Research press release


Nature Geoscience

Cold winters in America and Asia linked to separate Arctic warming hotspots



Jee-Hoon Jeongたちは、1979~2014年の観測に基づくデータに、互いに独立して現れる北極温暖化の強い空間パターンを2つ同定した。東アジアへの厳冬到来のおよそ15日前には北極バレンツ-カラ海で異常な温暖化が観測されており、一方、北極海のさらに東の東シベリア-チュクチ海における別の温暖化のパターンが、カナダとアメリカが厳寒に見舞われたおよそ5日前に観測されていた。


Cold winters in North America and East Asia are both linked to Arctic warming, but each is associated with a distinct warming pattern, according to a study published online in Nature Geoscience. The results suggest that the rapid warming of the Arctic region in recent years has favoured the frequent occurrence of unusually severe winters in these regions.

Sea-ice loss in the Barents-Kara Sea in autumn has been suggested to influence Northern Hemisphere atmospheric circulation in a way that favours stagnant cold winter weather over the mid-latitude continents. However, this idea is controversial, as these mechanisms are not yet well understood.

Jee-Hoon Jeong and colleagues identify the two strongest spatial patterns of Arctic warming that occur independently of each other in observation-based data that cover the period 1979 to 2014. They find that unusual warmth in the Arctic Barents-Kara Sea precedes severe winter weather in East Asia by about 15 days, whereas an independent pattern of warm temperatures in the East Siberian-Chukchi Sea, further east in the Arctic Ocean, often occurs about 5 days before cold spells in Canada and the US.

The researchers also use climate model simulations to identify the specific changes in the layout of high- and low-pressure systems in the atmosphere that link Arctic warming to cold mid-latitudes, and conclude that understanding the regional distribution of warming in the Arctic may help with assessing the risks of extremely cold winters in North America and East Asia.

doi: 10.1038/ngeo2517


メールマガジンリストの「Nature 関連誌今週のハイライト」にチェックをいれていただきますと、毎週各ジャーナルからの最新の「注目のハイライト」をまとめて皆様にお届けいたします。