrapolation

    Allow extrapolation during regridding.

    Type
    flag
    Default value

    no

    Option

    -allow_extrapolation

  236. grid.ice_vertical_spacing

    vertical spacing in the ice

    Type
    keyword
    Default value

    quadratic

    Choices

    quadratic, equal

    Option

    -z_spacing

  237. grid.lambda

    Vertical grid spacing parameter. Roughly equal to the factor by which the grid is coarser at an end away from the ice-bedrock interface.

    Type
    number
    Default value

    4 (pure number)

  238. grid.max_stencil_width

    Maximum width of the finite-difference stencil used in PISM.

    Type
    integer
    Default value

    2 (count)

  239. grid.periodicity

    horizontal grid periodicity

    Type
    keyword
    Default value

    xy

    Choices

    none, x, y, xy

    Option

    -periodicity

  240. grid.recompute_longitude_and_latitude

    Re-compute longitude and latitude using grid information and provided projection parameters. Requires PROJ.

    Type
    flag
    Default value

    yes

  241. grid.registration

    horizontal grid registration

    Type
    keyword
    Default value

    center

    Choices

    center, corner

  242. hydrology.add_water_input_to_till_storage

    Add surface input to water stored in till. If no it will be added to the transportable water.

    Type
    flag
    Default value

    yes

  243. hydrology.cavitation_opening_coefficient

    c_1 in notes; coefficient of cavitation opening term in evolution of layer thickness in hydrology::Distributed

    Type
    number
    Default value

    0.5 (meter-1)

    Option

    -hydrology_cavitation_opening_coefficient

  244. hydrology.creep_closure_coefficient

    c_2 in notes; coefficient of creep closure term in evolution of layer thickness in hydrology::Distributed

    Type
    number
    Default value

    0.04 (pure number)

    Option

    -hydrology_creep_closure_coefficient

  245. hydrology.distributed.init_p_from_steady

    if “yes”, initialize subglacial water pressure from P(W) formula that applies in steady state

    Type
    flag
    Default value

    no

    Option

    -hydrology_init_p_form_steady

  246. hydrology.distributed.sliding_speed_file

    name of the file containing velbase_mag, the basal sliding speed to use with hydrology.distributed.init_p_from_steady

    Type
    string
    Default value

    empty

    Option

    -hydrology_sliding_speed_file

  247. hydrology.gradient_power_in_flux

    power \(\beta\) in Darcy’s law \(q = - k W^{\alpha} |\nabla \psi|^{\beta-2} \nabla \psi\), for subglacial water layer; used by hydrology::Routing and hydrology::Distributed

    Type
    number
    Default value

    1.5 (pure number)

    Option

    -hydrology_gradient_power_in_flux

  248. hydrology.hydraulic_conductivity

    = k in notes; lateral conductivity, in Darcy’s law, for subglacial water layer; units depend on powers alpha = hydrology.thickness_power_in_flux and beta = hydrology_potential_gradient_power_in_flux; used by hydrology::Routing and hydrology::Distributed

    Type
    number
    Default value

    0.001 (`m^{2 \beta - \alpha} s^{2 \beta - 3} kg^{1-\beta}`)

    Option

    -hydrology_hydraulic_conductivity

  249. hydrology.maximum_time_step

    maximum allowed time step length used by hydrology::Routing and hydrology::Distributed

    Type
    number
    Default value

    1 (365days)

  250. hydrology.model

    Basal hydrology sub-model.

    Type
    keyword
    Default value

    null

    Choices

    null, routing, steady, distributed

    Option

    -hydrology

  251. hydrology.null_diffuse_till_water

    Diffuse stored till water laterally. See equation (11) of [29]

    Type
    flag
    Default value

    no

  252. hydrology.null_diffusion_distance

    diffusion distance for till water thickness; see equation (11) in [29]; only active if hydrology.null_diffuse_till_water is set

    Type
    number
    Default value

    20000 (meters)

  253. hydrology.null_diffusion_time

    diffusion time for till water thickness; see equation (11) in [29]; only active if hydrology.null_diffuse_till_water is set

    Type
    number
    Default value

    1000 (365days)

  254. hydrology.null_strip_width

    if negative then mechanism is inactive; width of strip around computational domain in which water velocity and water amount are set to zero; used by hydrology::Routing and hydrology::Distributed

    Type
    number
    Default value

    -1 (meters)

  255. hydrology.regularizing_porosity

    phi_0 in notes; regularizes pressure equation by multiplying time derivative term

    Type
    number
    Default value

    0.01 (pure number)

    Option

    -hydrology_regularizing_porosity

  256. hydrology.roughness_scale

    W_r in notes; roughness scale determining maximum amount of cavitation opening in hydrology::Distributed

    Type
    number
    Default value

    0.1 (meters)

    Option

    -hydrology_roughness_scale

  257. hydrology.routing.include_floating_ice

    Route subglacial water under ice shelves. This may be appropriate if a shelf is close to floatation. Note that this has no effect on ice flow.

    Type
    flag
    Default value

    no

  258. hydrology.steady.flux_update_interval

    interval between updates of the steady state flux

    Type
    number
    Default value

    1 (365days)

  259. hydrology.steady.input_rate_scaling

    input rate scaling

    Type
    number
    Default value

    1e+07 (seconds)

  260. hydrology.steady.n_iterations

    maxinum number of iterations to use in while estimating steady-state water flux

    Type
    integer
    Default value

    7500 (count)

  261. hydrology.steady.potential_delta

    potential adjustment used to fill sinks (smaller values require more iterations but produce fewer artifacts)

    Type
    number
    Default value

    10000 (Pa)

  262. hydrology.steady.potential_n_iterations

    maxinum number of iterations to take while pre-processing hydraulic potential

    Type
    integer
    Default value

    1000 (count)

  263. hydrology.steady.volume_ratio

    water volume ratio used as the stopping criterion

    Type
    number
    Default value

    0.1 (1)

  264. hydrology.surface_input.file

    Name of the file containing water_input_rate, the rate at which water from the ice surface is added to the subglacial hydrology system

    Type
    string
    Default value

    empty

  265. hydrology.surface_input.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  266. hydrology.surface_input_from_runoff

    Use surface runoff as surface input.

