Arctic ice loss not a big culprit in harsh winters
La perte de glace arctique n'est pas un grand responsable des hivers rigoureux
Voosen, Paul
For more than 10 years, climate scientists have explored a provocative idea: As Arctic sea ice melts and the polar atmosphere warms, the swirling winds that confine cold Arctic air could weaken, letting it spill farther south. But this idea has long faced skepticism from many atmospheric scientists. Now, the most comprehensive modeling investigation into this link has delivered the heaviest blow yet: Even after the massive sea ice loss expected by midcentury, the polar jet stream will only weaken by tiny amounts-at most only 10% of its natural swings. And in today's world, the influence of ice loss on winter weather is negligible, finds the Polar Amplification Model Intercomparison Project (PAMIP). More than 100 scientists used a host of standardized climate models to probe the question. But as the experiment ran, it was also becoming apparent that the fast past of Arctic warming is less tied to sea ice loss and more to intruding warm temperatures from the south-a factor PAMIP did not explore. </p>
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