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.