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:
Strings (mostly file names),
Scalars (a number representing a physical quantify, usually with units),
Integers (an integer number, usually corresponding to a count),
Flags (True/False, on/off, yes/no),
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.
age.enabled(flag)- Value
no
- Option
-age- Description
Solve age equation (advection equation for ice age).
age.initial_value(number)- Value
0 (years)
- Description
Initial age of ice
atmosphere.anomaly.file(string)- Value
no default
- Option
-atmosphere_anomaly_file- Description
Name of the file containing climate forcing fields.
atmosphere.anomaly.period(integer)- Value
0
- Option
-atmosphere_anomaly_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
atmosphere.anomaly.reference_year(integer)- Value
0
- Option
-atmosphere_anomaly_reference_year- Description
Reference year to use when
atmosphere.anomaly.periodis active.
atmosphere.delta_P.file(string)- Value
no default
- Option
-atmosphere_delta_P_file- Description
Name of the file containing scalar precipitation offsets.
atmosphere.delta_P.period(integer)- Value
0
- Option
-atmosphere_delta_P_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
atmosphere.delta_P.reference_year(integer)- Value
0
- Option
-atmosphere_delta_P_reference_year- Description
Reference year to use when
atmosphere.delta_P.periodis active.
atmosphere.delta_T.file(string)- Value
no default
- Option
-atmosphere_delta_T_file- Description
Name of the file containing temperature offsets.
atmosphere.delta_T.period(integer)- Value
0
- Option
-atmosphere_delta_T_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
atmosphere.delta_T.reference_year(integer)- Value
0
- Option
-atmosphere_delta_T_reference_year- Description
Reference year to use when
atmosphere.delta_T.periodis active.
atmosphere.elevation_change.file(string)- Value
no default
- Option
-atmosphere_lapse_rate_file- Description
Name of the file containing the reference surface elevation field (variable
usurf).
atmosphere.elevation_change.period(integer)- Value
0
- Option
-atmosphere_lapse_rate_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
atmosphere.elevation_change.precipitation.lapse_rate(number)- Value
0 ((kg m-2 / year) / km)
- Option
-precip_lapse_rate- Description
Elevation lapse rate for the surface mass balance
atmosphere.elevation_change.precipitation.method(keyword)- Value
shift- Choices
scale, shift- Option
-precip_adjustment- Description
Choose the precipitation adjustment method.
scale: use temperature-change-dependent scaling factor.shift: use the precipitation lapse rate.
atmosphere.elevation_change.reference_year(integer)- Value
0
- Option
-atmosphere_lapse_rate_reference_year- Description
Reference year to use when
atmosphere.elevation_change.periodis active.
atmosphere.elevation_change.temperature_lapse_rate(number)- Value
0 (Kelvin / km)
- Option
-temp_lapse_rate- Description
Elevation lapse rate for the surface temperature
atmosphere.fausto_air_temp.c_ma(number)- Value
-0.718900 (Kelvin / degree_north)
- Description
latitude-dependence coefficient for formula (1) in [1]
atmosphere.fausto_air_temp.c_mj(number)- Value
-0.158500 (Kelvin / degree_north)
- Description
latitude-dependence coefficient for formula (2) in [1]
atmosphere.fausto_air_temp.d_ma(number)- Value
314.980000 (Kelvin)
- Description
41.83+273.15; base temperature for formula (1) in [1]
atmosphere.fausto_air_temp.d_mj(number)- Value
287.850000 (Kelvin)
- Description
= 14.70+273.15; base temperature for formula (2) in [1]
atmosphere.fausto_air_temp.gamma_ma(number)- Value
-0.006309 (Kelvin / meter)
- Description
= -6.309 / 1km; mean slope lapse rate for formula (1) in [1]
atmosphere.fausto_air_temp.gamma_mj(number)- Value
-0.005426 (Kelvin / meter)
- Description
= -5.426 / 1km; mean slope lapse rate for formula (2) in [1]
atmosphere.fausto_air_temp.kappa_ma(number)- Value
0.067200 (Kelvin / degree_west)
- Description
longitude-dependence coefficient for formula (1) in [1]
atmosphere.fausto_air_temp.kappa_mj(number)- Value
0.051800 (Kelvin / degree_west)
- Description
longitude-dependence coefficient for formula (2) in [1]
atmosphere.fausto_air_temp.summer_peak_day(integer)- Value
196
- Description
day of year for July 15; used in corrected formula (4) in [1]
atmosphere.frac_P.file(string)- Value
no default
- Option
-atmosphere_frac_P_file- Description
Name of the file containing scalar precipitation scaling.
atmosphere.frac_P.period(integer)- Value
0
- Option
-atmosphere_frac_P_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
atmosphere.frac_P.reference_year(integer)- Value
0
- Option
-atmosphere_frac_P_reference_year- Description
Reference year to use when
atmosphere.frac_P.periodis active.
atmosphere.given.file(string)- Value
no default
- Option
-atmosphere_given_file- Description
Name of the file containing climate forcing fields.
atmosphere.given.period(integer)- Value
0
- Option
-atmosphere_given_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
atmosphere.given.reference_year(integer)- Value
0
- Option
-atmosphere_given_reference_year- Description
Reference year to use when
atmosphere.given.periodis active.
atmosphere.models(string)- Value
given
- Option
-atmosphere- Description
Comma-separated list of atmosphere melt models and modifiers.
atmosphere.one_station.file(string)- Value
no default
- Option
-atmosphere_one_station_file- Description
Specifies a file containing scalar time-series ‘precipitation’ and ‘air_temp’.
atmosphere.orographic_precipitation.background_precip_post(number)- Value
0 (mm/hr)
- Option
-background_precip_post- Description
Adding background precipitation after truncation
atmosphere.orographic_precipitation.background_precip_pre(number)- Value
0 (mm/hr)
- Option
-background_precip_pre- Description
Adding background precipitation before truncation
atmosphere.orographic_precipitation.conversion_time(number)- Value
1000 (s)
- Option
-conversion_time- Description
Cloud conversion time
atmosphere.orographic_precipitation.coriolis_latitude(number)- Value
0 (degrees_N)
- Option
-coriolis_latitude- Description
Latitude used to compute Coriolis force
atmosphere.orographic_precipitation.fallout_time(number)- Value
1000 (s)
- Option
-fallout_time- Description
Fallout time
atmosphere.orographic_precipitation.grid_size_factor(integer)- Value
2
- Description
The spectral grid size is (Z*(grid.Mx - 1) + 1, Z*(grid.My - 1) + 1) where Z is given by this parameter.
atmosphere.orographic_precipitation.lapse_rate(number)- Value
-5.800000 (K / km)
- Option
-lapse_rate- Description
Lapse rate
atmosphere.orographic_precipitation.moist_adiabatic_lapse_rate(number)- Value
-6.500000 (K / km)
- Option
-moist_adiabatic_lapse_rate- Description
Water vapor scale height
atmosphere.orographic_precipitation.moist_stability_frequency(number)- Value
0.050000 (1/s)
- Option
-moist_stability_frequency- Description
Moist stability frequency
atmosphere.orographic_precipitation.reference_density(number)- Value
0.007400 (kg m-3)
- Option
-reference_density- Description
Water vapor scale height
atmosphere.orographic_precipitation.scale_factor(number)- Value
1 (1)
- Option
-scale_factor- Description
Precipitation scaling factor
atmosphere.orographic_precipitation.truncate(flag)- Value
true
- Option
-truncate- Description
Truncate precipitation at 0
atmosphere.orographic_precipitation.water_vapor_scale_height(number)- Value
2500 (m)
- Option
-water_vapor_scale_height- Description
Water vapor scale height
atmosphere.orographic_precipitation.wind_direction(number)- Value
270 (degrees)
- Option
-wind_direction- Description
The direction the wind is coming from
atmosphere.orographic_precipitation.wind_speed(number)- Value
10 (m/s)
- Option
-wind_speed- Description
The direction the wind is coming from
atmosphere.pik.file(string)- Value
no default
- Option
-atmosphere_pik_file- Description
Name of the file containing the reference surface elevation field (variable
usurf).
atmosphere.pik.parameterization(keyword)- Value
martin- Choices
martin, huybrechts_dewolde, martin_huybrechts_dewolde, era_interim, era_interim_sin, era_interim_lon- Option
-atmosphere_pik- Description
Selects parameterizations of mean annual and mean summer near-surface air temperatures.
atmosphere.precip_exponential_factor_for_temperature(number)- Value
0.070417 (Kelvin-1)
- Description
= 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]
atmosphere.precip_scaling.file(string)- Value
no default
- Option
-atmosphere_precip_scaling_file- Description
Name of the file containing temperature offsets to use for a precipitation correction.
atmosphere.precip_scaling.period(integer)- Value
0
- Option
-atmosphere_precip_scaling_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
atmosphere.precip_scaling.reference_year(integer)- Value
0
- Option
-atmosphere_precip_scaling_reference_year- Description
Reference year to use when
atmosphere.precip_scaling.periodis active.
atmosphere.searise_greenland.file(string)- Value
no default
- Option
-atmosphere_searise_greenland_file- Description
Name of the file containing a precipitation field.
atmosphere.uniform.precipitation(number)- Value
1000 (kg m-2 year-1)
- Description
Precipitation used by the ‘uniform’ atmosphere model.
atmosphere.uniform.temperature(number)- Value
273.150000 (Kelvin)
- Description
Air temperature used by the ‘uniform’ atmosphere model.
atmosphere.yearly_cycle.file(string)- Value
no default
- Option
-atmosphere_yearly_cycle_file- Description
Name of the file containing mean annual and mean July temperatures (\(air_temp_mean_annual\) and \(air_temp_mean_summer\)) and the \(precipitation\) field.
