pyissm.model.classes.hydrology

Hydrology classes for ISSM.

Classes

`armapw`([other])	ARMAPW hydrology class for ISSM.
`dc`([other])	Dual Porous Continuum Equivalent (DC) hydrology class for ISSM.
`glads`([other])	GlaDS hydrology class for ISSM.
`pism`([other])	PISM hydrology class for ISSM.
`shakti`([other])	Shakti hydrology class for ISSM.
`shreve`([other])	Shreve hydrology class for ISSM.
`tws`([other])	TWS hydrology class for ISSM.

class pyissm.model.classes.hydrology.armapw(other=None)

Bases: manage_state

ARMAPW hydrology class for ISSM.

This class contains the default parameters for the ARMA piecewise (armapw) hydrology model in the ISSM framework.

Parameters:: other (any, optional) – Any other class object that contains common fields to inherit from. If values in other differ from default values, they will override the default values.

num_basins

Number of different basins [unitless].

Type:: int, default=0

num_params

Number of different parameters in the piecewise-polynomial (1:intercept only, 2:with linear trend, 3:with quadratic trend, etc.).

Type:: int, default=0

num_breaks

Number of different breakpoints in the piecewise-polynomial (separating num_breaks+1 periods).

Type:: int, default=0

polynomialparams

Coefficients for the polynomial (const, trend, quadratic, etc.), dimensioned by basins, periods, and orders.

Type:: numpy.ndarray, default=np.nan

arma_timestep

Time resolution of the ARMA model [yr].

Type:: float, default=0

ar_order

Order of the autoregressive model [unitless].

Type:: int, default=0

ma_order

Order of the moving-average model [unitless].

Type:: int, default=0

arlag_coefs

Basin-specific vectors of AR lag coefficients [unitless].

Type:: numpy.ndarray, default=np.nan

malag_coefs

Basin-specific vectors of MA lag coefficients [unitless].

Type:: numpy.ndarray, default=np.nan

datebreaks

Dates at which the breakpoints in the piecewise polynomial occur (1 row per basin) [yr].

Type:: numpy.ndarray, default=np.nan

basin_id

Basin number assigned to each element [unitless].

Type:: numpy.ndarray, default=np.nan

monthlyfactors

Monthly multiplicative factor on the subglacial water pressure, specified per basin (size: [num_basins, 12]).

Type:: numpy.ndarray, default=np.nan

requested_outputs

Additional outputs requested.

Type:: list, default=[‘default’]

Examples

>>> md.hydrology = pyissm.model.classes.hydrology.armapw()

check_consistency(md, solution, analyses)

Check consistency of the [hydrology.armapw] parameters.

Parameters:

md (pyissm.model.Model) – The model object to check.
solution (str) – The solution name to check.
analyses (list of str) – List of analyses to check consistency for.

Returns:

md – The model object with any consistency errors noted.

Return type:

pyissm.model.Model

marshall_class(fid, prefix, md=None)

Marshall [hydrology.armapw] parameters to a binary file.

Parameters:

fid (file object) – The file object to write the binary data to.
prefix (str) – Prefix string used for data identification in the binary file.
md (pyissm.model.Model, optional) – ISSM model object needed in some cases.

Return type:

None

class pyissm.model.classes.hydrology.dc(other=None)

Bases: manage_state

Dual Porous Continuum Equivalent (DC) hydrology class for ISSM.

This class contains the default parameters for the dual continuum (dc) hydrology model in the ISSM framework.

Parameters:: other (any, optional) – Any other class object that contains common fields to inherit from. If values in other differ from default values, they will override the default values.

water_compressibility

Compressibility of water [Pa^-1].

Type:: float, default=5.04e-10

isefficientlayer

Use efficient drainage system [1: true, 0: false].

Type:: int, default=1

penalty_factor

Exponent used in the penalisation method [dimensionless].

Type:: int, default=3

penalty_lock

Stabilize unstable constraints (default 0: no stabilization).

Type:: int, default=0

rel_tol

Tolerance for nonlinear iteration between layers [dimensionless].

Type:: float, default=1.0e-06

max_iter

Maximum number of nonlinear iterations.

Type:: int, default=100

steps_per_step

Number of hydrology steps per time step.

Type:: int, default=1

step_adapt

Adaptive sub-stepping [1: true, 0: false].

Type:: int, default=0

averaging

Averaging method for steps (0: Arithmetic, 1: Geometric, 2: Harmonic).

Type:: int, default=0

sedimentlimit_flag

Type of upper limit for the inefficient layer (0: none, 1: user, 2: hydrostatic, 3: normal stress).

