glacier_mod – ISOFT

Provides an abstract type to represent large masses of ice, such as ice sheets and ice shelves.

Uses

- iso_fortran_env
- factual_mod
- nitsol_mod
- hdf5
- penf
- logger_mod
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Used by

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Graph Key

Nodes of different colours represent the following:

Solid arrows point from a submodule to the (sub)module which it is descended from. Dashed arrows point from a module or program unit to modules which it uses.

Variables

Type	Visibility	Attributes		Name		Initial
character(len=12),	public,	parameter	::	hdf_type_attr	=	'glacier_type'

Abstract Interfaces

abstract interface

private function get_scalar(this) result(property)

Arguments

Type Intent Optional Attributes Name

class(glacier), intent(in) :: this

Return Value class(scalar_field), pointer

The value of whatever property of the glacier is being returned.

abstract interface

private pure function get_r8(this) result(property)

Arguments

Type Intent Optional Attributes Name

class(glacier), intent(in) :: this

Return Value real(kind=r8)

The value of whatever property of the glacier is being returned.

abstract interface

private function get_residual(this, previous_states, melt_rate, basal_drag_parameter, water_density) result(residual)

Arguments

Type	Intent	Attributes		Name
class(glacier),	intent(in)		::	this
class(glacier),	intent(in),	dimension(:)	::	previous_states	The states of the glacier in the previous time steps. The first element of the array should be the most recent. The default implementation will only make use of the most recent state, but the fact that this is an array allows overriding methods to use older states for higher-order integration methods.
class(scalar_field),	intent(in)		::	melt_rate	Thickness of the ice above the glacier
class(scalar_field),	intent(in)		::	basal_drag_parameter	A paramter, e.g. coefficient of friction, needed to calculate the drag on basal surface of the glacier.
real(kind=r8),	intent(in)		::	water_density	The density of the water below the glacier

Return Value real(kind=r8), dimension(:), allocatable

The residual of the system of equations describing the glacier

abstract interface

private function precond(this, previous_states, melt_rate, basal_drag_parameter, water_density, delta_state) result(preconditioned)

Arguments

Type	Intent	Attributes		Name
class(glacier),	intent(inout)		::	this
class(glacier),	intent(in),	dimension(:)	::	previous_states	The states of the glacier in the previous time steps. The first element of the array should be the most recent. The default implementation will only make use of the most recent state, but the fact that this is an array allows overriding methods to use older states for higher-order integration methods.
class(scalar_field),	intent(in)		::	melt_rate	Thickness of the ice above the glacier
class(scalar_field),	intent(in)		::	basal_drag_parameter	A paramter, e.g. coefficient of friction, needed to calculate the drag on basal surface of the glacier.
real(kind=r8),	intent(in)		::	water_density	The density of the water below the glacier
real(kind=r8),	intent(in),	dimension(:)	::	delta_state	The change to the state vector which is being preconditioned.

Return Value real(kind=r8), dimension(:), allocatable

The result of applying the preconditioner to delta_state.

abstract interface

private function get_r81d(this) result(state_vector)

Arguments

Type Intent Optional Attributes Name

class(glacier), intent(in) :: this

Return Value real(kind=r8), dimension(:), allocatable

The state vector of the glacier

abstract interface

private pure function get_i(this) result(property)

Arguments

Type Intent Optional Attributes Name

class(glacier), intent(in) :: this

Return Value integer

The value of whatever property of the glacier is being returned.

abstract interface

private function t_step(this)

Arguments

Type Intent Optional Attributes Name

class(glacier), intent(in) :: this

Return Value real(kind=r8)

A time step which will allow integration of the ice shelf without causing numerical instability.

abstract interface

private subroutine solve_vel(this, basal_drag, success)

Arguments

Type	Intent		Name
class(glacier),	intent(inout)	::	this
class(scalar_field),	intent(in)	::	basal_drag	A paramter, e.g. coefficient of friction, needed to calculate the drag on basal surface of the glacier.
logical,	intent(out)	::	success	True if the integration is successful, false otherwise

abstract interface

private subroutine setter(this, state_vector)

