Antarctic sea ice can incorporate high levels of iron (Fe) during its formation and has been suggested as an important source of this essential micronutrient to Southern Ocean surface waters during the melt season. Over the last decade, a limited number of studies have quantified the Fe pool in Antarctic sea ice, with a focus on late winter and spring. Here we study the distribution of operationally defined dissolved and particulate Fe from nine sites sampled between Wilkes Land and King George V Land during austral summer 2016/2017. Results point toward a net heterotrophic sea‐ice community, consistent with the observed nitrate limitation (<1 μM). We postulate that the recycling of the high particulate Fe pool in summer sea ice supplies sufficient (∼3 nM) levels of dissolved Fe to sustain ice algal growth. The remineralization of particulate Fe is likely favored by high concentrations of exopolysaccharides (113–16,290 μg xeq L⁻¹) which can serve as a hotspot for bacterial activity. Finally, results indicate a potential relationship between glacial meltwater discharged from the Moscow University Ice Shelf and the occurrence of Fe‐rich (∼4.3 μM) platelet ice in its vicinity. As climate change is expected to result in enhanced Fe‐rich glacial discharge and changes in summer sea‐ice extent and quality, the processes influencing Fe distribution in sea ice that persists into summer need to be better constrained.

中文翻译：

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东极南极夏季海冰中的营养分布：冰川基底融化的潜在铁贡献

南极海冰在形成过程中会掺入高水平的铁（Fe），并已被建议作为融化季节南部海洋表层水这种重要微量营养素的重要来源。在过去的十年中，有限的研究对南极海冰中的铁矿池进行了量化，重点是冬末和春末。在这里，我们研究了在2016/2017夏季夏季从Wilkes Land和King George V Land之间采样的9个地点的可操作确定的溶解态铁和颗粒铁的分布。结果指向净异养海冰群落，与观察到的硝酸盐限制（<1μM）一致。我们假设夏季海冰中高颗粒铁池的再循环提供了足够的（约3 nM）水平的溶解铁，以维持冰藻的生长。^-1）可以作为细菌活性的热点。最后，结果表明莫斯科大学冰架排出的冰川融水与附近富铁（约4.3μM）血小板冰的存在之间存在潜在的关系。由于预计气候变化将导致富铁冰河流量的增加以及夏季海冰范围和质量的变化，因此需要更好地限制影响到夏季持续存在的影响海冰中铁分布的过程。