Tuesday, March 17, 2015

Arctic Sea Ice Dwindling Toward Record Winter Low

While balmy hints of spring melt piles of snow in the eastern U.S., the impending end of winter marks peak season for Arctic sea ice. But this year, that winter maximum area is currently on track to hit a record low since satellite records began in 1979.
What that low-ice mark means for the spring and summer melting seasons is unclear, but the milestone would still be notable in the global warming-fueled cycle of Arctic sea ice decline.
“The fact that we're starting the melt season with low — maybe record low — winter extents cannot be good,” Jennifer Francis, a Rutgers University Arctic researcher, said in an email. Sea ice extent is crucial to the Arctic's ecology and economy, affecting wildlife habitats, weather patterns and shipping lanes. Sea ice is a key part of the habitats of animals like polar bears and walruses, as well as fish and other creatures that live below it. When it is missing, it can make it difficult for some of the animals to find food. For humans, ice-free areas of water are prime real estate for oil drilling and shipping, and an Arctic low on ice would open the region to more of both, a controversial proposition. There has also been research that indicates the disappearance of sea ice, along with the broader warming of the Arctic, is affecting weather patterns over North America, Europe and Asia, though there is still much work to be done to fully explain such a connection.
Global warming triggers a self-reinforcing downslide in the area the ice covers, as well as how thick the ice is. Warming Arctic temperatures triggered by the buildup of greenhouse gases in the atmosphere cause more ice melt, which exposes more of the open ocean. Whereas the bright white ice reflects the sun’s rays, the dark ocean absorbs them, causing even further warming and melt.
The average extent has declined by 4.52 percent per decade, according to the National Snow & Ice Data Center (NSIDC) in Boulder, Colorado. The summer minimum has declined even more steeply, by 13.7 percent per decade. This warming-driven cycle helped lead to 2012’s record low summer sea ice minimum, though what happens year to year is also driven by varying weather patterns. There’s a good chance sea ice area will stay at a record-low level as it begins its warm season retreat.

http://www.weather.com/science/environment/news/arctic-sea-ice-dwindling-record-low-levels

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