Spatial Complexity in Dissolved Organic Matter and Trace Elements Driven by Hydrography and Freshwater Input Across the Arctic Ocean During 2015 Arctic GEOTRACES Expeditions Academic Article uri icon

abstract

  • AbstractThis 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. Highresolution in situ fluorescence profiles revealed that DOM distribution closely followed isopycnals, indicating the strong influence of seaice 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 longrange transport of TE to the North Atlantic.

published proceedings

  • JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS

altmetric score

  • 3.6

author list (cited authors)

  • Williford, T., Amon, R., Kaiser, K., Benner, R., Stedmon, C., Bauch, D., ... Yan, G. e.

citation count

  • 3

complete list of authors

  • Williford, Tatiana||Amon, Rainer MW||Kaiser, Karl||Benner, Ronald||Stedmon, Colin||Bauch, Dorothea||Fitzsimmons, Jessica N||Gerringa, Loes JA||Newton, Robert||Hansell, Dennis A||Granskog, Mats A||Jensen, Laramie||Laglera, Luis M||Pasqualini, Angelica||Rabe, Benjamin||Reader, Heather||van der Loeff, Michiel Rutgers||Yan, Ge

publication date

  • November 2022