atmosphere.yearly_cycle.scaling.file(string)- Value
no default
- Option
-atmosphere_yearly_cycle_scaling_file- Description
Name of the file containing amplitude scaling (\(amplitude_scaling\)) for the near-surface air temperature.
atmosphere.yearly_cycle.scaling.period(integer)- Value
0
- Description
Length of the period of the climate forcing data. Set to zero to disable.
atmosphere.yearly_cycle.scaling.reference_year(integer)- Value
0
- Description
Reference year to use when
atmosphere.yearly_cycle.scaling.periodis active.
basal_resistance.beta_ice_free_bedrock(number)- Value
1.800000e+09 (Pascal second meter-1)
- Description
value is for ice stream E from [97]; 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
basal_resistance.beta_lateral_margin(number)- Value
1.000000e+19 (Pascal second meter-1)
- Description
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
basal_resistance.plastic.regularization(number)- Value
0.010000 (meter / year)
- Option
-plastic_reg- Description
Set the value of \(\epsilon\) regularization of plastic till; this is the second \(\epsilon\) in formula (4.1) in [41]
basal_resistance.pseudo_plastic.enabled(flag)- Value
no
- Option
-pseudo_plastic- Description
Use the pseudo-plastic till model (basal sliding law).
basal_resistance.pseudo_plastic.q(number)- Value
0.250000 (pure number)
- Option
-pseudo_plastic_q- Description
The exponent of the pseudo-plastic basal resistance model
basal_resistance.pseudo_plastic.sliding_scale_factor(number)- Value
-1 (1)
- Option
-sliding_scale_factor_reduces_tauc- Description
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
basal_resistance.pseudo_plastic.u_threshold(number)- Value
100 (meter / year)
- Option
-pseudo_plastic_uthreshold- Description
threshold velocity of the pseudo-plastic sliding law
basal_yield_stress.add_transportable_water(flag)- Value
no
- Option
-tauc_add_transportable_water- Description
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.
basal_yield_stress.constant.value(number)- Value
200000 (Pascal)
- Option
-tauc- Description
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
basal_yield_stress.ice_free_bedrock(number)- Value
1000000 (Pascal)
- Option
-high_tauc- Description
the ‘high’ yield stress value used in grounded ice-free areas.
basal_yield_stress.model(keyword)- Value
mohr_coulomb- Choices
constant, mohr_coulomb- Option
-yield_stress- Description
The basal yield stress model to use when sliding is active.
basal_yield_stress.mohr_coulomb.delta.file(string)- Value
no default
- Option
-mohr_coulomb_delta_file- Description
Name of the file containing space- and time-dependent variable \(mohr_coulomb_delta\) to use instead of \(basal_yield_stress.mohr_coulomb.till_effective_fraction_overburden\).
basal_yield_stress.mohr_coulomb.delta.period(integer)- Value
0
- Option
-mohr_coulomb_delta_period- Description
Length of the period. Set to zero to disable.
basal_yield_stress.mohr_coulomb.delta.reference_year(integer)- Value
0
- Option
-mohr_coulomb_delta_reference_year- Description
Reference year to use when
basal_yield_stress.mohr_coulomb.delta.periodis active.
basal_yield_stress.mohr_coulomb.tauc_to_phi.file(string)- Value
no default
- Option
-tauc_to_phi- Description
File containing the basal yield stress field that should be used to recover the till friction angle distribution.
basal_yield_stress.mohr_coulomb.till_cohesion(number)- Value
0 (Pascal)
- Option
-till_cohesion- Description
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…’
basal_yield_stress.mohr_coulomb.till_compressibility_coefficient(number)- Value
0.120000 (pure number)
- Option
-till_compressibility_coefficient- Description
coefficient of compressiblity of till; value from [89]
basal_yield_stress.mohr_coulomb.till_effective_fraction_overburden(number)- Value
0.020000 (pure number)
- Option
-till_effective_fraction_overburden- Description
\(\delta\) 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 [89]; default value from Greenland and Antarctic model runs
basal_yield_stress.mohr_coulomb.till_log_factor_transportable_water(number)- Value
0.100000 (meters)
- Option
-till_log_factor_transportable_water- Description
If basal_yield_stress.add_transportable_water = yes 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.
basal_yield_stress.mohr_coulomb.till_phi_default(number)- Value
30 (degrees)
- Option
-plastic_phi- Description
fill value for till friction angle
basal_yield_stress.mohr_coulomb.till_reference_effective_pressure(number)- Value
1000 (Pascal)
- Description
reference effective pressure N_0; value from [89]
basal_yield_stress.mohr_coulomb.till_reference_void_ratio(number)- Value
0.690000 (pure number)
- Option
-till_reference_void_ratio- Description
void ratio at reference effective pressure N_0; value from [89]
basal_yield_stress.mohr_coulomb.topg_to_phi.enabled(flag)- Value
no
- Description
If the option
-topg_to_phiis set then this will be set to ‘yes’, and then MohrCoulombYieldStress will initialize thetillphifield using a piece-wise linear function of depth described by four parameters.
basal_yield_stress.mohr_coulomb.topg_to_phi.phi_max(number)- Value
15 (degrees)
- Description
upper value of the till friction angle; see the implementation of MohrCoulombYieldStress
basal_yield_stress.mohr_coulomb.topg_to_phi.phi_min(number)- Value
5 (degrees)
- Description
lower value of the till friction angle; see the implementation of MohrCoulombYieldStress
basal_yield_stress.mohr_coulomb.topg_to_phi.topg_max(number)- Value
1000 (meters)
- Description
the elevation at which the upper value of the till friction angle is used; see the implementation of MohrCoulombYieldStress
basal_yield_stress.mohr_coulomb.topg_to_phi.topg_min(number)- Value
-1000 (meters)
- Description
the elevation at which the lower value of the till friction angle is used; see the implementation of MohrCoulombYieldStress
basal_yield_stress.slippery_grounding_lines(flag)- Value
no
- Option
-tauc_slippery_grounding_lines- Description
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.
bed_deformation.bed_topography_delta_file(string)- Value
no default
- Option
-topg_delta_file- Description
The name of the file to read the topg_delta from. This field is added to the bed topography during initialization.
bed_deformation.bed_uplift_file(string)- Value
no default
- Option
-uplift_file- Description
The name of the file to read the uplift (dbdt) from. Leave empty to read it from an input file or a regridding file.
bed_deformation.lc.elastic_model(flag)- Value
yes
- Option
-bed_def_lc_elastic_model- Description
Use the elastic part of the Lingle-Clark bed deformation model.
bed_deformation.lc.grid_size_factor(integer)bed_deformation.lc.update_interval(number)- Value
10 (years)
- Description
Interval between updates of the Lingle-Clark model
bed_deformation.lithosphere_flexural_rigidity(number)bed_deformation.mantle_density(number)bed_deformation.mantle_viscosity(number)bed_deformation.model(keyword)- Value
none- Choices
none, iso, lc- Option
-bed_def- Description
Selects a bed deformation model to use. ‘iso’ is point-wise isostasy, ‘lc’ is the Lingle-Clark model (see [91], requires FFTW3).
bootstrapping.defaults.bed(number)- Value
1 (meters)
- Description
bed elevation value to use if topg (bedrock_altitude) variable is absent in bootstrapping file
bootstrapping.defaults.bmelt(number)- Value
0 (meter / second)
- Description
basal melt rate value to use if variable bmelt is absent in bootstrapping file
bootstrapping.defaults.bwat(number)- Value
0 (meters)
- Description
till water thickness value to use if variable tillwat is absent in bootstrapping file
bootstrapping.defaults.bwp(number)- Value
0 (Pascal)
- Description
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
bootstrapping.defaults.enwat(number)- Value
0 (meters)
- Description
effective englacial water thickness value to use if variable enwat is absent in bootstrapping file
bootstrapping.defaults.geothermal_flux(number)- Value
0.042000 (Watt meter-2)
- Description
geothermal flux value to use if bheatflx variable is absent in bootstrapping file
bootstrapping.defaults.ice_thickness(number)- Value
0 (meters)
- Description
thickness value to use if thk (land_ice_thickness) variable is absent in bootstrapping file
bootstrapping.defaults.tillwat(number)- Value
0 (meters)
- Description
till water thickness value to use if variable tillwat is absent in bootstrapping file
bootstrapping.defaults.uplift(number)- Value
0 (meter / second)
- Description
uplift value to use if dbdt variable is absent in bootstrapping file
bootstrapping.temperature_heuristic(keyword)- Value
smb- Choices
smb, quartic_guess- Option
-boot_temperature_heuristic- Description
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.
calving.eigen_calving.K(number)calving.float_kill.calve_near_grounding_line(flag)- Value
yes
- Option
-float_kill_calve_near_grounding_line- Description
Calve floating ice near the grounding line.
calving.float_kill.margin_only(flag)- Value
no
- Option
-float_kill_margin_only- Description
Apply float_kill at ice margin cells only.
calving.hayhurst_calving.B_tilde(number)- Value
65 ((MPa)^r / year)
- Description
Effective damage rate [98]
calving.hayhurst_calving.exponent_r(number)- Value
0.430000 (1)
- Description
Damage law exponent [98]
calving.hayhurst_calving.sigma_threshold(number)- Value
0.170000 (MPa)
- Description
Damage threshold stress [98]
calving.methods(string)- Value
no default
- Option
-calving- Description
comma-separated list of calving methods; one or more of ‘eigen_calving’, ‘float_kill’, ‘thickness_calving’
calving.thickness_calving.threshold(number)- Value
50 (meters)
- Option
-thickness_calving_threshold- Description
When terminal ice thickness of floating ice shelf is less than this threshold, it will be calved off.
calving.thickness_calving.threshold_file(string)- Value
no default
- Option
-thickness_calving_threshold_file- Description
Name of the file containing the spatially-variable thickness calving threshold.