Arguments

Type	Intent	Optional	Attributes		Name
class(glacier),	intent(inout)			::	this
real(kind=r8),	intent(in),		dimension(:)	::	state_vector	A real array containing the data describing the state of the glacier.

abstract interface

private subroutine time_setter(this, time)

Arguments

Type	Intent	Optional	Attributes		Name
class(glacier),	intent(inout)			::	this
real(kind=r8),	intent(in)			::	time	The time at which the glacier is in the present state.

abstract interface

private subroutine read_dat(this, file_id, group_name, error)

Arguments

Type	Intent		Name
class(glacier),	intent(inout)	::	this
integer(kind=hid_t),	intent(in)	::	file_id	The identifier for the HDF5 file/group from which the data will be read.
character(len=*),	intent(in)	::	group_name	The name of the group in the HDF5 file from which to read glacier's data.
integer,	intent(out)	::	error	Flag indicating whether routine ran without error. If no error occurs then has value 0.

abstract interface

private subroutine write_dat(this, file_id, group_name, error)

Arguments

Type	Intent		Name
class(glacier),	intent(in)	::	this
integer(kind=hid_t),	intent(in)	::	file_id	The identifier for the HDF5 file/group in which this data is meant to be written.
character(len=*),	intent(in)	::	group_name	The name to give the group in the HDF5 file storing the glacier's data.
integer,	intent(out)	::	error	Flag indicating whether routine ran without error. If no error occurs then has value 0.

abstract interface

private subroutine assign_ice(this, rhs)

Arguments

Type Intent Optional Attributes Name

class(glacier), intent(out) :: this

class(glacier), intent(in) :: rhs

Type	Intent	Optional	Attributes		Name
class(glacier),	intent(out)			::	this
class(glacier),	intent(in)			::	rhs

abstract interface

public pure function thickness_func(location) result(thickness)

Abstract interface for function providing the glacier thickness when a concrete object is being instantiated.

Arguments

Type Intent Optional Attributes Name

real(kind=r8), intent(in), dimension(:) :: location
The position $\vec{x}$ at which to compute the thickness

Return Value real(kind=r8)

The thickness of the glacier at location

Type	Intent	Optional	Attributes		Name
real(kind=r8),	intent(in),		dimension(:)	::	location	The position $\vec{x}$ at which to compute the thickness

abstract interface

public pure function velocity_func(location) result(velocity)

Abstract interface for function providing the glacier velocity when a concrete object is being instantiated.

Arguments

Type Intent Optional Attributes Name

real(kind=r8), intent(in), dimension(:) :: location
The position $\vec{x}$ at which to compute the thickness

Return Value real(kind=r8), dimension(:), allocatable

The velocity vector of the ice in the glacier at location

Type	Intent	Optional	Attributes		Name
real(kind=r8),	intent(in),		dimension(:)	::	location	The position $\vec{x}$ at which to compute the thickness

Derived Types

type, public, abstract :: glacier

An abstract data type which represents large masses of ice, such as ice shelves and ice sheets.

Type-Bound Procedures

procedure(get_scalar), public :: ice_thickness	Returns the thickness of the ice in the glacier across the domain.
procedure(get_r8), public :: ice_density	Returns the density of the ice, which is assumed to be uniform.
procedure(get_r8), public :: ice_temperature	Returns the temperature of the ice, which is assumed to be uniform.
procedure(get_residual), public :: residual	Computes the residual of the system of equations describing the glacier.
procedure(precond), public :: precondition	Applies a preconditioner to the passed state vector.
procedure(solve_vel), public :: solve_velocity	Solves for the velocity field using the current thickness.
procedure(setter), public :: update	Sets the state of the glacier.
procedure(time_setter), public :: set_time	Sets the time record for this glacier.
procedure(get_i), public :: data_size	Returns the number of elements in the glacier's state vector
procedure(get_r81d), public :: state_vector	Returns the glacier's state vector, a 1D array with all necessary data to describe its state.
procedure(read_dat), public :: read_data	Read the glacier data from an HDF5 file on the disc.
procedure(write_dat), public :: write_data	Writes the data describing the glacier to the disc as an HDF5 file.
procedure(t_step), public :: time_step	Calculates the appropriate time step for integration.
procedure(assign_ice), private :: assign	Copies the data from one glacier into another. This is only needed due to a bug in gfortran which means that the intrinsic assignment for glacier types is not using the appropriate defined assignment for the field components.
generic, public :: assignment(=) => assign
procedure, public :: integrate => glacier_integrate	Performs a time-step of the integration, taking the state of the glacier to the specified time using the provided melt-rate data.
procedure, public :: integrate_layers => glacier_integrate_layers	Dummy routine which can be over-ridden to integrate internal layers of the glacier to the specified time.

