Global Warming

Arctic Sea Ice Plunges To Record Low Extent For Late Winter

Instead of easing toward its typical March maximum in coverage, the Arctic’s sea ice appears to be more inclined toward getting a head start on its yearly summer melt-out. As of Sunday, March 8, Arctic sea ice as calculated by Japan’s National Institute of Polar Research extended across 13.65 million square kilometres. This value is more than 450,000 sq km - roughly the size of California - below the record extent for the date.

Even more striking is the consistency of the ice loss over the last couple of weeks. March is often a time of rapid gains and losses in ice cover, as seasonal warming and melting battle it out with quick refreezing when shots of cold air return. This year, the ice extent peaked on February 15 at 13.94 million sq km, and it looks increasingly unlikely that the ice will manage to return to that very early peak over the next couple of weeks.

No season in the Japanese database has fallen short of the 14-million mark, so if the February peak stands, it will mark the lowest maximum in the Arctic since satellite monitoring began in 1979. Not only is Arctic sea ice essential to many ecosystems: it serves as a powerful tracer of recent warming, and its absence in summer allows open water to absorb much more heat from sunlight. While the ice has seen some modest recovery in recent years, it has failed to fully mend the fabric torn by the record-setting drop of 2007. The overall thickness of the ice, and the fraction that’s survived for multiple years (multiyear ice), have both suffered major losses.