Antarctic sea ice also below average
Arctic sea ice extent in January was the lowest in the satellite record, according to the latest monthly update from the National Snow and Ice Data Center. Scientists said the new record monthly low was likely the result of unusually high air temperatures over the Arctic Ocean and a strong negative phase of the Arctic Oscillation for the first three weeks of the month.
Meanwhile in the Antarctic, this year’s extent was lower than average for January, in contrast to the record high extents in January 2015.
In the Arctic, the ice extent average 5.2 million square miles, 402,000 square miles below the 1981 to 2010 average and 35,000 square miles below the previous record January low that occurred in 2011.
Across most of the Arctic Ocean, air temperatures ran more than 13 degrees above average for most of January as a cyclical air pressure shift enabled warm air to flow northward toward the Arctic.
Over the long term, January sea ice extent is shrinking at a rate of about 3.2 percent per decade. Sea ice extent has been below 14.25 million square miles every year since 2005, according to the NSIDC.
But some projections suggest that winter sea ice extent could hold steady or even increase in the short term because of changes in a key Atlantic Ocean current that transports cold water northward. Observational data show a slight upward trend in Arctic sea ice extent from 2005 to 2015.
See the full NSIDC update here.