Is Arctic Transpolar Drift Predictable?
Thursday, 18 December 2014
Recent decline in summer arctic sea ice extent is often attributed to the overall warming and changes in the intensity of the transpolar drift pattern, also called Arctic Dipole. The warming is influencing sea ice thickness, while a more intense transpolar drift in the summer promotes faster removal of ice from the Siberian and Alaskan coasts towards Fram Strait. We are analyzing factors potentially responsible for the recent changes in the large-scale circulation, focusing specifically on the pronounced transpolar drift pattern in late summer. Experiments with an atmospheric GCM forced with prescribed SST anomalies typical for recent decades show that both warming in the North Atlantic (positive AMO) and PDO switching towards the negative phase might be contributing to those circulation changes. Teleconnection patterns from our GCM experiments compare well with results from different reanalysis products