Polar heat pushing jet stream south, bringing Harder Winters for U.S./E.U./Japan - 0 views
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Last winter's big snowfall and cold temperatures in the eastern United States and Europe were likely caused by the loss of Arctic sea ice, researchers concluded at the International Polar Year Oslo Science Conference in Norway last week.Climate change has warmed the entire Arctic region, melting 2.5 million square kilometres of sea ice, and that, paradoxically, is producing colder and snowier winters for Europe, Asia and parts of North America. "The exceptional cold and snowy winter of 2009-2010 in Europe, eastern Asia and eastern North America is connected to unique physical processes in the Arctic," said James Overland of the NOAA/Pacific Marine Environmental Laboratory in the United States. "In future, cold and snowy winters will be the rule rather than the exception" in these regions, Overland told IPS.
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Temperatures in January were -2C over the water, while the land was -25C, making conditions far windier and producing more snowfall than normal. Heavy snow on the remaining ice insulates it from the cold air, preventing it from thickening during the long winter.
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This huge mass of warmer air over the Arctic in the late fall not only generates more wind and snow locally, several studies have now documented the impacts on global weather patterns. The winter of 2005-6 was the coldest in 50 years in Japan and eastern Eurasia, reported Meiji Honda, a senior scientist with the Climate Diagnosis Group at Japan's Agency for Marine-Earth Science and Technology. Honda's studies show that the air over the Arctic was quite warm in the fall of 2005, which altered normal wind patterns, pushing the jet stream further south and bringing arctic cold to much of Eurasia and Japan. He also documented the same mechanism for the colder winters of 2007-8 and 2009-10, he told participants. In eastern North America, the same conditions of 2007-8 produced increased precipitation and colder temperatures in the winter. As the sea ice declines, big impacts are likely to be seen in this region, said Sara Strey of the University of Illinois.