The role of anthropogenic aerosol forcing in the 1850-1985 strengthening of the AMOC in CMIP6 historical simulations
Previous work has shown that anthropogenic aerosol (AA) forcing drives a strengthening in the Atlantic Meridional Overturning Circulation (AMOC) in CMIP6 historical simulations over 1850–1985, but the mechanisms have not been fully understood. Across CMIP6 models, it is shown that there is a strong...
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American Meteorological Society
2022
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ftunivreading:oai:centaur.reading.ac.uk:105935 2024-06-23T07:55:11+00:00 The role of anthropogenic aerosol forcing in the 1850-1985 strengthening of the AMOC in CMIP6 historical simulations Robson, Jon Menary, Matthew B. Sutton, Rowan T. Mecking, Jenny Gregory, Jonathan M. Jones, Colin Sinha, Bablu Stevens, David P. Wilcox, Laura J. 2022-10 text https://centaur.reading.ac.uk/105935/ https://centaur.reading.ac.uk/105935/9/1520-0442-JCLI-D-22-0124.1.pdf https://centaur.reading.ac.uk/105935/1/robson22amoc.pdf en eng American Meteorological Society https://centaur.reading.ac.uk/105935/9/1520-0442-JCLI-D-22-0124.1.pdf https://centaur.reading.ac.uk/105935/1/robson22amoc.pdf Robson, J. <https://centaur.reading.ac.uk/view/creators/90002607.html> orcid:0000-0002-3467-018X , Menary, M. B., Sutton, R. T. <https://centaur.reading.ac.uk/view/creators/90000057.html> orcid:0000-0001-8345-8583 , Mecking, J., Gregory, J. M. <https://centaur.reading.ac.uk/view/creators/90000874.html> orcid:0000-0003-1296-8644 , Jones, C., Sinha, B., Stevens, D. P. and Wilcox, L. J. <https://centaur.reading.ac.uk/view/creators/90004004.html> orcid:0000-0001-5691-1493 (2022) The role of anthropogenic aerosol forcing in the 1850-1985 strengthening of the AMOC in CMIP6 historical simulations. Journal of Climate, 35 (20). pp. 3243-3263. ISSN 1520-0442 doi: https://doi.org/10.1175/JCLI-D-22-0124.1 <https://doi.org/10.1175/JCLI-D-22-0124.1> cc_by_4 Article PeerReviewed 2022 ftunivreading https://doi.org/10.1175/JCLI-D-22-0124.1 2024-06-11T15:11:42Z Previous work has shown that anthropogenic aerosol (AA) forcing drives a strengthening in the Atlantic Meridional Overturning Circulation (AMOC) in CMIP6 historical simulations over 1850–1985, but the mechanisms have not been fully understood. Across CMIP6 models, it is shown that there is a strong correlation between surface heat loss over the subpolar North Atlantic (SPNA) and the forced strengthening of the AMOC. Despite the link to AA forcing, the AMOC response is not strongly related to the contribution of anomalous downwelling surface shortwave radiation to SPNA heat loss. Rather, the spread in AMOC response is primarily due to the spread in turbulent heat loss. We hypothesize that turbulent heat loss is larger in models with strong AA forcing because the air advected over the ocean is colder and drier, in turn because of greater AA forced cooling over the continents upwind, especially North America. The strengthening of the AMOC also feeds back on itself positively in two distinct ways: by raising the sea surface temperature and hence further increasing turbulent heat loss in the SPNA, and by increasing the sea surface density across the SPNA due to increased northward transport of saline water. A comparison of key indices suggests that the AMOC response in models with strong AA forcing is not likely to be consistent with observations. Article in Journal/Newspaper North Atlantic CentAUR: Central Archive at the University of Reading Journal of Climate 1 48 |
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CentAUR: Central Archive at the University of Reading |
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ftunivreading |
language |
English |
description |
