英国利物浦大学Tagliabue, Alessandro团队报道了上层海洋铁循环驱动力的自生矿物相。该研究于2023年8月2日发表于国际一流学术期刊《自然》杂志上。

研究人员提出了一个新的溶解铁，配体和颗粒铁季节性数据集，来自百慕大大西洋时间序列研究(BATS)地区。研究发现，海洋上层溶解铁的动力学与配体，需要一个过程，通过这个过程，溶解铁脱离配体的稳定，生成一个沉淀到深处的自生铁颗粒库。当这个“胶体分流”机制在全球范围的生物地球化学模型中实施时，它再现了季节性铁循环动力学观察和以前模型失败时的独立全球数据集。

总体而言，研究人员认为，自生颗粒铁相的转换必须与生物活性和配体一起考虑，以控制溶解铁池和颗粒铁池之间的耦合。

据介绍，铁对调节海洋碳循环很重要。尽管存在几种溶解和颗粒物质参与海洋铁循环，但目前的认识强调了有机配体络合作用在稳定海洋溶解铁浓度中的重要性。然而，很难将配体作为溶解铁循环的主要控制因素这一观点与观察到的溶解铁物种的粒度分布、深度处溶解铁的低效再生或颗粒铁观察数据集中自生铁相的潜在重要性调和一致。

附：英文原文

Title: Authigenic mineral phases as a driver of the upper-ocean iron cycle

Author: Tagliabue, Alessandro, Buck, Kristen N., Sofen, Laura E., Twining, Benjamin S., Aumont, Olivier, Boyd, Philip W., Caprara, Salvatore, Homoky, William B., Johnson, Rod, Knig, Daniela, Ohnemus, Daniel C., Sohst, Bettina, Sedwick, Peter

Issue&Volume: 2023-08-02

Abstract: Iron is important in regulating the ocean carbon cycle. Although several dissolved and particulate species participate in oceanic iron cycling, current understanding emphasizes the importance of complexation by organic ligands in stabilizing oceanic dissolved iron concentrations. However, it is difficult to reconcile this view of ligands as a primary control on dissolved iron cycling with the observed size partitioning of dissolved iron species, inefficient dissolved iron regeneration at depth or the potential importance of authigenic iron phases in particulate iron observational datasets. Here we present a new dissolved iron, ligand and particulate iron seasonal dataset from the Bermuda Atlantic Time-series Study (BATS) region. We find that upper-ocean dissolved iron dynamics were decoupled from those of ligands, which necessitates a process by which dissolved iron escapes ligand stabilization to generate a reservoir of authigenic iron particles that settle to depth. When this ‘colloidal shunt’ mechanism was implemented in a global-scale biogeochemical model, it reproduced both seasonal iron-cycle dynamics observations and independent global datasets when previous models failed. Overall, we argue that the turnover of authigenic particulate iron phases must be considered alongside biological activity and ligands in controlling ocean-dissolved iron distributions and the coupling between dissolved and particulate iron pools.

DOI: 10.1038/s41586-023-06210-5

Source: https://www.nature.com/articles/s41586-023-06210-5