Projected changes in regional climate extremes arising from Arctic sea ice loss
Projected changes in regional climate extremes arising from Arctic sea ice loss
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DOI：
10.1088/1748-9326/10/8/084006
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发表时间：
2015-08
影响因子：
6.7
通讯作者：
J. Screen;C. Deser;Lantao Sun
中科院分区：
文献类型：
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作者：
J. Screen;C. Deser;Lantao Sun
北极海冰覆盖面积的减少已被广泛记录，很明显，这一变化对当地产生了深远的影响。然而，科学研究的一个新兴和高度不确定的领域是，这种北极变化是否会对低纬度的天气和气候产生切实影响。特别具有社会意义的是一个悬而未决的问题：北极海冰的持续减少是否会使中纬度天气更加极端？在这里，我们分析理想化的大气环流模式模拟，使用两个独立的模型，都被迫在二十一世纪后期预计北极海冰损失。我们确定了强大的预测变化，区域温度和降水极端所产生的完全是由于北极海冰的损失。预计在高纬度地区和北美洲中部和东部地区，极端寒冷天气的可能性和持续时间将减少，但在中亚地区将增加。预计在高纬度地区，极端炎热天气的频率和持续时间将增加。在高纬度地区、地中海和中亚，极端潮湿天气的可能性和严重程度预计将增加;在高纬度地区和中亚及东亚，极端潮湿天气的强度预计将增加。欧亚大陆中纬度地区的干旱天数和高纬度地区的干旱持续时间预计都将减少。与极端降水量相比，极端温度的预测变化与模型的一致性更接近。总体而言，我们发现，北美中部和东部的极端天气对北极海冰的损失比其他中纬度地区更敏感。我们的研究结果有助于限制北极海冰损失在改变极端天气几率方面的作用，但不能被视为确定性预测，因为它们不考虑北极海冰损失以外的驱动因素。
The decline in Arctic sea ice cover has been widely documented and it is clear that this change is having profound impacts locally. An emerging and highly uncertain area of scientific research, however, is whether such Arctic change has a tangible effect on weather and climate at lower latitudes. Of particular societal relevance is the open question: will continued Arctic sea ice loss make mid-latitude weather more extreme? Here we analyse idealized atmospheric general circulation model simulations, using two independent models, both forced by projected Arctic sea ice loss in the late twenty-first century. We identify robust projected changes in regional temperature and precipitation extremes arising solely due to Arctic sea ice loss. The likelihood and duration of cold extremes are projected to decrease over high latitudes and over central and eastern North America, but to increase over central Asia. Hot extremes are projected to increase in frequency and duration over high latitudes. The likelihood and severity of wet extremes are projected to increase over high latitudes, the Mediterranean and central Asia; and their intensity is projected to increase over high latitudes and central and eastern Asia. The number of dry days over mid-latitude Eurasia and dry spell duration over high latitudes are both projected to decrease. There is closer model agreement for projected changes in temperature extremes than for precipitation extremes. Overall, we find that extreme weather over central and eastern North America is more sensitive to Arctic sea ice loss than over other mid-latitude regions. Our results are useful for constraining the role of Arctic sea ice loss in shifting the odds of extreme weather, but must not be viewed as deterministic projections, as they do not account for drivers other than Arctic sea ice loss.