Predictable decadal forcing of the North Atlantic jet speed by sub-polar North Atlantic sea surface temperatures
It has been demonstrated that decadal variations in the North Atlantic Oscillation (NAO) can be predicted by current forecast models. While Atlantic Multidecadal Variability (AMV) in sea surface temperatures (SSTs) has been hypothesised as the source of this skill, the validity of this hypothesis an...
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2023
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ftdoajarticles:oai:doaj.org/article:0858aab40b78466bbe8b1b876da398b0 2023-11-12T04:21:38+01:00 Predictable decadal forcing of the North Atlantic jet speed by sub-polar North Atlantic sea surface temperatures K. Strommen T. Woollings P. Davini P. Ruggieri I. R. Simpson 2023-10-01T00:00:00Z https://doi.org/10.5194/wcd-4-853-2023 https://doaj.org/article/0858aab40b78466bbe8b1b876da398b0 EN eng Copernicus Publications https://wcd.copernicus.org/articles/4/853/2023/wcd-4-853-2023.pdf https://doaj.org/toc/2698-4016 doi:10.5194/wcd-4-853-2023 2698-4016 https://doaj.org/article/0858aab40b78466bbe8b1b876da398b0 Weather and Climate Dynamics, Vol 4, Pp 853-874 (2023) Meteorology. Climatology QC851-999 article 2023 ftdoajarticles https://doi.org/10.5194/wcd-4-853-2023 2023-10-15T00:39:31Z It has been demonstrated that decadal variations in the North Atlantic Oscillation (NAO) can be predicted by current forecast models. While Atlantic Multidecadal Variability (AMV) in sea surface temperatures (SSTs) has been hypothesised as the source of this skill, the validity of this hypothesis and the pathways involved remain unclear. We show, using reanalysis and data from two forecast models, that the decadal predictability of the NAO can be entirely accounted for by the predictability of decadal variations in the speed of the North Atlantic eddy-driven jet, with no predictability of decadal variations in the jet latitude. The sub-polar North Atlantic (SPNA) is identified as the only obvious common source of an SST-based signal across the models and reanalysis, and the predictability of the jet speed is shown to be consistent with a forcing from the SPNA visible already within a single season. The pathway is argued to be tropospheric in nature, with the SPNA-associated heating extending up to the mid-troposphere, which alters the meridional temperature gradient around the climatological jet core. The relative roles of anthropogenic aerosol emissions and the Atlantic Meridional Overturning Circulation (AMOC) at generating predictable SPNA variability are also discussed. The analysis is extensively supported by the novel use of a set of seasonal hindcasts spanning the 20th century and forced with prescribed SSTs. Article in Journal/Newspaper North Atlantic North Atlantic oscillation Directory of Open Access Journals: DOAJ Articles Weather and Climate Dynamics 4 4 853 874 |
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Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Meteorology. Climatology QC851-999 |
spellingShingle |
Meteorology. Climatology QC851-999 K. Strommen T. Woollings P. Davini P. Ruggieri I. R. Simpson Predictable decadal forcing of the North Atlantic jet speed by sub-polar North Atlantic sea surface temperatures |
topic_facet |
Meteorology. Climatology QC851-999 |
description |
It has been demonstrated that decadal variations in the North Atlantic Oscillation (NAO) can be predicted by current forecast models. While Atlantic Multidecadal Variability (AMV) in sea surface temperatures (SSTs) has been hypothesised as the source of this skill, the validity of this hypothesis and the pathways involved remain unclear. We show, using reanalysis and data from two forecast models, that the decadal predictability of the NAO can be entirely accounted for by the predictability of decadal variations in the speed of the North Atlantic eddy-driven jet, with no predictability of decadal variations in the jet latitude. The sub-polar North Atlantic (SPNA) is identified as the only obvious common source of an SST-based signal across the models and reanalysis, and the predictability of the jet speed is shown to be consistent with a forcing from the SPNA visible already within a single season. The pathway is argued to be tropospheric in nature, with the SPNA-associated heating extending up to the mid-troposphere, which alters the meridional temperature gradient around the climatological jet core. The relative roles of anthropogenic aerosol emissions and the Atlantic Meridional Overturning Circulation (AMOC) at generating predictable SPNA variability are also discussed. The analysis is extensively supported by the novel use of a set of seasonal hindcasts spanning the 20th century and forced with prescribed SSTs. |
format |
Article in Journal/Newspaper |
author |
K. Strommen T. Woollings P. Davini P. Ruggieri I. R. Simpson |
author_facet |
K. Strommen T. Woollings P. Davini P. Ruggieri I. R. Simpson |
author_sort |
K. Strommen |
title |
Predictable decadal forcing of the North Atlantic jet speed by sub-polar North Atlantic sea surface temperatures |
title_short |
Predictable decadal forcing of the North Atlantic jet speed by sub-polar North Atlantic sea surface temperatures |
title_full |
Predictable decadal forcing of the North Atlantic jet speed by sub-polar North Atlantic sea surface temperatures |
title_fullStr |
Predictable decadal forcing of the North Atlantic jet speed by sub-polar North Atlantic sea surface temperatures |
title_full_unstemmed |
Predictable decadal forcing of the North Atlantic jet speed by sub-polar North Atlantic sea surface temperatures |
title_sort |
predictable decadal forcing of the north atlantic jet speed by sub-polar north atlantic sea surface temperatures |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/wcd-4-853-2023 https://doaj.org/article/0858aab40b78466bbe8b1b876da398b0 |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_source |
Weather and Climate Dynamics, Vol 4, Pp 853-874 (2023) |
op_relation |
https://wcd.copernicus.org/articles/4/853/2023/wcd-4-853-2023.pdf https://doaj.org/toc/2698-4016 doi:10.5194/wcd-4-853-2023 2698-4016 https://doaj.org/article/0858aab40b78466bbe8b1b876da398b0 |
op_doi |
https://doi.org/10.5194/wcd-4-853-2023 |
container_title |
Weather and Climate Dynamics |
container_volume |
4 |
container_issue |
4 |
container_start_page |
853 |
op_container_end_page |
874 |
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1782336958595334144 |