On the recent evolution of Atlantic Water at the entrance to the Arctic Ocean : observations and Mercator Ocean operational model
Combination of observations and Mercator Ocean operational model (PSY4 hereafter) outputs provided insights on the recent oceanic conditions in the changing Western Eurasian and Nansen basins, entry region for the warm and salty Atlantic Water (AW) to the Arctic Ocean. Autonomous platforms showed th...
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Other Authors: | , , , , , , , , , |
Format: | Doctoral or Postdoctoral Thesis |
Language: | English |
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HAL CCSD
2020
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Online Access: | https://theses.hal.science/tel-03433179 https://theses.hal.science/tel-03433179v2/document https://theses.hal.science/tel-03433179v2/file/ATHANASE_Marylou_2020.pdf |
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ftsorbonneuniv:oai:HAL:tel-03433179v2 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
HAL Sorbonne Université |
op_collection_id |
ftsorbonneuniv |
language |
English |
topic |
Arctic Oceanography Observations Model Hydrography Circulation Atlantic Waters Changes Arctique Océanographie Modèle Hydrographie Eaux Atlantiques Changements [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDE.MCG]Environmental Sciences/Global Changes |
spellingShingle |
Arctic Oceanography Observations Model Hydrography Circulation Atlantic Waters Changes Arctique Océanographie Modèle Hydrographie Eaux Atlantiques Changements [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDE.MCG]Environmental Sciences/Global Changes Athanase, Marylou On the recent evolution of Atlantic Water at the entrance to the Arctic Ocean : observations and Mercator Ocean operational model |
topic_facet |
Arctic Oceanography Observations Model Hydrography Circulation Atlantic Waters Changes Arctique Océanographie Modèle Hydrographie Eaux Atlantiques Changements [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDE.MCG]Environmental Sciences/Global Changes |
description |
Combination of observations and Mercator Ocean operational model (PSY4 hereafter) outputs provided insights on the recent oceanic conditions in the changing Western Eurasian and Nansen basins, entry region for the warm and salty Atlantic Water (AW) to the Arctic Ocean. Autonomous platforms showed that the Western Eurasian Basin exhibited a fresher surface layer and shallower warm AW layer in 2017 than in the 2005‐2012 World Ocean Atlas climatology. PSY4 brought insights on the mesoscale structures observed in the halocline and warm layer. In particular, in the Nansen Basin a large mesoscale structure of AW from the boundary current turned into an anticyclonic eddy after the platforms passage. A second AW structure northwest of the Yermak Plateau, was a branch of AW recirculating back toward Fram Strait. The performance of PSY4 was assessed using independent observations over 2007-2020 in the Western Nansen Basin (WNB). We took advantage of 14 years of fields from PSY4 to examine winter conditions in the WNB over 2007-2020. PSY4 showed that deep winter convection and recurrent outflows from troughs northeast of Svalbard dramatically modified the AW. The northern Yermak Plateau-Sofia Deep and continental slope areas became “Marginal Convection Zones" in 2011 with, from then on, occurrences of ice-free conditions and mixed layer depths deeper than 200m in winter, and highly variable ocean-to-atmosphere heat fluxes. PSY4 also showed changes in circulation in the WNB over 2008-2020, with the strengthening of the Yermak Branch, which fed the southward Return Yermak Branch along the eastern flank of the Plateau. PSY4 highlighted the onset of new AW pathways: a recurrent anticyclonic circulation established in Sofia Deep. An offshore AW circulation developed downstream of the Yermak Plateau (following the 3800m isobaths). East of 20°E, additional AW from boundary current was injected in this offshore circulation, via enhanced basin-ward mesoscale activity. L’analyse combinée d’observations et de sorties du modèle ... |
author2 |
Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN) Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)) École normale supérieure - Paris (ENS-PSL) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X) Institut Polytechnique de Paris (IP Paris)-Institut Polytechnique de Paris (IP Paris)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X) Institut Polytechnique de Paris (IP Paris)-Institut Polytechnique de Paris (IP Paris)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité) Sorbonne Université Christine Provost Nathalie Sennéchael |
format |
Doctoral or Postdoctoral Thesis |
author |
Athanase, Marylou |
author_facet |
Athanase, Marylou |
author_sort |
Athanase, Marylou |
title |
On the recent evolution of Atlantic Water at the entrance to the Arctic Ocean : observations and Mercator Ocean operational model |
title_short |
On the recent evolution of Atlantic Water at the entrance to the Arctic Ocean : observations and Mercator Ocean operational model |
title_full |
On the recent evolution of Atlantic Water at the entrance to the Arctic Ocean : observations and Mercator Ocean operational model |
