The oldest and thickest Arctic sea ice is disappearing twice as fast as ice in the rest of the Arctic Ocean, according to new research.
A new study in AGU’s journal Geophysical Research Letters finds ice in the Arctic Ocean north of Greenland is more mobile than previously thought, as ocean currents and atmospheric winds are likely transporting the old, thick ice found there to other parts of the Arctic. As a result, ice mass in the area – the last place researchers think will lose its year-round ice cover – is declining twice as fast as ice in the rest of the Arctic, according to the new findings.
Climate models predict Arctic summers will soon be ice-free – perhaps as early as 2030 – meaning less than 1 million square kilometers (386,000 square miles) of summer sea ice will blanket the Arctic Ocean. Arctic warming has already created an environment which leads to younger sea ice.
Most ice covering the Arctic is only one to four years old, according to the National Snow and Ice Data Center. As thin, young ice melts in future summers, only a 2,000-kilometer (1,240-mile) arc of ice will remain, stretching from the western Canadian Arctic Archipelago to Greenland’s northern coast. In this slice of the Arctic, which experts call the Last Ice Area, sea ice is more than five years old and can measure more than four meters (13 feet) thick.
The new research suggests the Last Ice Area is a dynamic place encompassing two sub-regions where ice thickness fluctuates by 1.2 meters (4 feet) from year to year. Ice is becoming thinner in two distinct subregions, which are losing 0.4 meters (1.3 feet) of ice thickness per decade, amounting to a 1.5-meter (5 foot) loss of ice since the late 1970s, according to the new study.
“We can’t treat the Last Ice Area as a monolithic area of ice which is going to last a long time,” said Kent Moore, an atmospheric physicist at the University of Toronto in Canada and lead author of the new study. “There’s actually lots of regional variability.”