Tropical climate responses to projected Arctic and Antarctic sea-ice loss
Tropical climate responses to projected Arctic and Antarctic sea-ice loss
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DOI：
10.1038/s41561-020-0546-9
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发表时间：
2020-03-16
影响因子：
18.3
通讯作者：
Deser, Clara
中科院分区：
文献类型：
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作者：
England, Mark R.;Polvani, Lorenzo M.;Deser, Clara
预计北极和南极海冰范围在下个世纪都将急剧下降。北极海冰消失的影响不仅限于北部高纬度地区，还深入到热带地区。然而，人们对未来南极海冰消失对南部高纬度地区以外的影响知之甚少。在这里，我们使用完全耦合的气候模型，研究了热带对南极海冰消失的反应，并将其与北极海冰消失的反应进行了比较。我们发现，南极海冰消失与北极海冰消失类似，会导致赤道东太平洋变暖加剧，以及热带辐合带向赤道方向加剧。我们证明，南极海冰消失引起的微型全球变暖信号与北极海冰消失引起的信号相当，并且让人想起对温室气体的反应。我们还表明，海洋动力学是捕捉热带对海冰损失的反应的关键。简而言之，我们发现未来南极海冰的消失将对热带地区产生深远的影响。在高排放情景代表性浓度路径8.5下，北极和南极海冰损失合计将占预计热带变暖和降水变化的20-30%。气候模型模拟表明，南极海冰损失导致赤道东部太平洋变暖加剧，与北极海冰损失一起导致热带地区预计变暖和降雨变化的20-30%。
Arctic and Antarctic sea-ice extent are both projected to dramatically decline over the coming century. The effects of Arctic sea-ice loss are not limited to the northern high latitudes, and reach deep into the tropics. Yet little is known about the effects of future Antarctic sea-ice loss outside of the southern high latitudes. Here, using a fully coupled climate model, we investigate the tropical response to Antarctic sea-ice loss and compare it with the response to Arctic sea-ice loss. We show that Antarctic sea-ice loss, similar to Arctic sea-ice loss, causes enhanced warming in the eastern equatorial Pacific and an equatorward intensification of the Intertropical Convergence Zone. We demonstrate that Antarctic sea-ice loss causes a mini global warming signal comparable to the one caused by Arctic sea-ice loss, and reminiscent of the response to greenhouse gases. We also show that ocean dynamics are key to capturing the tropical response to sea-ice loss. In short, we find that future Antarctic sea-ice loss will exert a profound influence on the tropics. Combined Arctic and Antarctic sea-ice losses will account for 20-30% of the projected tropical warming and precipitation changes under the high-emissions scenario Representative Concentration Pathway 8.5.Antarctic sea-ice loss causes enhanced warming in the eastern equatorial Pacific, and together with Arctic sea-ice loss accounts for 20-30% of projected warming and rainfall changes in the tropics, suggest climate model simulations.