    Type
    flag
    Default value

    no

  267. hydrology.thickness_power_in_flux

    power \(\alpha\) in Darcy’s law \(q = - k W^{\alpha} |\nabla \psi|^{\beta-2} \nabla \psi\), for subglacial water layer; used by hydrology::Routing and hydrology::Distributed

    Type
    number
    Default value

    1.25 (1)

    Option

    -hydrology_thickness_power_in_flux

  268. hydrology.tillwat_decay_rate

    rate at which tillwat is reduced to zero, in absence of other effects like input

    Type
    number
    Default value

    1 (mm / year)

    Option

    -hydrology_tillwat_decay_rate

  269. hydrology.tillwat_max

    maximum effective thickness of the water stored in till

    Type
    number
    Default value

    2 (meters)

    Option

    -hydrology_tillwat_max

  270. hydrology.use_const_bmelt

    if “yes”, subglacial hydrology model sees basal melt rate which is constant and given by hydrology.const_bmelt

    Type
    flag
    Default value

    no

    Option

    -hydrology_use_const_bmelt

  271. input.bootstrap

    It true, use bootstrapping heuristics when initializing PISM.

    Type
    flag
    Default value

    no

    Option

    -bootstrap

  272. input.file

    Input file name

    Type
    string
    Default value

    empty

    Option

    -i

  273. input.forcing.buffer_size

    number of 2D climate forcing records to keep in memory; = 5 years of monthly records

    Type
    integer
    Default value

    60 (count)

  274. input.forcing.time_extrapolation

    If ‘true’, time-dependent forcing inputs are extrapolated in time

    Type
    flag
    Default value

    false

  275. input.regrid.file

    Regridding (input) file name

    Type
    string
    Default value

    empty

    Option

    -regrid_file

  276. input.regrid.vars

    Comma-separated list of variables to regrid. Leave empty to regrid all model state variables.

    Type
    string
    Default value

    empty

    Option

    -regrid_vars

  277. inverse.design.cH1

    weight of derivative part of an H1 norm for inversion design variables

    Type
    number
    Default value

    0 (1)

    Option

    -inv_design_cH1

  278. inverse.design.cL2

    weight of derivative-free part of an H1 norm for inversion design variables

    Type
    number
    Default value

    1 (1)

    Option

    -inv_design_cL2

  279. inverse.design.func

    functional used for inversion design variables

    Type
    keyword
    Default value

    sobolevH1

    Choices

    sobolevH1, tv

    Option

    -inv_design_func

  280. inverse.design.param

    parameterization of design variables used during inversion

    Type
    keyword
    Default value

    exp

    Choices

    ident, trunc, square, exp

    Option

    -inv_design_param

  281. inverse.design.param_hardav_eps

    tiny vertically-averaged hardness used as a substitute for 0 in some tauc parameterizations

    Type
    number
    Default value

    10000 (Pascal second^(1/3))

  282. inverse.design.param_hardav_scale

    typical size of ice hardness

    Type
    number
    Default value

    1e+08 (Pascal second^(1/3))

  283. inverse.design.param_tauc_eps

    tiny yield stress used as a substitute for 0 in some tauc parameterizations

    Type
    number
    Default value

    100 (Pascal)

  284. inverse.design.param_tauc_scale

    typical size of yield stresses

    Type
    number
    Default value

    100000 (Pascal)

  285. inverse.design.param_trunc_hardav0

    transition point of change to linear behaviour for design variable parameterization type trunc

    Type
    number
    Default value

    1e+06 (Pascal second^(1/3))

  286. inverse.design.param_trunc_tauc0

    transition point of change to linear behaviour for design variable parameterization type trunc

    Type
    number
    Default value

    1000 (Pascal)

  287. inverse.log_ratio_scale

    Reference scale for log-ratio functionals

    Type
    number
    Default value

    10 (pure number)

    Option

    -inv_log_ratio_scale

  288. inverse.max_iterations

    maximum iteration count

    Type
    integer
    Default value

    1000 (count)

    Option

    -inv_max_it

  289. inverse.ssa.hardav_max

    Maximum allowed value of hardav for inversions with bound constraints

    Type
    number
    Default value

    1e+10 (Pascal second^(1/3))

  290. inverse.ssa.hardav_min

    Minimum allowed value of hardav for inversions with bound constraints

    Type
    number
    Default value

    0 (Pascal second^(1/3))

  291. inverse.ssa.length_scale

    typical length scale for rescaling derivative norms

    Type
    number
    Default value

    50000 (meters)

  292. inverse.ssa.method

    algorithm to use for SSA inversions

    Type
    keyword
    Default value

    tikhonov_lmvm

    Choices

    sd, nlcg, ign, tikhonov_lmvm, tikhonov_cg, tikhonov_blmvm, tikhonov_lcl, tikhonov_gn

    Option

    -inv_method

  293. inverse.ssa.tauc_max

    Maximum allowed value of tauc for inversions with bound constraints

    Type
    number
    Default value

    5e+07 (Pascal)

  294. inverse.ssa.tauc_min

    Minimum allowed value of tauc for inversions with bound constraints

    Type
    number
    Default value

    0 (Pascal)

  295. inverse.ssa.tv_exponent

    Lebesgue exponent for pseudo-TV norm

    Type
    number
    Default value

    1.2 (pure number)

    Option

    -inv_ssa_tv_exponent

  296. inverse.ssa.velocity_eps

    tiny size of ice velocities during inversion

    Type
    number
    Default value

    0.1 (meter / year)

  297. inverse.ssa.velocity_scale

    typical size of ice velocities expected during inversion

    Type
    number
    Default value

    100 (meter / year)

  298. inverse.state_func

    functional used for inversion design variables

    Type
    keyword
    Default value

    meansquare

    Choices

    meansquare, log_ratio, log_relative

    Option

    -inv_state_func

  299. inverse.target_misfit

    desired root misfit for SSA inversions

    Type
    number
    Default value

    100 (meter / year)

    Option

    -inv_target_misfit

  300. inverse.tikhonov.atol

    absolute threshold for Tikhonov stopping criterion

    Type
    number
    Default value

    1e-10 (meter / year)

    Option

    -tikhonov_atol

  301. inverse.tikhonov.penalty_weight

    penalty parameter for Tikhonov inversion

    Type
    number
    Default value

    1 (1)

    Option

    -tikhonov_penalty

  302. inverse.tikhonov.ptol

    threshold for reaching desired misfit for adaptive Tikhonov algorithms

    Type
    number
    Default value

    0.1 (pure number)

    Option

    -tikhonov_ptol

  303. inverse.tikhonov.rtol

    relative threshold for Tikhonov stopping criterion

    Type
    number
    Default value

    0.05 (1)

    Option

    -tikhonov_rtol

  304. inverse.use_design_prior

    Use prior from inverse data file as initial guess.

    Type
    flag
    Default value

    yes

    Option

    -inv_use_design_prior

  305. inverse.use_zeta_fixed_mask

    Enforce locations where the parameterized design variable should be fixed. (Automatically determined if not provided)

    Type
    flag
    Default value

    yes

    Option

    -inv_use_zeta_fixed_mask

  306. ocean.anomaly.file

    Name of the file containing shelf basal mass flux offset fields.

