Dissolved iron in the North Atlantic Ocean and Labrador Sea along the GEOVIDE section (GEOTRACES section GA01)

• Published in: Biogeosciences
• Main Authors: Tonnard, Manon, Planquette, Hélène, Bowie, Andrew R., van der Merwe, Pier, Gallinari, Morgane, Desprez de Gésincourt, Floriane, Germain, Yoan, Gourain, Arthur, Benetti, Marion, Reverdin, Gilles, Tréguer, Paul, Boutorh, Julia, Cheize, Marie, Lacan, François, Menzel Barraqueta, Jan-Lukas, Pereira-Contreira, Leonardo, Shelley, Rachel, Lherminier, Pascale, Sarthou, Géraldine
• Other Authors: Jarðvísindastofnun (HÍ), Institute of Earth Sciences (UI), Verkfræði- og náttúruvísindasvið (HÍ), School of Engineering and Natural Sciences (UI), Háskóli Íslands, University of Iceland
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus GmbH 2020
• Subjects: GEOVIDE voyage; North Atlantic Ocean; Norður-Atlantshaf; Greenland; Irminger Sea; Newfoundland; Denmark Strait; Labrador Sea; North Atlantic
• Online Access: https://hdl.handle.net/20.500.11815/2413; https://doi.org/10.5194/bg-17-917-2020

Publisher's version (útgefin grein) Dissolved Fe (DFe) samples from the GEOVIDE voyage (GEOTRACES GA01, May-June 2014) in the North Atlantic Ocean were analyzed using a seaFAST-pico™ coupled to an Element XR sector field inductively coupled plasma mass spectrometer (SF-ICP-MS) and provided interesting insights into the Fe sources in this area. Overall, DFe concentrations ranged from 0:09 ± 0:01 to 7:8 ± 0:5 nmol L-1. Elevated DFe concentrations were observed above the Iberian, Greenland, and Newfoundland margins likely due to riverine inputs from the Tagus River, meteoric water inputs, and sedimentary inputs. Deep winter convection occurring the previous winter provided iron-to-nitrate ratios sufficient to sustain phytoplankton growth and lead to relatively elevated DFe concentrations within subsurface waters of the Irminger Sea. Increasing DFe concentrations along the flow path of the Labrador Sea Water were attributed to sedimentary inputs from the Newfoundland Margin. Bottom waters from the Irminger Sea displayed high DFe concentrations likely due to the dissolution of Fe-rich particles in the Denmark Strait Overflow Water and the Polar Intermediate Water. Finally, the nepheloid layers located in the different basins and at the Iberian Margin were found to act as either a source or a sink of DFe depending on the nature of particles, with organic particles likely releasing DFe and Mn particle scavenging DFe. This research has been supported by the French National Research Agency ANR GEOVIDE (grant no. ANR-13-BS06-0014), the RPDOC BITMAP (grant no. ANR-12-PDOC-0025-01), the French National Center for Scientific Research (grant no. CNRS-LEFE-CYBER), the LabexMER (grant no. ANR-10-LABX-19), and Ifremer (Institut français de recherche pour l'exploitation de la mer). Peer Reviewed