Type:: int, default=0

sedimentlimit

User-defined upper limit for the inefficient layer [m].

Type:: float, default=0

transfer_flag

Transfer method between layers (0: none, 1: constant leakage).

Type:: int, default=1

unconfined_flag

Use unconfined scheme (0: confined only, 1: confined-unconfined).

Type:: int, default=0

leakage_factor

User-defined leakage factor [m].

Type:: float, default=1.0e-10

basal_moulin_input

Water flux at a given point [m3 s^-1].

Type:: numpy.ndarray, default=np.nan

requested_outputs

Additional outputs requested.

Type:: list, default=[‘default’]

spcsediment_head

Sediment water head constraints [m above MSL].

Type:: numpy.ndarray, default=np.nan

mask_thawed_node

Mask for thawed nodes (0: frozen).

Type:: numpy.ndarray, default=np.nan

sediment_transmitivity

Sediment transmissivity [m^2/s].

Type:: float, default=8.0e-04

sediment_compressibility

Sediment compressibility [Pa^-1].

Type:: float, default=1.0e-08

sediment_porosity

Sediment porosity [dimensionless].

Type:: float, default=0.4

sediment_thickness

Sediment thickness [m].

Type:: float, default=20.0

spcepl_head

EPL water head constraints [m above MSL].

Type:: numpy.ndarray, default=np.nan

mask_eplactive_node

Mask for active EPL nodes (1: active, 0: inactive).

Type:: numpy.ndarray, default=np.nan

epl_compressibility

EPL compressibility [Pa^-1].

Type:: float, default=1.0e-08

epl_porosity

EPL porosity [dimensionless].

Type:: float, default=0.4

epl_initial_thickness

EPL initial thickness [m].

Type:: float, default=1.0

epl_thick_comp

EPL thickness computation flag.

Type:: int, default=1

epl_max_thickness

EPL maximal thickness [m].

Type:: float, default=5.0

epl_conductivity

EPL conductivity [m^2/s].

Type:: float, default=8.0e-02

epl_colapse_thickness

EPL collapsing thickness [m] (computed as sediment_transmitivity / epl_conductivity).

Type:: float

eplflip_lock

Lock EPL activity to avoid flip-flopping (default 0: no stabilization).

Type:: int, default=0

Examples

>>> md.hydrology = pyissm.model.classes.hydrology.dc()

check_consistency(md, solution, analyses)

Check consistency of the [hydrology.dc] parameters.

Parameters:

md (pyissm.model.Model) – The model object to check.
solution (str) – The solution name to check.
analyses (list of str) – List of analyses to check consistency for.

Returns:

md – The model object with any consistency errors noted.

Return type:

pyissm.model.Model

initialize(md)

Initialise [hydrology.dc] empty fields.

If current values of required fields are np.nan, they will be set to default required shapes/values and warnings will be issued.

Examples

>>> md.hydrology = pyissm.model.classes.hydrology.dc()
# At this point, initial fields are np.nan
# After calling initialize, they will be set to default shapes/values with warnings issued.
>>> md.hydrology.initialize(md)

marshall_class(fid, prefix, md=None)

Marshall [hydrology.dc] parameters to a binary file.

Parameters:

fid (file object) – The file object to write the binary data to.
prefix (str) – Prefix string used for data identification in the binary file.
md (pyissm.model.Model, optional) – ISSM model object needed in some cases.

Return type:

None

class pyissm.model.classes.hydrology.glads(other=None)

Bases: manage_state

GlaDS hydrology class for ISSM.

This class contains the default parameters for the Glacier Drainage System (GlaDS) hydrology model in the ISSM framework.

Parameters:: other (any, optional) – Any other class object that contains common fields to inherit from. If values in other differ from default values, they will override the default values.

pressure_melt_coefficient

Pressure melt coefficient (c_t) [K Pa^-1].

Type:: float, default=7.5e-8

sheet_conductivity

Sheet conductivity (k) [m^(7/4) kg^(-1/2)].

Type:: float or ndarray, default=np.nan

cavity_spacing

Cavity spacing (l_r) [m].

Type:: float, default=2.0

bump_height

Typical bump height (h_r) [m].

Type:: float or ndarray, default=np.nan

omega

Transition parameter (omega) [].

Type:: float, default=1./2000.

sheet_alpha

First sheet-flow exponent (alpha_s) [].

Type:: float, default=5.0/4.0

sheet_beta

Second sheet-flow exponent (beta_s) [].

