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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ftunibolognairis:oai:cris.unibo.it:11585/950376 2024-04-14T08:15:22+00:00 Predictable decadal forcing of the North Atlantic jet speed by sub-polar North Atlantic sea surface temperatures Kristian Strommen Tim Woollings Paolo Davini Paolo Ruggieri Isla R. Simpson Kristian Strommen Tim Woolling Paolo Davini Paolo Ruggieri Isla R. Simpson 2023 ELETTRONICO https://hdl.handle.net/11585/950376 https://doi.org/10.5194/wcd-4-853-2023 https://wcd.copernicus.org/articles/4/853/2023/ eng eng volume:4 issue:4 firstpage:853 lastpage:874 numberofpages:22 journal:WEATHER AND CLIMATE DYNAMICS (ONLINE) https://hdl.handle.net/11585/950376 doi:10.5194/wcd-4-853-2023 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85178217260 https://wcd.copernicus.org/articles/4/853/2023/ info:eu-repo/semantics/openAccess Climate variability decadal predictions info:eu-repo/semantics/article 2023 ftunibolognairis https://doi.org/10.5194/wcd-4-853-2023 2024-03-21T17:04:58Z 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 IRIS Università degli Studi di Bologna (CRIS - Current Research Information System) Weather and Climate Dynamics 4 4 853 874 |
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Open Polar |
collection |
IRIS Università degli Studi di Bologna (CRIS - Current Research Information System) |
op_collection_id |
ftunibolognairis |
language |
English |
topic |
Climate variability decadal predictions |
spellingShingle |
Climate variability decadal predictions Kristian Strommen Tim Woollings Paolo Davini Paolo Ruggieri Isla R. Simpson Predictable decadal forcing of the North Atlantic jet speed by sub-polar North Atlantic sea surface temperatures |
topic_facet |
Climate variability decadal predictions |
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. |
author2 |
Kristian Strommen Tim Woolling Paolo Davini Paolo Ruggieri Isla R. Simpson |
format |
Article in Journal/Newspaper |
author |
Kristian Strommen Tim Woollings Paolo Davini Paolo Ruggieri Isla R. Simpson |
author_facet |
Kristian Strommen Tim Woollings Paolo Davini Paolo Ruggieri Isla R. Simpson |
author_sort |
Kristian 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 |
publishDate |
2023 |
url |
https://hdl.handle.net/11585/950376 https://doi.org/10.5194/wcd-4-853-2023 https://wcd.copernicus.org/articles/4/853/2023/ |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_relation |
volume:4 issue:4 firstpage:853 lastpage:874 numberofpages:22 journal:WEATHER AND CLIMATE DYNAMICS (ONLINE) https://hdl.handle.net/11585/950376 doi:10.5194/wcd-4-853-2023 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85178217260 https://wcd.copernicus.org/articles/4/853/2023/ |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/wcd-4-853-2023 |
container_title |
Weather and Climate Dynamics |
container_volume |
4 |
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4 |
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853 |
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874 |
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