SNOWPACK 3.7.0
Constants Namespace Reference

Variables

const double undefined = -999.
 This is the snowpack undefined value. More...
 
const int iundefined = -999
 This is the snowpack undefined value. More...
 
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
 Total Solar Irradiance (W m-2) (Froehlich, 2006) More...
 
const double gas_constant = 461.9
 (J kg-1 K-1) More...
 
const double gas_constant_air = 287.0
 for air (J kg-1 K-1) More...
 
const double gas_constant_mol = 8.31
 (J mol-1 K-1) More...
 
const double karman = 0.4
 Karman constant. More...
 
Albedo (1)
const double min_albedo = 0.3
 
const double max_albedo = 0.9
 
const double glacier_albedo = 0.3
 
Emissivity (1)
const double emissivity_snow = 0.98
 
const double emissivity_soil = 0.95
 
Density (kg m-3)
const double density_air = 1.1
 Approximation: use ideal gas law. More...
 
const double density_ice = 917.0
 At T = 0 degC. More...
 
const double density_water = 1000.0
 At T = 0 degC. More...
 
const double density_vapor = 1.0
 Approximation: use ideal gas law. More...
 
Specific heat (J kg-1 K-1)
const double specific_heat_ice = 2100.0
 at T = 0 degC More...
 
const double specific_heat_water = 4190.0
 at T = 0 degC More...
 
const double specific_heat_air = 1004.67
 see Stull "Meteorology for scientists and engineers" p44 More...
 
Thermal conductivity of snow components ice, water and air (W m-1 K-1)
const double conductivity_ice = 2.2
 (W m-1 K-1) More...
 
const double conductivity_water = 0.598
 (W m-1 K-1) More...
 
const double conductivity_air = 0.026
 (W m-1 K-1) More...
 
Vapor Diffusion in Air and Snow (m2 s-1)
const double diffusion_coefficient_in_air = 22.0e-6
 This value was taken from: Colbeck, S.C., 1993. The vapor diffusion coefficient for snow, Water Resources Research, 29(1) More...
 
const double diffusion_coefficient_in_snow = 85.0e-6
 It is larger (see Colbeck) according to work prior to 2008! More...
 
Phase change constants
const double meltfreeze_tk = 273.15
 (K) More...
 
const double triple_point_t = 273.16
 (K) More...
 
const double triple_point_p = 611.73
 (Pa) More...
 
const double lh_sublimation = 2.838e6
 (J kg-1) (solid to vapor) More...
 
const double lh_vaporization = 2.504e6
 (J kg-1) (liquid to vapor) More...
 
const double lh_fusion = 3.34e5
 (J kg-1) (solid to liquid) More...
 
Numerical Constants
const double min_slope_angle = 3.
 Smallest angle a flat field may show (deg) More...
 
const double eps = 1.e-6
 Small numbers for comparisons and to avoid divisions by zero. More...
 
const double eps2 = eps*eps
 
const double big = 1.0e200
 used for Dirichlet boundary conditions More...
 

Variable Documentation

◆ big

const double Constants::big = 1.0e200

used for Dirichlet boundary conditions

◆ conductivity_air

const double Constants::conductivity_air = 0.026

(W m-1 K-1)

◆ conductivity_ice

const double Constants::conductivity_ice = 2.2

(W m-1 K-1)

◆ conductivity_water

const double Constants::conductivity_water = 0.598

(W m-1 K-1)

◆ density_air

const double Constants::density_air = 1.1

Approximation: use ideal gas law.

◆ density_ice

const double Constants::density_ice = 917.0

At T = 0 degC.

◆ density_vapor

const double Constants::density_vapor = 1.0

Approximation: use ideal gas law.

◆ density_water

const double Constants::density_water = 1000.0

At T = 0 degC.

◆ diffusion_coefficient_in_air

const double Constants::diffusion_coefficient_in_air = 22.0e-6

This value was taken from: Colbeck, S.C., 1993. The vapor diffusion coefficient for snow, Water Resources Research, 29(1)

◆ diffusion_coefficient_in_snow

const double Constants::diffusion_coefficient_in_snow = 85.0e-6

It is larger (see Colbeck) according to work prior to 2008!

◆ emissivity_snow

const double Constants::emissivity_snow = 0.98

◆ emissivity_soil

const double Constants::emissivity_soil = 0.95

◆ eps

const double Constants::eps = 1.e-6

Small numbers for comparisons and to avoid divisions by zero.

◆ eps2

const double Constants::eps2 = eps*eps

◆ g

const double Constants::g = 9.80665

◆ gas_constant

const double Constants::gas_constant = 461.9

(J kg-1 K-1)

◆ gas_constant_air

const double Constants::gas_constant_air = 287.0

for air (J kg-1 K-1)

◆ gas_constant_mol

const double Constants::gas_constant_mol = 8.31

(J mol-1 K-1)

◆ glacier_albedo

const double Constants::glacier_albedo = 0.3

◆ iundefined

const int Constants::iundefined = -999

This is the snowpack undefined value.

◆ karman

const double Constants::karman = 0.4

Karman constant.

◆ lh_fusion

const double Constants::lh_fusion = 3.34e5

(J kg-1) (solid to liquid)

◆ lh_sublimation

const double Constants::lh_sublimation = 2.838e6

(J kg-1) (solid to vapor)

◆ lh_vaporization

const double Constants::lh_vaporization = 2.504e6

(J kg-1) (liquid to vapor)

◆ max_albedo

const double Constants::max_albedo = 0.9

◆ meltfreeze_tk

const double Constants::meltfreeze_tk = 273.15

(K)

◆ min_albedo

const double Constants::min_albedo = 0.3

◆ min_percent_values

const double Constants::min_percent_values = 0.9

◆ min_slope_angle

const double Constants::min_slope_angle = 3.

Smallest angle a flat field may show (deg)

◆ pi

const double Constants::pi = 3.14159265358979323846

◆ solcon

const double Constants::solcon = 1366.1

Total Solar Irradiance (W m-2) (Froehlich, 2006)

◆ specific_heat_air

const double Constants::specific_heat_air = 1004.67

see Stull "Meteorology for scientists and engineers" p44

◆ specific_heat_ice

const double Constants::specific_heat_ice = 2100.0

at T = 0 degC

◆ specific_heat_water

const double Constants::specific_heat_water = 4190.0

at T = 0 degC

◆ stefan_boltzmann

const double Constants::stefan_boltzmann = 5.67051e-8

◆ stundefined

const size_t Constants::stundefined = static_cast<size_t>(-999)

◆ triple_point_p

const double Constants::triple_point_p = 611.73

(Pa)

◆ triple_point_t

const double Constants::triple_point_t = 273.16

(K)

◆ undefined

const double Constants::undefined = -999.

This is the snowpack undefined value.