Trends in Arctic sea ice drift and role of wind forcing: 1992-2009

• Published in: Geophysical research letters Vol. 38; no. 19
• Main Authors: Spreen, Gunnar, Kwok, Ron, Menemenlis, Dimitris
• Format: Journal Article
• Language: English
• Published: Washington, DC Blackwell Publishing Ltd 01.10.2011; American Geophysical Union
• Subjects: Arctic; Basins; Drift; Earth sciences; Earth, ocean, space; Exact sciences and technology; Ice cover; Marine; reanalysis; Sea ice; Thinning; Trends; wind; Wind speed; Winter; Europe; Arctic region; Arctic Ocean; Southern Europe; Italy; polar regions; Marches Italy; trend-surface analysis; Spatial correlation; Space remote sensing; Wind velocity; Satellite observation; Ice cover; Thinning; Winter; winds; sea ice; ice drift; Reanalysis; Polar region; Forcing
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2011GL048970

We examine the spatial trends in Arctic sea ice drift speed from satellite data and the role of wind forcing for the winter months of October through May. Between 1992 and 2009, the spatially averaged trend in drift speed within the Arctic Basin is 10.6% ± 0.9%/decade, and ranges between −4% and 16%/decade depending on the location. The mean trend is dominated by the second half of the period. In fact, for the five years after a clear break point in March 2004, the average trend increased to 46% ± 5%/decade. Over the 1992–2009 period, averaged trends of wind speed from four atmospheric reanalyses are only 1% to 2%/decade. Regionally, positive trends in wind speed (of up to 9%/decade) are seen over a large fraction of the Central Arctic, where the trends in drift speeds are highest. Spatial correlations between the basin‐wide trends in wind and drift speeds are moderate (between 0.40 and 0.52). Our results suggest that changes in wind speed explain a fraction of the observed increase in drift speeds in the Central Arctic but not over the entire basin. In other regions thinning of the ice cover is a more likely cause of the increase in ice drift speed. Key Points Between 1992 and 2009 the trend in Arctic sea ice drift speed is +11%/decade During the same period wind speed increased by only 1‐2%/decade Wind contributed to the Central Arctic drift trend but not in the entire basin