EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

AMOC thresholds in CMIP6 models: NAHosMIP

Laura Jackson1, Eduardo Alastrue-De-Asenjo2, Katinka Bellomo3, Gokhan Danabasoglu4, Aixue Hu4, Johann Jungclaus2, Virna Meccia3, Oleg Saenko5, Andrew Shao5, and Didier Swingedouw6
Laura Jackson et al.
  • 1Met Office, Exeter, UK
  • 2MPI, Germany
  • 3ISAC, Italy
  • 4NCAR, USA
  • 5ECCC, Canada
  • 6University of Bordeaux, France

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.  

How to cite: Jackson, L., Alastrue-De-Asenjo, E., Bellomo, K., Danabasoglu, G., Hu, A., Jungclaus, J., Meccia, V., Saenko, O., Shao, A., and Swingedouw, D.: AMOC thresholds in CMIP6 models: NAHosMIP, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2778,, 2022.


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