Alkenone carbon isotopes, unsatutation measurements, coccolith size and stable planktic foraminifera carbon isotopes for estimation of atmospheric CO2 at ODP Site 999 ...

• Main Authors: Badger, Marcus P S, Chalk, Thomas B, Foster, Gavin L, Bown, Paul R, Gibbs, Samantha J, Sexton, Philip F, Schmidt, Daniela N, Pälike, Heiko, Mackensen, Andreas, Pancost, Richard D
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2019
• Subjects: Andreas; ice core
• Online Access: https://dx.doi.org/10.1594/pangaea.899353; https://doi.pangaea.de/10.1594/PANGAEA.899353

Atmospheric _p_CO~2~ is a critical component of the global carbon system and is considered to be the major control of Earth's past, present and future climate. Accurate and precise reconstructions of its concentration through geological time are, therefore, crucial to our understanding of the Earth system. Ice core records document _p_CO~2~ for the past 800 kyrs, but at no point during this interval were CO~2~ levels higher than today. Interpretation of older _p_CO~2~ has been hampered by discrepancies during some time intervals between two of the main ocean-based proxy methods used to reconstruct _p_CO~2~: the carbon isotope fractionation that occurs during photosynthesis as recorded by haptophyte biomarkers (alkenones) and the boron isotope composition (δ^11^B) of foraminifer shells. Here we present alkenone and δ^11^B-based _p_CO~2~ reconstructions generated from the same samples from the Plio-Pleistocene at ODP Site 999 across a glacial-interglacial cycle. We find a muted response to _p_CO~2~ in the ... : Supplement to: Badger, Marcus P S; Chalk, Thomas B; Foster, Gavin L; Bown, Paul R; Gibbs, Samantha J; Sexton, Philip F; Schmidt, Daniela N; Pälike, Heiko; Mackensen, Andreas; Pancost, Richard D (2019): Insensitivity of alkenone carbon isotopes to atmospheric CO2 at low to moderate CO2 levels. Climate of the Past Discussions, 15, 539-554 ...