半球间的气候联系是由智利南部的晚冰期冷却事件揭示的
P I Moreno1, G L Jacobson, T V Lowell
1Institute for Quaternary and Climate Studies, University of Maine, Orono 04469, USA. pimoreno@uchile.cl
Nature
|March 10, 2001
概括
降冰期间南半球气候事件与北半球变化同步,表明大气联系. 当地的海洋影响可能改变了南半球其他地区的时间.
科学领域:
- 古气候学 古气候学
- 四分学科学 四分学科学
- 气候动力学 气候动力学
背景情况:
- 了解半球间气候同步性对于识别突然气候变化的驱动因素至关重要.
- 以前南半球 (巴塔哥尼亚,新西兰) 的气候记录显示,在最后一次脱冰期 (14.6-10 kyr BP) 中,与北半球数据存在差异.
- 解决这些差异是评估北半球冰盖和其他因素在晚冰期气候变化中的作用的关键.
研究的目的:
- 调查最后一次脱冰期间南半球气候事件的时间和同步性.
- 为了将南半球气候记录与北大西洋地区的气候记录进行比较.
- 评估控制半球间气候联系的机制.
主要方法:
- 分析了来自智利南部 (41°S) 湖区的三个地点的花粉记录.
- 放射性碳测年法 (14C kyr BP) 建立了花粉记录的时间框架.
- 推断的气候条件与北大西洋的既定古气候记录进行比较.
主要成果:
- 花粉记录显示,智利南部的间冰期状况大约在13至12.2 14C kyr BP.
- 在大约12.2和11.4 14C kyr BP时确定了冷却事件,随后在9.8 14C kyr BP左右变暖.
- 这些智利南部的气候事件与北大西洋地区显著的古气候变化密切相关.
结论:
- 智利南部和北大西洋近同步的气候事件支持大气半球间的联系,作为最后一次脱冰期间气候的主要驱动因素.
- 南半球其他地区的差异表明,当地的海洋影响可以抵消或修改大气传播的气候信号.
- 这项研究强调了大气和海洋因素在降冰过程中调节全球气候的复杂相互作用.
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