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Whitmore LM, Shiller AM, Horner TJ, Xiang Y, Auro ME, Bauch D, Dehairs F, Lam PJ, Li J, Maldonado MT, Mears C, Newton R, Pasqualini A, Planquette H, Rember R, Thomas H. Strong Margin Influence on the Arctic Ocean Barium Cycle Revealed by Pan-Arctic Synthesis. JOURNAL OF GEOPHYSICAL RESEARCH. OCEANS 2022; 127:e2021JC017417. [PMID: 35865799 PMCID: PMC9285926 DOI: 10.1029/2021jc017417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 02/17/2022] [Accepted: 03/16/2022] [Indexed: 06/15/2023]
Abstract
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. But, what controls the distribution of barium (Ba) in the oceans? 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 (δ138Ba) 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 δ138Ba 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-2 day-1 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.
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Affiliation(s)
- Laura M. Whitmore
- School of Ocean Science and EngineeringUniversity of Southern MississippiStennis Space CenterMSUSA
- Now at College of Fisheries and Ocean SciencesUniversity of Alaska FairbanksFairbanksAKUSA
| | - Alan M. Shiller
- School of Ocean Science and EngineeringUniversity of Southern MississippiStennis Space CenterMSUSA
| | - Tristan J. Horner
- NIRVANA LaboratoriesWoods Hole Oceanographic InstitutionWoods HoleMAUSA
| | - Yang Xiang
- Department of Ocean SciencesUniversity of CaliforniaSanta CruzCAUSA
| | - Maureen E. Auro
- NIRVANA LaboratoriesWoods Hole Oceanographic InstitutionWoods HoleMAUSA
| | | | - Frank Dehairs
- Department of Analytical, Environmental and GeochemistryVrije Universiteit BrusselBrusselsBelgium
| | - Phoebe J. Lam
- Department of Ocean SciencesUniversity of CaliforniaSanta CruzCAUSA
| | - Jingxuan Li
- Department of Earth Ocean & Atmospheric SciencesUniversity of British ColumbiaVancouverBCCanada
| | - Maria T. Maldonado
- Department of Earth Ocean & Atmospheric SciencesUniversity of British ColumbiaVancouverBCCanada
| | - Chantal Mears
- Institute of Carbon CyclesHelmholtz Centre HereonGeesthachtGermany
| | - Robert Newton
- Lamont‐Doherty Earth ObservatoryColumbia UniversityNew YorkNYUSA
| | - Angelica Pasqualini
- Department of Earth and Environmental EngineeringColumbia UniversityNew YorkNYUSA
| | | | - Robert Rember
- International Arctic Research CenterUniversity of Alaska FairbanksFairbanksAKUSA
| | - Helmuth Thomas
- Institute of Carbon CyclesHelmholtz Centre HereonGeesthachtGermany
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Charette MA, Lam PJ, Lohan MC, Kwon EY, Hatje V, Jeandel C, Shiller AM, Cutter GA, Thomas A, Boyd PW, Homoky WB, Milne A, Thomas H, Andersson PS, Porcelli D, Tanaka T, Geibert W, Dehairs F, Garcia-Orellana J. Coastal ocean and shelf-sea biogeochemical cycling of trace elements and isotopes: lessons learned from GEOTRACES. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2016; 374:20160076. [PMID: 29035267 PMCID: PMC5069537 DOI: 10.1098/rsta.2016.0076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/30/2016] [Indexed: 05/06/2023]
Abstract
Continental shelves and shelf seas play a central role in the global carbon cycle. However, their importance with respect to trace element and isotope (TEI) inputs to ocean basins is less well understood. Here, we present major findings on shelf TEI biogeochemistry from the GEOTRACES programme as well as a proof of concept for a new method to estimate shelf TEI fluxes. The case studies focus on advances in our understanding of TEI cycling in the Arctic, transformations within a major river estuary (Amazon), shelf sediment micronutrient fluxes and basin-scale estimates of submarine groundwater discharge. The proposed shelf flux tracer is 228-radium (T1/2 = 5.75 yr), which is continuously supplied to the shelf from coastal aquifers, sediment porewater exchange and rivers. Model-derived shelf 228Ra fluxes are combined with TEI/ 228Ra ratios to quantify ocean TEI fluxes from the western North Atlantic margin. The results from this new approach agree well with previous estimates for shelf Co, Fe, Mn and Zn inputs and exceed published estimates of atmospheric deposition by factors of approximately 3-23. Lastly, recommendations are made for additional GEOTRACES process studies and coastal margin-focused section cruises that will help refine the model and provide better insight on the mechanisms driving shelf-derived TEI fluxes to the ocean.This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.
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Affiliation(s)
- Matthew A Charette
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Phoebe J Lam
- Department of Ocean Sciences, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Maeve C Lohan
- Ocean and Earth Science, National Oceanography Centre, University of Southampton, Southampton SO14 3ZH, UK
| | - Eun Young Kwon
- Research Institute of Oceanography, Seoul National University, Seoul 151-742, Korea
| | - Vanessa Hatje
- Centro Interdisciplinar de Energia e Ambiente, Inst. de Química, Universidade Federal da Bahia, Salvador 40170-115, Brazil
| | - Catherine Jeandel
- University of Toulouse/CNRS/UPS/IRD/CNES, Observatoire Midi-Pyrénées, Toulouse 31400, France
| | - Alan M Shiller
- Department of Marine Science, University of Southern Mississippi, Stennis Space Center, MS 39529, USA
| | - Gregory A Cutter
- Department of Ocean, Earth, and Atmospheric Sciences, Old Dominion University, Norfolk, VA 23529, USA
| | - Alex Thomas
- School of GeoSciences, University of Edinburgh, Edinburgh EH9 3FE, UK
| | - Philip W Boyd
- Institute of Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania 7005, Australia
| | - William B Homoky
- Department of Earth Sciences, University of Oxford, Oxford OX1 3AN, UK
| | - Angela Milne
- School of Geography, Earth and Environmental Sciences, Plymouth University, Plymouth PL4 8AA, UK
| | - Helmuth Thomas
- Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
| | - Per S Andersson
- Department of Geosciences, Swedish Museum of Natural History, Stockholm 104 05, Sweden
| | - Don Porcelli
- Department of Earth Sciences, University of Oxford, Oxford OX1 3AN, UK
| | - Takahiro Tanaka
- Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa Chiba 277-8564, Japan
| | - Walter Geibert
- Marine Geochemistry Department, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Frank Dehairs
- Earth System Sciences and Analytical, Environmental and Geo-Chemistry, Vrije Universiteit Brussel, Brussels 1050, Belgium
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Else BGT, Papakyriakou TN, Galley RJ, Mucci A, Gosselin M, Miller LA, Shadwick EH, Thomas H. Annual cycles ofpCO2swin the southeastern Beaufort Sea: New understandings of air-sea CO2exchange in arctic polynya regions. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jc007346] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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