The Expansion of the Marginal Ice Zone in the Pacific Arctic

Monday, 15 December 2014: 1:55 PM
Jennifer K Hutchings, Oregon State University, College of Earth, Ocean and Atmospheric Sciences, Corvallis, OR, United States, Kim I Martini, University of Washington Seattle Campus, Seattle, WA, United States, Donald K Perovich, Dartmouth College, Hanover, NH, United States, Ignatius G Rigor, Applied Physics Laboratory University of Washington, Kenmore, WA, United States, Alek Petty, Cooperative Institute for Climate and Satellites University of Maryland, College Park, MD, United States, Sinead L Farrell, University of Maryland College Park, College Park, MD, United States, Rudiger Gens, University of Alaska Fairbanks, Anchorage, AK, United States and Ed Barker, University of Alaska Fairbanks, Fairbanks, AK, United States
Since 2007 the Beaufort and Chukchi Seas have experienced persistently low summer minimum ice extents and the Marginal Ice Zone has grown in latitudinal extent. Here we describe the dynamic preconditioning of the ice pack for enhanced ice-albedo feedback that has facilitated this change. Enhanced meridional drift transported sea ice from the Pacific Arctic into the Transpolar Drift, preconditioning the ice loss in 2007. Since then mechanical weakening of the ice pack has led to enhanced opening and shear along the southern sector of the Beaufort Gyre, which preconditions further ice loss in subsequent summers. To determine the fate of Arctic sea ice the relationship between this dynamic preconditioning and the magnitude of positive feedbacks to summer ice loss due to ice-albedo feedback, wave-ice interaction and oceanic heat flux to the ice must all be quantified.