Barium and carbon fluxes in the Canadian Arctic Archipelago

• Published in: Journal of Geophysical Research
• Main Authors: Thomas, Helmuth, Shadwick, Elizabeth, Dehairs, Frank, Lansard, Bruno, Mucci, Alfonso, Navez, Jacques, Gratton, Yves, Prowe, Friederike, Chierici, Melissa, Fransson, Agneta, Papakyriakou, Tim N., Sternberg, Erika, Miller, Lisa A., Tremblay, Jean-Éric, Monnin, Christophe
• Other Authors: Department of Oceanography Halifax (DO), Dalhousie University Halifax, Analytical and Environmental Chemistry and Earth System Sciences, Vrije Universiteit Brussel (VUB), Centre d'océanologie de Marseille (COM), Université de la Méditerranée - Aix-Marseille 2-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), GEOTOP and Department of Earth and Planetary Sciences, McGill University = Université McGill Montréal, Canada, Geology and mineralogy, section of Mineralogy and Petrography, Royal Museum for Central Africa Tervuren (RMCA), Centre Eau Terre Environnement Québec (INRS - ETE), Institut National de la Recherche Scientifique Québec (INRS), Leibniz-Institut für Meereswissenschaften (IFM-GEOMAR), Department of Chemistry, University of Gothenburg (GU), Department of Earth Sciences Gothenburg, Centre for Earth Observation Science Winnipeg, University of Manitoba Winnipeg, Institute of Ocean Sciences, Fisheries and Oceans Canada, Institute of Ocean Sciences, Fisheries and Oceans Canada, Department de Biologie, Université Laval Québec (ULaval), Laboratoire des Mécanismes et Transfert en Géologie (LMTG), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2011
• Subjects: Biogeosciences: Biogeochemical cycles; processes; and modeling (0412; 0793; 1615; 4805; 4912); Biogeosciences: Carbon cycling (4806); Biogeosciences: Diel; seasonal; and annual cycles (4227); Biogeosciences: Trace element cycling (4875); Oceanography: Biological and Chemical: Marine inorganic chemistry (1050); [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry; [SDE.MCG]Environmental Sciences/Global Changes; Arctic; Canadian Arctic Archipelago; Amundsen Gulf; Arctic Archipelago; Beaufort Sea; Sea ice
• Online Access: https://hal.science/hal-00662988; https://hal.science/hal-00662988/document; https://hal.science/hal-00662988/file/2011JC007120proof-1.pdf; https://doi.org/10.1029/2011JC007120

International audience The seasonal and spatial variability of dissolved Barium (Ba) in the Amundsen Gulf, southeastern Beaufort Sea, was monitored over a full year from September 2007 to September 2008. Dissolved Ba displays a nutrient-type behavior: the maximum water column concentration is located below the surface layer. The highest Ba concentrations are typically observed at river mouths, the lowest concentrations are found in water masses of Atlantic origin. Barium concentrations decrease eastward through the Canadian Arctic Archipelago. Barite (BaSO4) saturation is reached at the maximum dissolved Ba concentrations in the subsurface layer, whereas the rest of the water column is undersaturated. A three end-member mixing model comprising freshwater from sea-ice melt and rivers, as well as upper halocline water, is used to establish their relative contributions to the Ba concentrations in the upper water column of the Amundsen Gulf. Based on water column and riverine Ba contributions, we assess the depletion of dissolved Ba by formation and sinking of biologically bound Ba (bio-Ba), from which we derive an estimate of the carbon export production. In the upper 50 m of the water column of the Amundsen Gulf, riverine Ba accounts for up to 15% of the available dissolved Ba inventory, of which up to 20% is depleted by bio-Ba formation and export. Since riverine inputs and Ba export occur concurrently, the seasonal variability of dissolved Ba in the upper water column is moderate. Assuming a fixed organic carbon to bio-Ba flux ratio, carbon export out of the surface layer is estimated at 1.8 ± 0.45 mol C m‑2 yr‑1. Finally, we propose a climatological carbon budget for the Amundsen Gulf based on recent literature data and our findings, the latter bridging the surface and subsurface water carbon cycles.