The Arctic Ocean ice cap peaked for the winter on 24 March at 14.52 million square kilometres – a record low and 20,000 square kilometres less than the previous record low maximum extent.
The 13 smallest maximum extents on the satellite record have happened in the last 13 years.
Record high temperatures were recorded in December, January and February around the world. In the Artic average air temperatures were up to 5.5 °C above average at the edges of the ice pack.
Walt Meier, a sea ice scientist at NASA’s Goddard Space Flight Centre in Greenbelt, Maryland, said wind patterns in the Arctic during January and February did not help, bringing warmer air from the south.
“It is likely that we're going to keep seeing smaller wintertime maximums in the future because in addition to a warmer atmosphere, the ocean has also warmed up," says Meier.
"That warmer ocean will not let the ice edge expand as far south as it used to,” Meier said. “Although the maximum reach of the sea ice can vary a lot each year depending on winter weather conditions, we’re seeing a significant downward trend, and that’s ultimately related to the warming atmosphere and oceans.”
Since 1979, that trend has led to a loss of 1.6 million square kilometres of winter sea ice cover, an area more than twice the size of Texas.
The US Navy is already working on strategies for dealing with an ice-free summer Arctic, which Rear Admiral David Titley believes could be ice-free in 15 years (see Battle stations for an ice-free Arctic).