Right about now, Arctic sea ice should be building up toward its annual maximum, making most of the region impenetrable to all but the most hardened icebreakers. Instead, January and indeed much of the winter so far has been unusually mild throughout large parts of the Arctic...

Sea ice is virtually absent from the Barents and Kara Seas, which constitute a large swath of the Atlantic Arctic, located northeast of Scandinavia and north of the Russian mainland. “For the Arctic this is definitely the strangest winter I’ve ever seen," said Mark Serreze, the director of the National Snow and Ice Data Center (NSIDC) in Boulder, Colorado, which tracks sea and land ice around the world