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北大西洋深水通风的间冰期不稳定性
Eirik Vinje Galaasen1, Ulysses S Ninnemann2, Augustin Kessler3
1Department of Earth Science and Bjerknes Centre for Climate Research, University of Bergen, Bergen, Norway. eirik.galaasen@uib.no.
概括
北大西洋深水 (NADW) 通风的中断在间冰期期间是常见的,不需要极端条件. 过去的NADW减少在各种气候条件下发生,这表明破坏比以前想象的更容易.
科学领域:
- 古代海洋学
- 气候科学
- 海洋学
背景情况:
- 北大西洋深水通风对于全球气候调节至关重要.
- 了解NADW稳定性对于准确的气候预测至关重要.
- 过去的冰河间期为我们提供了潜在的气候变化.
研究的目的:
- 评估过去冰河间大规模北大西洋深水 (NADW) 减少的频率和气候触发因素.
- 确定是否需要灾难性的淡水洪水来引起NADW的重大干扰.
- 评估NADW在各种间冰期气候条件下的易受破坏.
主要方法:
- 分析 (次) 百年级的深海核记录.
- 在过去的50万年中,地下水 δ13C (NADW循环的代理) 的重建.
- NADW变化的相关性与冰河间时期的古气候数据.
主要成果:
- NADW的大幅减少是冰河间时期的频繁且有时长期的特征.
- 在跨冰期气候背景的频谱中发生了NADW破坏.
- 证据表明,主要的淡水爆发洪水并不是NADW严重扰乱的先决条件.
结论:
- 大规模的NADW干扰比以前理解的更容易触发.
- 类似于未来预测的冰河间气候条件可能导致NADW显著减弱.
- 过去的NADW行为表明对变化的敏感性高于通常的假设,对未来的气候稳定性有影响.
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