The silicon stable isotope distribution along the GEOVIDE section (GEOTRACES GA-01) of the North Atlantic Ocean

• Published in: Biogeosciences
• Main Authors: Sutton, Jill, Souza, Gregory F., De, Garcia-Ibiliez, Maribel I., de La Rocha, Christina L.
• Other Authors: Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institute of Geochemistry and Petrology ETH Zürich, Department of Earth Sciences Swiss Federal Institute of Technology - ETH Zürich (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology Zürich (ETH Zürich)-Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology Zürich (ETH Zürich), Bjerknes Centre for Climate Research (BCCR), Department of Biological Sciences Bergen (BIO / UiB), University of Bergen (UiB)-University of Bergen (UiB), Consejo Superior de Investigaciones Cientificas = Spanish National Research Council (CSIC), ANR-10-LABX-0019,LabexMER,LabexMER Marine Excellence Research: a changing ocean(2010), ANR-13-BS06-0014,GEOVIDE,GEOVIDE, Une étude internationale GEOTRACES le long de la section OVIDE en Atlantique Nord et en Mer du Labrador(2013), ANR-12-PDOC-0025,BITMAP,Biodisponibilité du fer et des métaux traces dans les particules marines(2012), European Project: 708407,H2020,H2020-MSCA-IF-2015,SOSiC(2016)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: ACL; southern-ocean; biogenic silica; marine diatoms; natural-waters; fractionation; labrador sea; hydrography; mediterranean outflow; deep-water masses; eastern equatorial pacific; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Arctic; Arctic Ocean; Pacific; Southern Ocean; Labrador Sea; North Atlantic
• Online Access: https://hal.science/hal-02651012; https://hal.science/hal-02651012/document; https://hal.science/hal-02651012/file/Sutton_etal_silicon-stable-isotope_Biogeosciences_2018.pdf; https://doi.org/10.5194/bg-15-5663-2018

WOS:000445272300001 International audience The stable isotope composition of dissolved silicon in seawater (delta Si-30(DSi)) was examined at 10 stations along the GEOVIDE section (GEOTRACES GA-01), spanning the North Atlantic Ocean (40-60 degrees N) and Labrador Sea. Variations in delta Si-30(DSi) below 500 m were closely tied to the distribution of water masses. Higher delta Si-30(DSi) values are associated with intermediate and deep water masses of northern Atlantic or Arctic Ocean origin, whilst lower delta Si-30(DSi) values are associated with DSi-rich waters sourced ultimately from the Southern Ocean. Correspondingly, the lowest delta Si-30(DSi) values were observed in the deep and abyssal eastern North Atlantic, where dense southern-sourced waters dominate. The extent to which the spreading of water masses influences the delta Si-30(DSi) distribution is marked clearly by Labrador Sea Water (LSW), whose high delta Si-30(DSi) signature is visible not only within its region of formation within the Labrador and Irminger seas, but also throughout the mid-depth western and eastern North Atlantic Ocean. Both delta Si-30(DSi) and hydrographic parameters document the circulation of LSW into the eastern North Atlantic, where it overlies southern-sourced Lower Deep Water. The GEOVIDE delta Si-30(DSi) distribution thus provides a clear view of the direct interaction between subpolar/polar water masses of northern and southern origin, and allow examination of the extent to which these far-field signals influence the local delta Si-30(DSi) distribution.