The impact of remineralization depth on the air-sea carbon balance
The impact of remineralization depth on the air-sea carbon balance
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DOI：
10.1038/ngeo612
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发表时间：
2009-09-01
影响因子：
18.3
通讯作者：
Sarmiento, Jorge L.
中科院分区：
文献类型：
--
作者：
Kwon, Eun Young;Primeau, Francois;Sarmiento, Jorge L.
当微粒有机碳从海洋表面降落时，它被呼吸回二氧化碳并释放到海洋内部。下沉的碳转化为二氧化碳的深度--被称为矿化深度--取决于颗粒下沉速度和它们的衰变率之间的平衡。许多气候敏感因素会影响这种平衡，包括温度（1），氧气浓度（2），分层，群落组成（3，4）和下沉颗粒的矿物质含量（5）。在这里，我们使用一个三维的全球海洋生态地球化学模型，以表明，适度的变化，在海水化深度可以对大气中的二氧化碳浓度产生重大影响。例如，当全球63%的下沉碳被呼吸的深度增加24米时，大气二氧化碳浓度下降10-27 ppm。大气中二氧化碳浓度的减少是由于矿化碳从中层沃茨重新分布到底层沃茨的结果。由于上层海洋沃茨中呼吸碳浓度降低，大气中的二氧化碳优先储存在新形成的北大西洋深水中。我们认为，大气中的二氧化碳浓度是高度敏感的潜在的变化，可能会导致气候变化的土壤化深度。
As particulate organic carbon rains down from the surface ocean it is respired back to carbon dioxide and released into the ocean's interior. The depth at which this sinking carbon is converted back to carbon dioxide-known as the remineralization depth-depends on the balance between particle sinking speeds and their rate of decay. A host of climate-sensitive factors can affect this balance, including temperature(1), oxygen concentration(2), stratification, community composition(3,4) and the mineral content of the sinking particles(5). Here we use a three-dimensional global ocean biogeochemistry model to show that a modest change in remineralization depth can have a substantial impact on atmospheric carbon dioxide concentrations. For example, when the depth at which 63% of sinking carbon is respired increases by 24 m globally, atmospheric carbon dioxide concentrations fall by 10-27 ppm. This reduction in atmospheric carbon dioxide concentration results from the redistribution of remineralized carbon from intermediate waters to bottom waters. As a consequence of the reduced concentration of respired carbon in upper ocean waters, atmospheric carbon dioxide is preferentially stored in newly formed North Atlantic Deep Water. We suggest that atmospheric carbon dioxide concentrations are highly sensitive to the potential changes in remineralization depth that may be caused by climate change.