Atlantic circulation changes across a stadial-interstadial transition ...

• Main Authors: Waelbroeck, Claire, Tjiputra, Jerry, Guo, Chuncheng, Nisancioglu, Kerim H., Jansen, Eystein, Vazquez Riveiros, Natalia, Toucanne, Samuel, Eynaud, Frédérique, Rossignol, Linda, Dewilde, Fabien, Marches, Elodie, Lebreiro, Susana, Nave, Silvia
• Format: Dataset
• Language: unknown
• Published: SEANOE 2022
• Subjects: benthic carbon isotopes; stadial-interstadial transition; Heinrich Stadial 4; NorESM climate model; Atlantic meridional overturning circulation; North Atlantic
• Online Access: https://dx.doi.org/10.17882/91130; https://www.seanoe.org/data/00799/91130/

We combine consistently dated benthic carbon isotopic records distributed over the entire Atlantic Ocean with numerical simulations performed by a glacial configuration of the Norwegian Earth System Model with active ocean biogeochemistry, in order to interpret the observed Cibicides δ13C changes at the stadial-interstadial transition corresponding to the end of Heinrich Stadial 4 (HS4) in terms of ocean circulation and remineralization changes. We show that the marked increase in Cibicides δ13C observed at the end of HS4 between ~2000 and 4200 m in the Atlantic can be explained by changes in nutrient concentrations as simulated by the model in response to the halting of freshwater input in the high latitude glacial North Atlantic. Our model results show that this Cibicides δ13C signal is associated with changes in the ratio of southern-sourced (SSW) versus northern-sourced (NSW) water masses at the core sites, whereby SSW is replaced by NSW as a consequence of the resumption of deep water formation in the ...