Summer retreat of Arctic sea ice: Role of summer winds

The unprecedented retreat of first-year ice during summer 2007 was enhanced by strong poleward drift over the western Arctic induced by anomalously high sea-level pressure (SLP) over the Beaufort Sea that persisted throughout much of the summer. Comparison of the tracks of drifting buoys with monthly mean SLP charts shows a substantial Ekman drift. By means of linear regression analysis it is shown that Ekman drift during summer has played an important role in regulating annual minimum Arctic sea-ice extent in prior years as well. In combination, the preconditioning by events in prior years, as represented by an index of May multi-year ice, and current atmospheric conditions, as represented by an index of July-August-September SLP anomalies over the Arctic basin account for similar to 60% of the year-to-year variance of September sea-ice extent since 1979. Citation: Ogi, M., I. G. Rigor, M. G. McPhee, and J. M. Wallace (2008), Summer retreat of Arctic sea ice: Role of summer winds, Geophys. Res. Lett., 35, L24701, doi: 10.1029/2008GL035672.