Effects of a Changing Arctic Sea-Ice Cover Upon On-Ice Snow Depths

Snow cover is an important aspect of the heat and mass budget of Arctic sea-ice: it impacts the ice thermal regime as well as transmission and reflection of incoming radiation. Recent changes in Arctic sea-ice extent warrant a re-examination of the relationship between sea-ice and its snow cover in greater detail. Previously examined measurements from Soviet drifting stations have been combined with data from Arctic coastal stations and the International Arctic Buoy Programme and interpolated onto a pan-Arctic Ocean grid. From these snow-depth fields, monthly snow accumulation rates have been calculated over perennial ice. These accumulation rates are combined with freeze-up/melt dates, derived from QuikSCAT and SSM/I satellite data, in a simple model in which the amount of snow accumulation on ice of varying age is determined. Total snow accumulation has been calculated annually at each grid point, based on ice type and melt season duration for the time period 1979-2007. Calculated values have been compared with previous studies, as well as changes in Arctic precipitation and sea-ice patterns over the past three decades, to assess any changes in snow depth distribution over sea-ice. In addition to changes in precipitation patterns driven by sea-ice change, a delay in the onset of fall ice formation and a reduction in multiyear ice have led to a significant reduction in on-ice snow volume.