    Type
    string
    Default value

    empty

    Option

    -ocean_anomaly_file

  307. ocean.anomaly.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  308. ocean.cache.update_interval

    update interval of the cache ocean modifier

    Type
    integer
    Default value

    10 (365days)

    Option

    -ocean_cache_update_interval

  309. ocean.constant.melt_rate

    default melt rate used by the constant ocean model (computed as \(Q / (L \rho_i)\))

    Type
    number
    Default value

    0.0519142 (m / year)

    Option

    -shelf_base_melt_rate

  310. ocean.delta_MBP.file

    Name of the file containing melange back-pressure offsets

    Type
    string
    Default value

    empty

  311. ocean.delta_MBP.melange_thickness

    Melange thickness (assumed to be constant in space and time)

    Type
    number
    Default value

    100 (meters)

    Option

    -melange_thickness

  312. ocean.delta_MBP.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  313. ocean.delta_T.file

    Name of the file containing temperature offsets.

    Type
    string
    Default value

    empty

    Option

    -ocean_delta_T_file

  314. ocean.delta_T.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  315. ocean.delta_mass_flux.file

    Name of the file containing sub-shelf mass flux offsets.

    Type
    string
    Default value

    empty

    Option

    -ocean_delta_mass_flux_file

  316. ocean.delta_mass_flux.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  317. ocean.delta_sl.file

    Name of the file containing sea level offsets.

    Type
    string
    Default value

    empty

    Option

    -ocean_delta_sl_file

  318. ocean.delta_sl.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  319. ocean.delta_sl_2d.file

    Name of the file containing climate forcing fields.

    Type
    string
    Default value

    empty

  320. ocean.delta_sl_2d.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  321. ocean.frac_MBP.file

    Name of the file containing melange back-pressure scaling.

    Type
    string
    Default value

    empty

    Option

    -ocean_frac_MBP_file

  322. ocean.frac_MBP.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  323. ocean.frac_mass_flux.file

    Name of the file containing sub-shelf mass flux scaling.

    Type
    string
    Default value

    empty

    Option

    -ocean_frac_mass_flux_file

  324. ocean.frac_mass_flux.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  325. ocean.given.file

    Name of the file containing climate forcing fields.

    Type
    string
    Default value

    empty

    Option

    -ocean_given_file

  326. ocean.given.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  327. ocean.models

    Comma-separated list of ocean models and modifiers.

    Type
    string
    Default value

    constant

    Option

    -ocean

  328. ocean.pico.continental_shelf_depth

    Specifies the depth up to which oceanic input temperatures and salinities are averaged over the continental shelf areas in front of the ice shelf cavities.

    Type
    number
    Default value

    -800 (meters)

    Option

    -continental_shelf_depth

  329. ocean.pico.exclude_ice_rises

    If set to true, grounding lines of ice rises are excluded in the geometrical routines that determine the ocean boxes; using this option is recommended.

    Type
    flag
    Default value

    yes

    Option

    -exclude_icerises

  330. ocean.pico.file

    Specifies the NetCDF file containing potential temperature (theta_ocean), salinity (salinity_ocean) and ocean basins (basins).

    Type
    string
    Default value

    empty

    Option

    -ocean_pico_file

  331. ocean.pico.heat_exchange_coefficent

    Sets the coefficient for turbulent heat exchange from the ambient ocean across the boundary layer beneath the ice shelf base.

    Type
    number
    Default value

    2e-05 (meters second-1)

    Option

    -gamma_T

  332. ocean.pico.maximum_ice_rise_area

    Specifies an area threshold that separates ice rises from continental regions.

    Type
    number
    Default value

    100000 (km2)

  333. ocean.pico.number_of_boxes

    For each ice shelf the number of ocean boxes is determined by interpolating between 1 and number_of_boxes depending on its size and geometry such that larger ice shelves are resolved with more boxes; a value of 5 is suitable for the Antarctic setup.

    Type
    integer
    Default value

    5 (pure number)

    Option

    -number_of_boxes

  334. ocean.pico.overturning_coefficent

    Sets the overturning strength coefficient.

    Type
    number
    Default value

    1e+06 (meters6 seconds-1 kg-1)

    Option

    -overturning_coeff

  335. ocean.pico.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  336. ocean.pik_melt_factor

    dimensionless tuning parameter in the -ocean pik ocean heat flux parameterization; see [3]

    Type
    number
    Default value

    0.005 (1)

    Option

    -meltfactor_pik

  337. ocean.runoff_to_ocean_melt.b

    parameter B in eqn. 1 in [120]

    Type
    number
    Default value

    0.15 (1)

  338. ocean.runoff_to_ocean_melt.file

    Name of the file containing the delta_T variable used to scale ocean melt

    Type
    string
    Default value

    empty

    Option

    -ocean_runoff_smb

  339. ocean.runoff_to_ocean_melt.power_alpha

    exponent \(\alpha\) in eqn. 1 in [119]

    Type
    number
    Default value

    0.54 (1)

  340. ocean.runoff_to_ocean_melt.power_beta

    exponent \(\beta\) in eqn. 1 in [119]

    Type
    number
    Default value

    1.17 (1)

  341. ocean.sub_shelf_heat_flux_into_ice

    = J meter-2 second-1; naively chosen default value for heat from ocean; see comments in pism::ocean::Constant::shelf_base_mass_flux().

    Type
    number
    Default value

    0.5 (W meter-2)

  342. ocean.th.clip_salinity

    Clip shelf base salinity so that it is in the range [4, 40] k/kg. See [11].

    Type
    flag
    Default value

    yes

    Option

    -clip_shelf_base_salinity

  343. ocean.th.file

    Name of the file containing climate forcing fields.

    Type
    string
    Default value

    empty

    Option

    -ocean_th_file

  344. ocean.th.gamma_S

    Turbulent salt transfer coefficient. See [11].

    Type
    number
    Default value

    5.05e-07 (m s-1)

    Option

    -gamma_T

  345. ocean.th.gamma_T

    Turbulent heat transfer coefficient. See [11].

    Type
    number
    Default value

    0.0001 (m s-1)

    Option

    -gamma_T

  346. ocean.th.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  347. output.ISMIP6

    Follow ISMIP6 conventions (units, variable names, “standard names”) when writing output variables.

    Type
    flag
    Default value

    false

  348. output.ISMIP6_extra_variables

    Comma-separated list of fields reported by models participating in ISMIP6 simulations.

