Internal ocean dynamics contribution to North Atlantic interdecadal variability strengthened by ocean-atmosphere thermal coupling
International audience Abstract Identifying the primary drivers of North Atlantic interdecadal climate variability is crucial for improving climatic prediction over the coming decades. Here the effect of thermal coupling on the leading energy sources of the interdecadal variability of the ocean-atmo...
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Online Access: | https://hal.science/hal-03860612 https://hal.science/hal-03860612/document https://hal.science/hal-03860612/file/manuscript_as_revised_20220613.pdf https://doi.org/10.1175/JCLI-D-22-0191.1 |
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ftinsu:oai:HAL:hal-03860612v1 2024-04-14T08:15:43+00:00 Internal ocean dynamics contribution to North Atlantic interdecadal variability strengthened by ocean-atmosphere thermal coupling Arzel, Olivier Huck, Thierry Hochet, Antoine Mussa, Alexandre Laboratoire d'Océanographie Physique et Spatiale (LOPS) Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS) 2022-09-09 https://hal.science/hal-03860612 https://hal.science/hal-03860612/document https://hal.science/hal-03860612/file/manuscript_as_revised_20220613.pdf https://doi.org/10.1175/JCLI-D-22-0191.1 en eng HAL CCSD American Meteorological Society info:eu-repo/semantics/altIdentifier/doi/10.1175/JCLI-D-22-0191.1 hal-03860612 https://hal.science/hal-03860612 https://hal.science/hal-03860612/document https://hal.science/hal-03860612/file/manuscript_as_revised_20220613.pdf doi:10.1175/JCLI-D-22-0191.1 info:eu-repo/semantics/OpenAccess ISSN: 0894-8755 EISSN: 1520-0442 Journal of Climate https://hal.science/hal-03860612 Journal of Climate, 2022, pp.1-43. ⟨10.1175/JCLI-D-22-0191.1⟩ [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere info:eu-repo/semantics/article Journal articles 2022 ftinsu https://doi.org/10.1175/JCLI-D-22-0191.1 2024-03-21T17:10:21Z International audience Abstract Identifying the primary drivers of North Atlantic interdecadal climate variability is crucial for improving climatic prediction over the coming decades. Here the effect of thermal coupling on the leading energy sources of the interdecadal variability of the ocean-atmosphere system is examined by means of a stochastically-forced idealized coupled model. The effect of coupling is quantified from a comparison of the buoyancy variance budget of coupled and uncoupled model configurations. The simplicity of the model allows us to contrast the effect of coupling between a super-critical regime where the deterministic ocean dynamics drive the variability and a damped regime where noise forcing is central to its existence. The results show that changes in surface buoyancy fluxes act as a sink of temperature variance in the super-critical regime, and only become a source in the strongly damped regime. By contrast, internal ocean dynamics associated with the interaction of transient buoyancy fluxes with mean buoyancy gradients always act as a source of interdecadal variability. In addition to the reduced thermal damping effect in coupled integrations, thermal coupling with the atmosphere is shown to significantly increase the role of internal ocean dynamics in the variability, in particular in the regime where interdecadal modes are damped. Only for oceanic background states in the strongly damped regime do changes in surface buoyancy fluxes play a leading role in the upper ocean variability. A stochastically-forced coupled box model is proposed that captures the basic effect of thermal coupling on atmospheric and oceanic energy sources of variability. Article in Journal/Newspaper North Atlantic Institut national des sciences de l'Univers: HAL-INSU Journal of Climate 35 24 4605 4624 |
institution |
Open Polar |
collection |
Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
English |
topic |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere |
spellingShingle |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere Arzel, Olivier Huck, Thierry Hochet, Antoine Mussa, Alexandre Internal ocean dynamics contribution to North Atlantic interdecadal variability strengthened by ocean-atmosphere thermal coupling |
topic_facet |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere |
description |
International audience Abstract Identifying the primary drivers of North Atlantic interdecadal climate variability is crucial for improving climatic prediction over the coming decades. Here the effect of thermal coupling on the leading energy sources of the interdecadal variability of the ocean-atmosphere system is examined by means of a stochastically-forced idealized coupled model. The effect of coupling is quantified from a comparison of the buoyancy variance budget of coupled and uncoupled model configurations. The simplicity of the model allows us to contrast the effect of coupling between a super-critical regime where the deterministic ocean dynamics drive the variability and a damped regime where noise forcing is central to its existence. The results show that changes in surface buoyancy fluxes act as a sink of temperature variance in the super-critical regime, and only become a source in the strongly damped regime. By contrast, internal ocean dynamics associated with the interaction of transient buoyancy fluxes with mean buoyancy gradients always act as a source of interdecadal variability. In addition to the reduced thermal damping effect in coupled integrations, thermal coupling with the atmosphere is shown to significantly increase the role of internal ocean dynamics in the variability, in particular in the regime where interdecadal modes are damped. Only for oceanic background states in the strongly damped regime do changes in surface buoyancy fluxes play a leading role in the upper ocean variability. A stochastically-forced coupled box model is proposed that captures the basic effect of thermal coupling on atmospheric and oceanic energy sources of variability. |
author2 |
Laboratoire d'Océanographie Physique et Spatiale (LOPS) Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Arzel, Olivier Huck, Thierry Hochet, Antoine Mussa, Alexandre |
author_facet |
Arzel, Olivier Huck, Thierry Hochet, Antoine Mussa, Alexandre |
author_sort |
Arzel, Olivier |
title |
Internal ocean dynamics contribution to North Atlantic interdecadal variability strengthened by ocean-atmosphere thermal coupling |
title_short |
Internal ocean dynamics contribution to North Atlantic interdecadal variability strengthened by ocean-atmosphere thermal coupling |
title_full |
Internal ocean dynamics contribution to North Atlantic interdecadal variability strengthened by ocean-atmosphere thermal coupling |
title_fullStr |
Internal ocean dynamics contribution to North Atlantic interdecadal variability strengthened by ocean-atmosphere thermal coupling |
title_full_unstemmed |
Internal ocean dynamics contribution to North Atlantic interdecadal variability strengthened by ocean-atmosphere thermal coupling |
title_sort |
internal ocean dynamics contribution to north atlantic interdecadal variability strengthened by ocean-atmosphere thermal coupling |
publisher |
HAL CCSD |
publishDate |
2022 |
url |
https://hal.science/hal-03860612 https://hal.science/hal-03860612/document https://hal.science/hal-03860612/file/manuscript_as_revised_20220613.pdf https://doi.org/10.1175/JCLI-D-22-0191.1 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
ISSN: 0894-8755 EISSN: 1520-0442 Journal of Climate https://hal.science/hal-03860612 Journal of Climate, 2022, pp.1-43. ⟨10.1175/JCLI-D-22-0191.1⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1175/JCLI-D-22-0191.1 hal-03860612 https://hal.science/hal-03860612 https://hal.science/hal-03860612/document https://hal.science/hal-03860612/file/manuscript_as_revised_20220613.pdf doi:10.1175/JCLI-D-22-0191.1 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1175/JCLI-D-22-0191.1 |
container_title |
Journal of Climate |
container_volume |
35 |
container_issue |
24 |
container_start_page |
4605 |
op_container_end_page |
4624 |
_version_ |
1796314138476019712 |