SNOW HYDROLOGY (GEOG 4321): HOMEWORK ASSIGNMENT 9

Instuctor: Mark Williams
Telephone: 492-8830

Homework 9

• Assigned 23 May
• Due before class on Tuesday.
• There are 30 possible points.

1. Do a unit analysis of the Planck equation (5 points).
   • E lambda = 2 pi h c^2 / lambda^5[exp(h c /k lambda T) - 1]; where
   • speed of light (c) is 3x10^8 m/s
   • Planck's constant (energy in each photon, h) is 6.626x10^-34 J s
   • Boltzmann's constant (distribution of energy, k) is 1.381x10^ -23 J/deg
   • T is temperature in deg
2. Calculate net radiation, given (15 points):
   • Incoming direct visible is 500 W/m2
   • Incoming diffuse is 150 W/m2
   • Albedo of incoming direct is 0.90
   • Albedo of incoming diffuse is 0.50
   • Emissivity of snow is 0.97
   • Emissivity of the atmosphere is 0.90
   • Snow surface temperature is -10 deg C
   • Air temperature is -20 deg C
   • Viewfactor is 0
3. Calculate sensible heat flux (H) using the simularity hypothesis and the aerodynamic profile method, with data from these two measurement heights (5 points):
   • U ₂ = 4.0 m/s
   • U ₁ = 2.0 m/s
   • T ₂ = 4.0 deg C
   • T ₁ = 0.0 deg C
   • Z ₂ = 2.0 m
   • Z ₁ = 1.5 m
   • k = 0.4
4. Calculate latent heat flux (LE) using the simularity hypothesis and the aerodynamic profile method, with data from these two measurement heights (5 points):
   • U ₂ = 4.0 m/s
   • U ₁ = 2.0 m/s
   • q ₂ = 0.001
   • q ₁ = 0.004
   • Z ₂ = 2.0 m
   • Z ₁ = 1.5 m
   • k = 0.4