Spatial Complexity in Dissolved Organic Matter and Trace Elements Driven by Hydrography and Freshwater Input Across the Arctic Ocean During 2015 Arctic GEOTRACES Expeditions
Spatial Complexity in Dissolved Organic Matter and Trace Elements Driven by Hydrography and Freshwater Input Across the Arctic Ocean During 2015 Arctic GEOTRACES Expeditions
复制标题
2015 年北极 GEOTRACES 探险期间北冰洋水文学和淡水输入驱动的溶解有机物和微量元素的空间复杂性
DOI：
10.1029/2022jc018917
复制
发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Hansell, Dennis A.
中科院分区：
文献类型：
--
作者：
Williford, Tatiana;Amon, Rainer M. W.;Kaiser, Karl;Benner, Ronald;Stedmon, Colin;Bauch, Dorothea;Fitzsimmons, Jessica N.;Gerringa, Loes J. A.;Newton, Robert;Hansell, Dennis A.
利用溶解有机质（DOM）的荧光特性和陆源生物标志物木质素，研究了北冰洋不同水团中DOM的示踪及其对微量元素（Fe、Cu、Mn、Ni、Zn、Cd）分布的影响。南森，阿蒙森和马卡罗夫盆地的特点是大西洋水和河流排放的西伯利亚河流的陆源DOM（tDOM）浓度高的影响。加拿大海盆和楚科奇海的特点是太平洋水，通过与海洋DOM水平升高的生产性陆架沉积物接触而改变。在博福特环流的表层，大气降水（河水和降水）的特点是低浓度的木质素和tDOM荧光代理DOM在冻结过程中被删除。高分辨率原位荧光剖面显示，DOM分布密切遵循等密度线，表明海冰形成和融化的强烈影响，这也反映在DOM荧光和盐水贡献之间的强相关性。DOM和水文地理特征与TE的关系表明，陆源和海洋DOM可能是溶解态Fe、Ni、Cu从欧亚大陆架进入北冰洋中部的载体。楚科奇大陆架沉积物是dCd、dZn和dNi的重要来源，也是加拿大盆地上盐跃层内结合并携带这些TE离岸的海洋配体的重要来源。我们的数据表明，tDOM组分代表了相对于海洋DOM组分更强的配体，可能有助于TE向北大西洋的远距离传输。
This study traces dissolved organic matter (DOM) in different water masses of the Arctic Ocean and its effect on the distributions of trace elements (TEs; Fe, Cu, Mn, Ni, Zn, Cd) using fluorescent properties of DOM and the terrigenous biomarker lignin. The Nansen, Amundsen, and Makarov Basins were characterized by the influence of Atlantic water and the fluvial discharge of the Siberian Rivers with high concentrations of terrigenous DOM (tDOM). The Canada Basin and the Chukchi Sea were characterized by Pacific water, modified through contact with productive shelf sediments with elevated levels of marine DOM. Within the surface layer of the Beaufort Gyre, meteoric water (river water and precipitation) was characterized by low concentrations of lignin and tDOM fluorescence proxies as DOM is removed during freezing. High‐resolution in situ fluorescence profiles revealed that DOM distribution closely followed isopycnals, indicating the strong influence of sea‐ice formation and melt, which was also reflected in strong correlations between DOM fluorescence and brine contributions. The relationship of DOM and hydrography to TEs showed that terrigenous and marine DOM were likely carriers of dissolved Fe, Ni, Cu from the Eurasian shelves into the central Arctic Ocean. Chukchi shelf sediments were important sources of dCd, dZn, and dNi, as well as marine ligands that bind and carry these TEs offshore within the upper halocline in the Canada Basin. Our data suggest that tDOM components represent stronger ligands relative to marine DOM components, potentially facilitating the long‐range transport of TE to the North Atlantic.