Talk at DMI by PhD student Rasmus Anker Pedersen

Title: The atmospheric response to regional Arctic sea ice loss. 

Abstract: The climatic response to reduction of the Arctic sea ice cover may be sensitive to the geographical location of the ice loss. The atmospheric sensitivity to the location of sea ice loss is studied using a general circulation model in a configuration that allows combination of a prescribed sea ice cover and an active mixed layer ocean. Contrary to traditional fixed SST experiments, this hybrid setup makes it possible to isolate the impact of the sea ice changes. Three idealized sea ice scenarios are investigated: overall Arctic ice loss and ice loss in the Pacific and Atlantic sectors of the Arctic. The experiments indicate that the atmospheric response in regions both within and beyond the Arctic are sensitive the location sea ice reduction. Analysis of the North Atlantic Oscillation reveals clear circulation changes, as the location of the northern center of action shifts in response to the different sea ice reductions. Sea ice loss in the Atlantic and Pacific sectors of the Arctic cause westward and eastward shifts, respectively.