    Type
    string
    Default value

    lithk, orog, topg, hfgeoubed, acabf, libmassbfgr, libmassbffl, dlithkdt, velsurf, zvelsurf, velbase, zvelbase, velmean, litemptop, litempbotgr, litempbotfl, strbasemag, licalvf, lifmassbf, sftgif, sftgrf, sftflf

  349. output.ISMIP6_ts_variables

    Comma-separated list of scalar variables (time series) reported by models participating in ISMIP6 simulations.

    Type
    string
    Default value

    lim, limnsw, iareagr, iareafl, tendacabf, tendlibmassbf, tendlibmassbffl, tendlicalvf, tendlifmassbf

  350. output.backup_interval

    wall-clock time between automatic backups

    Type
    number
    Default value

    1 (hours)

    Option

    -backup_interval

  351. output.backup_size

    The “size” of a backup file. See parameters output­.sizes­.medium, output­.sizes­.big_2d, output­.sizes­.big

    Type
    keyword
    Default value

    small

    Choices

    none, small, medium, big_2d, big

    Option

    -backup_size

  352. output.compression_level

    Compression level for 2D and 3D output variables (if supported by output­.format)

    Type
    integer
    Default value

    0 (count)

  353. output.extra.append

    Append to an existing output file. No effect if file does not yet exist, and no effect if output­.extra­.split is set.

    Type
    flag
    Default value

    no

    Option

    -extra_append

  354. output.extra.file

    Name of the file that will contain spatially-variable diagnostics. Should be different from output­.file_name.

    Type
    string
    Default value

    empty

    Option

    -extra_file

  355. output.extra.split

    Save spatially-variable diagnostics to separate files (one per time record).

    Type
    flag
    Default value

    no

    Option

    -extra_split

  356. output.extra.stop_missing

    Stop if requested variable is not available instead of warning.

    Type
    flag
    Default value

    yes

    Option

    -extra_stop_missing

  357. output.extra.times

    List or a range of times defining reporting intervals for spatially-variable diagnostics.

    Type
    string
    Default value

    empty

    Option

    -extra_times

  358. output.extra.vars

    Comma-separated list of spatially-variable diagnostics.

    Type
    string
    Default value

    empty

    Option

    -extra_vars

  359. output.file_name

    The file to save final model results to.

    Type
    string
    Default value

    unnamed.nc

    Option

    -o

  360. output.fill_value

    _FillValue used when saving diagnostic quantities

    Type
    number
    Default value

    -2e+09 (none)

  361. output.format

    The I/O format used for spatial fields; netcdf3 is the default, netcd4_parallel is available if PISM was built with parallel NetCDF-4, and pnetcdf is available if PISM was built with PnetCDF.

    Type
    keyword
    Default value

    netcdf3

    Choices

    netcdf3, netcdf4_serial, netcdf4_parallel, pnetcdf, pio_pnetcdf, pio_netcdf4p, pio_netcdf4c, pio_netcdf

    Option

    -o_format

  362. output.ice_free_thickness_standard

    If ice is thinner than this standard then a grid cell is considered ice-free for purposes of reporting glacierized area, volume, etc.

    Type
    number
    Default value

    10 (meters)

  363. output.pio.base

    Rank of the first I/O task

    Type
    integer
    Default value

    0 (count)

  364. output.pio.n_writers

    Number of I/O tasks to use

    Type
    integer
    Default value

    1 (count)

  365. output.pio.stride

    Offset between I/O tasks

    Type
    integer
    Default value

    1 (count)

  366. output.runtime.area_scale_factor_log10

    an integer; log base 10 of scale factor to use for area (in km^2) in summary line to stdout

    Type
    integer
    Default value

    6 (pure number)

    Option

    -summary_area_scale_factor_log10

  367. output.runtime.time_unit_name

    Time units used when printing model time, time step, and maximum horizontal velocity at summary to stdout. Must be valid udunits for time. (E.g. choose from year,month,day,hour,minute,second.)

    Type
    string
    Default value

    year

  368. output.runtime.time_use_calendar

    Whether to use the current calendar when printing model time in summary to stdout.

    Type
    flag
    Default value

    yes

  369. output.runtime.viewer.size

    default diagnostic viewer size (number of pixels of the longer side)

    Type
    integer
    Default value

    320 (count)

    Option

    -view_size

  370. output.runtime.viewer.variables

    comma-separated list of map-plane diagnostic quantities to view at runtime

    Type
    string
    Default value

    empty

    Option

    -view

  371. output.runtime.volume_scale_factor_log10

    an integer; log base 10 of scale factor to use for volume (in km^3) in summary line to stdout

    Type
    integer
    Default value

    6 (pure number)

    Option

    -summary_vol_scale_factor_log10

  372. output.size

    The “size” of an output file. See parameters output­.sizes­.medium, output­.sizes­.big_2d, output­.sizes­.big

    Type
    keyword
    Default value

    medium

    Choices

    none, small, medium, big_2d, big

    Option

    -o_size

  373. output.sizes.big

    Comma-separated list of variables to write to the output (in addition to model_state variables and variables listed in output­.sizes­.medium and output­.sizes­.big_2d) if big output size is selected. Does not include fields written by sub-models.

    Type
    string
    Default value

    cts, liqfrac, temp, temp_pa, uvel, vvel, wvel, wvel_rel

  374. output.sizes.big_2d

    Comma-separated list of variables to write to the output (in addition to model_state variables and variables listed in output­.sizes­.medium) if big_2d output size is selected. Does not include fields written by boundary models.

    Type
    string
    Default value

    age, bfrict, bheatflx, bmelt, bwp, bwprel, dbdt, effbwp, enthalpybase, enthalpysurf, flux_divergence, hardav, hydroinput, lat, litho_temp, lon, nuH, rank, tempbase, tempicethk, tempicethk_basal, temppabase, tempsurf, thk, thksmooth, tillphi, topg, velbar, velbase, wallmelt, wvelbase

  375. output.sizes.medium

    Comma-separated list of variables to write to the output (in addition to model_state variables) if medium output size (the default) is selected. Does not include fields written by sub-models.

    Type
    string
    Default value

    bwat, bwatvel, climatic_mass_balance, diffusivity, enthalpy, flux, flux_mag, ice_surface_temp, liqfrac, mask, schoofs_theta, strain_rates, taub_mag, tauc, taud_mag, temp_pa, tillwat, topgsmooth, usurf, velbar_mag, velbase_mag, velsurf, velsurf_mag, wvelsurf

  376. output.snapshot.file

    Snapshot (output) file name (or prefix, if saving to individual files).

