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

Duchamp-Alphonse, Stéphanie; Siani, Giuseppe; Michel, Elisabeth; Beaufort, Luc; Gally, Yves; Jaccard, Samuel (2018). Enhanced ocean-atmosphere carbon partitioning via the carbonate counter pump during the last deglacial. Nature communications, 9(1) Nature Publishing Group 10.1038/s41467-018-04625-7

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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.

Item Type:

Journal Article (Original Article)

Division/Institute:

10 Strategic Research Centers > Oeschger Centre for Climate Change Research (OCCR)
08 Faculty of Science > Institute of Geological Sciences

UniBE Contributor:

Jaccard, Samuel

Subjects:

500 Science > 550 Earth sciences & geology

ISSN:

2041-1723

Publisher:

Nature Publishing Group

Language:

English

Submitter:

Samuel Jaccard

Date Deposited:

20 Jun 2018 07:45

Last Modified:

29 Oct 2019 06:08

Publisher DOI:

10.1038/s41467-018-04625-7

BORIS DOI:

10.7892/boris.116983

URI:

https://boris.unibe.ch/id/eprint/116983

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