video transcript

NASA says a powerful cyclone formed off the coast of Alaska in early August and moved toward the centre of the Arctic ocean, weakening the already thin sea ice as it went. A large section north of the Chukchi Sea was cut off by the churning storm, and pushed south to warmer waters where it melted. The cyclone remained stalled over the Arctic for several days. The strongest winds are represented here in red, with the blue vectors indicating slower winds. Scientists say a similar storm decades ago would have had much less impact on the sea ice because they say, "the ice wasn't as vulnerable then as it is now."