    Type
    string
    Default value

    empty

    Option

    -save_file

  377. output.snapshot.size

    The “size” of a snapshot file. See parameters output­.sizes­.medium, output­.sizes­.big_2d, output­.sizes­.big

    Type
    keyword
    Default value

    small

    Choices

    none, small, medium, big_2d, big

    Option

    -save_size

  378. output.snapshot.split

    Save model state snapshots to separate files (one per time record).

    Type
    flag
    Default value

    no

    Option

    -save_split

  379. output.snapshot.times

    List or a range of times to save model state snapshots at.

    Type
    string
    Default value

    empty

    Option

    -save_times

  380. output.timeseries.append

    If true, append to the scalar time series output file.

    Type
    flag
    Default value

    false

    Option

    -ts_append

  381. output.timeseries.buffer_size

    Number of scalar diagnostic time-series records to hold in memory before writing to disk. (PISM writes this many time-series records to reduce I/O costs.) Send the USR2 signal to flush time-series.

    Type
    integer
    Default value

    10000 (count)

  382. output.timeseries.filename

    Name of the file to save scalar time series to. Leave empty to disable reporting scalar time-series.

    Type
    string
    Default value

    empty

    Option

    -ts_file

  383. output.timeseries.times

    List or range of times defining reporting time intervals.

    Type
    string
    Default value

    empty

    Option

    -ts_times

  384. output.timeseries.variables

    Requested scalar (time-series) diagnostics. Leave empty to save all available diagnostics.

    Type
    string
    Default value

    empty

    Option

    -ts_vars

  385. output.use_MKS

    Use MKS units in output files.

    Type
    flag
    Default value

    false

  386. regional.no_model_strip

    Default width of the “no model strip” in regional setups.

    Type
    number
    Default value

    5 (km)

    Option

    -no_model_strip

  387. regional.no_model_yield_stress

    High yield stress used in the no_model_mask area in the regional mode.

    Type
    number
    Default value

    1000 (kPa)

  388. regional.zero_gradient

    Use zero ice thickness and ice surface gradient in the no_model_mask area.

    Type
    flag
    Default value

    false

    Option

    -zero_grad_where_no_model

  389. run_info.institution

    Institution name. This string is written to output files as the institution global attribute.

    Type
    string
    Default value

    empty

    Option

    -institution

  390. run_info.title

    Free-form string containing a concise description of the current run. This string is written to output files as the title global attribute.

    Type
    string
    Default value

    empty

    Option

    -title

  391. sea_level.constant.value

    Sea level elevation used by the constant sea level model

    Type
    number
    Default value

    0 (meters)

  392. sea_level.models

    Comma-separated list of sea level models and modifiers.

    Type
    string
    Default value

    constant

    Option

    -sea_level

  393. stress_balance.blatter.Glen_exponent

    Glen exponent in ice flow law for the Blatter stress balance solver

    Type
    number
    Default value

    3 (pure number)

  394. stress_balance.blatter.Mz

    Number of vertical grid levels in the ice

    Type
    integer
    Default value

    5 (count)

    Option

    -blatter_Mz

  395. stress_balance.blatter.coarsening_factor

    Coarsening factor in the \(z\) direction

    Type
    integer
    Default value

    2 (count)

    Option

    -blatter_coarsening_factor

  396. stress_balance.blatter.enhancement_factor

    Flow enhancement factor for the Blatter stress balance flow law

    Type
    number
    Default value

    1 (1)

    Option

    -blatter_e

  397. stress_balance.blatter.flow_law

    The flow law used by the Blatter-Pattyn stress balance model

    Type
    keyword
    Default value

    gpbld

    Choices

    arr, arrwarm, gpbld, hooke, isothermal_glen, pb

  398. stress_balance.blatter.use_eta_transform

    Use the \(\eta\) transform to improve the accuracy of the surface gradient approximation near grounded margins (see [33] for details).

    Type
    flag
    Default value

    no

  399. stress_balance.calving_front_stress_bc

    Apply CFBC condition as in [98], [37]. May only apply to some stress balances; e.g. SSAFD as of May 2011. If not set then a strength-extension is used, as in [29].

    Type
    flag
    Default value

    no

    Option

    -cfbc

  400. stress_balance.ice_free_thickness_standard

    If ice is thinner than this standard then a cell is considered ice-free for purposes of computing ice velocity distribution.

    Type
    number
    Default value

    10 (meters)

  401. stress_balance.model

    Stress balance model

    Type
    keyword
    Default value

    sia

    Choices

    none, prescribed_sliding, weertman_sliding, sia, ssa, prescribed_sliding+sia, weertman_sliding+sia, ssa+sia, blatter

    Option

    -stress_balance

  402. stress_balance.prescribed_sliding.file

    The name of the file containing prescribed sliding velocity (variable names: ubar, vbar).

    Type
    string
    Default value

    empty

  403. stress_balance.sia.Glen_exponent

    Glen exponent in ice flow law for SIA

    Type
    number
    Default value

    3 (pure number)

    Option

    -sia_n

  404. stress_balance.sia.bed_smoother.range

    half-width of smoothing domain in the bed roughness parameterization for SIA [83]; set to zero to disable

    Type
    number
    Default value

    5000 (meters)

    Option

    -bed_smoother_range

  405. stress_balance.sia.bed_smoother.theta_min

    minimum value of \(\theta\) in the bed roughness parameterization for SIA [83]

    Type
    number
    Default value

    0 (1)

  406. stress_balance.sia.e_age_coupling

    Couple the SIA enhancement factor to age as in [36].

    Type
    flag
    Default value

    no

    Option

    -e_age_coupling

  407. stress_balance.sia.enhancement_factor

    Flow enhancement factor for SIA

    Type
    number
    Default value

    1 (1)

    Option

    -sia_e

  408. stress_balance.sia.enhancement_factor_interglacial

    Flow enhancement factor for SIA; used for ice accumulated during interglacial periods.

    Type
    number
    Default value

    1 (1)

    Option

    -sia_e_interglacial

  409. stress_balance.sia.flow_law

    The SIA flow law.

    Type
    keyword
    Default value

    gpbld

    Choices

    arr, arrwarm, gk, gpbld, hooke, isothermal_glen, pb

    Option

    -sia_flow_law

  410. stress_balance.sia.grain_size_age_coupling

    Use age of the ice to compute grain size to use with the Goldsby-Kohlstedt [25] flow law

    Type
    flag
    Default value

    no

    Option

    -grain_size_age_coupling

  411. stress_balance.sia.limit_diffusivity

    Limit SIA diffusivity by stress_balance­.sia­.max_diffusivity.

    Type
    flag
    Default value

    no

    Option

    -limit_sia_diffusivity

  412. stress_balance.sia.max_diffusivity

    Maximum allowed diffusivity of the SIA flow. PISM stops with an error message if the SIA diffusivity exceeds this limit.

