Global warming doesn’t necessarily refer to the actual warming of the planet. There are places on Earth where excessive warming determines cooling in other places.
The reduction of the Arctic Ocean’s ice surface generated by climate warming could constitute an explanation for the snow and frost of the latest years in Europe and some Northern hemisphere areas, says a study published on Monday by Georgia Tech.
After the floating ice surface had dropped below record levels in 2007, abnormally-abundant snowing have been observed on wide areas of North America, Europe and China. During the 2009-2010 and 2010-2011 winters, the northern hemisphere recorded the highest accumulations of snow.
The data, recorded since 1979, when satellites began their mission, until 2010, shows the Arctic Ocean shrinking by a million square kilometers in autumn, which is twice the area of France.
“Our study demonstrates that the decrease in Arctic sea ice area is linked to changes in the winter Northern Hemisphere atmospheric circulation,” said Judith Curry, chair of the School of Earth and Atmospheric Sciences at Georgia Tech. “The circulation changes result in more frequent episodes of atmospheric blocking patterns, which lead to increased cold surges and snow over large parts of the northern continents.”
“We think the recent snowy winters could be caused by the retreating Arctic ice altering atmospheric circulation patterns by weakening westerly winds, increasing the amplitude of the jet stream and increasing the amount of moisture in the atmosphere,” explained Jiping Liu, a senior research scientist in the School of Earth and Atmospheric Sciences at Georgia Tech.
“These pattern changes enhance blocking patterns that favor more frequent movement of cold air masses to middle and lower latitudes, leading to increased heavy snowfall in Europe and the Northeast and Midwest regions of the United States,” he added.
[via sciencedaily]
