Back to overview

Enhanced ocean-atmosphere carbon partitioning via the carbonate counter pump during the last deglacial

Type of publication Peer-reviewed
Publikationsform Original article (peer-reviewed)
Author Duchamp-Alphonse Stéphanie, Siani Giuseppe, Michel Elisabeth, Beaufort Luc, Gally Yves, Jaccard Samuel L.,
Project SeaO2 - Past changes in Southern Ocean overturning circulation - implications for the partitioning of carbon and oxygen between the ocean and the atmosphere
Show all

Original article (peer-reviewed)

Journal Nature Communications
Volume (Issue) 9(1)
Page(s) 2396 - 2396
Title of proceedings Nature Communications
DOI 10.1038/s41467-018-04625-7

Open Access

Type of Open Access Publisher (Gold Open Access)


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.