Variability of the meridional circulation in the north Atlantic Ocean during the last 2000 years
The purpose of this thesis was to study the surface oceanic circulation in the North Atlantic Ocean during the last 2,000 years, and its link with the intensity of the subpolar and the subtropical gyres. To fulfill these objectives, I studied sediment cores with a high sedimentation rate to reconstr...
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ftinsu:oai:HAL:tel-00679528v1 2024-04-28T08:30:00+00:00 Variability of the meridional circulation in the north Atlantic Ocean during the last 2000 years Variabilité de la circulation méridienne dans l’Océan Atlantique Nord au cours des 2000 dernières années Bouinot, Thomas Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE) Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)) Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA) Université Paris Sud - Paris XI Elsa Cortijo Laurent Labeyrie 2011-11-15 https://theses.hal.science/tel-00679528 https://theses.hal.science/tel-00679528/document https://theses.hal.science/tel-00679528/file/VA2_BOUINOT_THOMAS_15122011.pdf fr fre HAL CCSD NNT: 2011PA112322 tel-00679528 https://theses.hal.science/tel-00679528 https://theses.hal.science/tel-00679528/document https://theses.hal.science/tel-00679528/file/VA2_BOUINOT_THOMAS_15122011.pdf info:eu-repo/semantics/OpenAccess https://theses.hal.science/tel-00679528 Sciences de la Terre. Université Paris Sud - Paris XI, 2011. Français. ⟨NNT : 2011PA112322⟩ Subpolar gyre Paleoceanography North atlantic ocean Micropaleontology Geochemistry Heat transport Micropaléontologie Océan Atlantique Nord Paléocéanographie Transport de chaleur Gyre subpolaire Géochimie [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/doctoralThesis Theses 2011 ftinsu 2024-04-05T00:22:56Z The purpose of this thesis was to study the surface oceanic circulation in the North Atlantic Ocean during the last 2,000 years, and its link with the intensity of the subpolar and the subtropical gyres. To fulfill these objectives, I studied sediment cores with a high sedimentation rate to reconstruct the multidecadal variability of the temperature and the water column stratification, controlled by the dynamic of oceanic gyres. To improve the marine paleoclimatic signal recorded from planktonic foraminifera, I constrained their growing season and their calcification depth by analyzing the oxygen isotopic composition of their calcitic shells. I also established calibrations between Mg/Ca ratio and temperature for the main species used.I applied these calibrations to reconstruct the hydrological conditions in key areas of the North Atlantic Ocean. I constructed an index of the subpolar gyre that traduces the dynamic intensity of the subpolar gyre and the subtropical gyre. I also studied the variability of the upper water column based on the analysis of deep-dwelling foraminifera. I interpret past changes in the water column stratification as resulting from changes in the intensity of Westerly winds. The similarities between the wind forcing evolution and the index of the subpolar gyre dynamics led me to propose a coupling between the ocean and the atmosphere on the multidecadal time scale. The consequences of the gyres dynamic on heat transport and the impacts of the change in westerly wind strength on European climate are studied in the last part of the manuscript. L’objectif de ce travail était d’étudier la variabilité de la circulation océanique méridienne aux échelles de temps pluri décennales dans l’océan Atlantique nord au cours des deux mille dernières années, ainsi que son lien avec la variation de l’extension des gyres subtropicales et subpolaires. J’ai donc étudié, à partir de carottes de sédiments marins à fort taux de sédimentation, l’évolution de la température des eaux de surface et de la ... Doctoral or Postdoctoral Thesis North Atlantic Planktonic foraminifera Institut national des sciences de l'Univers: HAL-INSU |
institution |
Open Polar |
collection |
Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
French |
topic |
Subpolar gyre Paleoceanography North atlantic ocean Micropaleontology Geochemistry Heat transport Micropaléontologie Océan Atlantique Nord Paléocéanographie Transport de chaleur Gyre subpolaire Géochimie [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
