大西洋东南部的冰川表面温度
J P Sachs1, R F Anderson, S J Lehman
1Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Room E34-254, Cambridge, MA 02139, USA. jsachs@mit.edu
概括
来自开普盆地的海洋气候记录显示,在最后一个冰川时期,海洋发生了意想不到的变暖. 这种温带海洋在4万1千年前至2万5千年前的变暖与典型的冷却趋势形成鲜明对比.
科学领域:
- 古海洋学是古海洋学.
- 气候科学 气候科学
- 海洋地质学海洋地质学
背景情况:
- 海洋沉积物记录为重建过去海面温度提供了关键数据.
- 最后一个冰川时期的特点是全球气候发生了重大变化,冰的体积也发生了变化.
- 了解过去的海洋学变化是预测未来气候变化的关键.
研究的目的:
- 记录和分析过去冰川时期亚热带南大西洋的海洋气候变化.
- 为了调查海洋表面温度变化的未经记录的进展.
- 将区域海洋学变化与全球气候模式和轨道强迫进行比较.
主要方法:
- 从开普盆地的深海沉积物核心中分析海面温度的代理值.
- 沉积层的年代测定,以确定气候事件的精确时间表.
- 开普盆地温度记录与已建立的古气候档案和阳光照射数据的比较.
主要成果:
- 来自开普盆地的详细海面温度记录,涵盖了现在前41到18000年的时间.
- 确定了从现在前41万年到2万5千年的温和海洋变暖的显著间隔.
- 观察到的变暖模式与由于地球轨道变化的预期阳光照射变化相关.
结论:
- 开普盆地记录显示,在最后一个冰河时期,有着独特的区域海洋变暖事件,挑战了典型的冷却解释.
- 这一变暖阶段表明全球冰量,海洋循环和轨道强迫之间存在复杂的相互作用.
- 需要进一步的研究,才能充分了解驱动这种以前未经记录的海洋气候进展的机制.
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