Arctic sea ice was measured at a record-low extent this winter, as climate change continues to warm the poles. This research was first reported in the Russian newspaper Tass.
National Snow and Ice Data Centre (Nsidc) researchers, located in Boulder, Colo., conducted a study showing the maximum ice cover in the Arctic this year was lower than ever seen before. The 2016 ice cap, recorded using the agency's own space-borne observatories, measured just over 5.6 million square miles.
"This is the smallest Arctic ice cap on the satellite record," Natasha Vizcarra, Nsidc spokeswoman, said.
Air temperatures were above average throughout the Arctic from December 2015 to February 2016. North of Svalbard, above Russia, air temperatures were 22 degrees Fahrenheit warmer than normal. Temperatures in the region between the North Pole and Greenland were 11 degrees Fahrenheit above average, researchers report.
"These unusually warm conditions have no doubt played a role in the record low ice extent this winter. Another contributing factor has been a predominance of southerly winds in the Kara and Barents seas that have helped to keep the ice edge northward of its typical position. This area has also seen an influx of warm Atlantic waters from the Norwegian Sea," Nsidc officials reported on their Web site.
The maximum ice cover for the winter of 2015-16 was roughly 40,000 square miles smaller than 2011, the previous record-holder. The greatest coverage of ice was seen on March 24, which is 12 days later than the average seen from 1981 to 2010. The latest date ever recorded was April 2 in 2010, and the earliest was Feb. 24, 1996.
No correlation appears between the maximum extent of Arctic ice in the winter and minimum coverage during summer. So, just because the reach of ice was at a record-low in winter, it does not follow that this summer will see the greatest retreat.
Melting in the high Arctic is one factor that does seem to play a role in determining ice coverage in the region. During years when ice melts earlier than normal, the ground darkens, absorbing additional energy from the sun. This creates a feedback loop, where heating darkens the ground, gathering more thermal energy, leading to additional darkening.
A full analysis of the measurements will be released by the Nsidc in April 2016.
Photo: NASA Goddard Space Flight Center | Flickr