Mechanisms of the recent sea ice decay in theArctic Ocean related to the Pacific-to-Atlanticpathway

摘要

The sea ice cover in the Arctic Ocean has been reducing and hit the low record inthe summer of 2007. The anomaly was extremely large in the Pacific sector. Thesea level height in the Bering Sea vs. the Greenland Sea has been analyzed andcompared with the current meter data through the Bering Strait. A recent peakexisted as a consequence of atmospheric circulation and is considered tocontribute to inflow of the Pacific Water into the Arctic Basin. The timing of thePacific Water inflow matched with the sea ice reduction in the Pacific sector andsuggests a significant increase in heat flux. The other component is the ArcticDipole Mode (ADM) as the second EOF of sea level pressure with dipoles overSiberia and Canada at opposite signs. In last 50 years, the Pacific sector had lowice cover at a 1-2 year lag from the ADM with a low pressure over Siberia. Sincethis mode was extremely intense in 2007 summer, the sea ice is predicted tobe low in 2008. It has been claimed that most projections underestimate sea icereduction in the Arctic during this century. Our tasks include removal of possiblebiases due to different sensors and accurate estimates of the important feedbackscontained in the atmosphere-ice-ocean system. Then, an answer will be found forthe questions when the Arctic sea ice becomes a seasonal ice cover.