Whitmore Laura M, Shiller Alan M, Horner Tristan J, Xiang Yang, Auro Maureen E, Bauch Dorothea, Dehairs Frank, Lam Phoebe J, Li Jingxuan, Maldonado Maria T, Mears Chantal, Newton Robert, Pasqualini Angelica, Planquette Hélène, Rember Robert, Thomas Helmuth
School of Ocean Science and Engineering University of Southern Mississippi Stennis Space Center MS USA.
Now at College of Fisheries and Ocean Sciences University of Alaska Fairbanks Fairbanks AK USA.
J Geophys Res Oceans. 2022 Apr;127(4):e2021JC017417. doi: 10.1029/2021JC017417. Epub 2022 Mar 30.
Early studies revealed relationships between barium (Ba), particulate organic carbon and silicate, suggesting applications for Ba as a paleoproductivity tracer and as a tracer of modern ocean circulation. Here, we investigated the Arctic Ocean Ba cycle through a one-of-a-kind data set containing dissolved (dBa), particulate (pBa), and stable isotope Ba ratio (δBa) data from four Arctic GEOTRACES expeditions conducted in 2015. We hypothesized that margins would be a substantial source of Ba to the Arctic Ocean water column. The dBa, pBa, and δBa distributions all suggest significant modification of inflowing Pacific seawater over the shelves, and the dBa mass balance implies that ∼50% of the dBa inventory (upper 500 m of the Arctic water column) was supplied by nonconservative inputs. Calculated areal dBa fluxes are up to 10 μmol m day on the margin, which is comparable to fluxes described in other regions. Applying this approach to dBa data from the 1994 Arctic Ocean Survey yields similar results. The Canadian Arctic Archipelago did not appear to have a similar margin source; rather, the dBa distribution in this section is consistent with mixing of Arctic Ocean-derived waters and Baffin Bay-derived waters. Although we lack enough information to identify the specifics of the shelf sediment Ba source, we suspect that a sedimentary remineralization and terrigenous sources (e.g., submarine groundwater discharge or fluvial particles) are contributors.
早期研究揭示了钡（Ba）、颗粒有机碳和硅酸盐之间的关系，这表明钡可作为古生产力示踪剂和现代海洋环流示踪剂。在此，我们通过一个独一无二的数据集研究了北冰洋的钡循环，该数据集包含2015年进行的四次北极地球化学追踪考察中的溶解钡（dBa）、颗粒钡（pBa）和稳定同位素钡比率（δBa）数据。我们假设边缘海域是北冰洋水柱中钡的一个重要来源。dBa、pBa和δBa的分布都表明流入的太平洋海水在陆架上发生了显著变化，dBa的质量平衡意味着约50%的dBa存量（北冰洋水柱上部500米）由非保守输入提供。计算得出边缘海域的面dBa通量高达10 μmol m⁻² d⁻¹，这与其他区域描述的通量相当。将这种方法应用于1994年北冰洋调查的dBa数据也得出了类似结果。加拿大北极群岛似乎没有类似的边缘海域来源；相反，该区域的dBa分布与北冰洋源水和巴芬湾源水的混合情况一致。尽管我们缺乏足够信息来确定陆架沉积物钡源的具体情况，但我们怀疑沉积再矿化和陆源（如海底地下水排放或河流颗粒）是其贡献因素。
