Enhanced ocean-atmosphere carbon partitioning via the carbonate counter pump during the last deglacial
Publisher DOI
Abstract
Several synergistic mechanisms were likely involved in the last deglacial atmospheric pCO2 rise. Leading hypotheses invoke a release of deep-ocean carbon through enhanced convec- tion in the Southern Ocean (SO) and concomitant decreased efficiency of the global soft- tissue pump (STP). However, the temporal evolution of both the STP and the carbonate counter pump (CCP) remains unclear, thus preventing the evaluation of their contributions to the pCO2 rise. Here we present sedimentary coccolith records combined with export pro- duction reconstructions from the Subantarctic Pacific to document the leverage the SO biological carbon pump (BCP) has imposed on deglacial pCO2. Our data suggest a weakening of BCP during the phases of carbon outgassing, due in part to an increased CCP along with higher surface ocean fertility and elevated [CO2aq]. We propose that reduced BCP efficiency combined with enhanced SO ventilation played a major role in propelling the Earth out of the last ice age.
Date Issued
2018-06-19
Publication Type
Article
Subject(s)
Language(s)
en
Author(s)
Duchamp-Alphonse, Stéphanie | |
Siani, Giuseppe | |
Michel, Elisabeth | |
Beaufort, Luc | |
Gally, Yves |
Additional Credits
Journal
Nature communications
Publisher
Nature Publishing Group
ISSN
2041-1723
Access(Rights)
open.access