Water Vapor Transport in Snow A 2-D Simulation of Temperature Gradient Metamorphism

Abstract

In dry snow packs experiencing a temperature gradient, heat and mass transport is responsible for the metamorphism of ice crystals. The work presented herein investigates the influence of geometry, density, and temperature on the coupled, simultaneous heat and mass transport in idealized, two dimensional ice lattice cells. Mass transfer rates, mass flux rates, concentration and temperature distributions, and effective diffusion coefficients and thermal conductivities are presented as functions of temperature, geometry, density, and time. The results of the analysis show clearly that both the mass and heat transport are strongly dependent upon the ice lattice geometry. The effective diffusion coefficient is enhanced relative to the diffusion coefficient for water vapor in air for all of the two dimensional geometries studied. In addition, the preferential growth of branch grains has been verified using both static and dynamic, computer generated images of the ice lattice cells undergoing temperature gradient metamorphism.