Arctic sea ice enjoyed a brief—but temporary—respite from melting in 2013

Rachel Tilling

Arctic sea ice enjoyed a brief—but temporary—respite from melting in 2013

The first comprehensive measurements of Arctic sea ice volume reveal that floating floes didn’t melt as extensively in 2013 as they had in previous years due to a cooler-than-recent-average summer that year, a respite from melting that may be as brief as it is refreshing. Using data gathered by the European Space Agency’s CryoSat-2 satellite from October 2010 through November 2014—and corroborated by field measurements, including some made at an ice camp north of Greenland (shown) in March 2014—researchers assembled a month-by-month record of sea ice volume throughout the Arctic Ocean, with the exception of a state-of-Georgia-sized area closest to the North Pole that was invisible to the satellite. (Scientists have been using satellites to gauge sea ice extent, a measure of how much of the ocean’s area is covered by ice, since 1979; the new data allow oceanwide estimates of sea ice thickness as well.) Between autumn 2010 and 2012, the volume of Arctic sea ice dropped by 14%—a decline that’s in line with the measurements of sea ice extent during that same period, the researchers say. But in the fall of 2013, sea ice volume was 33% higher than the average seen in the previous 3 years, the team reports online today in Nature Geoscience. Alas, 2013’s increase in sea ice volume may be only temporary: Autumn 2014’s volume measured only 25% above the 2010 to 2012 average, a sign that melting has resumed nibbling away at the frozen water. Indeed, last week the National Oceanic and Atmospheric Administration reported in their annual State of the Climate report that 2014 was the fourth warmest year in the Arctic since 1900