Any day now Arctic sea-ice is going to hit its lowest extent for the year, and once again it’s set to be one of the lowest years on record (the four lowest years have all occurred since 2007). The 2014 minimum was 1.94 million square miles (5.03 million square kilometers), the seventh lowest on record. The ice covered 1.7 million square miles (4.41 million square kilometers), seen here superimposed on the 1981-2010 average, drawn as a gold line.
Advertisement
According to NSIDC, this year’s maximum Arctic ice, measured in February, was the lowest on record. After analyzing satellite data, scientists have found that the 2015 Arctic sea ice minimum was startlingly low.
With human-caused warming continuing, computer simulations show on average that around the year 2040, sea ice will disappear from the Arctic during some summers, Stroeve said.
This level marks the fourth lowest Arctic ice level, consistent with the long term decline in Arctic ice coverage. That was lower than any other year in history except 2007, 2011, and the worst year ever, 2012. In response to the setting sun and falling temperatures, ice extent will now climb through autumn and winter. Since the late 1970s, its minimum summertime extent, which occurs at the end of the melt season, has been decreasing due to warming temperatures. Since 1996, the ocean ice decrease has quickened, and Meier said the ice spread is turning out to be less and less versatile: “The ocean ice top, which used to be a strong sheet of ice, now is divided into littler floes that are more presented to warm sea water”. Until recently, killer whales were a rare sight in the Arctic, as their dorsal fins make swimming among heavy sea ice virtually impossible. The ocean could only attack it from the sides. North of Alaska, an ice-free “hole” opened up in the icepack covering the Beaufort and Chukchi Seas, which allowed the ocean to absorb more heat, further eating away at the ice. “Presently it’s similar to the intruders have burrowed in from underneath and the ice pack softens from inside”.
Advertisement
Starting next week, NASA’s Operation IceBridge, an airborne survey of polar ice, will be carrying science flights over sea ice in the Arctic, to help validate satellite readings and provide insight into the impact of the summer melt season on land and sea ice.
