Sea-ice-free Arctic during the Last Interglacial supports fast future loss
Sea-ice-free Arctic during the Last Interglacial supports fast future loss
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DOI：
10.1038/s41558-020-0865-2
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发表时间：
2020-08-10
影响因子：
30.7
通讯作者：
Sellar, Alistair
中科院分区：
文献类型：
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作者：
Guarino, Maria-Vittoria;Sime, Louise C.;Sellar, Alistair
末次间冰期（LIG）是距今13万年至11.6万年的一个较暖时期，是未来气候变化的潜在类似物。北半球高纬度地区夏季日照强度更强，导致北极陆地夏季气温比工业化前高4-5摄氏度。气候模型模拟以前未能捕捉到这些升高的温度，可能是因为它们无法正确捕捉到LIG海冰的变化。在这里，我们展示了完全耦合的英国哈德利中心气候模式（HadGEM3）的最新版本更准确地模拟了北极LIG气候，包括温度升高。改进的模型物理，包括一个复杂的海冰融化池方案，在LIG期间完全模拟了北极海冰在夏季的损失，这在过去几代模型中尚未模拟。这个无冰的北极为长期存在的谜团提供了一个令人信服的解决方案：是什么驱动了北极的温暖，并支持未来北极夏季海冰的快速消退。末次间冰期（13万至11万6千年前的温暖时期）的北极气候在现代气候模型中模拟得很差。一个改进的海冰融化池物理模型再现了LIG北极温度，表明在此期间北极将无冰，并预测到2035年。
The Last Interglacial (LIG), a warmer period 130,000-116,000 years before present, is a potential analogue for future climate change. Stronger LIG summertime insolation at high northern latitudes drove Arctic land summer temperatures 4-5 degrees C higher than in the pre-industrial era. Climate model simulations have previously failed to capture these elevated temperatures, possibly because they were unable to correctly capture LIG sea-ice changes. Here, we show that the latest version of the fully coupled UK Hadley Center climate model (HadGEM3) simulates a more accurate Arctic LIG climate, including elevated temperatures. Improved model physics, including a sophisticated sea-ice melt-pond scheme, result in a complete simulated loss of Arctic sea ice in summer during the LIG, which has yet to be simulated in past generations of models. This ice-free Arctic yields a compelling solution to the long-standing puzzle of what drove LIG Arctic warmth and supports a fast retreat of future Arctic summer sea ice.Arctic climate in the Last Interglacial (LIG)-a warm period 130,000-116,000 years ago-is poorly simulated by modern climate models. A model with improved sea-ice melt-pond physics reproduces LIG Arctic temperatures, suggests an ice-free Arctic during this period and predicts the same by 2035.