Aerosol-forced AMOC changes in CMIP6 historical simulations

Menary, M. B., Robson, J. ORCID: https://orcid.org/0000-0002-3467-018X, Allan, R. ORCID: https://orcid.org/0000-0003-0264-9447, Booth, B. B. B., Cassou, C., Gastineau, G., Gregory, J. ORCID: https://orcid.org/0000-0003-1296-8644, Hodson, D. ORCID: https://orcid.org/0000-0001-7159-6700, Jones, C., Mignot, J., Ringer, M., Sutton, R. ORCID: https://orcid.org/0000-0001-8345-8583, Wilcox, L. ORCID: https://orcid.org/0000-0001-5691-1493 and Zhang, R. (2020) Aerosol-forced AMOC changes in CMIP6 historical simulations. Geophysical Research Letters. e2020GL088166. ISSN 0094-8276 doi: 10.1029/2020GL088166

Abstract/Summary

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.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/91305
Identification Number/DOI	10.1029/2020GL088166
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > NCAS Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	American Geophysical Union
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