calving.vonmises_calving.Glen_exponent(number)- Value
3 (pure number)
- Option
-vonmises_calving_n- Description
Glen exponent in ice flow law for von Mises calving
calving.vonmises_calving.enhancement_factor(number)- Value
1 (1)
- Description
Flow enhancement factor used by the flow law in the von Mises stress computation
calving.vonmises_calving.enhancement_factor_interglacial(number)- Value
1 (1)
- Description
Flow enhancement factor used by the flow law in the von Mises stress computation (for ice accumulated during interglacial periods).
calving.vonmises_calving.flow_law(keyword)- Value
gpbld- Choices
arr, arrwarm, gpbld, hooke, isothermal_glen, pb- Description
The custom flow law for the von Mises stress computation
calving.vonmises_calving.sigma_max(number)- Value
1000000 (Pa)
- Option
-vonmises_calving_calving_sigma_max- Description
Set maximum tensile stress. Note references [79] use 1.0e6 Pa.
calving.vonmises_calving.threshold_file(string)- Value
no default
- Option
-vonmises_calving_threshold_file- Description
Name of the file containing the spatially-variable vonmises_calving calving threshold.
calving.vonmises_calving.use_custom_flow_law(flag)- Value
no
- Option
-vonmises_calving_use_custom_flow_law- Description
Use custom flow law in the von Mises stress computation
constants.fresh_water.density(number)- Value
1000 (kg meter-3)
- Description
density of fresh water
constants.fresh_water.latent_heat_of_fusion(number)- Value
334000 (Joule / kg)
- Description
latent heat of fusion for water [68]
constants.fresh_water.melting_point_temperature(number)- Value
273.150000 (Kelvin)
- Description
melting point of pure water
constants.fresh_water.specific_heat_capacity(number)- Value
4170 (Joule / (kg Kelvin))
- Description
at melting point T_0 [68]
constants.global_ocean_area(number)- Value
3.625000e+14 (meter2)
- Description
area of the global ocean [99]
constants.ice.beta_Clausius_Clapeyron(number)- Value
7.900000e-08 (Kelvin / Pascal)
- Description
Clausius-Clapeyron constant relating melting temperature and pressure: \(\beta = dT / dP\) [100]
constants.ice.density(number)- Value
910 (kg meter-3)
- Description
\(\rho_i\); density of ice in ice sheet
constants.ice.grain_size(number)- Value
1 (mm)
- Option
-ice_grain_size- Description
Default constant ice grain size to use with the Goldsby-Kohlstedt [70] flow law
constants.ice.specific_heat_capacity(number)- Value
2009 (Joule / (kg Kelvin))
- Description
specific heat capacity of pure ice at melting point T_0
constants.ice.thermal_conductivity(number)- Value
2.100000 (Joule / (meter Kelvin second))
- Description
= W m-1 K-1; thermal conductivity of pure ice
constants.ideal_gas_constant(number)- Value
8.314410 (Joule / (mol Kelvin))
- Description
ideal gas constant
constants.sea_water.density(number)- Value
1028 (kg meter-3)
- Description
density of sea water
constants.sea_water.specific_heat_capacity(number)- Value
3985 (Joule / (kg Kelvin))
- Description
at 35 psu, value taken from Kaye and Laby, section 2.7.9
constants.standard_gravity(number)- Value
9.810000 (meter second-2)
- Description
acceleration due to gravity on Earth geoid
energy.allow_temperature_above_melting(flag)- Value
no
- Description
If set to ‘yes’, allow temperatures above the pressure-malting point in the cold mode temperature code. Used by some verifiaction tests.
energy.basal_melt.use_grounded_cell_fraction(flag)- Value
true
- Option
-subgl_basal_melt- Description
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.
energy.bedrock_thermal.conductivity(number)- Value
3 (Joule / (meter Kelvin second))
- Description
= W m-1 K-1; for bedrock used in thermal model [7]
energy.bedrock_thermal.density(number)- Value
3300 (kg meter-3)
- Description
for bedrock used in thermal model
energy.bedrock_thermal.file(string)- Value
no default
- Description
Name of the file containing the geothermal flux field
bheatflx. Leave empty to read it from theinput.file.
energy.bedrock_thermal.specific_heat_capacity(number)- Value
1000 (Joule / (kg Kelvin))
- Description
for bedrock used in thermal model [7]
energy.ch_warming.average_channel_spacing(number)- Value
20 (meters)
- Description
Average spacing between elements of the cryo-hydrologic system (controls the rate of heat transfer from the CH system into the ice).
energy.ch_warming.enabled(flag)- Value
no
- Description
Enable the cryo-hydrologic warming model
energy.ch_warming.residual_water_fraction(number)- Value
0.005000 (pure number)
- Description
residual water fraction in the cryo-hydrologic system at the end of a melt season
energy.ch_warming.temperate_ice_thermal_conductivity_ratio(number)- Value
1 (pure number)
- Description
ratio of thermal conductivities of temperate and cold ice in the cryo-hydrologic system
energy.drainage_maximum_rate(number)- Value
1.584438e-09 (second-1)
- Description
0.05 year-1; maximum rate at which liquid water fraction in temperate ice could possibly drain; see [31]
energy.drainage_target_water_fraction(number)- Value
0.010000 (1)
- Description
liquid water fraction (omega) above which drainage occurs, but below which there is no drainage; see [31]
energy.enabled(flag)- Value
yes
- Description
Solve energy conservation equations.
energy.enthalpy.cold_bulge_max(number)- Value
60270 (Joule / kg)
- Description
= (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
energy.enthalpy.temperate_ice_thermal_conductivity_ratio(number)- Value
0.100000 (pure number)
- Description
K in cold ice is multiplied by this fraction to give K0 in [31]
energy.margin_exclude_horizontal_advection(flag)- Value
yes
- Description
Exclude horizontal advection of energy at grid points near ice margins. See
energy.margin_ice_thickness_limit.
energy.margin_exclude_strain_heating(flag)- Value
yes
- Description
Exclude strain heating at grid points near ice margins. See
energy.margin_ice_thickness_limit.
energy.margin_exclude_vertical_advection(flag)- Value
yes
- Description
Exclude vertical advection of energy at grid points near ice margins. See
energy.margin_ice_thickness_limit.
energy.margin_ice_thickness_limit(number)- Value
100 (meters)
- Description
use special margin treatment at grid points with a neighbor with the thickness below this limit.
energy.max_low_temperature_count(integer)- Value
10
- Option
-max_low_temps- Description
Maximum number of grid points with ice temperature below energy.minimum_allowed_temperature.
energy.minimum_allowed_temperature(number)- Value
200 (Kelvin)
- Option
-low_temp- Description
Minimum allowed ice temperature
energy.temperature_based(flag)- Value
no
- Description
Use cold ice (i.e. not polythermal) methods.
energy.temperature_dependent_thermal_conductivity(flag)- Value
no
- Option
-vark- Description
If yes, use varkenthSystemCtx class in the energy step. It is base on formula (4.37) in [52]. Otherwise use enthSystemCtx, which has temperature-independent thermal conductivity set by constant ice.thermal_conductivity.
enthalpy_converter.T_reference(number)- Value
223.150000 (Kelvin)
- Description
= T_0 in enthalpy formulas in [31]
enthalpy_converter.relaxed_is_temperate_tolerance(number)- Value
0.001000 (Kelvin)
- Description
Tolerance within which ice is treated as temperate (cold-ice mode and diagnostics).
flow_law.Hooke.A(number)- Value
4.421650e-09 (Pascal-3 second-1)
- Description
\(A_{\text{Hooke}} = (1/B_0)^n\) where n=3 and B_0 = 1.928 \(a^{1/3}\) Pa. See [73]
flow_law.Hooke.C(number)- Value
0.166120 (Kelvin^{flow_law.Hooke.k})
- Description
See [73]
flow_law.Hooke.Q(number)- Value
78800 (Joule / mol)
- Description
Activation energy, see [73]
flow_law.Hooke.Tr(number)- Value
273.390000 (Kelvin)
- Description
See [73]
flow_law.Hooke.k(number)- Value
1.170000 (pure number)
- Description
See [73]
flow_law.Paterson_Budd.A_cold(number)- Value
3.610000e-13 (Pascal-3 / second)
- Description
Paterson-Budd A_cold, see [69]
flow_law.Paterson_Budd.A_warm(number)- Value
1730 (Pascal-3 / second)
- Description
Paterson-Budd A_warm, see [69]
flow_law.Paterson_Budd.Q_cold(number)- Value
60000 (Joule / mol)
- Description
Paterson-Budd Q_cold, see [69]
flow_law.Paterson_Budd.Q_warm(number)- Value
139000 (Joule / mol)
- Description
Paterson-Budd Q_warm, see [69]
flow_law.Paterson_Budd.T_critical(number)- Value
263.150000 (Kelvin)
- Description
Paterson-Budd critical temperature, see [69]
flow_law.Schoof_regularizing_length(number)- Value
1000 (km)
- Description
Regularizing length (Schoof definition)
flow_law.Schoof_regularizing_velocity(number)- Value
1 (meter / year)
- Description
Regularizing velocity (Schoof definition)
flow_law.gpbld.water_frac_coeff(number)flow_law.gpbld.water_frac_observed_limit(number)flow_law.isothermal_Glen.ice_softness(number)- Value
3.168900e-24 (Pascal-3 second-1)
- Description
ice softness used by IsothermalGlenIce [30]
fracture_density.constant_fd(flag)- Value
no
- Option
-constant_fd- Description
FIXME
fracture_density.constant_healing(flag)- Value
no
- Option
-constant_healing- Description
Constant healing
fracture_density.enabled(flag)- Value
no
- Option
-fractures- Description
Calculation of fracture density according to stresses and strain rate field.
