Converts between specific enthalpy and temperature or liquid content. More...

#include <EnthalpyConverter.hh>

Inheritance diagram for pism::EnthalpyConverter:

Public Types
typedef std::shared_ptr< EnthalpyConverter >	Ptr

Public Member Functions
	EnthalpyConverter (const Config &config)

virtual	~EnthalpyConverter ()=default

bool	is_temperate (double E, double P) const

bool	is_temperate_relaxed (double E, double P) const
	A relaxed version of `is_temperate()`.

double	temperature (double E, double P) const
	Get absolute (not pressure-adjusted) ice temperature (K) from enthalpy and pressure.

double	melting_temperature (double P) const
	Get melting temperature from pressure p.

double	pressure_adjusted_temperature (double E, double P) const
	Get pressure-adjusted ice temperature, in kelvin, from enthalpy and pressure.

double	water_fraction (double E, double P) const
	Get liquid water fraction from enthalpy and pressure.

double	enthalpy (double T, double omega, double P) const
	Compute enthalpy from absolute temperature, liquid water fraction, and pressure.

double	enthalpy_cts (double P) const
	Get enthalpy E_s(p) at cold-temperate transition point from pressure p.

double	enthalpy_liquid (double P) const
	Compute the maximum allowed value of ice enthalpy (corresponds to $\omega = 1$ ).

double	enthalpy_permissive (double T, double omega, double P) const
	Compute enthalpy more permissively than enthalpy().

double	c () const
	Specific heat capacity of ice.

double	L (double T_pm) const

double	pressure (double depth) const
	Get pressure in ice from depth below surface using the hydrostatic assumption.

void	pressure (const std::vector< double > &depth, unsigned int ks, std::vector< double > &result) const
	Compute pressure in a column of ice. Does not check validity of `depth`.

Protected Member Functions
double	temperature_cold (double E) const
	Convert enthalpy into temperature (cold case).

double	enthalpy_cold (double T) const
	Convert temperature into enthalpy (cold case).

Static Protected Member Functions
static void	validate_E_P (double E, double P)

static void	validate_T_omega_P (double T, double omega, double P)

Protected Attributes
double	m_T_melting
	melting temperature of pure water at atmospheric pressure

double	m_L
	latent heat of fusion of water at atmospheric pressure

double	m_c_i
	specific heat capacity of ice

double	m_c_w
	specific heat capacity of pure water

double	m_rho_i
	density of ice

double	m_g
	acceleration due to gravity

double	m_p_air
	atmospheric pressure

double	m_beta
	beta in the Clausius-Clapeyron relation ( $\diff{T_m}{p} = - \beta$ ).

double	m_T_tolerance
	temperature tolerance used in `is_temperate()` in cold ice mode

double	m_T_0
	reference temperature in the definition of ice enthalpy

bool	m_cold_mode
	if cold ice methods are selected, use `is_temperate()` check based on temperature, not enthalpy

Detailed Description

Converts between specific enthalpy and temperature or liquid content.

Use this way, for example within IceModel with Config config member:

#include "enthalpyConverter.hh"
 
EnthalpyConverter EC(&config);  // runs constructor; do after initialization of Config config
...
for (...) {
...
E_s = EC.enthalpy_cts(p);
... etc ...
}   

The three methods that get the enthalpy from temperatures and liquid fractions, namely enthalpy(), enthalpy_permissive() are more strict about error checking. They throw RuntimeError if their arguments are invalid.

This class is documented by [AschwandenBuelerKhroulevBlatter].

Maps from $(H,p)$ to $(T,\omega,p)$ and back.

Requirements:

A converter has to implement an invertible map $(H,p) \to (T, \omega, p)$ and its inverse. Both the forward map and the inverse need to be defined for all permissible values of $(H,p)$ and $(T, \omega, p)$ , respectively.
A converter has to be consistent with laws and parameterizations used elsewhere in the model. This includes models coupled to PISM.
For a fixed volume of liquid (or solid) water and given two energy states $(H_1, p_1)$ and $(H_2, p_2)$ , let $\Delta U_H$ be the difference in internal energy of this volume between the two states computed using enthalpy. We require that $\Delta U_T = \Delta U_H$ , where $\Delta U_T$ is the difference in internal energy computed using corresponding $(T_1, \omega_1, p_1)$ and $(T_2, \omega_2, p_2)$ .
We assume that ice and water are incompressible, so a change in pressure does no work, and $\Diff{H}{p} = 0$ . In addition to this, for cold ice and liquid water $\Diff{T}{p} = 0$ .

Definition at line 51 of file EnthalpyConverter.hh.

The documentation for this class was generated from the following files:

src/util/EnthalpyConverter.hh
src/util/EnthalpyConverter.cc

Public Types

Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Detailed Description