Sea ice acts as an iron (Fe) reservoir in the Southern Ocean (SO) where primary productivity is largely Fe limited. The mechanisms leading to Fe enrichment in sea ice result from the combination of poorly understood and largely unexplored physical and biological processes. We analyze the biogeochemical impacts of three plausible idealized formulations of dissolved Fe (DFe) incorporation into sea ice corresponding to (i) constant Fe concentration in sea ice, (ii) constant ocean‐ice Fe flux, and (iii) ocean‐ice Fe flux linearly varying with seawater Fe concentration in a global ocean‐sea‐ice‐biogeochemical model, focusing on the SO. The three formulations simulate different geographical distributions of DFe concentrations in sea ice. Iron in sea ice remains largely uncertain due to the limited number of spatial and seasonal observations, poorly constrained Fe sources and sinks, and significant uncertainties in simulated sea ice and hydrography. Despite these differences, the fertilization effect by sea ice on phytoplankton photosynthesis is qualitatively similar regardless of the formulation considered. Iron incorporation during sea‐ice formation, transport, and melt release, common to all formulations, dominates over differences in sea‐ice Fe concentrations. Formulating the Fe incorporation rate as proportional to seawater Fe concentrations gives the closest agreement to field observations. With this formulation, sediments work in synergy with Fe transport to fertilize the waters north of the continental shelf. Southern Ocean primary production and export production increase by 5–10% and 9–19%, respectively, when Fe incorporation into sea ice is considered, suggesting a moderate effect of Fe‐bearing sea ice on marine productivity.

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海水中铁掺入南极海冰的模型研究

海冰在南部海洋（SO）中充当铁（Fe）储集层，那里的初级生产力在很大程度上受到Fe的限制。导致铁在海冰中富集的机制是由于人们对物理和生物学过程的了解不多以及很大程度上未经探索而导致的。我们分析了溶解的铁（DFe）掺入海冰的三种可能的理想化配方的生物地球化学影响，这些配方对应于（i）海冰中恒定的Fe浓度，（ii）恒定的海冰铁通量和（iii）海冰铁在全球海洋-海冰-生物地球化学模型中，通量随海水中铁的浓度线性变化，重点是SO。这三种配方模拟了海冰中DFe浓度的不同地理分布。由于空间和季节观测的数量有限，海冰中的铁仍然存在很大不确定性，铁源和汇的约束性差，模拟海冰和水文学的不确定性很大。尽管存在这些差异，但无论采用何种配方，海冰对浮游植物光合作用的施肥效果在质量上都是相似的。对于所有配方而言，在海冰形成，运输和熔体释放过程中铁的掺入均占海冰中Fe浓度差异的主导。将Fe的掺入率与海水中的Fe浓度成正比，可以得出与实地观测最接近的结论。通过这种配方，沉积物与铁的运输协同作用，使大陆架以北的水肥。如果考虑将铁掺入海冰，南大洋的初级生产和出口生产分别增加了5-10％和9-19％，