Aerosol-forced AMOC changes in CMIP6 historical simulations.
- 1LOCEAN, Sorbonne Université, Paris, France (matthewbmenary@gmail.com)
- 2LMD, Ecole Normale Supérieure, France
- 3NCAS, Department of Meteorology, University of Reading, UK
- 4Department of Meteorology, University of Reading, UK
- 5Met Office Hadley Centre, Met Office, UK
- 6CECI CNRS-Cerfacs, France
- 7NCAS, School of Earth and the Environment, University of Leeds, UK
- 8NOAA/GFDL, Princeton, USA
The Atlantic Meridional Overturning Circulation (AMOC) has been, and will continue to be, a key factor in the modulation of climate change both locally and globally. However, there remains considerable uncertainty in recent AMOC evolution. Here, we show that the multi-model mean AMOC strengthened by approximately 10% from 1850-1985 in new simulations from the 6th Coupled Model Inter-comparison Project (CMIP6), a larger change than was seen in CMIP5. Across the models, the strength of the AMOC trend up to 1985 is related to a proxy for the strength of the aerosol forcing. Therefore, the multi-model difference is a result of stronger anthropogenic aerosol forcing on average in CMIP6 than CMIP5, which is primarily due to more models including aerosol-cloud interactions. However, observational constraints - including a historical sea surface temperature fingerprint and shortwave radiative forcing in recent decades - suggest that anthropogenic forcing and/or the AMOC response may be overestimated.
How to cite: Menary, M., Allan, R., Robson, J., Booth, B., Cassou, C., Gregory, J., Hodson, D., Jones, C., Mignot, J., Ringer, M., Sutton, R., Wilcox, L., Zhang, R., and Gastineau, G.: Aerosol-forced AMOC changes in CMIP6 historical simulations., EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8693, https://doi.org/10.5194/egusphere-egu21-8693, 2021.
