由于海冰悬崖的不稳定性而导致南极冰的损失
Tamsin L Edwards1, Mark A Brandon2, Gael Durand3
1Department of Geography, King's College London, London, UK. tamsin.edwards@kcl.ac.uk.
Nature
|February 8, 2019
概括
海冰悬崖的不稳定性 (MICI) 可能会高估本世纪南极海平面的上升. 新的建模表明,即使在高排放的情况下,融的预测也较低,而MICI对于过去的海平面变化并不重要.
科学领域:
- * 冰川学和气候科学
- * 南极冰盖的动态
背景情况:
- 由于南极冰川融化,本世纪海平面上升的预测有很大差异,高端估计依赖于海洋冰崖不稳定性 (MICI) 假设.
- 由于全球变暖引起的融化,
- *现代MICI的发生尚未得到证实,其解释过去海平面变化的必要性尚不确定.
研究的目的:
- * 量化与MICI假设相关的冰盖建模中的不确定性.
- 评估MICI在解释过去和未来南极海平面贡献中的作用.
- 根据模拟不确定性和MICI假设重新评估目前的海平面上升预测.
主要方法:
- * 用冰盖模型分析与原始MICI研究相关的不确定性.
- * 模型输出与普略纪中期的海平面数据,最后的间冰期和1992-2017年期间进行了比较.
- * 进行了概率分析,以确定不同海平面上升场景的可能性.
主要成果:
- *冰盖模型的不确定性表明概率分布偏向于较低的海平面上升值,在非常高的温室气体度下,最可能的值为45厘米.
- * MICI假设不需要准确地重现在普略纪中期,最后的间冰期和最近的 (1992-2017) 时期观察到的海平面变化.
- *除MICI外,海平面上升预测与之前的研究一致,其中95个百分位均低于43厘米.
结论:
- 之前对MICI预测的解释可能高估了本世纪海平面的潜在上升.
- * MICI假设没有得到当前数据的充分支持,因此需要进一步研究.
- *采用MICI的可靠预测需要更广泛的观察性限制模型来评估冰架脆弱性和冰崖崩机制.
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