Constants.h

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/*
 *  SNOWPACK stand-alone
 *
 *  Copyright WSL Institute for Snow and Avalanche Research SLF, DAVOS, SWITZERLAND
*/
/*  This file is part of Snowpack.
    Snowpack 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 3 of the License, or
    (at your option) any later version.
 
    Snowpack 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 Snowpack.  If not, see <http://www.gnu.org/licenses/>.
*/
 
#ifndef CONSTANTS_H
#define CONSTANTS_H
 
#include <cstddef> //needed for size_t
 
#ifndef SN_VERSION
        //here below, the double-expansion stringification macro trick...
        #define STR1(x) #x
        #define STR2(x) STR1(x)
        #define SN_VERSION STR2( _VERSION )
#endif
 
#define INIT_STABILITY 999.
 
namespace Constants {
        const double undefined = -999.; 
        const int iundefined = -999; 
        const size_t stundefined = static_cast<size_t>(-999);
        const double min_percent_values = 0.9;
 
        const double pi = 3.14159265358979323846;
        const double g  = 9.80665;
        const double stefan_boltzmann = 5.67051e-8;
 
        const double solcon = 1366.1; 
 
        const double gas_constant = 461.9; 
        const double gas_constant_air = 287.0; 
        const double gas_constant_mol = 8.31;  
        const double karman = 0.4; 
 
 
        const double min_albedo = 0.3;
        const double max_albedo = 0.9;
        const double glacier_albedo = 0.3;
 
        const double emissivity_snow = 0.98;
  const double emissivity_soil = 0.95;
 
 
        const double density_air = 1.1; 
        const double density_ice = 917.0; 
        const double density_water = 1000.0; 
        const double density_vapor = 1.0; 
 
 
        const double specific_heat_ice = 2100.0; 
        const double specific_heat_water = 4190.0; 
        const double specific_heat_air = 1004.67; 
 
 
        const double conductivity_ice = 2.2; 
        const double conductivity_water = 0.598; 
        const double conductivity_air = 0.026; 
 
 
        const double diffusion_coefficient_in_air = 22.0e-6;
        const double diffusion_coefficient_in_snow = 85.0e-6; 
 
 
        const double meltfreeze_tk = 273.15; 
        const double triple_point_t = 273.16; 
        const double triple_point_p = 611.73; 
        const double lh_sublimation = 2.838e6; 
        const double lh_vaporization = 2.504e6; 
        const double lh_fusion = 3.34e5; 
 
 
        const double min_slope_angle = 3.; 
 
        const double eps = 1.e-6;
        const double eps2 = eps*eps;
        const double big = 1.0e200; 
}
 
#endif