Ice layer and surface crust permeability in a seasonal snow pack

Ice layers in snowpacks are thought to retard or obstruct gas and melt water flow through the pack, yet there has been little published information on the permeability of ice layers in seasonal snow. In this paper, investigations of ice layer permeabilities are reported for prominent ice layers 1 to 3 mm thick in a seasonal snowpack. For distinct, fairly solid ice layers 1 to 3 mm thick, permeabilities ranged from 1 to 19 × 10−10 m2; these values are significantly lower than values for the surrounding snow. Within 24 h early in the melt season, the permeability of the surface crust increased 160%, from approximately 70 to 120 × 10−10 m2. This increase in permeability was accompanied by a small increase in grain size and a decrease in albedo. The snow– air interface can exhibit dramatic changes in transport properties over relatively short periods of time, even without precipitation events. These changes, driven by the surface meteorology, affect transport properties such as permeability as well as albedo.