fracture_density.fd2d_scheme(flag)- Value
no
- Option
-scheme_fd2d- Description
FIXME
fracture_density.fracture_weighted_healing(flag)- Value
no
- Option
-fracture_weighted_healing- Description
Fracture weighted healing
fracture_density.include_grounded_ice(flag)- Value
no
- Option
-do_frac_on_grounded- Description
model fracture density in grounded areas
fracture_density.lefm(flag)- Value
no
- Option
-lefm- Description
FIXME
fracture_density.max_shear_stress(flag)- Value
no
- Option
-max_shear- Description
Use the max. shear stress criterion.
fracture_density.phi0(number)- Value
0 (1)
- Option
-phi0- Description
FIXME
fracture_density.softening_lower_limit(number)- Value
1 (1)
- Option
-fracture_softening- Description
epsilon in equation (6) in Albrecht and Levermann, ‘Fracture-induced softening for large-scale ice dynamics’
frontal_melt.constant.melt_rate(number)- Value
1 (m / day)
- Option
-frontal_melt_rate- Description
default melt rate used by the ‘constant’ frontal_melt model
frontal_melt.discharge_given.file(string)- Value
no default
- Option
-frontal_melt_discharge_given_file- Description
Name of the file containing climate forcing fields.
frontal_melt.discharge_given.period(integer)- Value
0
- Option
-frontal_melt_discharge_given_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
frontal_melt.discharge_given.reference_year(integer)- Value
0
- Option
-frontal_melt_discharge_given_reference_year- Description
Reference year to use when
frontal_melt.discharge_given.periodis active.
frontal_melt.given.file(string)- Value
no default
- Option
-frontal_melt_given_file- Description
Name of the file containing climate forcing fields.
frontal_melt.given.period(integer)- Value
0
- Option
-frontal_melt_given_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
frontal_melt.given.reference_year(integer)- Value
0
- Option
-frontal_melt_given_reference_year- Description
Reference year to use when
frontal_melt.given.periodis active.
frontal_melt.include_floating_ice(flag)- Value
no
- Description
Apply frontal melt to all grid icy cells next to ocean cells
frontal_melt.models(string)- Value
no default
- Option
-frontal_melt- Description
Comma-separated list of frontal melt models and modifiers. (Leave empty to disable.)
frontal_melt.routing.file(string)- Value
no default
- Option
-frontal_melt_routing_file- Description
Name of the file containing climate forcing fields.
frontal_melt.routing.parameter_a(number)- Value
0.000300 (m-alpha day^(alpha-1) Celsius-beta)
- Description
parameter A in eqn. 1 in [101]
frontal_melt.routing.parameter_b(number)- Value
0.150000 (m day^(alpha-1) Celsius-beta)
- Description
parameter B in eqn. 1 in [101]
frontal_melt.routing.period(integer)- Value
0
- Option
-frontal_melt_routing_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
frontal_melt.routing.power_alpha(number)- Value
0.390000 (1)
- Description
exponent \(\alpha\) in eqn. 1 in [101]
frontal_melt.routing.power_beta(number)- Value
1.180000 (1)
- Description
exponent \(\beta\) in eqn. 1 in [101]
frontal_melt.routing.reference_year(integer)- Value
0
- Option
-frontal_melt_routing_reference_year- Description
Reference year to use when
frontal_melt.routing.periodis active.
geometry.front_retreat.prescribed.file(string)- Value
no default
- Option
-front_retreat_file- Description
Name of the file containing the maximum ice extent mask \(land_ice_area_fraction_retreat\)
geometry.front_retreat.prescribed.period(integer)- Value
0
- Description
Length of the period of the front retreat data. Set to zero to disable.
geometry.front_retreat.prescribed.reference_year(integer)- Value
0
- Description
Reference year to use when \(geometry.front_retreat.prescribed.period\) is active.
geometry.front_retreat.use_cfl(flag)- Value
false
- Option
-front_retreat_cfl- Description
apply CFL criterion for eigen-calving rate front retreat
geometry.front_retreat.wrap_around(flag)- Value
false
- Option
-front_retreat_wrap_around- Description
If true, wrap around domain boundaries. This may be needed in some regional synthetic geometry setups.
geometry.grounded_cell_fraction(flag)- Value
false
- Option
-subgl- Description
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.
geometry.ice_free_thickness_standard(number)- Value
0.010000 (meters)
- Description
If ice is thinner than this standard then the mask is set to MASK_ICE_FREE_BEDROCK or MASK_ICE_FREE_OCEAN.
geometry.part_grid.enabled(flag)- Value
no
- Option
-part_grid- Description
apply partially filled grid cell scheme
geometry.part_grid.max_iterations(integer)- Value
10
- Description
maximum number of residual redistribution iterations
geometry.remove_icebergs(flag)- Value
no
- Option
-kill_icebergs- Description
identify and kill detached ice-shelf areas
geometry.update.enabled(flag)- Value
yes
- Option
-mass- Description
Solve the mass conservation equation
geometry.update.use_basal_melt_rate(flag)- Value
yes
- Option
-bmr_in_cont- Description
Include basal melt rate in the continuity equation
grid.Lbz(number)- Value
1000 (meters)
- Option
-Lbz- Description
Thickness of the thermal bedrock layer. (Inactive if
grid.Mbz< 2)
grid.Lx(number)- Value
1500000 (meters)
- Description
Default computational box is 3000 km x 3000 km (= 2 Lx x 2 Ly) in horizontal.
grid.Ly(number)- Value
1500000 (meters)
- Description
Default computational box is 3000 km x 3000 km (= 2 Lx x 2 Ly) in horizontal.
grid.Lz(number)- Value
4000 (meters)
- Option
-Lz- Description
Height of the computational domain.
grid.Mbz(integer)- Value
1
- Option
-Mbz- Description
Number of thermal bedrock layers; 1 level corresponds to no bedrock.
grid.Mx(integer)- Value
61
- Option
-Mx- Description
Number of grid points in the x direction.
grid.My(integer)- Value
61
- Option
-My- Description
Number of grid points in the y direction.
grid.Mz(integer)- Value
31
- Option
-Mz- Description
Number of vertical grid levels in the ice.
grid.allow_extrapolation(flag)- Value
no
- Option
-allow_extrapolation- Description
Allow extrapolation during regridding.
grid.ice_vertical_spacing(keyword)- Value
quadratic- Choices
quadratic, equal- Option
-z_spacing- Description
vertical spacing in the ice
grid.lambda(number)- Value
4 (pure number)
- Description
Vertical grid spacing parameter. Roughly equal to the factor by which the grid is coarser at an end away from the ice-bedrock interface.
grid.max_stencil_width(integer)- Value
2
- Description
Maximum width of the finite-difference stencil used in PISM.
grid.periodicity(keyword)- Value
xy- Choices
none, x, y, xy- Option
-periodicity- Description
horizontal grid periodicity
grid.recompute_longitude_and_latitude(flag)- Value
yes
- Description
Re-compute longitude and latitude using grid information and provided projection parameters. Requires PROJ.
grid.registration(keyword)- Value
center- Choices
center, corner- Description
horizontal grid registration
hydrology.add_water_input_to_till_storage(flag)- Value
yes
- Description
Add surface input to water stored in till. If no it will be added to the transportable water.
hydrology.cavitation_opening_coefficient(number)- Value
0.500000 (meter-1)
- Option
-hydrology_cavitation_opening_coefficient- Description
c_1 in notes; coefficient of cavitation opening term in evolution of layer thickness in hydrology::Distributed
hydrology.creep_closure_coefficient(number)- Value
0.040000 (pure number)
- Option
-hydrology_creep_closure_coefficient- Description
c_2 in notes; coefficient of creep closure term in evolution of layer thickness in hydrology::Distributed
hydrology.distributed.init_p_from_steady(flag)- Value
no
- Option
-hydrology_init_p_form_steady- Description
if ‘yes’, initialize subglacial water pressure from P(W) formula that applies in steady state
hydrology.distributed.sliding_speed_file(string)- Value
no default
- Option
-hydrology_sliding_speed_file- Description
name of the file containing velbase_mag, the basal sliding speed to use with
hydrology.distributed.init_p_from_steady
hydrology.gradient_power_in_flux(number)- Value
1.500000 (pure number)
- Option
-hydrology_gradient_power_in_flux- Description
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
hydrology.hydraulic_conductivity(number)- Value
0.001000 (\(m^{2 \beta - \alpha} s^{2 \beta - 3} kg^{1-\beta}\))
- Option
-hydrology_hydraulic_conductivity- Description
= 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
hydrology.maximum_time_step(number)- Value
1 (years)
- Description
maximum allowed time step length used by hydrology::Routing and hydrology::Distributed
hydrology.model(keyword)- Value
null- Choices
null, routing, steady, distributed- Option
-hydrology- Description
Basal hydrology sub-model.
hydrology.null_diffuse_till_water(flag)- Value
no
- Description
Diffuse stored till water laterally. See equation (11) of [25]
hydrology.null_diffusion_distance(number)- Value
20000 (meters)
- Description
diffusion distance for till water thickness; see equation (11) in [25]; only active if hydrology.null_diffuse_till_water is set
hydrology.null_diffusion_time(number)- Value
1000 (years)
- Description
diffusion time for till water thickness; see equation (11) in [25]; only active if hydrology.null_diffuse_till_water is set
hydrology.null_strip_width(number)- Value
-1 (meters)
- Description
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
hydrology.regularizing_porosity(number)- Value
0.010000 (pure number)
- Option
-hydrology_regularizing_porosity- Description
phi_0 in notes; regularizes pressure equation by multiplying time derivative term
hydrology.roughness_scale(number)- Value
0.100000 (meters)
- Option
-hydrology_roughness_scale- Description
W_r in notes; roughness scale determining maximum amount of cavitation opening in hydrology::Distributed
hydrology.routing.include_floating_ice(flag)- Value
no
- Description
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.