Subpolar gyre Paleoceanography North atlantic ocean Micropaleontology Geochemistry Heat transport Micropaléontologie Océan Atlantique Nord Paléocéanographie Transport de chaleur Gyre subpolaire Géochimie [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Bouinot, Thomas Variability of the meridional circulation in the north Atlantic Ocean during the last 2000 years |
topic_facet |
Subpolar gyre Paleoceanography North atlantic ocean Micropaleontology Geochemistry Heat transport Micropaléontologie Océan Atlantique Nord Paléocéanographie Transport de chaleur Gyre subpolaire Géochimie [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
The purpose of this thesis was to study the surface oceanic circulation in the North Atlantic Ocean during the last 2,000 years, and its link with the intensity of the subpolar and the subtropical gyres. To fulfill these objectives, I studied sediment cores with a high sedimentation rate to reconstruct the multidecadal variability of the temperature and the water column stratification, controlled by the dynamic of oceanic gyres. To improve the marine paleoclimatic signal recorded from planktonic foraminifera, I constrained their growing season and their calcification depth by analyzing the oxygen isotopic composition of their calcitic shells. I also established calibrations between Mg/Ca ratio and temperature for the main species used.I applied these calibrations to reconstruct the hydrological conditions in key areas of the North Atlantic Ocean. I constructed an index of the subpolar gyre that traduces the dynamic intensity of the subpolar gyre and the subtropical gyre. I also studied the variability of the upper water column based on the analysis of deep-dwelling foraminifera. I interpret past changes in the water column stratification as resulting from changes in the intensity of Westerly winds. The similarities between the wind forcing evolution and the index of the subpolar gyre dynamics led me to propose a coupling between the ocean and the atmosphere on the multidecadal time scale. The consequences of the gyres dynamic on heat transport and the impacts of the change in westerly wind strength on European climate are studied in the last part of the manuscript. L’objectif de ce travail était d’étudier la variabilité de la circulation océanique méridienne aux échelles de temps pluri décennales dans l’océan Atlantique nord au cours des deux mille dernières années, ainsi que son lien avec la variation de l’extension des gyres subtropicales et subpolaires. J’ai donc étudié, à partir de carottes de sédiments marins à fort taux de sédimentation, l’évolution de la température des eaux de surface et de la ... |
author2 |
Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE) Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)) Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA) Université Paris Sud - Paris XI Elsa Cortijo Laurent Labeyrie |
format |
Doctoral or Postdoctoral Thesis |
author |
Bouinot, Thomas |
author_facet |
Bouinot, Thomas |
author_sort |
Bouinot, Thomas |
title |
Variability of the meridional circulation in the north Atlantic Ocean during the last 2000 years |
title_short |
Variability of the meridional circulation in the north Atlantic Ocean during the last 2000 years |
title_full |
Variability of the meridional circulation in the north Atlantic Ocean during the last 2000 years |
title_fullStr |
Variability of the meridional circulation in the north Atlantic Ocean during the last 2000 years |
title_full_unstemmed |
Variability of the meridional circulation in the north Atlantic Ocean during the last 2000 years |
title_sort |
variability of the meridional circulation in the north atlantic ocean during the last 2000 years |
publisher |
HAL CCSD |
publishDate |
2011 |
url |
https://theses.hal.science/tel-00679528 https://theses.hal.science/tel-00679528/document https://theses.hal.science/tel-00679528/file/VA2_BOUINOT_THOMAS_15122011.pdf |
genre |
North Atlantic Planktonic foraminifera |
genre_facet |
North Atlantic Planktonic foraminifera |
op_source |
https://theses.hal.science/tel-00679528 Sciences de la Terre. Université Paris Sud - Paris XI, 2011. Français. ⟨NNT : 2011PA112322⟩ |
op_relation |
NNT: 2011PA112322 tel-00679528 https://theses.hal.science/tel-00679528 https://theses.hal.science/tel-00679528/document https://theses.hal.science/tel-00679528/file/VA2_BOUINOT_THOMAS_15122011.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1797588023091658752 |