Type:: float, default=3.0/2.0

rheology_B_base

Ice rheology factor B at base of ice (B) [Pa s^(-1/3)].

Type:: float or ndarray, default=np.nan

isincludesheetthickness

Add rho_w*g*h in effective pressure calculation? 1: yes, 0: no.

Type:: int, default=0

creep_open_flag

Allow cavities to open by creep when N<0? 1: yes, 0: no.

Type:: int, default=1

ischannels

Allow for channels? True or False.

Type:: bool, default=False

channel_conductivity

Channel conductivity (k_c) [m^(3/2) kg^(-1/2)].

Type:: float, default=5.e-2

channel_sheet_width

Channel sheet width [m].

Type:: float, default=2.0

channel_alpha

First channel-flow exponent (alpha_c) [].

Type:: float, default=5.0/4.0

channel_beta

Second channel-flow exponent (beta_c) [].

Type:: float, default=3.0/2.0

spcphi

Hydraulic potential Dirichlet constraints [Pa].

Type:: float or numpy.ndarray, default=np.nan

moulin_input

Moulin input (Q_s) [m^3/s].

Type:: float or numpy.ndarray, default=np.nan

neumannflux

Water flux applied along the model boundary [m^2/s].

Type:: float or numpy.ndarray, default=np.nan

englacial_void_ratio

Englacial void ratio (e_v).

Type:: float, default=1.e-5

requested_outputs

Additional outputs requested.

Type:: list, default=[‘default’]

melt_flag

User specified basal melt? 0: no (default), 1: use md.basalforcings.groundedice_melting_rate.

Type:: int, default=0

istransition

Use standard [0, default] or transition model [1].

Type:: int, default=0

Examples

>>> md.hydrology = pyissm.model.classes.hydrology.glads()

check_consistency(md, solution, analyses)

Check consistency of the [hydrology.glads] parameters.

Parameters:

md (pyissm.model.Model) – The model object to check.
solution (str) – The solution name to check.
analyses (list of str) – List of analyses to check consistency for.

Returns:

md – The model object with any consistency errors noted.

Return type:

pyissm.model.Model

marshall_class(fid, prefix, md=None)

Marshall [hydrology.glads] parameters to a binary file.

Parameters:

fid (file object) – The file object to write the binary data to.
prefix (str) – Prefix string used for data identification in the binary file.
md (pyissm.model.Model, optional) – ISSM model object needed in some cases.

Return type:

None

class pyissm.model.classes.hydrology.pism(other=None)

Bases: manage_state

PISM hydrology class for ISSM.

This class contains the default parameters for the PISM hydrology model in the ISSM framework.

Parameters:: other (any, optional) – Any other class object that contains common fields to inherit from. If values in other differ from default values, they will override the default values.

drainage_rate

Fixed drainage rate [mm/yr].

Type:: numpy.ndarray, default=np.nan

watercolumn_max

Maximum water column height [m], recommended default: 2 m.

Type:: float, default=np.nan

requested_outputs

List of requested output variables.

Type:: list, default=[‘default’]

Examples

>>> md.hydrology = pyissm.model.classes.hydrology.pism()

check_consistency(md, solution, analyses)

Check consistency of the [hydrology.pism] parameters.

Parameters:

md (pyissm.model.Model) – The model object to check.
solution (str) – The solution name to check.
analyses (list of str) – List of analyses to check consistency for.

Returns:

md – The model object with any consistency errors noted.

Return type:

pyissm.model.Model

marshall_class(fid, prefix, md=None)

Marshall [hydrology.pism] parameters to a binary file.

Parameters:

fid (file object) – The file object to write the binary data to.
prefix (str) – Prefix string used for data identification in the binary file.
md (pyissm.model.Model, optional) – ISSM model object needed in some cases.

Return type:

None

class pyissm.model.classes.hydrology.shakti(other=None)

Bases: manage_state

Shakti hydrology class for ISSM.

This class contains the default parameters for the Shakti hydrology model in the ISSM framework.

Parameters:: other (any, optional) – Any other class object that contains common fields to inherit from. If values in other differ from default values, they will override the default values.

head

Subglacial hydrology water head [m].

Type:: float or numpy.ndarray, default=np.nan

gap_height

Height of gap separating ice from bed [m].

Type:: float or numpy.ndarray, default=np.nan

gap_height_min

Minimum allowed gap height [m].

Type:: float, default=1e-3

gap_height_max

Maximum allowed gap height [m].

Type:: float, default=1.0

bump_spacing

Characteristic bedrock bump spacing [m].

