PISM, A Parallel Ice Sheet Model  stable v2.0.5 committed by Constantine Khrulev on 2022-10-14 09:56:26 -0800
PatersonBudd.cc
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19 
20 #include <cmath>
21 
22 #include "PatersonBudd.hh"
23 
24 namespace pism {
25 namespace rheology {
26 
27 // PatersonBudd
28 
29 PatersonBudd::PatersonBudd(const std::string &prefix,
30  const Config &config,
32  : FlowLaw(prefix, config, ec) {
33  m_name = "Paterson-Budd";
34 }
35 
36 /*! Converts enthalpy to temperature and uses the Paterson-Budd formula. */
37 double PatersonBudd::softness_impl(double E, double pressure) const {
38  double T_pa = m_EC->pressure_adjusted_temperature(E, pressure);
39  return softness_from_temp(T_pa);
40 }
41 
42 /*! Converts enthalpy to temperature and calls flow_from_temp. */
43 double PatersonBudd::flow_impl(double stress, double E,
44  double pressure, double gs) const {
45  double temp = m_EC->temperature(E, pressure);
46  return flow_from_temp(stress, temp, pressure, gs);
47 }
48 
49 //! The flow law (temperature-dependent version).
50 double PatersonBudd::flow_from_temp(double stress, double temp,
51  double pressure, double /*gs*/) const {
52  // pressure-adjusted temperature:
53  const double T_pa = temp + (m_beta_CC_grad / (m_rho * m_standard_gravity)) * pressure;
54  return softness_from_temp(T_pa) * pow(stress, m_n-1);
55 }
56 
57 double PatersonBudd::softness_from_temp(double T_pa) const {
58  return softness_paterson_budd(T_pa);
59 }
60 
61 double PatersonBudd::hardness_from_temp(double T_pa) const {
62  return pow(softness_from_temp(T_pa), m_hardness_power);
63 }
64 
65 } // end of namespace rheology
66 } // end of namespace pism
A class for storing and accessing PISM configuration flags and parameters.
std::shared_ptr< EnthalpyConverter > Ptr
double softness_paterson_budd(double T_pa) const
Return the softness parameter A(T) for a given temperature T.
Definition: FlowLaw.cc:81
double m_standard_gravity
acceleration due to gravity
Definition: FlowLaw.hh:149
std::string m_name
Definition: FlowLaw.hh:116
double m_rho
ice density
Definition: FlowLaw.hh:119
double m_hardness_power
; used to compute hardness
Definition: FlowLaw.hh:135
double m_beta_CC_grad
Clausius-Clapeyron gradient.
Definition: FlowLaw.hh:121
double m_n
power law exponent
Definition: FlowLaw.hh:153
EnthalpyConverter::Ptr m_EC
Definition: FlowLaw.hh:125
virtual double flow_from_temp(double stress, double temp, double pressure, double gs) const
The flow law (temperature-dependent version).
Definition: PatersonBudd.cc:50
virtual double hardness_from_temp(double T_pa) const
Definition: PatersonBudd.cc:61
virtual double softness_from_temp(double T_pa) const
Definition: PatersonBudd.cc:57
virtual double flow_impl(double stress, double E, double pressure, double gs) const
Definition: PatersonBudd.cc:43
virtual double softness_impl(double enthalpy, double pressure) const
Definition: PatersonBudd.cc:37
PatersonBudd(const std::string &prefix, const Config &config, EnthalpyConverter::Ptr EC)
Definition: PatersonBudd.cc:29