This summer, the Artic Sea ice has dropped to its eighth lowest level on record, new federal data shows. Arctic sea ice appeared to have reached its yearly lowest extent on Sept. 13, NASA and the NASA-supported National Snow and Ice Data Center (NSIDC) at the University of Colorado Boulder have reported about this dropdown.
The National Snow and Ice Data Center said Tuesday that on Sept. 13 sea ice in Arctic shrank to its smallest area of the season: 4.64 million square kilometres.
Data centre scientist Ted Scambos said the Arctic sea ice set a record for the smallest winter amount earlier this year and was close to 2012's record low levels through July. Then a cloudy and cooler-than-normal August kept melt to a minimum.
"Weather patterns in August saved the day," Scambos said.
The Arctic acts as a crucial refrigerator for Earth's climate, scientists say. A growing number of studies have linked Arctic sea ice decline to changes in the jet stream and some bouts of extreme weather.
"It's bound to have an impact on global climate," Scambos said.
This year's low is 1.58 million square kilometres below the 30-year average but it is also 1.25 million square kilometres above 2012's record low.
The data centre uses satellite readings that go back to 1979.
The latest findings do not mark a recovery from 2012, he said. Instead, they suggest that 2012 was an outlier, with a combination of freak conditions that dropped levels lower than normal man-made global warming would cause, Scambos said.
"It's not going to be a staircase heading down to zero every year," Scambos said. "It's not the same as in the '50s, '60s, '70s, '80s or '90s.
"The Arctic will continue to evolve towards less ice," he added. "There's no dodging that."
"How much ice is left at the end of summer in any given year depends on both the state of the ice cover earlier in the year and the weather conditions affecting the ice," said Claire Parkinson, senior climate scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "The weather conditions have not been particularly noteworthy this summer. The fact that we still ended up with low sea ice extents is because the baseline ice conditions today are worse than the baseline 38 years ago."
"What had been most surprising about the changing sea ice coverage in the past three decades was the fact that the Antarctic sea ice was increasing instead of decreasing," Parkinson said. "The fact of Arctic sea ice decreases was not as shocking because this was expected with a warming climate, although the overall rate of the decreases was greater than most models had forecast."
"In fact, this year, every single month from January through August experienced a new monthly record low in global sea ice extents," Parkinson said.