title_fullStr |
On the recent evolution of Atlantic Water at the entrance to the Arctic Ocean : observations and Mercator Ocean operational model |
title_full_unstemmed |
On the recent evolution of Atlantic Water at the entrance to the Arctic Ocean : observations and Mercator Ocean operational model |
title_sort |
on the recent evolution of atlantic water at the entrance to the arctic ocean : observations and mercator ocean operational model |
publisher |
HAL CCSD |
publishDate |
2020 |
url |
https://theses.hal.science/tel-03433179 https://theses.hal.science/tel-03433179v2/document https://theses.hal.science/tel-03433179v2/file/ATHANASE_Marylou_2020.pdf |
genre |
Arctic Ocean Arctique* Fram Strait Nansen Basin Svalbard Yermak plateau |
genre_facet |
Arctic Ocean Arctique* Fram Strait Nansen Basin Svalbard Yermak plateau |
op_source |
https://theses.hal.science/tel-03433179 Oceanography. Sorbonne Université, 2020. English. ⟨NNT : 2020SORUS263⟩ |
op_relation |
NNT: 2020SORUS263 tel-03433179 https://theses.hal.science/tel-03433179 https://theses.hal.science/tel-03433179v2/document https://theses.hal.science/tel-03433179v2/file/ATHANASE_Marylou_2020.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1810429840683171840 |
spelling |
ftsorbonneuniv:oai:HAL:tel-03433179v2 2024-09-15T17:53:47+00:00 On the recent evolution of Atlantic Water at the entrance to the Arctic Ocean : observations and Mercator Ocean operational model De l’évolution récente des eaux Atlantiques à l’entrée de l’Océan Arctique : observations et modèle opérationnel Mercator Océan Athanase, Marylou Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN) Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)) École normale supérieure - Paris (ENS-PSL) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X) Institut Polytechnique de Paris (IP Paris)-Institut Polytechnique de Paris (IP Paris)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL) Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X) Institut Polytechnique de Paris (IP Paris)-Institut Polytechnique de Paris (IP Paris)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité) Sorbonne Université Christine Provost Nathalie Sennéchael 2020-11-05 https://theses.hal.science/tel-03433179 https://theses.hal.science/tel-03433179v2/document https://theses.hal.science/tel-03433179v2/file/ATHANASE_Marylou_2020.pdf en eng HAL CCSD NNT: 2020SORUS263 tel-03433179 https://theses.hal.science/tel-03433179 https://theses.hal.science/tel-03433179v2/document https://theses.hal.science/tel-03433179v2/file/ATHANASE_Marylou_2020.pdf info:eu-repo/semantics/OpenAccess https://theses.hal.science/tel-03433179 Oceanography. Sorbonne Université, 2020. English. ⟨NNT : 2020SORUS263⟩ Arctic Oceanography Observations Model Hydrography Circulation Atlantic Waters Changes Arctique Océanographie Modèle Hydrographie Eaux Atlantiques Changements [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDE.MCG]Environmental Sciences/Global Changes info:eu-repo/semantics/doctoralThesis Theses 2020 ftsorbonneuniv 2024-08-01T23:46:52Z Combination of observations and Mercator Ocean operational model (PSY4 hereafter) outputs provided insights on the recent oceanic conditions in the changing Western Eurasian and Nansen basins, entry region for the warm and salty Atlantic Water (AW) to the Arctic Ocean. Autonomous platforms showed that the Western Eurasian Basin exhibited a fresher surface layer and shallower warm AW layer in 2017 than in the 2005‐2012 World Ocean Atlas climatology. PSY4 brought insights on the mesoscale structures observed in the halocline and warm layer. In particular, in the Nansen Basin a large mesoscale structure of AW from the boundary current turned into an anticyclonic eddy after the platforms passage. A second AW structure northwest of the Yermak Plateau, was a branch of AW recirculating back toward Fram Strait. The performance of PSY4 was assessed using independent observations over 2007-2020 in the Western Nansen Basin (WNB). We took advantage of 14 years of fields from PSY4 to examine winter conditions in the WNB over 2007-2020. PSY4 showed that deep winter convection and recurrent outflows from troughs northeast of Svalbard dramatically modified the AW. The northern Yermak Plateau-Sofia Deep and continental slope areas became “Marginal Convection Zones" in 2011 with, from then on, occurrences of ice-free conditions and mixed layer depths deeper than 200m in winter, and highly variable ocean-to-atmosphere heat fluxes. PSY4 also showed changes in circulation in the WNB over 2008-2020, with the strengthening of the Yermak Branch, which fed the southward Return Yermak Branch along the eastern flank of the Plateau. PSY4 highlighted the onset of new AW pathways: a recurrent anticyclonic circulation established in Sofia Deep. An offshore AW circulation developed downstream of the Yermak Plateau (following the 3800m isobaths). East of 20°E, additional AW from boundary current was injected in this offshore circulation, via enhanced basin-ward mesoscale activity. L’analyse combinée d’observations et de sorties du modèle ... Doctoral or Postdoctoral Thesis Arctic Ocean Arctique* Fram Strait Nansen Basin Svalbard Yermak plateau HAL Sorbonne Université |