Type:: float or numpy.ndarray, default=np.nan

bump_height

Characteristic bedrock bump height [m].

Type:: float or numpy.ndarray, default=np.nan

englacial_input

Liquid water input from englacial to subglacial system [m/yr].

Type:: float or numpy.ndarray, default=np.nan

moulin_input

Liquid water input from moulins (at the vertices) to subglacial system [m^3/s].

Type:: float or numpy.ndarray, default=np.nan

reynolds

Reynolds number.

Type:: float or numpy.ndarray, default=np.nan

spchead

Water head constraints (NaN means no constraint) [m].

Type:: float or numpy.ndarray, default=np.nan

neumannflux

Water flux applied along the model boundary [m^2/s].

Type:: float or numpy.ndarray, default=np.nan

relaxation

Under-relaxation coefficient for nonlinear iteration.

Type:: float, default=1

storage

Englacial storage coefficient (void ratio).

Type:: float or numpy.ndarray, default=np.nan

requested_outputs

Additional outputs requested.

Type:: list, default=[‘default’]

Examples

>>> md.hydrology = pyissm.model.classes.hydrology.shakti()

check_consistency(md, solution, analyses)

Check consistency of the [hydrology.shakti] parameters.

Parameters:

md (pyissm.model.Model) – The model object to check.
solution (str) – The solution name to check.
analyses (list of str) – List of analyses to check consistency for.

Returns:

md – The model object with any consistency errors noted.

Return type:

pyissm.model.Model

marshall_class(fid, prefix, md=None)

Marshall [hydrology.shakti] parameters to a binary file.

Parameters:

fid (file object) – The file object to write the binary data to.
prefix (str) – Prefix string used for data identification in the binary file.
md (pyissm.model.Model, optional) – ISSM model object needed in some cases.

Return type:

None

class pyissm.model.classes.hydrology.shreve(other=None)

Bases: manage_state

Shreve hydrology class for ISSM.

This class contains the default parameters for the Shreve hydrology model in the ISSM framework.

Parameters:: other (any, optional) – Any other class object that contains common fields to inherit from. If values in other differ from default values, they will override the default values.

spcwatercolumn

Water thickness constraints (NaN means no constraint) [m].

Type:: numpy.ndarray, default=np.nan

stabilization

Artificial diffusivity (default: 1). Can be more than 1 to increase diffusivity.

Type:: int, default=1

requested_outputs

Additional outputs requested.

Type:: list, default=[‘default’]

Examples

>>> md.hydrology = pyissm.model.classes.hydrology.shreve()

check_consistency(md, solution, analyses)

Check consistency of the [hydrology.shreve] parameters.

Parameters:

md (pyissm.model.Model) – The model object to check.
solution (str) – The solution name to check.
analyses (list of str) – List of analyses to check consistency for.

Returns:

md – The model object with any consistency errors noted.

Return type:

pyissm.model.Model

marshall_class(fid, prefix, md=None)

Marshall [hydrology.shreve] parameters to a binary file.

Parameters:

fid (file object) – The file object to write the binary data to.
prefix (str) – Prefix string used for data identification in the binary file.
md (pyissm.model.Model, optional) – ISSM model object needed in some cases.

Return type:

None

class pyissm.model.classes.hydrology.tws(other=None)

Bases: manage_state

TWS hydrology class for ISSM.

This class contains the default parameters for the TWS (two water sheet) hydrology model in the ISSM framework.

Parameters:: other (any, optional) – Any other class object that contains common fields to inherit from. If values in other differ from default values, they will override the default values.

spcwatercolumn

Water thickness constraints (NaN means no constraint) [m].

Type:: numpy.ndarray, default=np.nan

requested_outputs

Additional outputs requested.

Type:: list, default=[‘default’]

Examples

>>> md.hydrology = pyissm.model.classes.hydrology.tws()

check_consistency(md, solution, analyses)

Check consistency of the [hydrology.tws] parameters.

Parameters:

md (pyissm.model.Model) – The model object to check.
solution (str) – The solution name to check.
analyses (list of str) – List of analyses to check consistency for.

Returns:

md – The model object with any consistency errors noted.

Return type:

pyissm.model.Model

marshall_class(fid, prefix, md=None)

Marshall [hydrology.tws] parameters to a binary file.

Parameters:

fid (file object) – The file object to write the binary data to.
prefix (str) – Prefix string used for data identification in the binary file.
md (pyissm.model.Model, optional) – ISSM model object needed in some cases.

Return type:

None