Ice was the last thing David Barber was worried about when he and an international team of scientists made plans last year to have their research icebreaker frozen into the Beaufort Sea for the winter. But when the Amundsen sailed into the western Arctic in November, the ice that normally begins to take hold in October hadn't even begun to gel. "Even by mid-December, the southern Beaufort Sea was still wide open," said Barber, a University of Manitoba sea ice physicist and chief scientist aboard the Amundsen. "That's over a month longer than the time freeze-up normally occurs."
Barber and his colleagues got an even bigger surprise when they sailed north into M'Clure Strait, the main channel connecting the Northwest Passage to the western Arctic. The strait is legendary as a gateway for thick, rock-hard, multi-year ice that piles in from the Beaufort Sea, but Barber and his colleagues found nothing but clear sailing. "It was surreal," he said. "The weeks spent on the ship were some of the most remarkable of my career. The multi-year pack ice had migrated about 150 miles (240 kilometres) north from where it has traditionally been located. So the ice-associated, high-pressure system that traditionally forms over the southern Beaufort at this time of year was displaced. "All that cyclonic activity that was drawn in by the warm, open water not only made for some rough sailing, it also put more heat into the air, keeping the local climate warmer than usual."
Barber isn't alone in wondering whether this winter signals the climatic tipping point that many scientists have been anticipating. That's the moment in time when sea ice in the Arctic becomes so thin and vulnerable that the ice produced each winter can no longer keep up with the spring and summer melts.
EDIT
Because so much ice melted last summer, there wasn't enough old ice left to put the brakes on the multi-year ice that was driven so far north, towards Siberia, in December and January. So the sheer force of that migration left a huge fracture in the pack ice that was bigger than anything anyone has seen. "I think this summer really will tell the story," Barber says. "If we get yet another huge meltdown, as I suspect we might, then we could see more of these fractures occurring in the future. That kind of breakup only serves to accelerate the meltdowns we are already seeing.
EDIT
http://www.canada.com/vancouversun/news/story.html?id=643c7cba-bb80-4b52-a2a9-a266b607c31d&p=1
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