basins,
Python
Q_SW = net shortwave radiation (W / m^2) Q_LW = net longwave radiation (W / m^2) T_air = air temperature (deg C) T_surf = surface (snow) temperature (deg C) RH = relative humidity (none) (in (0,1)) p_0 = atmospheric pressure (mbar) u_z = wind velocity at height z (m / s) z = reference height for wind (m) z0_air = surface roughness height (m) h0_snow = initial snow depth (m) h0_swe = initial depth, snow water equivalent (m) ρ_snow = density of the snow (kg / m^3) c_snow = specific heat capacity of snow (J / (kg deg_C)) ρ_air = density of the air (kg / m^3) c_air = specific heat capacity of air (J / (kg deg_C)) L_f = latent heat of fusion, water (J / kg) (334000) L_v = latent heat of vaporization, water (J / kg) (2500000) e_air = air vapor pressure at height z (mbar) e_surf = vapor pressure at the surface (mbar) g = gravitational constant = 9.81 (m / s^2) κ = von Karman's constant = 0.41 (unitless)
The behavior of this component is controlled with a configuration (CFG) file, which may point to other files that contain input data. Here is a sample configuration (CFG) file for this component:
Method code: 2 Method name: Energy_Balance Time step: Scalar 3600.00000000 (sec) Cp_snow: Scalar 2090.00000000 (J/kg/K) rho_snow: Scalar 300.00000000 (kg/m^3) c0: Scalar 2.70000005 (mm/day/deg C) T0: Scalar -0.20000000 (deg C) h0_snow: Scalar 0.50000000 (m) h0_swe: Scalar 0.15000000 (m) Save grid timestep: Scalar 60.00000000 (sec) Save mr grids: 0 Case5_2D-SMrate.rts (m/s) Save hs grids: 0 Case5_2D-hsnow.rts (m) Save sw grids: 0 Case5_2D-hswe.rts (m) Save cc grids: 0 Case5_2D-Ecc.rts (J/m^2) Save pixels timestep: Scalar 60.00000000 (sec) Save mr pixels: 0 Case5_0D-SMrate.txt (m/s) Save hs pixels: 0 Case5_0D-hsnow.txt (m) Save sw pixels: 0 Case5_0D-hswe.txt (m) Save cc pixels: 0 Case5_0D-Ecc.txt (J/m^2)
M = (1000 * Q_m) / (ρ_water * L_f) = meltrate (mm / sec) M_max = (1000 * h_snow / dt) * (ρ_water / ρ_snow) = max possible meltrate (mm / sec) dh_snow = M * (ρ_water / ρ_snow) * dt = change in snow depth (m) Q_m = Q_SW + Q_LW + Q_h + Q_e - Q_cc = energy flux used to melt snow (W / m^2) Q_h = ρ_air * c_air * D_h * (T_air - T_surf) = sensible heat flux (W / m^2) Q_e = ρ_air * L_v * D_e * (0.662 / p_0) * (e_air - e_surf) = latent heat flux (W / m^2) D_n = κ^2 * u_z / LN((z - h_snow) / z0_air)^2 = bulk exchange coefficient (neutrally stable conditions) (m / s) D_h = D_n / (1 + (10 * Ri)), (T_air > T_surf) = bulk exchange coefficient for heat (m / s) (stable) = D_n * (1 - (10 * Ri)), (Tair < Tsurf) = bulk exchange coefficient for heat (m / s) (unstable) D_e = D_h = bulk exchange coefficient for vapor (m / s) Ri = g * z * (T_air - T_surf) / (u_z^2 (T_air + 273.15)) = Richardson's number (unitless) Q_cc = (see note below) = cold content flux (W / m^2) E_cc(0) = h0_snow * ρ_snow * c_snow * (T_0 - T_snow) = initial cold content (J / m^2) (T0 = 0 now) e_air = e_sat(T_air) * RH = vapor pressure of air (mbar) e_surf = e_sat(T_surf) = vapor pressure at surface (mbar) e_sat = 6.11 * exp((17.3 * T) / (T + 237.3)) = saturation vapor pressure (mbar, not KPa), Brutsaert (1975)
This part will be filled out by CSDMS staff
TopoFlow, TopoFlow-Meteorology, TopoFlow-Infiltration-Smith-Parlange, TopoFlow-Infiltration-Richards_1D, TopoFlow-Infiltration-Green-Ampt, Gc2d, TopoFlow-Evaporation-Read_File, TopoFlow-Evaporation-Priestley_Taylor, TopoFlow-Evaporation-Energy_Balance, TopoFlow-Channels-Kinematic_Wave, TopoFlow-Channels-Dynamic_Wave, TopoFlow-Channels-Diffusive_Wave,
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