南大洋深处的通风和脱冰的二氧化碳增加
L C Skinner1, S Fallon, C Waelbroeck
1Godwin Laboratory for Palaeoclimate Research, Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK. lcs32@esc.cam.ac.uk
概括
在冰河时代,深海二氧化碳 (CO2) 释放推动了大气二氧化碳的上升. 来自南大洋的放射性碳数据证实了这一点,显示了冰川时期更古老的深水. 这支了南洋的海洋.
科学领域:
- 古代海洋学 古代海洋学 古代海洋学
- 气候科学 气候科学
- 海洋学 海洋学 海洋学
背景情况:
- 大气中的二氧化碳 (CO2) 水平在过去的冰川-冰川间周期中大幅波动.
- 假设这些二氧化碳变化是由深海碳的释放驱动的,特别是来自南大洋的碳.
研究的目的:
- 研究南大洋在过去气候变化期间对大气二氧化碳的调节作用.
- 为了测试深海二氧化碳通过南大洋释放影响了冰川-冰川间大气二氧化碳度的假设.
主要方法:
- 分析南大洋大西洋部门的放射性碳 (14C) 水平.
- 冰川和冰川间的深水放射性碳年龄的比较.
- 模拟深水循环对大气二氧化碳的影响.
主要成果:
- 在南极地区的深水被发现,与大气相比,在最后的冰川时期,与今天的水位相比,其年龄是最后一次冰川时期的两倍多.
- 这种"旧"的深水很可能富含二氧化碳.
- 在脱冰过程中释放出这种富含二氧化碳的水,有助于大气二氧化碳的逐步增加.
结论:
- 这些发现强烈支持这样一个假设:南大洋在过去的脱冰过程中对被封存的二氧化碳的快速释放起到了关键作用.
- 南大洋深层水的年龄和二氧化碳含量,由南极翻转循环调节,是冰川-冰川间大气二氧化碳动态的关键因素.
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