src/coupler/localMassBalance.hh

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// Copyright (C) 2009, 2010, 2011 Ed Bueler and Constantine Khroulev
//
// This file is part of PISM.
//
// PISM is free software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the Free Software
// Foundation; either version 2 of the License, or (at your option) any later
// version.
//
// PISM is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
// FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
// details.
//
// You should have received a copy of the GNU General Public License
// along with PISM; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

#ifndef __localMassBalance_hh
#define __localMassBalance_hh

#include <petsc.h>
#include <gsl/gsl_rng.h>
#include "NCVariable.hh"
#include "iceModelVec.hh"  // only needed for FaustoGrevePDDObject



struct DegreeDayFactors {
  PetscScalar  snow, 
               ice,  
               refreezeFrac;  
};



class LocalMassBalance {
public:
  LocalMassBalance(const NCConfigVariable &myconfig)
    : config(myconfig) {}
  virtual ~LocalMassBalance() {}
  virtual PetscErrorCode init() { return 0; };

  virtual PetscErrorCode getNForTemperatureSeries(
                PetscScalar t, PetscScalar dt, PetscInt &N) = 0;


  virtual PetscScalar getPDDSumFromTemperatureTimeSeries(
                 PetscScalar pddStdDev, PetscScalar pddThresholdTemp,
                 PetscScalar t, PetscScalar dt_series, PetscScalar *T, PetscInt N) = 0;

  virtual PetscScalar getSnowFromPrecipAndTemperatureTimeSeries(
                 PetscScalar precip_rate,
                 PetscScalar t, PetscScalar dt_series, PetscScalar *T, PetscInt N) = 0;

  virtual PetscErrorCode getMassFluxesFromPDDs(const DegreeDayFactors &ddf,
                                               PetscScalar dt, PetscScalar pddsum,
                                               PetscScalar snow,
                                               PetscScalar &accumulation_rate,
                                               PetscScalar &melt_rate,
                                               PetscScalar &runoff_rate,
                                               PetscScalar &smb_rate) = 0;

protected:
  const NCConfigVariable& config;
};



class PDDMassBalance : public LocalMassBalance {

public:
  PDDMassBalance(const NCConfigVariable& myconfig);
  virtual ~PDDMassBalance() {}

  virtual PetscErrorCode getNForTemperatureSeries(
             PetscScalar t, PetscScalar dt, PetscInt &N);

  virtual PetscScalar getPDDSumFromTemperatureTimeSeries(
                 PetscScalar pddStdDev, PetscScalar pddThresholdTemp,
                 PetscScalar t, PetscScalar dt_series, PetscScalar *T, PetscInt N);

  virtual PetscScalar getSnowFromPrecipAndTemperatureTimeSeries(
                 PetscScalar precip_rate,
                 PetscScalar t, PetscScalar dt_series, PetscScalar *T, PetscInt N);

  virtual PetscErrorCode getMassFluxesFromPDDs(const DegreeDayFactors &ddf,
                                               PetscScalar dt, PetscScalar pddsum,
                                               PetscScalar snow,
                                               PetscScalar &accumulation_rate,
                                               PetscScalar &melt_rate,
                                               PetscScalar &runoff_rate,
                                               PetscScalar &smb_rate);

protected:
  PetscScalar CalovGreveIntegrand(PetscScalar sigma, PetscScalar TacC);

  bool precip_as_snow;          
  PetscScalar Tmin,             
              Tmax;             
};



class PDDrandMassBalance : public PDDMassBalance {

public:
  PDDrandMassBalance(const NCConfigVariable& myconfig, bool repeatable); 
  virtual ~PDDrandMassBalance();

  virtual PetscErrorCode getNForTemperatureSeries(
                PetscScalar t, PetscScalar dt, PetscInt &N);

  virtual PetscScalar getPDDSumFromTemperatureTimeSeries(
               PetscScalar pddStdDev, PetscScalar pddThresholdTemp,
               PetscScalar t, PetscScalar dt_series, PetscScalar *T, PetscInt N);

protected:
  gsl_rng *pddRandGen;
};


class FaustoGrevePDDObject {

public:
  FaustoGrevePDDObject(IceGrid &g, const NCConfigVariable &myconfig);
  virtual ~FaustoGrevePDDObject() {}

  virtual PetscErrorCode update_temp_mj(IceModelVec2S *surfelev, IceModelVec2S *lat, IceModelVec2S *lon);

  virtual PetscErrorCode setDegreeDayFactors(
              PetscInt i, PetscInt j,
              PetscScalar /* usurf */, PetscScalar lat, PetscScalar /* lon */,
              DegreeDayFactors &ddf);

protected:
  IceGrid &grid;
  const NCConfigVariable &config;
  PetscScalar beta_ice_w, beta_snow_w, T_c, T_w, beta_ice_c, beta_snow_c,
              fresh_water_density, ice_density, pdd_fausto_latitude_beta_w;
  IceModelVec2S temp_mj;
};


#endif