Arctic sea ice variability on a timescale of weeks and its relation to atmospheric forcing

Abstract

Northern Hemisphere sea ice concentration, 500-hPa height, sea level pressure, and 1000-500-hPa thickness at 7-day intervals are examined for the period 1972-1989, with emphasis on the winter season. The temporal variability of sea ice concentration is largest along the climatological mean ice edge where its frequency distribution is strongly bimodal with ice-free and ice-covered conditions being observed much more frequently than partial ice cover. These results confirm impressions, based on visual inspection of satellite imagery, that most of the variability in these regions is associated with the advance and retreat of the ice edge. The strongest sea ice pattern is comprised of a dipole with opposing centers of action in the Davis Straits/Labrador Sea region and the Greenland and Barents seas. Its temporal variability is strongly coupled to the atmospheric North Atlantic oscillation (NAO). The relationship between the two patterns is strongest with the atmosphere leading the ocean by two weeks. -from Authors