hydrology.steady.flux_update_interval(number)- Value
1 (years)
- Description
interval between updates of the steady state flux
hydrology.steady.input_rate_scaling(number)- Value
1.000000e+07 (seconds)
- Description
input rate scaling
hydrology.steady.n_iterations(integer)- Value
7500
- Description
maxinum number of iterations to use in while estimating steady-state water flux
hydrology.steady.potential_delta(number)- Value
10000 (Pa)
- Description
potential adjustment used to fill sinks (smaller values require more iterations but produce fewer artifacts)
hydrology.steady.potential_n_iterations(integer)- Value
1000
- Description
maxinum number of iterations to take while pre-processing hydraulic potential
hydrology.steady.volume_ratio(number)- Value
0.100000 (1)
- Description
water volume ratio used as the stopping criterion
hydrology.surface_input.file(string)- Value
no default
- Description
Name of the file containing
water_input_rate, the rate at which water from the ice surface is added to the subglacial hydrology system
hydrology.surface_input.period(integer)- Value
0
- Description
Length of the period of the water input rate. Set to zero to disable.
hydrology.surface_input.reference_year(integer)- Value
0
- Description
Reference year to use when
hydrology.surface_input.periodis active.
hydrology.surface_input_from_runoff(flag)- Value
no
- Description
Use surface runoff as surface input.
hydrology.thickness_power_in_flux(number)- Value
1.250000 (1)
- Option
-hydrology_thickness_power_in_flux- Description
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
hydrology.tillwat_decay_rate(number)- Value
1 (mm / year)
- Option
-hydrology_tillwat_decay_rate- Description
rate at which tillwat is reduced to zero, in absence of other effects like input
hydrology.tillwat_max(number)- Value
2 (meters)
- Option
-hydrology_tillwat_max- Description
maximum effective thickness of the water stored in till
hydrology.use_const_bmelt(flag)- Value
no
- Option
-hydrology_use_const_bmelt- Description
if ‘yes’, subglacial hydrology model sees basal melt rate which is constant and given by hydrology.const_bmelt
input.bootstrap(flag)- Value
no
- Option
-bootstrap- Description
It true, use bootstrapping heuristics when initializing PISM.
input.file(string)- Value
no default
- Option
-i- Description
Input file name
input.forcing.buffer_size(integer)- Value
60
- Description
number of 2D climate forcing records to keep in memory; = 5 years of monthly records
input.forcing.evaluations_per_year(integer)- Value
52
- Description
length of the time-series used to compute temporal averages of forcing data (such as mean annual temperature)
input.regrid.file(string)- Value
no default
- Option
-regrid_file- Description
Regridding (input) file name
input.regrid.vars(string)- Value
no default
- Option
-regrid_vars- Description
Comma-separated list of variables to regrid. Leave empty to regrid all model state variables.
inverse.design.cH1(number)- Value
0 (1)
- Option
-inv_design_cH1- Description
weight of derivative part of an H1 norm for inversion design variables
inverse.design.cL2(number)- Value
1 (1)
- Option
-inv_design_cL2- Description
weight of derivative-free part of an H1 norm for inversion design variables
inverse.design.func(keyword)- Value
sobolevH1- Choices
sobolevH1, tv- Option
-inv_design_func- Description
functional used for inversion design variables
inverse.design.param(keyword)- Value
exp- Choices
ident, trunc, square, exp- Option
-inv_design_param- Description
parameterization of design variables used during inversion
inverse.design.param_hardav_eps(number)- Value
10000 (Pascal second^(1/3))
- Description
tiny vertically-averaged hardness used as a substitute for 0 in some tauc parameterizations
inverse.design.param_hardav_scale(number)- Value
1.000000e+08 (Pascal second^(1/3))
- Description
typical size of ice hardness
inverse.design.param_tauc_eps(number)- Value
100 (Pascal)
- Description
tiny yield stress used as a substitute for 0 in some tauc parameterizations
inverse.design.param_tauc_scale(number)- Value
100000 (Pascal)
- Description
typical size of yield stresses
inverse.design.param_trunc_hardav0(number)- Value
1000000 (Pascal second^(1/3))
- Description
transition point of change to linear behaviour for design variable parameterization type ‘trunc’
inverse.design.param_trunc_tauc0(number)- Value
1000 (Pascal)
- Description
transition point of change to linear behaviour for design variable parameterization type ‘trunc’
inverse.log_ratio_scale(number)- Value
10 (pure number)
- Option
-inv_log_ratio_scale- Description
Reference scale for log-ratio functionals
inverse.max_iterations(integer)- Value
1000
- Option
-inv_max_it- Description
maximum iteration count
inverse.ssa.hardav_max(number)- Value
1.000000e+10 (Pascal second^(1/3))
- Description
Maximum allowed value of hardav for inversions with bound constraints
inverse.ssa.hardav_min(number)- Value
0 (Pascal second^(1/3))
- Description
Minimum allowed value of hardav for inversions with bound constraints
inverse.ssa.length_scale(number)- Value
50000 (meters)
- Description
typical length scale for rescaling derivative norms
inverse.ssa.method(keyword)- Value
tikhonov_lmvm- Choices
sd, nlcg, ign, tikhonov_lmvm, tikhonov_cg, tikhonov_blmvm, tikhonov_lcl, tikhonov_gn- Option
-inv_method- Description
algorithm to use for SSA inversions
inverse.ssa.tauc_max(number)- Value
5.000000e+07 (Pascal)
- Description
Maximum allowed value of tauc for inversions with bound constraints
inverse.ssa.tauc_min(number)- Value
0 (Pascal)
- Description
Minimum allowed value of tauc for inversions with bound constraints
inverse.ssa.tv_exponent(number)- Value
1.200000 (pure number)
- Option
-inv_ssa_tv_exponent- Description
Lebesgue exponent for pseudo-TV norm
inverse.ssa.velocity_eps(number)- Value
0.100000 (meter / year)
- Description
tiny size of ice velocities during inversion
inverse.ssa.velocity_scale(number)- Value
100 (meter / year)
- Description
typical size of ice velocities expected during inversion
inverse.state_func(keyword)- Value
meansquare- Choices
meansquare, log_ratio, log_relative- Option
-inv_state_func- Description
functional used for inversion design variables
inverse.target_misfit(number)- Value
100 (meter / year)
- Option
-inv_target_misfit- Description
desired root misfit for SSA inversions
inverse.tikhonov.atol(number)- Value
1.000000e-10 (meter / year)
- Option
-tikhonov_atol- Description
absolute threshold for Tikhonov stopping criterion
inverse.tikhonov.penalty_weight(number)- Value
1 (1)
- Option
-tikhonov_penalty- Description
penalty parameter for Tikhonov inversion
inverse.tikhonov.ptol(number)- Value
0.100000 (pure number)
- Option
-tikhonov_ptol- Description
threshold for reaching desired misfit for adaptive Tikhonov algorithms
inverse.tikhonov.rtol(number)- Value
0.050000 (1)
- Option
-tikhonov_rtol- Description
relative threshold for Tikhonov stopping criterion
inverse.use_design_prior(flag)- Value
yes
- Option
-inv_use_design_prior- Description
Use prior from inverse data file as initial guess.
inverse.use_zeta_fixed_mask(flag)- Value
yes
- Option
-inv_use_zeta_fixed_mask- Description
Enforce locations where the parameterized design variable should be fixed. (Automatically determined if not provided)
ocean.always_grounded(flag)- Value
no
- Option
-dry- Description
Dry (ocean-less) simulation; ice is considered grounded regardless of ice thickness, bed elevation, and sea level.
ocean.anomaly.file(string)- Value
no default
- Option
-ocean_anomaly_file- Description
Name of the file containing shelf basal mass flux offset fields.
ocean.anomaly.period(integer)- Value
0
- Option
-ocean_anomaly_period- Description
Length of the period of the ocean forcing data. Set to zero to disable.
ocean.anomaly.reference_year(integer)- Value
0
- Option
-ocean_anomaly_reference_year- Description
Reference year to use when
ocean.anomaly.periodis active.
ocean.cache.update_interval(integer)- Value
10
- Option
-ocean_cache_update_interval- Description
update interval of the ‘cache’ ocean modifier
ocean.constant.melange_back_pressure_fraction(number)- Value
0 (1)
- Description
default melange back pressure fraction in the ‘contant’ ocean model
ocean.constant.melt_rate(number)- Value
0.051914 (m / year)
- Option
-shelf_base_melt_rate- Description
default melt rate used by the ‘constant’ ocean model (computed as \(Q / (L \rho_i)\))
ocean.delta_T.file(string)- Value
no default
- Option
-ocean_delta_T_file- Description
Name of the file containing temperature offsets.
ocean.delta_T.period(integer)- Value
0
- Option
-ocean_delta_T_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
ocean.delta_T.reference_year(integer)- Value
0
- Option
-ocean_delta_T_reference_year- Description
Reference year to use when
ocean.delta_T.periodis active.
ocean.delta_mass_flux.file(string)- Value
no default
- Option
-ocean_delta_mass_flux_file- Description
Name of the file containing sub-shelf mass flux offsets.
ocean.delta_mass_flux.period(integer)- Value
0
- Option
-ocean_delta_mass_flux_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
ocean.delta_mass_flux.reference_year(integer)- Value
0
- Option
-ocean_delta_mass_flux_reference_year- Description
Reference year to use when
ocean.delta_mass_flux.periodis active.
ocean.delta_sl.file(string)- Value
no default
- Option
-ocean_delta_sl_file- Description
Name of the file containing sea level offsets.
