A new winter low for thin Arctic sea ice

Arctic sea ice extent for March 7, 2017 was 14.42 million sq km. The orange line shows the 1981 to 2010 median extent for that day. (IMAGE COURTESY OF THE NSIDC)

Arctic sea ice appeared to have reached its annual maximum extent March 7 and even at its greatest extent, the Arctic ice cover this year was much smaller than in 2015, and 2016, which produced the second and third lowest Arctic sea ice cover recorded during the past 38 years.

And, moreover, the 2017 ice was thinner than what grew in the past four years, data from the European Space Agency’s CryoSat-2 satellite showed.

“The long-term decline is a clear indicator of climate change,” said Walt Meier, a NASA scientist and an affiliate scientist at National Snow and Ice Data Center, which announced the low record set for Arctic winter sea ice maximum extent March 22.

That maximum extent for Arctic sea ice over this past winter came in at 14.42 million square kilometres, the NSIDC said.

That’s 1.22 million sq km below the 1981 to 2010 average maximum ice cover of 15.64 million sq km and 97,000 sq km below the previous lowest maximum of Feb. 25, 2015.

And this year’s maximum is 100,000 sq km below the 2016 maximum, which now ranks as the third lowest.

As for Arctic air temperatures, these were warm: At about 2,500 feet above sea level, over the five months spanning October 2016 through February 2017, the temperatures were about 2.5 C above average over the entire Arctic Ocean.

“These overall warm conditions were punctuated by a series of extreme heat waves over the Arctic Ocean,” the NSIDC said.

Here you can watch a NASA video of ice formation over this past winter.