In the depths of the long night that cloaks the Arctic in frigid darkness for three months each winter, a surprising patch of open water appeared, just to the north of Greenland.
It was a polynya – an area of unfrozen water surrounded by the polar ice pack. Though not especially rare in some parts of the Arctic, the north Greenland polynya of February of this year was an unexpected 50,000 square kilometres of open water in the Wandel Sea, an area the size of the province of Nova Scotia.
