Sea Ice in Arctic Melting for Longer Periods over Last 4 Decades [VIDEO]
The melting season of Arctic sea ice is melting for longer periods each decade, according to a new study led by National Snow and Ice Data Center (NSIDC) and NASA researchers.
The study shows that sea ice in the Arctic has been melting during summer by an additional fives days per decade since 1979, causing widespread weakening of sea ice in the region.
Rising sea surface temperatures are delaying the start of the sea ice-formation season, further compounding the effect across decades.
"The Arctic is warming and this is causing the melt season to last longer," lead study author Julienne Stroeve, a senior scientist at NSIDC, said in a statement. "The lengthening of the melt season is allowing for more of the Sun's energy to get stored in the ocean and increase ice melt during the summer, overall weakening the sea ice cover."
In some areas, such as the Beaufort and Chukchi Seas, each decade the freezing season was documented to start between six and 11 days later.
Taking regional variances into account, the researchers determined that sea ice melt season in the Arctic has lengthened by an average of five days per decade from 1979 to 2013.
"There is a trend for later freeze-up, but we can't tell whether a particular year is going to have an earlier or later freeze-up," Stroeve said. "There remains a lot of variability from year to year as to the exact timing of when the ice will reform, making it difficult for industry to plan when to stop operations in the Arctic."
In some areas, there researchers calculated the extended melt season to result in an extra 4 feet of melt per year.
Stroeve and her colleagues have their study accepted for publication in the journal Geophysical Research Letters.