Question: Calculate the evaporation (sublimation) rate from a snow bank if the ambient air temperature is - 23°C, solar energy is falling on the bank at a rate of 600 W/m2, the underside of the bank is effectively insulated, and the heat-transfer coefficient for free convection from an equivalent surface with no mass transfer is 6 W/(m2 • K). The absorptivity and emissivity of snow may be assumed to be 1. The absolute humidity of the air is 0.0003 kg H20/kg dry air.