Towards accounting for dissolved iron speciation in global ocean models
Towards accounting for dissolved iron speciation in global ocean models
复制标题
解释全球海洋模型中溶解的铁形态
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
C. Völker
中科院分区：
文献类型：
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作者：
A. Tagliabue;C. Völker
摘要。微量金属铁（Fe）现在通常被纳入最先进的海洋环流和生物地球化学模型（OGCBMs），因为它在世界海洋区域中作为一种限制性营养物质发挥着关键作用，对碳循环和海气二氧化碳交换至关重要。然而，海水铁循环的复杂性影响其形态和生物利用度，由于认识上的差距和避免高昂的计算成本，在这种OGCBMs中被简化了。与无机碳形态类似，我们概述了一种方法，通过这种方法，铁的复杂形态可以以合理的成本效益方式包括在全球OGCBMs中。我们基于速率常数与环境变量（温度、光、氧、pH、盐度）之间的假设关系，以及铁络合有机配体的结合强度假设，构建了铁形态模型，并对其分布假设进行了检验。结果表明，不同铁的全球分布受到时空环境变化和铁结合配体分布的严格控制。对生物可利用铁的影响对哪些铁物种是生物可利用的以及这些物种在空间和时间上如何变化的假设高度敏感。当受到未来海洋环流和气候的影响时，我们发现铁的形态发生了很大的变化，这是由pH介导的氧化还原动力学变化所控制的。我们推测这些变化可能对未来海洋浮游植物的铁吸收策略施加选择性压力。在未来的工作中，更多地了解海洋铁配体的来源和汇、它们的生物利用度、胶体铁的循环和铁表面配位反应的动力学将是非常宝贵的。我们希望我们的建模方法可以提供一种方法，通过这种方法，可以根据在综合意义上控制海洋铁循环的过程中存在的假设来测试铁形态形成的新观测结果
Abstract. The trace metal iron (Fe) is now routinely included in state-of-the-art ocean general circulation and biogeochemistry models (OGCBMs) because of its key role as a limiting nutrient in regions of the world ocean important for carbon cycling and air-sea CO2 exchange. However, the complexities of the seawater Fe cycle, which impact its speciation and bioavailability, are simplified in such OGCBMs due to gaps in understanding and to avoid high computational costs. In a similar fashion to inorganic carbon speciation, we outline a means by which the complex speciation of Fe can be included in global OGCBMs in a reasonably cost-effective manner. We construct an Fe speciation model based on hypothesised relationships between rate constants and environmental variables (temperature, light, oxygen, pH, salinity) and assumptions regarding the binding strengths of Fe complexing organic ligands and test hypotheses regarding their distributions. As a result, we find that the global distribution of different Fe species is tightly controlled by spatio-temporal environmental variability and the distribution of Fe binding ligands. Impacts on bioavailable Fe are highly sensitive to assumptions regarding which Fe species are bioavailable and how those species vary in space and time. When forced by representations of future ocean circulation and climate we find large changes to the speciation of Fe governed by pH mediated changes to redox kinetics. We speculate that these changes may exert selective pressure on phytoplankton Fe uptake strategies in the future ocean. In future work, more information on the sources and sinks of ocean Fe ligands, their bioavailability, the cycling of colloidal Fe species and kinetics of Fe-surface coordination reactions would be invaluable. We hope our modeling approach can provide a means by which new observations of Fe speciation can be tested against hypotheses of the processes present in governing the ocean Fe cycle in an integrated sense
影响因子：
3.6
作者：
Croot, P. L.;Frew, R. D.;Boyd, P. W.
通讯作者：
Boyd, P. W.