Anthropogenic carbon changes in the Irminger Basin (1981-2006): Coupling δ 13 C DIC and DIC observations

• Published in: Journal of Marine Systems
• Main Authors: Racapé, Virginie, Pierre, Catherine, Metzl, Nicolas, Lo Monaco, Claire, Reverdin, Gilles, Olsen, Are, Morin, Pascal, Vázquez-Rodríguez, M., Ríos, Aida F., Pérez, Fiz F.
• Other Authors: Paléoclimats, proxies, processus (PALEOPROXUS), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Couplage physique-biogéochimie-carbone (PHYBIOCAR), Échanges dans la couche de surface : des pôles aux tropiques (SURF), CHImie Marine (CHIM), Adaptation et diversité en milieu marin (AD2M), Station biologique de Roscoff Roscoff (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff Roscoff (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Instituto de Investigaciones Marinas, Consejo Superior de Investigaciones Cientificas España = Spanish National Research Council Spain (CSIC)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2013
• Subjects: Decadal variation; Anthropogenic carbon; Oceanic 13 C Suess effect; North Atlantic Ocean; [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph]; [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]; North Atlantic
• Online Access: https://hal.science/hal-00873502; https://doi.org/10.1016/J.JMARSYS.2012.12.005

International audience The North Atlantic subpolar gyre is considered to be one of the strongest marine anthropogenic CO 2 sinks, a consequence of extensive deep convection occurring during winter. Observations collected in this region since 1981 have shown large changes in Dissolved Inorganic Carbon (DIC) concentrations in intermediate and deep waters, which have been attributed to both anthropogenic CO 2 penetration and natural variability in the ocean carbon cycle (Wanninkhof et al., 2010). In this context, we describe new δ 13 C DIC observations obtained in the Irminger Basin during two OVIDE cruises (2002 and 2006) which we compare to historical data (TTO-NAS 1981) in order to estimate the oceanic 13 C Suess Effect over the more than twenty years that separates these surveys. The data reveal a significant decrease in δ 13 C DIC , of between - 0.3‰ and - 0.4‰ from 1981 to 2006. The anthropogenic change, extracted by using the extended Multi Linear Regression (eMLR) approach, explains 75% of this signal for oldest water mass and 90% for youngest. The reminding signal is due to the natural processes, such as remineralization and vertical mixing. The eMLR method was also applied to DIC measurements which i) reveal strong relationships between the increase of anthropogenic CO 2 and the oceanic 13 C Suess Effect over the whole water column during the 25-year period and ii) support the hypothesis of change in the Cant storage rate in the Irminger Basin between 1981 and 2006.