2018 Arctic Sea Ice Extent 6th-Lowest On Record
NASA
Arctic sea ice, the cap of frozen seawater blanketing most of the Arctic Ocean and neighboring seas in wintertime, follows seasonal patterns of growth and decay. It thickens and spreads during the fall and winter and thins and shrinks during the spring and summer. But in the past decades, increasing temperatures have led to prominent decreases in the Arctic sea ice extents, with particularly rapid decreases in the minimum summertime extent. The shrinking of the Arctic sea ice cover can ultimately affect the planets weather patterns and the circulation of the oceans.
This years minimum is relatively high compared to the record low extent we saw in 2012, but it is still low compared to what it used to be in the 1970s, 1980s and even the 1990s, said Claire Parkinson, a climate change senior scientist at NASAs Goddard Space Flight Center in Greenbelt, Maryland.
Parkinson and her colleague Nick DiGirolamo calculated that, since the late 1970s, the Arctic sea ice extent has shrunk on average about 21,000 square miles (54,000 square kilometers) with each passing year. That is equivalent to losing a chunk of sea ice the size of Maryland and New Jersey combined every year for the past four decades.
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One of the most unusual features of this years melt season has been the reopening of a polynya-like hole in the icepack north of Greenland, where the oldest and thickest sea ice of the Arctic typically resides. In February of this year, a similar opening appeared in the same area, catching the attention of sea ice scientists everywhere. The first appearance of the hole raised concerns about the possibility that the region could became vulnerable if the original, thicker ice cover was replaced with thinner ice as the exposed seawater refroze. NASAs Operation IceBridge mission probed the area in March, finding that the ice was indeed thinner and thus more susceptible to be pushed around by the winds and ocean currents.
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https://climatecrocks.com/2018/09/29/2018-sea-ice-tied-for-6th-lowest-in-record/