Deep through-flow in the Bight Fracture Zone
International audience Iceland-Scotland Overflow Water (ISOW) is exported from the Nordic Seas into the Iceland Basin to feed the lower limb of the Meridional Overturning Circulation. The Bight Fracture Zone (BFZ) is known to be a major route for ISOW toward the Irminger Sea, but the role of this ga...
Published in: | Ocean Science |
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Online Access: | https://hal-insu.archives-ouvertes.fr/insu-03779392 https://hal-insu.archives-ouvertes.fr/insu-03779392/document https://hal-insu.archives-ouvertes.fr/insu-03779392/file/os-18-1055-2022.pdf https://doi.org/10.5194/os-18-1055-2022 |
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ftunivnantes:oai:HAL:insu-03779392v1 2023-05-15T16:47:12+02:00 Deep through-flow in the Bight Fracture Zone Petit, Tillys Thierry, Virginie Mercier, Herlé 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 https://hal-insu.archives-ouvertes.fr/insu-03779392 https://hal-insu.archives-ouvertes.fr/insu-03779392/document https://hal-insu.archives-ouvertes.fr/insu-03779392/file/os-18-1055-2022.pdf https://doi.org/10.5194/os-18-1055-2022 en eng HAL CCSD info:eu-repo/semantics/altIdentifier/doi/10.5194/os-18-1055-2022 insu-03779392 https://hal-insu.archives-ouvertes.fr/insu-03779392 https://hal-insu.archives-ouvertes.fr/insu-03779392/document https://hal-insu.archives-ouvertes.fr/insu-03779392/file/os-18-1055-2022.pdf BIBCODE: 2022OcSci.18.1055P doi:10.5194/os-18-1055-2022 http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess OCEAN SCIENCE https://hal-insu.archives-ouvertes.fr/insu-03779392 OCEAN SCIENCE, 2022, 18, pp.1055-1071. ⟨10.5194/os-18-1055-2022⟩ [SDU]Sciences of the Universe [physics] [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography info:eu-repo/semantics/article Journal articles 2022 ftunivnantes https://doi.org/10.5194/os-18-1055-2022 2022-09-20T22:44:00Z International audience Iceland-Scotland Overflow Water (ISOW) is exported from the Nordic Seas into the Iceland Basin to feed the lower limb of the Meridional Overturning Circulation. The Bight Fracture Zone (BFZ) is known to be a major route for ISOW toward the Irminger Sea, but the role of this gateway in the evolution of ISOW properties over the subpolar gyre is unclear. A combination of ship-based and Deep-Argo data gathered between 2015 and 2018 allows us to investigate the pathways and hydrographic evolution of ISOW as it flows through the BFZ, as well as its influence on the North Atlantic Deep Water (NADW) properties in the Irminger Sea. The ISOW flow through the BFZ amounts to 0.8 ± 0.2 Sv and is mainly fed by the lighter part of the ISOW layer flowing west of 29-30 ∘ W as part of the East Reykjanes Ridge Current in the Iceland Basin. In the rift valley of the BFZ, between an eastern and a western sill, the bathymetry of the BFZ shapes a cyclonic circulation along which the ISOW layer is homogenized. The largest changes in ISOW properties are however observed downstream of the western sill, at the exit of the BFZ. There, ISOW is mixed isopycnally with comparatively fresher NADW circulating in the Irminger Sea. Hence, our analysis reveals the key role of the BFZ through-flow in the salinification of the NADW in the Irminger Current. Article in Journal/Newspaper Iceland NADW Nordic Seas North Atlantic Deep Water North Atlantic Université de Nantes: HAL-UNIV-NANTES Bight Fracture Zone ENVELOPE(-33.000,-33.000,56.833,56.833) Irminger Sea ENVELOPE(-34.041,-34.041,63.054,63.054) Reykjanes ENVELOPE(-22.250,-22.250,65.467,65.467) Ocean Science 18 4 1055 1071 |
institution |
Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
English |
topic |
[SDU]Sciences of the Universe [physics] [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
