Calibration of the carbon isotope composition (δ 13 C) of benthic foraminifera

• Published in: Paleoceanography
• Main Authors: Schmittner, Andreas, Bostock, Helen, Cartapanis, Olivier, Curry, William, Filipsson, Helena, Galbraith, Eric, Gottschalk, Julia, Herguera, Juan Carlos, Hoogakker, Babette, Jaccard, Samuel L., Lisiecki, Lorraine, Lund, David, Martínez-Méndez, Gema, Lynch-Stieglitz, Jean, Mackensen, Andreas, Michel, Elisabeth, Mix, Alan C., Oppo, Delia W., Peterson, Carlye, Repschläger, Janne, Sikes, Elisabeth, Spero, Howard J., Waelbroeck, Claire
• Other Authors: Oregon State University (OSU), National Institute of Water and Atmospheric Research Wellington (NIWA), Institute of Geological Sciences Bern, University of Bern, Woods Hole Oceanographic Institution (WHOI), Lund University Lund, Department of Earth and Planetary Sciences Montréal (EPS), McGill University = Université McGill Montréal, Canada, Centro de Investigacion Científica y de Educacion Superior de Ensenada, Heriot-Watt University Edinburgh (HWU), Oeschger Centre for Climate Change Research (OCCR), University of California Santa Barbara (UCSB), University of California, University of Connecticut (UCONN), Center for Marine Environmental Sciences Bremen (MARUM), Universität Bremen, Georgia Institute of Technology Atlanta, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Paléocéanographie (PALEOCEAN), Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), College of Earth, Ocean and Atmospheric Sciences Corvallis (CEOAS), University of California Davis (UC Davis), Max Planck Institute for Chemistry (MPIC), Max-Planck-Gesellschaft, WINLAB Rutgers University, Rutgers, The State University of New Jersey New Brunswick (RU), Rutgers University System (Rutgers)-Rutgers University System (Rutgers)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; Antarctic; Antarc*
• Online Access: https://hal.archives-ouvertes.fr/hal-02916860; https://hal.archives-ouvertes.fr/hal-02916860/document; https://hal.archives-ouvertes.fr/hal-02916860/file/2016PA003072.pdf; https://doi.org/10.1002/2016PA003072

International audience The carbon isotope composition (δ 13 C) of seawater provides valuable insight on ocean circulation, air-sea exchange, the biological pump, and the global carbon cycle and is reflected by the δ 13 C of foraminifera tests. Here more than 1700 δ 13 C observations of the benthic foraminifera genus Cibicides from late Holocene sediments (δ 13 C Cibnat) are compiled and compared with newly updated estimates of the natural (preindustrial) water column δ 13 C of dissolved inorganic carbon (δ 13 C DICnat) as part of the international Ocean Circulation and Carbon Cycling (OC3) project. Using selection criteria based on the spatial distance between samples, we find high correlation between δ 13 C Cibnat and δ 13 C DICnat , confirming earlier work. Regression analyses indicate significant carbonate ion (À2.6 ± 0.4) × 10 À3 ‰/(μmol kg À1) [CO 3 2À ] and pressure (À4.9 ± 1.7) × 10 À5 ‰ m À1 (depth) effects, which we use to propose a new global calibration for predicting δ 13 C DICnat from δ 13 C Cibnat. This calibration is shown to remove some systematic regional biases and decrease errors compared with the one-to-one relationship (δ 13 C DICnat = δ 13 C Cibnat). However, these effects and the error reductions are relatively small, which suggests that most conclusions from previous studies using a one-to-one relationship remain robust. The remaining standard error of the regression is generally σ ≅ 0.25‰, with larger values found in the southeast Atlantic and Antarctic (σ ≅ 0.4‰) and for species other than Cibicides wuellerstorfi. Discussion of species effects and possible sources of the remaining errors may aid future attempts to improve the use of the benthic δ 13 C record.