    Type
    number
    Default value

    100 (m2 s-1)

  413. stress_balance.sia.surface_gradient_method

    method used for surface gradient calculation at staggered grid points

    Type
    keyword
    Default value

    haseloff

    Choices

    eta, haseloff, mahaffy

    Option

    -gradient

  414. stress_balance.ssa.Glen_exponent

    Glen exponent in ice flow law for SSA

    Type
    number
    Default value

    3 (pure number)

    Option

    -ssa_n

  415. stress_balance.ssa.compute_surface_gradient_inward

    If yes then use inward first-order differencing in computing surface gradient in the SSA objects.

    Type
    flag
    Default value

    no

  416. stress_balance.ssa.dirichlet_bc

    apply SSA velocity Dirichlet boundary condition

    Type
    flag
    Default value

    no

    Option

    -ssa_dirichlet_bc

  417. stress_balance.ssa.enhancement_factor

    Flow enhancement factor for SSA

    Type
    number
    Default value

    1 (1)

    Option

    -ssa_e

  418. stress_balance.ssa.epsilon

    Initial amount of regularization in computation of product of effective viscosity and thickness (\(\nu H\)). This default value for \(\nu H\) comes e.g. from a hardness for the Ross ice shelf (\(\bar B\)) = 1.9e8 Pa \(s^{1/3}\) [68] and a typical strain rate of 0.001 1/year for the Ross ice shelf, giving \(\nu = (\bar B) / (2 \cdot 0.001^{2/3})\) = 9.49e+14 Pa s ~ 30 MPa year, the value in [87], but with a tiny thickness \(H\) of about 1 cm.

    Type
    number
    Default value

    1e+13 (Pascal second meter)

    Option

    -ssa_eps

  419. stress_balance.ssa.fd.brutal_sliding

    Enhance sliding speed brutally.

    Type
    flag
    Default value

    false

    Option

    -brutal_sliding

  420. stress_balance.ssa.fd.brutal_sliding_scale

    Brutal SSA Sliding Scale

    Type
    number
    Default value

    1 (1)

    Option

    -brutal_sliding_scale

  421. stress_balance.ssa.fd.flow_line_mode

    Set \(v\) (the \(y\) component of the ice velocity) to zero when assembling the system

    Type
    flag
    Default value

    false

  422. stress_balance.ssa.fd.lateral_drag.enabled

    Set viscosity at ice shelf margin next to ice free bedrock as friction parameterization

    Type
    flag
    Default value

    false

  423. stress_balance.ssa.fd.lateral_drag.viscosity

    Staggered viscosity used as side friction parameterization.

    Type
    number
    Default value

    5e+15 (Pascal second)

    Option

    -nu_bedrock

  424. stress_balance.ssa.fd.max_iterations

    Maximum number of Picard iterations for the ice viscosity computation, in the SSAFD object

    Type
    integer
    Default value

    300 (count)

    Option

    -ssafd_picard_maxi

  425. stress_balance.ssa.fd.max_speed

    Upper bound for the ice speed computed by the SSAFD solver.

    Type
    number
    Default value

    300000 (km s-1)

    Option

    -ssafd_max_speed

  426. stress_balance.ssa.fd.nuH_iter_failure_underrelaxation

    In event of “Effective viscosity not converged” failure, use outer iteration rule nuH <- nuH + f (nuH - nuH_old), where f is this parameter.

    Type
    number
    Default value

    0.8 (pure number)

    Option

    -ssafd_nuH_iter_failure_underrelaxation

  427. stress_balance.ssa.fd.relative_convergence

    Relative change tolerance for the effective viscosity in the SSAFD object

    Type
    number
    Default value

    0.0001 (1)

    Option

    -ssafd_picard_rtol

  428. stress_balance.ssa.fd.replace_zero_diagonal_entries

    Replace zero diagonal entries in the SSAFD matrix with :config:’basal_resistance.beta_ice_free_bedrock’ to avoid solver failures.

    Type
    flag
    Default value

    yes

  429. stress_balance.ssa.flow_law

    The SSA flow law.

    Type
    keyword
    Default value

    gpbld

    Choices

    arr, arrwarm, gpbld, hooke, isothermal_glen, pb

    Option

    -ssa_flow_law

  430. stress_balance.ssa.method

    Algorithm for computing the SSA solution.

    Type
    keyword
    Default value

    fd

    Choices

    fd, fem

    Option

    -ssa_method

  431. stress_balance.ssa.read_initial_guess

    Read the initial guess from the input file when re-starting.

    Type
    flag
    Default value

    yes

    Option

    -ssa_read_initial_guess

  432. stress_balance.ssa.strength_extension.constant_nu

    The SSA is made elliptic by use of a constant value for the product of viscosity (nu) and thickness (H). This value for nu comes from hardness (bar B)=1.9e8 \(Pa s^{1/3}\) [68] and a typical strain rate of 0.001 year-1: \(\nu = (\bar B) / (2 \cdot 0.001^{2/3})\). Compare the value of 9.45e14 Pa s = 30 MPa year in [87].

    Type
    number
    Default value

    9.48681e+14 (Pascal second)

  433. stress_balance.ssa.strength_extension.min_thickness

    The SSA is made elliptic by use of a constant value for the product of viscosity (nu) and thickness (H). At ice thicknesses below this value the product nu*H switches from the normal vertical integral to a constant value. The geometry itself is not affected by this value.

    Type
    number
    Default value

    50 (meters)

  434. stress_balance.vertical_velocity_approximation

    Vertical velocity FD approximation. “Upstream” uses first-order finite difference to compute u_x and v_y. Uses basal velocity to make decisions.

    Type
    keyword
    Default value

    centered

    Choices

    centered, upstream

    Option

    -vertical_velocity_approximation

  435. stress_balance.weertman_sliding.A

    Sliding parameter in the Weertman-style sliding parameterization [88]

    Type
    number
    Default value

    1.8e-16 (Pa-3 year-1 m-2)

  436. stress_balance.weertman_sliding.k

    The ratio of the basal water pressure and the ice overburden pressure in the Weertman-style sliding parameterization.

    Type
    number
    Default value

    0.2 (1)

  437. surface.anomaly.file

    Name of the file containing climate forcing fields.

    Type
    string
    Default value

    empty

    Option

    -surface_anomaly_file

  438. surface.anomaly.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  439. surface.cache.update_interval

    Update interval (in 365-day years) for the -surface cache modifier.

    Type
    integer
    Default value

    10 (365days)

  440. surface.delta_T.file

    Name of the file containing temperature offsets.

