千年气候变化的开始是北半球冰川化加剧的原因
David A Hodell1, Fátima Abrantes2,3, Carlos A Alvarez Zarikian4
1Godwin Laboratory for Palaeoclimate Research, Department of Earth Sciences, University of Cambridge, UK.
概括
大约270万年前北半球冰盖的扩张在冰川时期引入了千年气候变化 (MCV). 这种气候变化成为四季度冰川气候的永久特征.
科学领域:
- 古气候学 古气候学
- 四年纪地质学四年纪地质学
- 气候动力学 气候动力学
背景情况:
- 四季期 (过去2.580万年) 出现了北半球冰盖的显著波动.
- 了解这个时期气候变化的开始和影响对于古气候重建至关重要.
研究的目的:
- 研究四年纪期间千年气候变化 (MCV) 的出现.
- 为了确定北半球冰盖扩张和气候变化之间的关系.
主要方法:
- 来自伊比利亚边缘的沉积物序列的分析.
- 地质事件和气候振荡的年代.
- 与北大西洋冰上漂浮的碎片记录的相关性.
主要成果:
- 北半球冰盖大约在2.7亿年前的扩张与MCV的出现相吻合.
- 前体事件之后,出现了几千年的气候振荡,从大约2500万年前开始.
- 这些振荡与冰上漂浮的碎片相关,表明海洋终结冰盖的参与.
结论:
- 千年气候变化 (MCV) 在大约270万年前的北半球冰期出现.
- MCV成为四季度冰川气候的组成特征.
- 北半球的冰川在各种时间尺度上显著影响了气候变化.
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