1. Calibration of the carbon isotope composition (δ13C) of benthic foraminifera
- Author
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Andreas Mackensen, Delia W Oppo, Gema Martínez-Méndez, Juan Carlos Herguera, David C Lund, Claire Waelbroeck, Carlye D. Peterson, Elisabeth L. Sikes, William B Curry, Alan C. Mix, Janne Repschläger, Helen C Bostock, Jean Lynch-Stieglitz, Olivier Cartapanis, Elisabeth Michel, Babette A A Hoogakker, Howard J. Spero, Helena L. Filipsson, Julia Gottschalk, Lorraine E. Lisiecki, Samuel L Jaccard, Eric D. Galbraith, Andreas Schmittner, 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), University of California [Santa Barbara] (UC Santa Barbara), University of California (UC), 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-Saclay-Centre National de la Recherche Scientifique (CNRS), and 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-Saclay-Centre National de la Recherche Scientifique (CNRS)-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-Saclay-Centre National de la Recherche Scientifique (CNRS)
- Subjects
010504 meteorology & atmospheric sciences ,010502 geochemistry & geophysics ,Oceanography ,01 natural sciences ,Carbon cycle ,Foraminifera ,Water column ,Dissolved organic carbon ,14. Life underwater ,[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment ,Life Below Water ,550 Earth sciences & geology ,isotopes ,0105 earth and related environmental sciences ,[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,benthic ,biology ,Ecology ,carbon ,foraminifera ,Biological pump ,Paleontology ,biology.organism_classification ,calibration ,Geochemistry ,13. Climate action ,Benthic zone ,Seawater ,Cibicides ,Geology - Abstract
The carbon isotope composition (δ13C) of seawater provides valuable insight on ocean circulation, air-sea exchange, the biological pump, and the global carbon cycle and is reflected by the δ13C of foraminifera tests. Here more than 1700 δ13C observations of the benthic foraminifera genus Cibicides from late Holocene sediments (δ13CCibnat) are compiled and compared with newly updated estimates of the natural (preindustrial) water column δ13C of dissolved inorganic carbon (δ13CDICnat) 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 δ13CCibnat and δ13CDICnat, confirming earlier work. Regression analyses indicate significant carbonate ion (−2.6±0.4)×10−3‰/(μmolkg−1) [CO32−] and pressure (−4.9±1.7)×10−5‰m−1 (depth) effects, which we use to propose a new global calibration for predicting δ13CDICnat from δ13CCibnat. This calibration is shown to remove some systematic regional biases and decrease errors compared with the one-to-one relationship (δ13CDICnat=δ13CCibnat). 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 δ13C record.
- Published
- 2017
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