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高分辨率的二氧化碳度记录在65万至80万年前
Dieter Lüthi1, Martine Le Floch, Bernhard Bereiter
1Climate and Environmental Physics, Physics Institute, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland. luethi@climate.unibe.ch
Nature
|May 16, 2008
概括
大气中的二氧化碳水平在南极冰芯中测量,将记录延长到80万年. 在65万至75万年前,二氧化碳度较低,创下172ppmv的新低纪录.
科学领域:
- 古气候学 古气候学
- 冰核科学 冰核科学
- 大气化学 大气化学
背景情况:
- 大气中的二氧化碳 (CO2) 水平对于了解地球气候至关重要.
- 南极冰芯提供了关于过去大气组成的宝贵记录.
- 以前的沃斯托克和EPICA Dome C的记录延长到65万年.
研究的目的:
- 为了将大气二氧化碳记录进一步延伸到过去.
- 为了研究过去的冰川周期中的二氧化碳度.
- 在较长的时间范围内分析二氧化碳和南极温度之间的关系.
主要方法:
- 在EPICA Dome C冰芯最低200米处被困的空气的分析.
- 使用气相色谱测量二氧化碳度.
- 二氧化碳数据与南极温度重建的比较.
主要成果:
- 大气中的二氧化碳记录延长到现在之前的80万年,覆盖了另外两个冰川周期.
- 大气中的二氧化碳度与8个冰川周期的南极温度有很强的相关性.
- 显著降低二氧化碳度 (低于180 p.p.m.v.) 在65万到75万年前观察到的,包括一个3000年的时间在180 p.p.m.v.以下. 在海洋同位素阶段16期间.
- 测量到的最低二氧化碳度为每百万分之172的体积值 (ppmv). ),扩大了工业化前的范围.
结论:
- 过去大气中的二氧化碳水平与南极温度在多个冰川-冰川间周期中表现出强烈的相关性.
- 延长的冰芯记录揭示了极低二氧化碳度的时期,可能与海洋碳储存的增强有关.
- 这项研究完善了我们对大气二氧化碳的自然变化及其与过去80万年气候的关系的理解.
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