Routine Reversal of the AMOC in an Ocean Model Ensemble
We describe a form of AMOC variability that we believe has not previously appeared in observations or models. It is found in an ensemble of eddy-resolving North Atlantic simulations that the AMOC frequently reverses in sign at ∼35N with gyre-wide anomalies in size and that reach throughout the water...
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ftarchimer:oai:archimer.ifremer.fr:92274 2023-05-15T17:31:35+02:00 Routine Reversal of the AMOC in an Ocean Model Ensemble Dewar, William K. Parfitt, Rhys Wienders, Nicolas 2022-12 application/pdf https://archimer.ifremer.fr/doc/00811/92274/98301.pdf https://archimer.ifremer.fr/doc/00811/92274/98302.pdf https://doi.org/10.1029/2022GL100117 https://archimer.ifremer.fr/doc/00811/92274/ eng eng American Geophysical Union (AGU) https://archimer.ifremer.fr/doc/00811/92274/98301.pdf https://archimer.ifremer.fr/doc/00811/92274/98302.pdf doi:10.1029/2022GL100117 https://archimer.ifremer.fr/doc/00811/92274/ info:eu-repo/semantics/openAccess restricted use Geophysical Research Letters (0094-8276) (American Geophysical Union (AGU)), 2022-12 , Vol. 49 , N. 24 , P. e2022GL100117 (9p.) AMOC annual cycle ocean ensembles text Publication info:eu-repo/semantics/article 2022 ftarchimer https://doi.org/10.1029/2022GL100117 2023-03-14T23:55:22Z We describe a form of AMOC variability that we believe has not previously appeared in observations or models. It is found in an ensemble of eddy-resolving North Atlantic simulations that the AMOC frequently reverses in sign at ∼35N with gyre-wide anomalies in size and that reach throughout the water column. The duration of each reversal is roughly one month. The reversals are part of the annual AMOC cycle occurring in boreal winter, although not all years feature an actual reversal in sign. The occurrence of the reversals appears in our ensemble mean, suggesting it is a forced feature of the circulation. A partial explanation is found in an Ekman response to wind stress anomalies. Model ensemble simulations run with different combinations of climatological and realistic forcings argue that it is the atmospheric forcing specifically that results in the reversals, despite the signals extending into the deep ocean. Key Points The AMOC can reverse in sign Reversals appear in the annual cycle The reversals are the result of atmospheric forcing Plain Language Summary The Atlantic Meridional Overturning Circulation (AMOC) is a climatically important component of the ocean circulation. It is routinely thought to flow northward at the surface and southward at depths of 2000-3000m. Here we show that a significant component of the annual AMOC cycles are intervals during which it actually reverses this sense of flow and argue further that this is a response of the AMOC to the atmosphere. The AMOC anomaly is basin scale in size and extends over the full depth. These results have implications for annual heat storage in the North Atlantic. Article in Journal/Newspaper North Atlantic Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Geophysical Research Letters 49 24 |
institution |
Open Polar |
collection |
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) |
op_collection_id |
ftarchimer |
language |
English |
topic |
AMOC annual cycle ocean ensembles |
spellingShingle |
AMOC annual cycle ocean ensembles Dewar, William K. Parfitt, Rhys Wienders, Nicolas Routine Reversal of the AMOC in an Ocean Model Ensemble |
topic_facet |
AMOC annual cycle ocean ensembles |
description |
We describe a form of AMOC variability that we believe has not previously appeared in observations or models. It is found in an ensemble of eddy-resolving North Atlantic simulations that the AMOC frequently reverses in sign at ∼35N with gyre-wide anomalies in size and that reach throughout the water column. The duration of each reversal is roughly one month. The reversals are part of the annual AMOC cycle occurring in boreal winter, although not all years feature an actual reversal in sign. The occurrence of the reversals appears in our ensemble mean, suggesting it is a forced feature of the circulation. A partial explanation is found in an Ekman response to wind stress anomalies. Model ensemble simulations run with different combinations of climatological and realistic forcings argue that it is the atmospheric forcing specifically that results in the reversals, despite the signals extending into the deep ocean. Key Points The AMOC can reverse in sign Reversals appear in the annual cycle The reversals are the result of atmospheric forcing Plain Language Summary The Atlantic Meridional Overturning Circulation (AMOC) is a climatically important component of the ocean circulation. It is routinely thought to flow northward at the surface and southward at depths of 2000-3000m. Here we show that a significant component of the annual AMOC cycles are intervals during which it actually reverses this sense of flow and argue further that this is a response of the AMOC to the atmosphere. The AMOC anomaly is basin scale in size and extends over the full depth. These results have implications for annual heat storage in the North Atlantic. |
format |
Article in Journal/Newspaper |
author |
Dewar, William K. Parfitt, Rhys Wienders, Nicolas |
author_facet |
Dewar, William K. Parfitt, Rhys Wienders, Nicolas |
author_sort |
Dewar, William K. |
title |
Routine Reversal of the AMOC in an Ocean Model Ensemble |
title_short |
Routine Reversal of the AMOC in an Ocean Model Ensemble |
title_full |
Routine Reversal of the AMOC in an Ocean Model Ensemble |
title_fullStr |
Routine Reversal of the AMOC in an Ocean Model Ensemble |
title_full_unstemmed |
Routine Reversal of the AMOC in an Ocean Model Ensemble |
title_sort |
routine reversal of the amoc in an ocean model ensemble |
publisher |
American Geophysical Union (AGU) |
publishDate |
2022 |
url |
https://archimer.ifremer.fr/doc/00811/92274/98301.pdf https://archimer.ifremer.fr/doc/00811/92274/98302.pdf https://doi.org/10.1029/2022GL100117 https://archimer.ifremer.fr/doc/00811/92274/ |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Geophysical Research Letters (0094-8276) (American Geophysical Union (AGU)), 2022-12 , Vol. 49 , N. 24 , P. e2022GL100117 (9p.) |
op_relation |
https://archimer.ifremer.fr/doc/00811/92274/98301.pdf https://archimer.ifremer.fr/doc/00811/92274/98302.pdf doi:10.1029/2022GL100117 https://archimer.ifremer.fr/doc/00811/92274/ |
op_rights |
info:eu-repo/semantics/openAccess restricted use |
op_doi |
https://doi.org/10.1029/2022GL100117 |
container_title |
Geophysical Research Letters |
container_volume |
49 |
container_issue |
24 |
_version_ |
1766129240829329408 |