Occurrence and Potential Significance of Warm Weather during Winter in the Eastern Canadian Arctic

Abstract

Daily photographs from an automated camera show an event of snowmelt and flooding of the Weasel River sandur on Baffin Island on 10 January 1985. During this event strong winds (36 km h-1) and low humidity (46%) accompanied a rise in air temperature to -1?C at Pangnirtung, 40 km south. Analysis of weather data indicates that more than 100 similar events of warm weather (air temperature 0?C) occurred during winter at stations in southeastern Baffin Island during the periods of record, 10 to 20 in northern Baffin, and 3 or fewer in central and western Baffin. Severe winter cyclones migrating up the Davis Strait-Baffin Bay low pressure trough are the principal cause of these warm events, although they are apparently augmented in some instances by orographic effects. Melting of thin and discontinuous snow cover is probably associated with these events. This may influence the character of the snowpack on refreezing, the nature of freeze-thaw weathering, and the formation of icings on arctic streams.