A coupled model for carbon and radiocarbon evolution during the last deglaciation

Véronique Mariotti (1) , Didier Paillard (1, 2) , Laurent Bopp (1) , Didier M. Roche (1, 2) , Nathaëlle Bouttes (3)

1 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
2 CLIM - Modélisation du climat
3 EPOC - Environnements et Paléoenvironnements OCéaniques

Changes in the ventilation of the Southern Ocean are thought to play an important role on deglacial carbon and radiocarbon evolution but have not been tested within a coupled climate-carbon model. Here we present such a simulation based on a simple scenario of transient deglacial sinking of brines-sea ice salt rejections-around Antarctica, which modulates Southern Ocean ventilation. This experiment is able to reproduce deglacial atmospheric changes in carbon and radiocarbon and also ocean radiocarbon records measured in the Atlantic, Southern, and Pacific Oceans. Simulated for the first time in a fully coupled climate-carbon model of intermediate complexity including radiocarbon, our modeling results suggest that the deglacial changes in atmospheric carbon dioxide and radiocarbon were achieved by means of a breakdown in the glacial brine-induced stratification of the Southern Ocean.

Domaines: Océan, Atmosphère; Interfaces continentales, environnement

Véronique Mariotti, Didier Paillard, Laurent Bopp, Didier M. Roche, Nathaëlle Bouttes. A coupled model for carbon and radiocarbon evolution during the last deglaciation. Geophysical Research Letters, 2016, 43 (3), pp.1306-1313. ⟨10.1002/2015GL067489⟩. ⟨hal-01587469⟩