AMOC thresholds in CMIP6 models: NAHosMIP

• Main Authors: Jackson, Laura, Alastrue-De-Asenjo, Eduardo, Bellomo, Katinka, Danabasoglu, Gokhan, Hu, Aixue, Jungclaus, Johann, Meccia, Virna, Saenko, Oleg, Shao, Andrew, Swingedouw, Didier
• Other Authors: UMR 5805 Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2022
• Subjects: [SDE]Environmental Sciences; North Atlantic
• Online Access: https://hal.science/hal-03869321; https://doi.org/10.5194/egusphere-egu22-2778

International audience The Atlantic meridional overturning circulation (AMOC) is an important part of our climate system, which keeps the North Atlantic relatively warm. It is predicted to weaken under climate change. The AMOC may have a tipping point beyond which recovery is difficult, hence showing quasi-irreversibility (hysteresis). Although hysteresis has been seen in simple models, it has been difficult to demonstrate in comprehensive global climate models. We present initial results from the North Atlantic hosing model intercomparison project, where we applied an idealised forcing of a freshwater flux over the North Atlantic in 9 CMIP6 models. The AMOC weakens in all models from the freshening, but once the freshening ceases, the AMOC recovers in some models, and in others it stays in a weakened state. We discuss how differences in feedbacks affect the AMOC response.