Large diversity in AMOC internal variability across NEMO-based climate models
We characterise, and explore the drivers of, differences in the internal variability of the atlantic meridional overturning circulation (AMOC) across five NEMO-based CMIP6 class climate models. While the variability of AMOC variability is dominated by its lower dense limb in all models, there is lar...
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Language: | English |
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2024
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Online Access: | https://doi.org/10.1007/s00382-023-07069-y |
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ftncar:oai:drupal-site.org:articles_27275 2024-09-15T18:03:37+00:00 Large diversity in AMOC internal variability across NEMO-based climate models Zhao, Alcide (author) Robson, Jon (author) Sutton, Rowan (author) Lai, Michael W.K. (author) Mecking, Jennifer V. (author) Yeager, Stephen (author) Petit, Tillys (author) 2024-05 https://doi.org/10.1007/s00382-023-07069-y en eng Climate Dynamics--Clim Dyn--0930-7575--1432-0894 articles:27275 doi:10.1007/s00382-023-07069-y ark:/85065/d78s4v46 Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. article Text 2024 ftncar https://doi.org/10.1007/s00382-023-07069-y 2024-06-24T14:07:44Z We characterise, and explore the drivers of, differences in the internal variability of the atlantic meridional overturning circulation (AMOC) across five NEMO-based CMIP6 class climate models. While the variability of AMOC variability is dominated by its lower dense limb in all models, there is large diversity in the timescale, multidecadal variability, and latitudinal coherence of AMOC across models. In particular, the UK models have much weaker AMOC multidecadal variability and latitudinal coherence. The model diversity is associated with differences in salinity-governed surface density variations which drive high-density water mass transformation (WMT) in the Greenland-Iceland-Norwegian Seas (GIN) and the Arctic. Specifically, GIN Seas WMT shows large multidecadal variability which has a major impact on AMOC variability in non-UK models. In contrast, the smaller variability in GIN Seas WMT in the UK models has limited impact on the lower latitude AMOC via the Denmark strait overflow mass transport. This leads to a latitudinally less coherent and weaker multidecadal variability of the AMOC lower limb. Such differences between UK and non-UK models are related to differences in model mean states and densification processes in the Arctic and GIN Seas. Consequently, we recommend further in-depth studies to better understand and constrain processes driving salinity changes in the Arctic and GIN Seas for more reliable representation of the AMOC in climate models. Article in Journal/Newspaper Denmark Strait Greenland Iceland OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Climate Dynamics 62 5 3355 3374 |
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Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
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ftncar |
language |
English |
description |
We characterise, and explore the drivers of, differences in the internal variability of the atlantic meridional overturning circulation (AMOC) across five NEMO-based CMIP6 class climate models. While the variability of AMOC variability is dominated by its lower dense limb in all models, there is large diversity in the timescale, multidecadal variability, and latitudinal coherence of AMOC across models. In particular, the UK models have much weaker AMOC multidecadal variability and latitudinal coherence. The model diversity is associated with differences in salinity-governed surface density variations which drive high-density water mass transformation (WMT) in the Greenland-Iceland-Norwegian Seas (GIN) and the Arctic. Specifically, GIN Seas WMT shows large multidecadal variability which has a major impact on AMOC variability in non-UK models. In contrast, the smaller variability in GIN Seas WMT in the UK models has limited impact on the lower latitude AMOC via the Denmark strait overflow mass transport. This leads to a latitudinally less coherent and weaker multidecadal variability of the AMOC lower limb. Such differences between UK and non-UK models are related to differences in model mean states and densification processes in the Arctic and GIN Seas. Consequently, we recommend further in-depth studies to better understand and constrain processes driving salinity changes in the Arctic and GIN Seas for more reliable representation of the AMOC in climate models. |
author2 |
Zhao, Alcide (author) Robson, Jon (author) Sutton, Rowan (author) Lai, Michael W.K. (author) Mecking, Jennifer V. (author) Yeager, Stephen (author) Petit, Tillys (author) |
format |
Article in Journal/Newspaper |
title |
Large diversity in AMOC internal variability across NEMO-based climate models |
spellingShingle |
Large diversity in AMOC internal variability across NEMO-based climate models |
title_short |
Large diversity in AMOC internal variability across NEMO-based climate models |
title_full |
Large diversity in AMOC internal variability across NEMO-based climate models |
title_fullStr |
Large diversity in AMOC internal variability across NEMO-based climate models |
title_full_unstemmed |
Large diversity in AMOC internal variability across NEMO-based climate models |
title_sort |
large diversity in amoc internal variability across nemo-based climate models |
publishDate |
2024 |
url |
https://doi.org/10.1007/s00382-023-07069-y |
genre |
Denmark Strait Greenland Iceland |
genre_facet |
Denmark Strait Greenland Iceland |
op_relation |
Climate Dynamics--Clim Dyn--0930-7575--1432-0894 articles:27275 doi:10.1007/s00382-023-07069-y ark:/85065/d78s4v46 |
op_rights |
Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. |
op_doi |
https://doi.org/10.1007/s00382-023-07069-y |
container_title |
Climate Dynamics |
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62 |
container_issue |
5 |
container_start_page |
3355 |
op_container_end_page |
3374 |
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1810441106343591936 |