北极淡水迫使年轻的干时期的寒冷逆转
1Department of Physics, University of Toronto, Toronto, Ontario, Canada M5S 1A7. lev@atmosp.physics.utoronto.ca
Nature
|June 3, 2005
概括
年轻的干旱寒冷逆转是由淡水排放到北冰洋引发的. 这种北极融水流扰乱了北大西洋深水的形成,在最后一次脱冰期间导致全球冷却.
科学领域:
- 古气候学 古气候学
- 冰川学的冰川学
- 海洋学 海洋学 海洋学
背景情况:
- 最后一个脱冰期经历了千年规模的冰川条件的逆转,被称为年轻的德里亚斯寒冷事件.
- 这一寒冷时期与北大西洋深水形成的减少以及由于表面水清新而导致的海洋循环减弱有关.
- 早些时候的一次融水脉冲 (融水脉冲1a) 并没有类似地破坏海洋循环,这表明淡水的影响有所不同.
研究的目的:
- 为了确定在最后一次脱冰期间淡水强迫的地理来源.
- 调查可能引发年轻德里亚斯寒冷事件的特定淡水排放机制.
主要方法:
- 对北美冰盖排水时间表的一组模拟分析.
- 使用校准的冰川系统模型来评估淡水贡献和排放路径.
主要成果:
- 北美冰盖贡献了大约一半与融水脉冲1a.相关的淡水.
- 在较年轻的干旱期开始时,最重要的融水和冰山排放被引导到北冰洋.
- 确定了北冰洋进入格陵兰-冰岛-挪威海的唯一排水口,这是北大西洋深水形成的关键区域.
结论:
- 这项研究假设,进入北冰洋的淡水流是年轻德里亚斯寒冷逆转的主要触发因素.
- 这种北极淡水输入可能破坏了北大西洋深水形成,导致观察到的突然降温.
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