在北大西洋深水氧化中的变化
Nicola C Thomas1, Harold J Bradbury1, David A Hodell1
1Department of Earth Science, University of Cambridge, Cambridge, UK.
概括
大西洋深处的氧气水平在冰川时期显著下降,影响了二氧化碳的储存. 这项研究重建了过去的海洋氧化, 以了解气候变化.
科学领域:
- 古代海洋学
- 海洋地质化学
- 气候科学
背景情况:
- 海洋氧气度和大气中的二氧化碳 (pCO2) 通过海洋碳循环联系在一起.
- 深海有机碳重矿化影响溶解的无机碳储存和氧气水平.
研究的目的:
- 在过去的150万年里重建了北大西洋的氧气度.
- 调查海洋脱氧,冰体积和大气pCO2之间的关系
主要方法:
- 作为古氧的替代品,使用了来自地的高分辨率碳同位素梯度 (epifaunal vs. infaunal).
- 重建了北大西洋深水氧气水平的相对变化.
主要成果:
- 记录了大约960到900万年前大西洋冰川深水氧化的显著减少.
- 观察到这种脱氧事件与大陆冰的增加和海洋热循环的改变相吻合.
- 结果表明深水氧气减少,呼吸碳储量增加,冰川pCO2减少.
结论:
- 古氧数据支持冰川时期较低的深水氧气模型.
- 深海碳储量增加可能导致大气pCO2减少.
- 这些发现为海洋气候反提供了洞察力.
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