    Type
    string
    Default value

    empty

    Option

    -surface_delta_T_file

  441. surface.delta_T.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  442. surface.elevation_change.file

    Name of the file containing the reference surface elevation field (variable usurf).

    Type
    string
    Default value

    empty

    Option

    -surface_elevation_change_file

  443. surface.elevation_change.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  444. surface.elevation_change.smb.exp_factor

    Exponential for the surface mass balance.

    Type
    number
    Default value

    0 (Kelvin-1)

    Option

    -smb_exp_factor

  445. surface.elevation_change.smb.lapse_rate

    Lapse rate for the surface mass balance.

    Type
    number
    Default value

    0 ((m / year) / km)

    Option

    -smb_lapse_rate

  446. surface.elevation_change.smb.method

    Choose the SMB adjustment method. scale: use temperature-change-dependent scaling factor. shift: use the SMB lapse rate.

    Type
    keyword
    Default value

    shift

    Choices

    scale, shift

    Option

    -smb_adjustment

  447. surface.elevation_change.temperature_lapse_rate

    Lapse rate for the temperature at the top of the ice.

    Type
    number
    Default value

    0 (K / km)

    Option

    -temp_lapse_rate

  448. surface.force_to_thickness.alpha

    exponential coefficient in force-to-thickness mechanism

    Type
    number
    Default value

    0.01 (year-1)

    Option

    -force_to_thickness_alpha

  449. surface.force_to_thickness.ice_free_alpha_factor

    surface­.force_to_thickness­.alpha is multiplied by this factor in areas that are ice-free according to the target ice thickness and surface­.force_to_thickness­.ice_free_thickness_threshold

    Type
    number
    Default value

    1 (1)

    Option

    -force_to_thickness_ice_free_alpha_factor

  450. surface.force_to_thickness.ice_free_thickness_threshold

    threshold of ice thickness in the force-to-thickness target field. Used to determine whether to use surface­.force_to_thickness­.ice_free_alpha_factor.

    Type
    number
    Default value

    1 (meters)

    Option

    -force_to_thickness_ice_free_thickness_threshold

  451. surface.force_to_thickness.start_time

    Starting time for the “force to thickness” modifier; the default is “start from the creation of the Earth.”

    Type
    number
    Default value

    -4.54e+09 (years)

  452. surface.force_to_thickness_file

    The name of the file to read the target ice thickness from.

    Type
    string
    Default value

    empty

    Option

    -force_to_thickness_file

  453. surface.given.file

    Name of the file containing climate forcing fields.

    Type
    string
    Default value

    empty

    Option

    -surface_given_file

  454. surface.given.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  455. surface.given.smb_max

    Maximum climatic mass balance value (used to check input data). Corresponds to 100 m/year ice equivalent.

    Type
    number
    Default value

    91000 (kg m-2 year-1)

  456. surface.ismip6.file

    Name of the file containing climate forcing anomaly fields.

    Type
    string
    Default value

    empty

    Option

    -surface_ismip6_file

  457. surface.ismip6.periodic

    If true, interpret forcing data as periodic in time

    Type
    flag
    Default value

    no

  458. surface.ismip6.reference_file

    Name of the file containing reference climate forcing fields.

    Type
    string
    Default value

    empty

    Option

    -surface_ismip6_reference_file

  459. surface.models

    Comma-separated list of surface models and modifiers.

    Type
    string
    Default value

    given

    Option

    -surface

  460. surface.pdd.air_temp_all_precip_as_rain

    threshold temperature above which all precipitation is rain; must exceed surface­.pdd­.air_temp_all_precip_as_snow to avoid division by zero, because difference is in a denominator

    Type
    number
    Default value

    275.15 (Kelvin)

  461. surface.pdd.air_temp_all_precip_as_snow

    threshold temperature below which all precipitation is snow

    Type
    number
    Default value

    273.15 (Kelvin)

  462. surface.pdd.balance_year_start_day

    day of year for October 1st, beginning of the balance year in northern latitudes.

    Type
    integer
    Default value

    274 (ordinal day number)

  463. surface.pdd.factor_ice

    EISMINT-Greenland value [7]; = (8 mm liquid-water-equivalent) / (pos degree day)

    Type
    number
    Default value

    0.00879121 (meter / (Kelvin day))

  464. surface.pdd.factor_snow

    EISMINT-Greenland value [7]; = (3 mm liquid-water-equivalent) / (pos degree day)

    Type
    number
    Default value

    0.0032967 (meter / (Kelvin day))

  465. surface.pdd.fausto.T_c

    = -1 + 273.15; for formula (6) in [1]

    Type
    number
    Default value

    272.15 (Kelvin)

  466. surface.pdd.fausto.T_w

    = 10 + 273.15; for formula (6) in [1]

    Type
    number
    Default value

    283.15 (Kelvin)

  467. surface.pdd.fausto.beta_ice_c

    water-equivalent thickness; for formula (6) in [1]

    Type
    number
    Default value

    0.015 (meter / (Kelvin day))

  468. surface.pdd.fausto.beta_ice_w

    water-equivalent thickness; for formula (6) in [1]

    Type
    number
    Default value

    0.007 (meter / (Kelvin day))

  469. surface.pdd.fausto.beta_snow_c

    water-equivalent thickness; for formula (6) in [1]

    Type
    number
    Default value

    0.003 (meter / (Kelvin day))

  470. surface.pdd.fausto.beta_snow_w

    water-equivalent thickness; for formula (6) in [1]

    Type
    number
    Default value

    0.003 (meter / (Kelvin day))

  471. surface.pdd.fausto.enabled

    Set PDD parameters using formulas (6) and (7) in [1]

    Type
    flag
    Default value

    false

    Option

    -pdd_fausto

  472. surface.pdd.fausto.latitude_beta_w

    latitude below which to use warm case, in formula (6) in [1]

    Type
    number
    Default value

    72 (degree_north)

  473. surface.pdd.firn_compaction_to_accumulation_ratio

    How much firn as a fraction of accumulation is turned into ice

    Type
    number
    Default value

    0.75 (1)

  474. surface.pdd.firn_depth_file

    The name of the file to read the firn_depth from.

    Type
    string
    Default value

    empty

    Option

    -pdd_firn_depth_file

  475. surface.pdd.interpret_precip_as_snow

    Interpret precipitation as snow fall.

