Each month seems to bring new evidence of the transformation underway in the rapidly warming Arctic. Late last month, the National Snow and Ice Data Center (NSIDC) announced that the maximum Arctic sea ice extent for 2011, which occurred on March 7, tied for the lowest such value since satellites began making observations in 1979. The maximum extent for the year was 5.65 million square miles, which was 471,000 square miles - or approximately the area of the nation of Tibet - below the 1979 to 2000 average and within 0.1 percent of the record low set in 2006, NSIDC reported.
NASA recently released the captivating animation below (video and caption info) showing the ebb and flow of sea ice throughout the fall and winter months. It does a great job of communicating the vastness of the Arctic region, as well as the fact that sea ice extent is not fixed, but varies throughout the season.
Much of the Arctic experienced an unusually mild winter, particularly in northeastern Canada and Greenland, where warm weather prevented sea ice from forming on time.
According to NSIDC data, air temperatures over much of the Arctic Ocean were between four to seven degrees above average during February, with parts of the Arctic experiencing temperatures of nine to 13 degrees above average. Much of this warmth had to do with a so-called “negative phase” of the Arctic Oscillation, a natural climate cycle that plays a major role in influencing average winter weather conditions in the Northern Hemisphere.
The fact that the Arctic climate is warming at a rapid rate is hardly breaking news. Scientists are hard at work studying the global ramifications of the region transforming from an impenetrable ice scape into potentially a seasonally open ocean. Projections about when to expect a seasonally ice-free Arctic differ, with general agreement that this may occur by the middle of this century, as warming air and sea temperatures prevent a dwindling, thinning sea ice cover from surviving the summer melt season.
A recent National Academy of Sciences report prepared for the U.S. Navy, for example, projects that by 2030 ordinary ships will be able to traverse the Arctic Ocean during late summer. Currently, such feats are only possible using icebreakers or submarines.
Scientists are examining potential links between declining Arctic sea ice and changing weather patterns in the northern mid-latitudes, particularly during wintertime. I recently came across the video below from the State University of New York (SUNY) College of Environmental Science and Forestry, in which meteorologist Dave Eichorn succinctly explains how Arctic warming might actually be contributing to severe winter weather in parts of the U.S. (H/T Nick Sundt).