ocean.delta_sl.period(integer)- Value
0
- Option
-ocean_delta_sl_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
ocean.delta_sl.reference_year(integer)- Value
0
- Option
-ocean_delta_sl_reference_year- Description
Reference year to use when
ocean.delta_sl.periodis active.
ocean.delta_sl_2d.file(string)- Value
no default
- Description
Name of the file containing climate forcing fields.
ocean.delta_sl_2d.period(integer)- Value
0
- Description
Length of the period of the climate forcing data. Set to zero to disable.
ocean.delta_sl_2d.reference_year(integer)- Value
0
- Description
Reference year to use when
ocean.delta_sl_2d.periodis active.
ocean.frac_MBP.file(string)- Value
no default
- Option
-ocean_frac_MBP_file- Description
Name of the file containing melange back-pressure scaling.
ocean.frac_MBP.period(integer)- Value
0
- Option
-ocean_frac_MBP_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
ocean.frac_MBP.reference_year(integer)- Value
0
- Option
-ocean_frac_MBP_reference_year- Description
Reference year to use when
ocean.frac_MBP.periodis active.
ocean.frac_mass_flux.file(string)- Value
no default
- Option
-ocean_frac_mass_flux_file- Description
Name of the file containing sub-shelf mass flux scaling.
ocean.frac_mass_flux.period(integer)- Value
0
- Option
-ocean_frac_mass_flux_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
ocean.frac_mass_flux.reference_year(integer)- Value
0
- Option
-ocean_frac_mass_flux_reference_year- Description
Reference year to use when
ocean.frac_mass_flux.periodis active.
ocean.given.file(string)- Value
no default
- Option
-ocean_given_file- Description
Name of the file containing climate forcing fields.
ocean.given.period(integer)- Value
0
- Option
-ocean_given_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
ocean.given.reference_year(integer)- Value
0
- Option
-ocean_given_reference_year- Description
Reference year to use when
ocean.given.periodis active.
ocean.melange_back_pressure_fraction(number)- Value
0 (1)
- Description
default melange back pressure fraction
ocean.models(string)- Value
constant
- Option
-ocean- Description
Comma-separated list of ocean models and modifiers.
ocean.pico.continental_shelf_depth(number)- Value
-800 (meters)
- Option
-continental_shelf_depth- Description
Determines the edge of the continental shelf to calculate mean ocean properties
ocean.pico.exclude_ice_rises(flag)- Value
yes
- Option
-exclude_icerises- Description
Exclude ice rises for box calculation in PICO
ocean.pico.file(string)- Value
no default
- Option
-ocean_pico_file- Description
Name of the file containing climate forcing fields.
ocean.pico.heat_exchange_coefficent(number)- Value
0.000020 (meters second-1)
- Option
-gamma_T- Description
Turbulent heat exchange coefficient
ocean.pico.maximum_ice_rise_area(number)- Value
100000 (km2)
- Description
Maximum ice rise area. Patches of grounded ice that are bugger than this are treated as continental ice sheets.
ocean.pico.number_of_boxes(integer)- Value
5
- Option
-number_of_boxes- Description
Default maximum number of boxes (for the largest ice shelves)
ocean.pico.overturning_coefficent(number)- Value
1000000 (meters6 seconds-1 kg-1)
- Option
-overturning_coeff- Description
Overturning stregth coefficient
ocean.pico.period(integer)- Value
0
- Option
-ocean_pico_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
ocean.pico.reference_year(integer)- Value
0
- Option
-ocean_pico_reference_year- Description
Reference year to use when
ocean.pico.periodis active.
ocean.pik_melt_factor(number)- Value
0.005000 (1)
- Option
-meltfactor_pik- Description
dimensionless tuning parameter in the ‘-ocean pik’ ocean heat flux parameterization; see [3]
ocean.sub_shelf_heat_flux_into_ice(number)- Value
0.500000 (W meter-2)
- Description
= J meter-2 second-1; naively chosen default value for heat from ocean; see comments in pism::ocean::Constant::shelf_base_mass_flux().
ocean.th.file(string)- Value
no default
- Option
-ocean_th_file- Description
Name of the file containing climate forcing fields.
ocean.th.period(integer)- Value
0
- Option
-ocean_th_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
ocean.th.reference_year(integer)- Value
0
- Option
-ocean_th_reference_year- Description
Reference year to use when
ocean.th.periodis active.
ocean.three_equation_model_clip_salinity(flag)- Value
yes
- Option
-clip_shelf_base_salinity- Description
Clip shelf base salinity so that it is in the range [4, 40] k/kg. See [11].
output.ISMIP6(flag)- Value
false
- Description
Follow ISMIP6 conventions (units, variable names, “standard names”) when writing output variables.
output.ISMIP6_extra_variables(string)- Value
lithk, orog, topg, hfgeoubed, acabf, libmassbfgr, libmassbffl, dlithkdt, velsurf, zvelsurf, velbase, zvelbase, velmean, litemptop, litempbotgr, litempbotfl, strbasemag, licalvf, lifmassbf, sftgif, sftgrf, sftflf- Description
Comma-separated list of fields reported by models participating in ISMIP6 simulations.
output.ISMIP6_ts_variables(string)- Value
lim, limnsw, iareagr, iareafl, tendacabf, tendlibmassbf, tendlibmassbffl, tendlicalvf, tendlifmassbf- Description
Comma-separated list of scalar variables (time series) reported by models participating in ISMIP6 simulations.
output.backup_interval(number)- Value
1 (hours)
- Option
-backup_interval- Description
wall-clock time between automatic backups
output.backup_size(keyword)- Value
small- Choices
none, small, medium, big_2d, big- Option
-backup_size- Description
The ‘size’ of a backup file. See configuration parameters output.sizes.medium, output.sizes.big_2d, output.sizes.big
output.extra.append(flag)- Value
no
- Option
-extra_append- Description
Append to an existing output file.
output.extra.file(string)- Value
no default
- Option
-extra_file- Description
Name of the output file containing spatially-variable diagnostics.
output.extra.split(flag)- Value
no
- Option
-extra_split- Description
Save spatially-variable diagnostics to separate files (one per time record).
output.extra.stop_missing(flag)- Value
yes
- Option
-extra_stop_missing- Description
Stop if requested variable is not available instead of warning.
output.extra.times(string)- Value
no default
- Option
-extra_times- Description
List or a range of times defining reporting intervals for spatially-variable diagnostics.
output.extra.vars(string)- Value
no default
- Option
-extra_vars- Description
Comma-separated list of spatially-variable diagnostics.
output.file_name(string)- Value
unnamed.nc
- Option
-o- Description
The file to save final model results to.
output.fill_value(number)- Value
-2.000000e+09 (none)
- Description
_FillValue used when saving diagnostic quantities
output.format(keyword)- Value
netcdf3- Choices
netcdf3, netcdf4_parallel, pnetcdf, pio_pnetcdf, pio_netcdf4p, pio_netcdf4c, pio_netcdf- Option
-o_format- Description
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.
output.ice_free_thickness_standard(number)- Value
10 (meters)
- Description
If ice is thinner than this standard then a grid cell is considered ice-free for purposes of reporting glacierized area, volume, etc.
output.pio.base(integer)- Value
0
- Description
Rank of the first I/O task
output.pio.n_writers(integer)- Value
1
- Description
Number of I/O tasks to use
output.pio.stride(integer)- Value
1
- Description
Offset between I/O tasks
output.runtime.area_scale_factor_log10(integer)- Value
6
- Option
-summary_area_scale_factor_log10- Description
an integer; log base 10 of scale factor to use for area (in km^2) in summary line to stdout
output.runtime.time_unit_name(string)- Value
year
- Description
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.)
output.runtime.time_use_calendar(flag)- Value
yes
- Description
Whether to use the current calendar when printing model time in summary to stdout.
output.runtime.viewer.size(integer)- Value
320
- Option
-view_size- Description
default diagnostic viewer size (number of pixels of the longer side)
output.runtime.viewer.variables(string)- Value
no default
- Option
-view- Description
comma-separated list of map-plane diagnostic quantities to view at runtime
output.runtime.volume_scale_factor_log10(integer)- Value
6
- Option
-summary_vol_scale_factor_log10- Description
an integer; log base 10 of scale factor to use for volume (in km^3) in summary line to stdout
output.size(keyword)- Value
medium- Choices
none, small, medium, big_2d, big- Option
-o_size- Description
The ‘size’ of an output file. See configuration parameters output.sizes.medium, output.sizes.big_2d, output.sizes.big
output.sizes.big(string)- Value
cts, liqfrac, temp, temp_pa, uvel, vvel, wvel, wvel_rel- Description
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.
output.sizes.big_2d(string)- 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- Description
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.
output.sizes.medium(string)- 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- Description
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.
output.snapshot.file(string)- Value
no default
- Option
-save_file- Description
Snapshot (output) file name (or prefix, if saving to individual files).
output.snapshot.size(keyword)- Value
small- Choices
none, small, medium, big_2d, big- Option
-save_size- Description
The ‘size’ of a snapshot file. See configuration parameters output.sizes.medium, output.sizes.big_2d, output.sizes.big
output.snapshot.split(flag)- Value
no
- Option
-save_split- Description
Save model state snapshots to separate files (one per time record).
output.snapshot.times(string)- Value
no default
- Option
-save_times- Description
List or a range of times to save model state snapshots at.
output.timeseries.append(flag)- Value
false
- Option
-ts_append- Description
If true, append to the scalar time series output file.
output.timeseries.buffer_size(integer)- Value
10000
- Description
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.
output.timeseries.filename(string)- Value
no default
- Option
-ts_file- Description
Name of the file to save scalar time series to. Leave empty to disable reporting scalar time-series.
output.timeseries.times(string)- Value
no default
- Option
-ts_times- Description
List or range of times defining reporting time intervals.