    Type
    flag
    Default value

    no

  476. surface.pdd.max_evals_per_year

    maximum number of times the PDD scheme will ask for air temperature and precipitation to build location-dependent time series for computing (expected) number of positive degree days and snow accumulation; the default means the PDD uses weekly samples of the annual cycle; see also surface­.pdd­.std_dev­.value

    Type
    integer
    Default value

    52 (count)

  477. surface.pdd.method

    PDD implementation method

    Type
    keyword
    Default value

    expectation_integral

    Choices

    expectation_integral, repeatable_random_process, random_process

    Option

    -pdd_method

  478. surface.pdd.positive_threshold_temp

    temperature used to determine meaning of “positive” degree day

    Type
    number
    Default value

    273.15 (Kelvin)

  479. surface.pdd.refreeze

    EISMINT-Greenland value [7]

    Type
    number
    Default value

    0.6 (1)

  480. surface.pdd.refreeze_ice_melt

    If set to “yes”, refreeze surface­.pdd­.refreeze fraction of melted ice, otherwise all of the melted ice runs off.

    Type
    flag
    Default value

    yes

  481. surface.pdd.std_dev.file

    The name of the file to read air_temp_sd (standard deviation of air temperature) from.

    Type
    string
    Default value

    empty

    Option

    -pdd_sd_file

  482. surface.pdd.std_dev.lapse_lat_base

    standard deviationis is a function of latitude, with value surface­.pdd­.std_dev­.value at this latitude; this value is only active if surface­.pdd­.std_dev­.lapse_lat_rate is nonzero

    Type
    number
    Default value

    72 (degree_north)

  483. surface.pdd.std_dev.lapse_lat_rate

    standard deviation is a function of latitude, with rate of change with respect to latitude given by this constant

    Type
    number
    Default value

    0 (Kelvin / degree_north)

  484. surface.pdd.std_dev.param_a

    Parameter \(a\) in \(\Sigma = aT + b\), with \(T\) in degrees C. Used only if surface­.pdd­.std_dev­.use_param is set to yes.

    Type
    number
    Default value

    -0.15 (pure number)

  485. surface.pdd.std_dev.param_b

    Parameter \(b\) in \(\Sigma = aT + b\), with \(T\) in degrees C. Used only if surface­.pdd­.std_dev­.use_param is set to yes.

    Type
    number
    Default value

    0.66 (Kelvin)

  486. surface.pdd.std_dev.periodic

    If true, interpret air_temp_sd read from surface­.pdd­.std_dev­.file as periodic in time

    Type
    flag
    Default value

    no

  487. surface.pdd.std_dev.use_param

    Parameterize standard deviation as a linear function of air temperature over ice-covered grid cells. The region of application is controlled by geometry­.ice_free_thickness_standard.

    Type
    flag
    Default value

    no

  488. surface.pdd.std_dev.value

    standard deviation of daily temp variation; = EISMINT-Greenland value [7]

    Type
    number
    Default value

    5 (Kelvin)

  489. surface.pressure

    atmospheric pressure; = pressure at ice surface

    Type
    number
    Default value

    0 (Pascal)

  490. surface.temp_to_runoff_a

    a in runoff=a * temp + b

    Type
    number
    Default value

    0.5 (K-1)

  491. time.calendar

    The calendar to use.

    Type
    keyword
    Default value

    365_day

    Choices

    standard, gregorian, proleptic_gregorian, noleap, 365_day, 360_day, julian

    Option

    -calendar

  492. time.dimension_name

    The name of the time dimension in PISM output files.

    Type
    string
    Default value

    time

  493. time.eemian_end

    End of the Eemian interglacial period. See [86].

    Type
    number
    Default value

    -114500 (years)

  494. time.eemian_start

    Start of the Eemian interglacial period. See [86].

    Type
    number
    Default value

    -132000 (years)

  495. time.end

    End time, interpreted relative to time­.reference_date.

    Type
    string
    Default value

    empty

    Option

    -ye

  496. time.file

    Name of the file used to set time­.start, time­.end, time­.calendar, and time­.reference_date

    Type
    string
    Default value

    empty

    Option

    -time_file

  497. time.file.continue

    If true, don’t set time­.start using time­.file (helpful when continuing an interrupted simulation)

    Type
    flag
    Default value

    false

  498. time.holocene_start

    Start of the Holocene interglacial period. See [86].

    Type
    number
    Default value

    -11000 (years)

  499. time.reference_date

    year-month-day; reference date used for calendar computations and in PISM output files

    Type
    string
    Default value

    1-1-1

  500. time.run_length

    Run length

    Type
    number
    Default value

    1000 (365days)

    Option

    -y

  501. time.start

    Start time, interpreted relative to time­.reference_date.

    Type
    string
    Default value

    empty

    Option

    -ys

  502. time_stepping.adaptive_ratio

    Adaptive time stepping ratio for the explicit scheme for the mass balance equation; [30], inequality (25)

    Type
    number
    Default value

    0.12 (1)

    Option

    -adapt_ratio

  503. time_stepping.assume_bed_elevation_changed

    If set, assume that bed elevation changes every time step. If not set, PISM tries to avoid unnecessary computations if the bed deformation model did not update bed elevation (to reduce the computational cost a little bit).

    Type
    flag
    Default value

    no

  504. time_stepping.count_steps

    If yes, IceModel::run() will count the number of time steps it took. Sometimes useful for performance evaluation. Counts all steps, regardless of whether processes (mass continuity, energy, velocity, …) occurred within the step.

    Type
    flag
    Default value

    no

    Option

    -count_steps

  505. time_stepping.hit_extra_times

    Modify the time-stepping mechanism to hit times requested using output­.extra­.times.

    Type
    flag
    Default value

    yes

    Option

    -extra_force_output_times

  506. time_stepping.hit_multiples

    Hit every X years, where X is specified using this parameter. Use 0 to disable.

    Type
    integer
    Default value

    0 (years)

    Option

    -timestep_hit_multiples

  507. time_stepping.hit_save_times

    Modify the time-stepping mechanism to hit times requested using output­.snapshot­.times.

    Type
    flag
    Default value

    no

    Option

    -save_force_output_times

  508. time_stepping.hit_ts_times

    Modify the time-stepping mechanism to hit times requested using output­.timeseries­.times.

    Type
    flag
    Default value

    no

  509. time_stepping.maximum_time_step

    Maximum allowed time step length

    Type
    number
    Default value

    60 (365days)

    Option

    -max_dt

  510. time_stepping.resolution

    Time steps are rounded down to be a multiple of this number (set to zero to allow arbitrary time step lengths)

    Type
    number
    Default value

    1 (seconds)

  511. time_stepping.skip.enabled

    Use the temperature, age, and SSA stress balance computation skipping mechanism.

    Type
    flag
    Default value

    no

    Option

    -skip

  512. time_stepping.skip.max

    Number of mass-balance steps, including SIA diffusivity updates, to perform before a the temperature, age, and SSA stress balance computations are done

    Type
    integer
    Default value

    10 (count)

    Option

    -skip_max


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