Remember the North Pole winter thaw? A new study finds a rising trend in Arctic warming spikes in winter

During the N-ICE2015 expedition, scientists froze their boat, the Lance, into the Arctic sea ice to gather data from January to June of 2015. (Source: Norwegian Polar Institute) During each of the past three years, something quite bizarre has happened in the central Arctic. No, global warming did not cause some Thing to rise up out of the ice and go on a rampage. It was temperatures that rose up. And not just by a little. This occurred during extreme warming events near the North Pole that sent temperatures spiking close to, or above, the freezing mark for one to three days. Compare that to average winter temperatures in winter: typically lower than minus 30 degrees Celsius, or -22 F. Arctic warm spells in winter are by no means unheard of. But were the extreme conditions seen during the last three years a sign that warm episodes are becoming more common than in the past? And has the duration of warm episodes in winter been increasing? A new study published this week in the journal Geophysical Research Letters finds that the answer to both questions is yes. Since 1980, an additional six warming events — defined as temperatures rising above -10 degrees C, or 14 F — are occurring each winter in the North Pole region, according to the study by a team of Norwegian, American and German scientists. In addition, the average length of each event has grown from fewer than two days to nearly two and a half days.