浮游生物三角洲13C的度变化:对二氧化碳和过去海洋生产力的影响
G H Rau1, T Takahashi, D J Des Marais
1Institute of Marine Sciences, University of California, Santa Cruz 95064, USA.
Nature
|October 12, 1989
概括
海洋生物 海洋生物
科学领域:
- 古海洋学是古海洋学.
- 海洋生物地质化学海洋生物地质化学
- 同位素地球化学 同位素地球化学
背景情况:
- 海洋有机物质的稳定碳同位素组成随着地质时间的推移而变化.
- 这种变化反映了海洋生物对碳吸收分量的变化.
- 过去的研究将白纪沉积物和南极浮游生物中的低13C/12C比率与高大气CO2相关联.
研究的目的:
- 在高度海洋环境中调查二氧化碳可用性和碳同位素耗尽之间的关系.
- 重新评估白时期海洋有机物中13C耗尽的原因.
主要方法:
- 在海洋有机物质中分析稳定碳同位素成分 (13C/12C).
- 在地表水中测量二氧化碳部分压力 (pCO2).
- 基于温度和pCO2的溶解无机碳 (DIC) 度的计算2.
主要成果:
- 高度同位素耗尽发生在低于当前大气值的pCO2水平.
- 在高度地区较低的温度会增加二氧化碳的溶解度,从而导致更高的溶解二氧化碳度.
- 南极地表水的溶解二氧化碳度可能高达赤道水的2.5倍.
- 超过800微大气层的白时期海洋pCO2水平被计算为解释观察到的浮游生物13C耗尽.
结论:
- 高度的溶解二氧化碳,不一定是高的pCO2,导致高度浮游生物的碳同位素耗尽.
- 纪的海洋pCO2水平可能远高于以前的假设,以解释观察到的碳同位素数据.
- 取决于温度的二氧化碳溶解度在从碳同位素记录中解释过去的海洋二氧化碳水平方面发挥着关键作用.
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