Previous work has shown that anthropogenic aerosol (AA) forcing drives a strengthening in the Atlantic Meridional Overturning Circulation (AMOC) in CMIP6 historical simulations over 1850–1985, but the mechanisms have not been fully understood. Across CMIP6 models, it is shown that there is a strong correlation between surface heat loss over the subpolar North Atlantic (SPNA) and the forced strengthening of the AMOC. Despite the link to AA forcing, the AMOC response is not strongly related to the contribution of anomalous downwelling surface shortwave radiation to SPNA heat loss. Rather, the spread in AMOC response is primarily due to the spread in turbulent heat loss. We hypothesize that turbulent heat loss is larger in models with strong AA forcing because the air advected over the ocean is colder and drier, in turn because of greater AA forced cooling over the continents upwind, especially North America. The strengthening of the AMOC also feeds back on itself positively in two distinct ways: by raising the sea surface temperature and hence further increasing turbulent heat loss in the SPNA, and by increasing the sea surface density across the SPNA due to increased northward transport of saline water. A comparison of key indices suggests that the AMOC response in models with strong AA forcing is not likely to be consistent with observations. |
format |
Article in Journal/Newspaper |
author |
Robson, Jon Menary, Matthew B. Sutton, Rowan T. Mecking, Jenny Gregory, Jonathan M. Jones, Colin Sinha, Bablu Stevens, David P. Wilcox, Laura J. |
spellingShingle |
Robson, Jon Menary, Matthew B. Sutton, Rowan T. Mecking, Jenny Gregory, Jonathan M. Jones, Colin Sinha, Bablu Stevens, David P. Wilcox, Laura J. The role of anthropogenic aerosol forcing in the 1850-1985 strengthening of the AMOC in CMIP6 historical simulations |
author_facet |
Robson, Jon Menary, Matthew B. Sutton, Rowan T. Mecking, Jenny Gregory, Jonathan M. Jones, Colin Sinha, Bablu Stevens, David P. Wilcox, Laura J. |
author_sort |
Robson, Jon |
title |
The role of anthropogenic aerosol forcing in the 1850-1985 strengthening of the AMOC in CMIP6 historical simulations |
title_short |
The role of anthropogenic aerosol forcing in the 1850-1985 strengthening of the AMOC in CMIP6 historical simulations |
title_full |
The role of anthropogenic aerosol forcing in the 1850-1985 strengthening of the AMOC in CMIP6 historical simulations |
title_fullStr |
The role of anthropogenic aerosol forcing in the 1850-1985 strengthening of the AMOC in CMIP6 historical simulations |
title_full_unstemmed |
The role of anthropogenic aerosol forcing in the 1850-1985 strengthening of the AMOC in CMIP6 historical simulations |
title_sort |
role of anthropogenic aerosol forcing in the 1850-1985 strengthening of the amoc in cmip6 historical simulations |
publisher |
American Meteorological Society |
publishDate |
2022 |
url |
https://centaur.reading.ac.uk/105935/ https://centaur.reading.ac.uk/105935/9/1520-0442-JCLI-D-22-0124.1.pdf https://centaur.reading.ac.uk/105935/1/robson22amoc.pdf |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
https://centaur.reading.ac.uk/105935/9/1520-0442-JCLI-D-22-0124.1.pdf https://centaur.reading.ac.uk/105935/1/robson22amoc.pdf Robson, J. <https://centaur.reading.ac.uk/view/creators/90002607.html> orcid:0000-0002-3467-018X , Menary, M. B., Sutton, R. T. <https://centaur.reading.ac.uk/view/creators/90000057.html> orcid:0000-0001-8345-8583 , Mecking, J., Gregory, J. M. <https://centaur.reading.ac.uk/view/creators/90000874.html> orcid:0000-0003-1296-8644 , Jones, C., Sinha, B., Stevens, D. P. and Wilcox, L. J. <https://centaur.reading.ac.uk/view/creators/90004004.html> orcid:0000-0001-5691-1493 (2022) The role of anthropogenic aerosol forcing in the 1850-1985 strengthening of the AMOC in CMIP6 historical simulations. Journal of Climate, 35 (20). pp. 3243-3263. ISSN 1520-0442 doi: https://doi.org/10.1175/JCLI-D-22-0124.1 <https://doi.org/10.1175/JCLI-D-22-0124.1> |
op_rights |
cc_by_4 |
op_doi |
https://doi.org/10.1175/JCLI-D-22-0124.1 |
container_title |
Journal of Climate |
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1 |
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48 |
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1802647651514056704 |