output.timeseries.variables(string)- Value
no default
- Option
-ts_vars- Description
Requested scalar (time-series) diagnostics. Leave empty to save all available diagnostics.
output.use_MKS(flag)- Value
false
- Description
Use MKS units in output files.
regional.no_model_strip(number)- Value
5 (km)
- Option
-no_model_strip- Description
Default width of the ‘no model strip’ in regional setups.
regional.no_model_yield_stress(number)- Value
1000 (kPa)
- Description
High yield stress used in the ‘no_model_mask’ area in the regional mode.
regional.zero_gradient(flag)- Value
false
- Option
-zero_grad_where_no_model- Description
Use zero ice thickness and ice surface gradient in the no_model_mask area.
run_info.institution(string)- Value
no default
- Option
-institution- Description
Institution name. This string is written to output files as the ‘institution’ global attribute.
run_info.title(string)- Value
no default
- Option
-title- Description
Free-form string containing a concise description of the current run. This string is written to output files as the ‘title’ global attribute.
sea_level.models(string)- Value
constant
- Option
-sea_level- Description
Comma-separated list of sea level models and modifiers.
stress_balance.calving_front_stress_bc(flag)stress_balance.ice_free_thickness_standard(number)- Value
10 (meters)
- Description
If ice is thinner than this standard then a cell is considered ice-free for purposes of computing ice velocity distribution.
stress_balance.model(keyword)- Value
sia- Choices
none, prescribed_sliding, weertman_sliding, sia, ssa, prescribed_sliding+sia, weertman_sliding+sia, ssa+sia- Option
-stress_balance- Description
Stress balance model
stress_balance.prescribed_sliding.file(string)- Value
no default
- Description
The name of the file containing prescribed sliding velocity (variable names: \(ubar\), \(vbar\)).
stress_balance.sia.Glen_exponent(number)- Value
3 (pure number)
- Option
-sia_n- Description
Glen exponent in ice flow law for SIA
stress_balance.sia.bed_smoother.range(number)- Value
5000 (meters)
- Option
-bed_smoother_range- Description
half-width of smoothing domain for stressbalance::BedSmoother, in implementing [93] bed roughness parameterization for SIA; set value to zero to turn off mechanism
stress_balance.sia.bed_smoother.theta_min(number)- Value
0 (1)
- Description
minimum value of \(\theta\) in [93] bed roughness parameterization for SIA
stress_balance.sia.e_age_coupling(flag)- Value
no
- Option
-e_age_coupling- Description
Couple the SIA enhancement factor to age as in [32].
stress_balance.sia.enhancement_factor(number)- Value
1 (1)
- Option
-sia_e- Description
Flow enhancement factor for SIA
stress_balance.sia.enhancement_factor_interglacial(number)- Value
1 (1)
- Option
-sia_e_interglacial- Description
Flow enhancement factor for SIA; used for ice accumulated during interglacial periods.
stress_balance.sia.flow_law(keyword)- Value
gpbld- Choices
arr, arrwarm, gk, gpbld, hooke, isothermal_glen, pb- Option
-sia_flow_law- Description
The SIA flow law.
stress_balance.sia.grain_size_age_coupling(flag)- Value
no
- Option
-grain_size_age_coupling- Description
Use age of the ice to compute grain size to use with the Goldsby-Kohlstedt [70] flow law
stress_balance.sia.limit_diffusivity(flag)- Value
no
- Option
-limit_sia_diffusivity- Description
Limit SIA diffusivity by \(stress_balance.sia.max_diffusivity\).
stress_balance.sia.max_diffusivity(number)- Value
100 (m2 s-1)
- Description
Maximum allowed diffusivity of the SIA flow. PISM stops with an error message if the SIA diffusivity exceeds this limit.
stress_balance.sia.surface_gradient_method(keyword)- Value
haseloff- Choices
eta, haseloff, mahaffy- Option
-gradient- Description
method used for surface gradient calculation at staggered grid points
stress_balance.ssa.Glen_exponent(number)- Value
3 (pure number)
- Option
-ssa_n- Description
Glen exponent in ice flow law for SSA
stress_balance.ssa.compute_surface_gradient_inward(flag)- Value
no
- Description
If yes then use inward first-order differencing in computing surface gradient in the SSA objects.
stress_balance.ssa.dirichlet_bc(flag)- Value
no
- Option
-ssa_dirichlet_bc- Description
apply SSA velocity Dirichlet boundary condition
stress_balance.ssa.enhancement_factor(number)- Value
1 (1)
- Option
-ssa_e- Description
Flow enhancement factor for SSA
stress_balance.ssa.enhancement_factor_interglacial(number)- Value
1 (1)
- Option
-ssa_e_interglacial- Description
Flow enhancement factor for SSA; used for ice accumulated during interglacial periods.
stress_balance.ssa.epsilon(number)- Value
1.000000e+13 (Pascal second meter)
- Option
-ssa_eps- Description
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 \(s^{1/3}\) [64] 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 [102], but with a tiny thickness \(H\) of about 1 cm.
stress_balance.ssa.fd.brutal_sliding(flag)- Value
false
- Option
-brutal_sliding- Description
Enhance sliding speed brutally.
stress_balance.ssa.fd.brutal_sliding_scale(number)- Value
1 (1)
- Option
-brutal_sliding_scale- Description
Brutal SSA Sliding Scale
stress_balance.ssa.fd.lateral_drag.enabled(flag)- Value
false
- Description
set viscosity at ice shelf margin next to ice free bedrock as friction parameterization
stress_balance.ssa.fd.lateral_drag.viscosity(number)- Value
5.000000e+15 (Pascal second)
- Option
-nu_bedrock- Description
Staggered Viscosity used as side friction parameterization.
stress_balance.ssa.fd.max_iterations(integer)- Value
300
- Option
-ssafd_picard_maxi- Description
Maximum number of Picard iterations for the ice viscosity computation, in the SSAFD object
stress_balance.ssa.fd.max_speed(number)- Value
300000 (km s-1)
- Option
-ssafd_max_speed- Description
Upper bound for the ice speed computed by the SSAFD solver.
stress_balance.ssa.fd.nuH_iter_failure_underrelaxation(number)- Value
0.800000 (pure number)
- Option
-ssafd_nuH_iter_failure_underrelaxation- Description
In event of ‘Effective viscosity not converged’ failure, use outer iteration rule nuH <- nuH + f (nuH - nuH_old), where f is this parameter.
stress_balance.ssa.fd.relative_convergence(number)- Value
0.000100 (1)
- Option
-ssafd_picard_rtol- Description
Relative change tolerance for the effective viscosity in the SSAFD object
stress_balance.ssa.fd.replace_zero_diagonal_entries(flag)- Value
yes
- Description
Replace zero diagonal entries in the SSAFD matrix with basal_resistance.beta_ice_free_bedrock to avoid solver failures.
stress_balance.ssa.flow_law(keyword)- Value
gpbld- Choices
arr, arrwarm, gpbld, hooke, isothermal_glen, pb- Option
-ssa_flow_law- Description
The SSA flow law.
stress_balance.ssa.method(keyword)- Value
fd- Choices
fd, fem- Option
-ssa_method- Description
Algorithm for computing the SSA solution.
stress_balance.ssa.read_initial_guess(flag)- Value
yes
- Option
-ssa_read_initial_guess- Description
Read the initial guess from the input file when re-starting.
stress_balance.ssa.strength_extension.constant_nu(number)- Value
9.486807e+14 (Pascal second)
- Description
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 \(Pa s^{1/3}\) [64] 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 [102].
stress_balance.ssa.strength_extension.min_thickness(number)- Value
50 (meters)
- Description
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.
stress_balance.vertical_velocity_approximation(keyword)- Value
centered- Choices
centered, upstream- Option
-vertical_velocity_approximation- Description
Vertical velocity FD approximation. “Upstream” uses first-order finite difference to compute u_x and v_y. Uses basal velocity to make decisions.
stress_balance.weertman_sliding.A(number)- Value
1.800000e-16 (Pa-3 year-1 m-2)
- Description
Sliding parameter in the Weertman-style sliding parameterization [75]
stress_balance.weertman_sliding.k(number)- Value
0.200000 (1)
- Description
The ratio of the basal water pressure and the ice overburden pressure in the Weertman-style sliding parameterization.
surface.anomaly.file(string)- Value
no default
- Option
-surface_anomaly_file- Description
Name of the file containing climate forcing fields.
surface.anomaly.period(integer)- Value
0
- Option
-surface_anomaly_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
surface.anomaly.reference_year(integer)- Value
0
- Option
-surface_anomaly_reference_year- Description
Reference year to use when
surface.anomaly.periodis active.
surface.cache.update_interval(integer)- Value
10
- Description
Update interval (in years) for the \(-surface cache\) modifier.
surface.delta_T.file(string)- Value
no default
- Option
-surface_delta_T_file- Description
Name of the file containing temperature offsets.
surface.delta_T.period(integer)- Value
0
- Option
-surface_delta_T_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
surface.delta_T.reference_year(integer)- Value
0
- Option
-surface_delta_T_reference_year- Description
Reference year to use when
surface.delta_T.periodis active.
surface.elevation_change.file(string)- Value
no default
- Option
-surface_elevation_change_file- Description
Name of the file containing the reference surface elevation field (variable
usurf).
surface.elevation_change.period(integer)- Value
0
- Option
-surface_elevation_change_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
surface.elevation_change.reference_year(integer)- Value
0
- Option
-surface_elevation_change_reference_year- Description
Reference year to use when
surface.elevation_change.periodis active.
surface.elevation_change.smb.exp_factor(number)- Value
0 (Kelvin-1)
- Option
-smb_exp_factor- Description
Exponential for the surface mass balance.