Subroutines

private subroutine glacier_integrate(this, old_states, basal_melt, basal_drag, water_density, time, success)

Author: Chris MacMackin
Date: November 2016

Integrates the glacier's state to time. This is done using the NITSOL package of iterative Krylov solvers. If a different algorithm for the integration is desired, then this method may be overridden in the concrete implementations of the glacier type.

Arguments

Type	Intent	Attributes		Name
class(glacier),	intent(inout)		::	this
class(glacier),	intent(in),	dimension(:)	::	old_states	Previous states of the glacier, with the most recent one first.
class(scalar_field),	intent(in)		::	basal_melt	The melt rate that the bottom of the glacier experiences during this time step.
class(scalar_field),	intent(in)		::	basal_drag	A paramter, e.g. coefficient of friction, needed to calculate the drag on basal surface of the glacier.
real(kind=r8),	intent(in)		::	water_density	The density of the water below the glacier.
real(kind=r8),	intent(in)		::	time	The time to which the glacier should be integrated
logical,	intent(out)		::	success	True if the integration is successful, false otherwise

private subroutine glacier_integrate_layers(this, old_states, time, success)

Author: Chris MacMackin
Date: September 2018

Dummy routine which does nothing.

Arguments

Type	Intent	Attributes		Name
class(glacier),	intent(inout)		::	this
class(glacier),	intent(in),	dimension(:)	::	old_states	Previous states of the glacier, with the most recent one first.
real(kind=r8),	intent(in)		::	time	The time to which the glacier should be integrated
logical,	intent(out)		::	success	True if the integration is successful, false otherwise

glacier_mod Module

Contents

Uses

Used by

Contents

Variables

Abstract Interfaces

abstract interface

private function get_scalar(this) result(property)

Arguments

Return Value class(scalar_field), pointer

abstract interface

private pure function get_r8(this) result(property)

Arguments

Return Value real(kind=r8)

abstract interface

private function get_residual(this, previous_states, melt_rate, basal_drag_parameter, water_density) result(residual)

Arguments

Return Value real(kind=r8), dimension(:), allocatable

abstract interface

private function precond(this, previous_states, melt_rate, basal_drag_parameter, water_density, delta_state) result(preconditioned)

Arguments

Return Value real(kind=r8), dimension(:), allocatable

abstract interface

private function get_r81d(this) result(state_vector)

Arguments

Return Value real(kind=r8), dimension(:), allocatable

abstract interface

private pure function get_i(this) result(property)

Arguments

Return Value integer

abstract interface

private function t_step(this)

Arguments

Return Value real(kind=r8)

abstract interface

private subroutine solve_vel(this, basal_drag, success)

Arguments

abstract interface

private subroutine setter(this, state_vector)

Arguments

abstract interface

private subroutine time_setter(this, time)

Arguments

abstract interface

private subroutine read_dat(this, file_id, group_name, error)

Arguments

abstract interface

private subroutine write_dat(this, file_id, group_name, error)

Arguments

abstract interface

private subroutine assign_ice(this, rhs)

Arguments

abstract interface

public pure function thickness_func(location) result(thickness)

Arguments

Return Value real(kind=r8)

abstract interface

public pure function velocity_func(location) result(velocity)

Arguments

Return Value real(kind=r8), dimension(:), allocatable

Derived Types

type, public, abstract :: glacier

Type-Bound Procedures

Subroutines

private subroutine glacier_integrate(this, old_states, basal_melt, basal_drag, water_density, time, success)

Arguments

private subroutine glacier_integrate_layers(this, old_states, time, success)

Arguments