Pathways and supply of dissolved iron in the Amundsen Sea (Antarctica): PATHWAYS OF DISSOLVED IRON AMUNDSEN SEA
Pathways and supply of dissolved iron in the Amundsen Sea (Antarctica): PATHWAYS OF DISSOLVED IRON AMUNDSEN SEA
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阿蒙森海（南极洲）溶解铁的途径和供应：溶解铁的途径阿蒙森海
DOI：
10.1002/2017jc013162
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Dinniman, M. S.
中科院分区：
文献类型：
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作者：
St-Laurent, P.;Yager, P. L.;Sherrell, R. M.;Stammerjohn, S. E.;Dinniman, M. S.
许多沿海冰穴位于南极大陆的边缘，对南极大陆架系统的生产力有很大影响。在最近的一项研究中记录的46个南极沿海冰穴中，阿蒙森海冰穴（ASP）因其单位面积净初级生产量最高而脱颖而出。培养实验表明，这种生产率部分控制溶解铁（dFe）的可用性。作为了解ASP的铁供应的第一步，我们介绍了四个合理的dFe来源，并使用保守的数值示踪剂模拟其稳定的空间分布。模拟的分布复制的重要功能，包括dFe最大值在深槽底部的观测和增强浓度附近的冰架前。模拟夏季生物吸收和随后再补给的理想化降深的扰动实验表明，冰川融水和沉积物衍生的dFe是ASP顶部100 m的prebloom dFe库存的主要贡献者。沉积物产生的dFe在很大程度上取决于与融化的冰架（“融水泵”）相关的浮力驱动的翻转环流，以将dFe添加到水柱的上部300米。结果支持的观点，冰架融化在dFe的供应和输送到polynyas，如ASP中起着重要的直接和间接的作用。
Numerous coastal polynyas fringe the Antarctic continent and strongly influence the productivity of Antarctic shelf systems. Of the 46 Antarctic coastal polynyas documented in a recent study, the Amundsen Sea Polynya (ASP) stands out as having the highest net primary production per unit area. Incubation experiments suggest that this productivity is partly controlled by the availability of dissolved iron (dFe). As a first step toward understanding the iron supply of the ASP, we introduce four plausible sources of dFe and simulate their steady spatial distribution using conservative numerical tracers. The modeled distributions replicate important features from observations including dFe maxima at the bottom of deep troughs and enhanced concentrations near the ice shelf fronts. A perturbation experiment with an idealized drawdown mimicking summertime biological uptake and subsequent resupply suggests that glacial meltwater and sediment‐derived dFe are the main contributors to the prebloom dFe inventory in the top 100 m of the ASP. The sediment‐derived dFe depends strongly on the buoyancy‐driven overturning circulation associated with the melting ice shelves (the “meltwater pump”) to add dFe to the upper 300 m of the water column. The results support the view that ice shelf melting plays an important direct and indirect role in the dFe supply and delivery to polynyas such as the ASP.