南极海冰对冰川-冰川间二氧化碳变化的影响
1Scripps Institution of Oceanography, University of California, San Diego, La Jolla 92093-0244, USA. britt@cmdl.noaa.gov
Nature
|March 21, 2000
概括
冰川时期大气中二氧化碳 (CO2) 水平较低,与南极海冰有关. 这项研究模型减少了深水通风,解释了二氧化碳差异的67ppm和二氧化碳温度的关系.
科学领域:
- 古气候学 古气候学
- 海洋学 海洋学 海洋学
- 气候建模气候模型
背景情况:
- 冰芯显示,冰川大气中的二氧化碳比冰川间时期低约80ppm.
- 之前的模型很难将二氧化碳水平与深海O2,碳同位素和酸盐和度相协调.
- 南极空气温度和大气中的二氧化碳之间存在着强烈的联系,此前无法解释.
研究的目的:
- 为了研究南极空气温度和大气中的CO2之间的冰川-冰川间联系.
- 为了测试一个盒子模型,在55°S.以南的深水上游局限.
- 为了解释低冰川二氧化碳水平及其与南极条件的联系.
主要方法:
- 利用一个模拟海洋一般循环的盒子模型.
- 55°S以南的深水上游受限,挑战了以前的模型假设.
- 研究了由于南极海冰而减少深水通风的影响.
主要成果:
- 该模型重现了观察到的冰川和冰川间二氧化碳差异的67ppm.
- 南极地区空海气交换减少被确定为主要驱动因素.
- 这些发现与O2,碳同位素和酸盐和度的观测约束一致.
结论:
- 低冰川大气中的二氧化碳可能是由于南极海冰造成的深水通风减少造成的.
- 全年或冬季/夏季结合的海冰可以诱导分层,限制气体交换.
- 该模型为冰川二氧化碳减少及其与南极气候的联系提供了一致的解释.
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