spellingShingle |
[SDU]Sciences of the Universe [physics] [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography Petit, Tillys Thierry, Virginie Mercier, Herlé Deep through-flow in the Bight Fracture Zone |
topic_facet |
[SDU]Sciences of the Universe [physics] [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
description |
International audience Iceland-Scotland Overflow Water (ISOW) is exported from the Nordic Seas into the Iceland Basin to feed the lower limb of the Meridional Overturning Circulation. The Bight Fracture Zone (BFZ) is known to be a major route for ISOW toward the Irminger Sea, but the role of this gateway in the evolution of ISOW properties over the subpolar gyre is unclear. A combination of ship-based and Deep-Argo data gathered between 2015 and 2018 allows us to investigate the pathways and hydrographic evolution of ISOW as it flows through the BFZ, as well as its influence on the North Atlantic Deep Water (NADW) properties in the Irminger Sea. The ISOW flow through the BFZ amounts to 0.8 ± 0.2 Sv and is mainly fed by the lighter part of the ISOW layer flowing west of 29-30 ∘ W as part of the East Reykjanes Ridge Current in the Iceland Basin. In the rift valley of the BFZ, between an eastern and a western sill, the bathymetry of the BFZ shapes a cyclonic circulation along which the ISOW layer is homogenized. The largest changes in ISOW properties are however observed downstream of the western sill, at the exit of the BFZ. There, ISOW is mixed isopycnally with comparatively fresher NADW circulating in the Irminger Sea. Hence, our analysis reveals the key role of the BFZ through-flow in the salinification of the NADW in the Irminger Current. |
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 |
Petit, Tillys Thierry, Virginie Mercier, Herlé |
author_facet |
Petit, Tillys Thierry, Virginie Mercier, Herlé |
author_sort |
Petit, Tillys |
title |
Deep through-flow in the Bight Fracture Zone |
title_short |
Deep through-flow in the Bight Fracture Zone |
title_full |
Deep through-flow in the Bight Fracture Zone |
title_fullStr |
Deep through-flow in the Bight Fracture Zone |
title_full_unstemmed |
Deep through-flow in the Bight Fracture Zone |
title_sort |
deep through-flow in the bight fracture zone |
publisher |
HAL CCSD |
publishDate |
2022 |
url |
https://hal-insu.archives-ouvertes.fr/insu-03779392 https://hal-insu.archives-ouvertes.fr/insu-03779392/document https://hal-insu.archives-ouvertes.fr/insu-03779392/file/os-18-1055-2022.pdf https://doi.org/10.5194/os-18-1055-2022 |
long_lat |
ENVELOPE(-33.000,-33.000,56.833,56.833) ENVELOPE(-34.041,-34.041,63.054,63.054) ENVELOPE(-22.250,-22.250,65.467,65.467) |
geographic |
Bight Fracture Zone Irminger Sea Reykjanes |
geographic_facet |
Bight Fracture Zone Irminger Sea Reykjanes |
genre |
Iceland NADW Nordic Seas North Atlantic Deep Water North Atlantic |
genre_facet |
Iceland NADW Nordic Seas North Atlantic Deep Water North Atlantic |
op_source |
OCEAN SCIENCE https://hal-insu.archives-ouvertes.fr/insu-03779392 OCEAN SCIENCE, 2022, 18, pp.1055-1071. ⟨10.5194/os-18-1055-2022⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/os-18-1055-2022 insu-03779392 https://hal-insu.archives-ouvertes.fr/insu-03779392 https://hal-insu.archives-ouvertes.fr/insu-03779392/document https://hal-insu.archives-ouvertes.fr/insu-03779392/file/os-18-1055-2022.pdf BIBCODE: 2022OcSci.18.1055P doi:10.5194/os-18-1055-2022 |
op_rights |
http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.5194/os-18-1055-2022 |
container_title |
Ocean Science |
container_volume |
18 |
container_issue |
4 |
container_start_page |
1055 |
op_container_end_page |
1071 |
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1766037281052819456 |