title: Carbon isotope records reveal precise timing of enhanced Southern Ocean upwelling during the last deglaciation.
abstract: The Southern Ocean plays a prominent role in the Earth's climate and carbon cycle. Changes in the Southern Ocean circulation may have regulated the release of CO₂ to the atmosphere from a deep-ocean reservoir during the last deglaciation. However, the path and exact timing of this deglacial CO₂ release are still under debate. Here we present measurements of deglacial surface reservoir ¹⁴C age changes in the eastern Pacific sector of the Southern Ocean, obtained by ¹⁴C dating of tephra deposited over the marine and terrestrial regions. These results, along with records of foraminifera benthic-planktic ¹⁴C age and δ¹³C difference, provide evidence for three periods of enhanced upwelling in the Southern Ocean during the last deglaciation, supporting the hypothesis that Southern Ocean upwelling contributed to the deglacial rise in atmospheric CO₂. These independently dated marine records suggest synchronous changes in the Southern Ocean circulation and Antarctic climate during the last deglaciation.
authors.affiliation: Laboratoire des Interactions et Dynamique des Environnements de Surface (IDES), UMR 8148, CNRS-Université de Paris-Sud, Bâtiment 504, 91405 Orsay Cedex, France.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Siani
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Michel
authors.forename: Ricardo
authors.initials: R
authors.lastname: De Pol-Holz
authors.forename: Tim
authors.initials: T
authors.lastname: Devries
authors.forename: Frank
authors.initials: F
authors.lastname: Lamy
authors.forename: Mélanie
authors.initials: M
authors.lastname: Carel
authors.forename: Gulay
authors.initials: G
authors.lastname: Isguder
authors.forename: Fabien
authors.initials: F
authors.lastname: Dewilde
authors.forename: Anna
authors.initials: A
authors.lastname: Lourantou