Meteoconst.h

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// SPDX-License-Identifier: LGPL-3.0-or-later
/***********************************************************************************/
/*  Copyright 2009 WSL Institute for Snow and Avalanche Research    SLF-DAVOS      */
/***********************************************************************************/
/* This file is part of MeteoIO.
    MeteoIO is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
 
    MeteoIO 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 Lesser General Public License for more details.
 
    You should have received a copy of the GNU Lesser General Public License
    along with MeteoIO.  If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef METEOCONST_H
#define METEOCONST_H
 
#include <cfloat>
#include <cmath>
 
#ifndef MIO_VERSION
        //here below, the double-expansion stringification macro trick...
        #define STR1(x) #x
        #define STR2(x) STR1(x)
        #define MIO_VERSION STR2( _VERSION )
#endif
 
namespace mio {
 
namespace Cst {
        constexpr double stefan_boltzmann = 5.670373e-8; // (W m-2 K-4)
        constexpr double gravity = 9.80665; // (m s-2)
        constexpr double std_press = 101325.; // (Pa) at sea level
        constexpr double std_temp = 288.15; // (K) at sea level
        constexpr double mean_adiabatique_lapse_rate = 0.0065; // (K/m)
        constexpr double dry_adiabatique_lapse_rate = 0.0098; // (K/m)
 
        constexpr double gaz_constant_dry_air = 287.058; // (J kg-1 K-1)
        constexpr double gaz_constant_water_vapor = 461.9; // (J kg-1 K-1)
        constexpr double gaz_constant = 8.31451; // (J mol-1 K-1)
 
        constexpr double p_water_triple_pt = 611.73; // (Pa)
        constexpr double t_water_freezing_pt = 273.15; // (K)
        constexpr double t_water_triple_pt = 273.16; // (K)
        constexpr double l_water_sublimation = 2.838e6; // (J kg-1)
        constexpr double l_water_vaporization = 2.504e6; // (J kg-1)
        constexpr double l_water_fusion = 3.34e5; // (J Kg-1)
        constexpr double water_molecular_mass = 18.0153e-3; // (kg)
        constexpr double dry_air_mol_mass = 0.0289644; // (kg/mol)
 
        constexpr double specific_heat_ice = 2100.0; // (J K-1), at 0C
        constexpr double specific_heat_water = 4190.0; // (J K-1) at 0C
        constexpr double specific_heat_air = 1004.67; // (J K-1), see Stull "Meteorology for scientists and engineers" p44
 
        constexpr double earth_R0 = 6356766.0; // (m)
 
        constexpr double solcon = 1366.1; // (W/m^2)
        constexpr double albedo_short_grass = .23;
        constexpr double albedo_bare_soil = 0.17;
        constexpr double albedo_fresh_snow = .85;
        constexpr double snow_nosnow_thresh = .1; //if snow height greater than this threshold -> snow albedo
 
        //Math constants
        static const double phi = (1.+sqrt(5)) / 2.; //golden ratio
        constexpr double e = 2.71828182845904523536; // e
        constexpr double Log2e = 1.44269504088896340736; // log2(e)
        constexpr double Log10e = 0.434294481903251827651; // log10(e)
        constexpr double Ln2 = 0.693147180559945309417; // ln(2)
        constexpr double Ln10 = 2.30258509299404568402; // ln(10)
        constexpr double PI = 3.14159265358979323846; // pi
        constexpr double PI2 = 1.57079632679489661923; // pi/2
        constexpr double PI4 = 0.785398163397448309616; // pi/4
        constexpr double InvPI = 0.318309886183790671538; // 1/pi
        constexpr double TwoOverPI = 0.636619772367581343076; // 2/pi
        constexpr double TwoOverSqrtPI = 1.12837916709551257390; // 2/sqrt(pi)
        constexpr double Sqrt2 = 1.41421356237309504880; // sqrt(2)
        constexpr double InvSqrt2 = 0.707106781186547524401; // 1/sqrt(2)
        constexpr double to_rad = PI/180.; // conversion factor from deg to rad
        constexpr double to_deg = 180./PI; // conversion factor from rad to deg
 
        constexpr double dbl_max = DBL_MAX;
        constexpr double dbl_min = -DBL_MAX;
} //end CST namespace
 
} //end namespace
 
#endif