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. Relationships between large-scale patterns of atmospheric variability and sea ice variability are investigated, making use of singular value decomposition of the temporal covariance matrix. The analysis is conducted separately for the Atlantic and Pacific sectors. In agreement with earlier studies based upon monthly mean data on sea ice concentration, the strongest... 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. Relationships between large-scale patterns of atmospheric variability and sea ice variability are investigated, making use of singular value decomposition of the temporal covariance matrix. The analysis is conducted separately for the Atlantic and Pacific sectors. In agreement with earlier studies based upon monthly mean data on sea ice concentration, the strongest...