surface.elevation_change.smb.lapse_rate(number)- Value
0 ((m / year) / km)
- Option
-smb_lapse_rate- Description
Lapse rate for the surface mass balance.
surface.elevation_change.smb.method(keyword)- Value
shift- Choices
scale, shift- Option
-smb_adjustment- Description
Choose the SMB adjustment method.
scale: use temperature-change-dependent scaling factor.shift: use the SMB lapse rate.
surface.elevation_change.temperature_lapse_rate(number)- Value
0 (K / km)
- Option
-temp_lapse_rate- Description
Lapse rate for the temperature at the top of the ice.
surface.force_to_thickness.alpha(number)- Value
0.010000 (year-1)
- Option
-force_to_thickness_alpha- Description
exponential coefficient in force-to-thickness mechanism
surface.force_to_thickness.ice_free_alpha_factor(number)- Value
1 (1)
- Option
-force_to_thickness_ice_free_alpha_factor- Description
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
surface.force_to_thickness.ice_free_thickness_threshold(number)- Value
1 (meters)
- Option
-force_to_thickness_ice_free_thickness_threshold- Description
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.
surface.force_to_thickness.start_time(number)- Value
-4.540000e+09 (years)
- Description
Starting time for the “force to thickness” modifier; the default is “start from the creation of the Earth.”
surface.force_to_thickness_file(string)- Value
no default
- Option
-force_to_thickness_file- Description
The name of the file to read the target ice thickness from.
surface.given.file(string)- Value
no default
- Option
-surface_given_file- Description
Name of the file containing climate forcing fields.
surface.given.period(integer)- Value
0
- Option
-surface_given_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
surface.given.reference_year(integer)- Value
0
- Option
-surface_given_reference_year- Description
Reference year to use when
surface.given.periodis active.
surface.given.smb_max(number)- Value
91000 (kg m-2 year-1)
- Description
Maximum climatic mass balance value (used to check input data). Corresponds to 100 m/year ice equivalent.
surface.ismip6.file(string)- Value
no default
- Option
-surface_ismip6_file- Description
Name of the file containing climate forcing anomaly fields.
surface.ismip6.period(integer)- Value
0
- Option
-surface_ismip6_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
surface.ismip6.reference_file(string)- Value
no default
- Option
-surface_ismip6_reference_file- Description
Name of the file containing reference climate forcing fields.
surface.ismip6.reference_year(integer)- Value
0
- Description
Reference year to use when
surface.ismip6.periodis active.
surface.models(string)- Value
given
- Option
-surface- Description
Comma-separated list of surface models and modifiers.
surface.pdd.air_temp_all_precip_as_rain(number)- Value
275.150000 (Kelvin)
- Description
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
surface.pdd.air_temp_all_precip_as_snow(number)- Value
273.150000 (Kelvin)
- Description
threshold temperature below which all precipitation is snow
surface.pdd.balance_year_start_day(integer)- Value
274
- Description
day of year for October 1st, beginning of the balance year in northern latitudes.
surface.pdd.factor_ice(number)- Value
0.008791 (meter / (Kelvin day))
- Description
EISMINT-Greenland value [7]; = (8 mm liquid-water-equivalent) / (pos degree day)
surface.pdd.factor_snow(number)- Value
0.003297 (meter / (Kelvin day))
- Description
EISMINT-Greenland value [7]; = (3 mm liquid-water-equivalent) / (pos degree day)
surface.pdd.fausto.T_c(number)- Value
272.150000 (Kelvin)
- Description
= -1 + 273.15; for formula (6) in [1]
surface.pdd.fausto.T_w(number)- Value
283.150000 (Kelvin)
- Description
= 10 + 273.15; for formula (6) in [1]
surface.pdd.fausto.beta_ice_c(number)- Value
0.015000 (meter / (Kelvin day))
- Description
water-equivalent thickness; for formula (6) in [1]
surface.pdd.fausto.beta_ice_w(number)- Value
0.007000 (meter / (Kelvin day))
- Description
water-equivalent thickness; for formula (6) in [1]
surface.pdd.fausto.beta_snow_c(number)- Value
0.003000 (meter / (Kelvin day))
- Description
water-equivalent thickness; for formula (6) in [1]
surface.pdd.fausto.beta_snow_w(number)- Value
0.003000 (meter / (Kelvin day))
- Description
water-equivalent thickness; for formula (6) in [1]
surface.pdd.fausto.enabled(flag)- Value
false
- Option
-pdd_fausto- Description
Set PDD parameters using formulas (6) and (7) in [1]
surface.pdd.fausto.latitude_beta_w(number)- Value
72 (degree_north)
- Description
latitude below which to use warm case, in formula (6) in [1]
surface.pdd.firn_compaction_to_accumulation_ratio(number)- Value
0.750000 (1)
- Description
How much firn as a fraction of accumulation is turned into ice
surface.pdd.firn_depth_file(string)- Value
no default
- Option
-pdd_firn_depth_file- Description
The name of the file to read the firn_depth from.
surface.pdd.interpret_precip_as_snow(flag)- Value
no
- Description
Interpret precipitation as snow fall.
surface.pdd.max_evals_per_year(integer)- Value
52
- Description
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
surface.pdd.method(keyword)- Value
expectation_integral- Choices
expectation_integral, repeatable_random_process, random_process- Option
-pdd_method- Description
PDD implementation method
surface.pdd.positive_threshold_temp(number)- Value
273.150000 (Kelvin)
- Description
temperature used to determine meaning of ‘positive’ degree day
surface.pdd.refreeze(number)- Value
0.600000 (1)
- Description
EISMINT-Greenland value [7]
surface.pdd.refreeze_ice_melt(flag)- Value
yes
- Description
If set to ‘yes’, refreeze surface.pdd.refreeze fraction of melted ice, otherwise all of the melted ice runs off.
surface.pdd.std_dev(number)- Value
5 (Kelvin)
- Description
std dev of daily temp variation; = EISMINT-Greenland value [7]
surface.pdd.std_dev.file(string)- Value
no default
- Option
-pdd_sd_file- Description
The name of the file to read \(air_temp_sd\) (standard deviation of air temperature) from.
surface.pdd.std_dev.period(integer)- Value
0
- Option
-pdd_sd_period- Description
Length of the period of the climate forcing data. Set to zero to disable.
surface.pdd.std_dev.reference_year(integer)- Value
0
- Option
-pdd_sd_reference_year- Description
Reference year to use when
surface.pdd.std_dev.periodis active.
surface.pdd.std_dev_lapse_lat_base(number)- Value
72 (degree_north)
- Description
std_dev is a function of latitude, with value surface.pdd.std_dev at this latitude; this value only active if surface.pdd.std_dev_lapse_lat_rate is nonzero
surface.pdd.std_dev_lapse_lat_rate(number)- Value
0 (Kelvin / degree_north)
- Description
std_dev is a function of latitude, with rate of change with respect to latitude given by this constant
surface.pdd.std_dev_param_a(number)- Value
-0.150000 (pure number)
- Description
Parameter a in Sigma = a*T + b, with T in degrees C. Used only if surface.pdd.std_dev_use_param is set to yes.
surface.pdd.std_dev_param_b(number)- Value
0.660000 (Kelvin)
- Description
Parameter b in Sigma = a*T + b, with T in degrees C. Used only if surface.pdd.std_dev_use_param is set to yes.
surface.pdd.std_dev_use_param(flag)- Value
no
- Description
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.
surface.pressure(number)- Value
0 (Pascal)
- Description
atmospheric pressure; = pressure at ice surface
time.calendar(keyword)- Value
365_day- Choices
standard, gregorian, proleptic_gregorian, noleap, 365_day, 360_day, julian, none- Option
-calendar- Description
The calendar to use.
time.dimension_name(string)- Value
time
- Description
The name of the time dimension in PISM output files.
time.eemian_end(number)- Value
-114500 (years)
- Description
End of the Eemian interglacial period. See [67].
time.eemian_start(number)- Value
-132000 (years)
- Description
Start of the Eemian interglacial period. See [67].
time.holocene_start(number)- Value
-11000 (years)
- Description
Start of the Holocene interglacial period. See [67].
time.reference_date(string)- Value
1-1-1
- Description
year-month-day; reference date used for calendar computations and in PISM output files
time.run_length(number)- Value
1000 (years)
- Description
Default run length
time.start_year(number)- Value
0 (years)
- Description
Start year.
time_stepping.adaptive_ratio(number)- Value
0.120000 (1)
- Option
-adapt_ratio- Description
Adaptive time stepping ratio for the explicit scheme for the mass balance equation; [26], inequality (25)
time_stepping.count_steps(flag)- Value
no
- Option
-count_steps- Description
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.
time_stepping.hit_extra_times(flag)- Value
yes
- Option
-extra_force_output_times- Description
Modify the time-stepping mechanism to hit times requested using -extra_times.
time_stepping.hit_multiples(number)- Value
0 (years)
- Option
-timestep_hit_multiples- Description
Hit every X years, where X is specified using this parameter. Use 0 to disable
time_stepping.hit_save_times(flag)- Value
no
- Option
-save_force_output_times- Description
Modify the time-stepping mechanism to hit times requested using -save_times.
time_stepping.hit_ts_times(flag)- Value
no
- Description
Modify the time-stepping mechanism to hit times requested using -ts_times.
time_stepping.maximum_time_step(number)- Value
60 (years)
- Option
-max_dt- Description
Maximum allowed time step length
time_stepping.skip.enabled(flag)- Value
no
- Option
-skip- Description
Use the temperature, age, and SSA stress balance computation skipping mechanism.
time_stepping.skip.max(integer)- Value
10
- Option
-skip_max- Description
Number of mass-balance steps, including SIA diffusivity updates, to perform before a the temperature, age, and SSA stress balance computations are done
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