Structure and variability of the subtropical gyre
The subtropical gyre is a large system of ocean currents and water masses stretching across each of the oceans at mid-latitudes. Primarily driven by winds, the upper ocean circulation tends to accumulate water masses in the center of the gyre. This accumulation drives: a specific stratification, a l...
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ftccsdartic:oai:HAL:tel-03344568v1 2023-05-15T17:31:02+02:00 Structure and variability of the subtropical gyre Structure et variabilité du gyre subtropical Maze, Guillaume Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER) Université de Bretagne Occidentale, Brest Guillaume Roullet 2020-11-27 https://hal.archives-ouvertes.fr/tel-03344568 https://hal.archives-ouvertes.fr/tel-03344568/document https://hal.archives-ouvertes.fr/tel-03344568/file/gmaze_hdr_jury_20200312_hal.pdf en eng HAL CCSD tel-03344568 https://hal.archives-ouvertes.fr/tel-03344568 https://hal.archives-ouvertes.fr/tel-03344568/document https://hal.archives-ouvertes.fr/tel-03344568/file/gmaze_hdr_jury_20200312_hal.pdf info:eu-repo/semantics/OpenAccess https://hal.archives-ouvertes.fr/tel-03344568 Ocean, Atmosphere. Université de Bretagne Occidentale, Brest, 2020 Mid-latitude ocean dynamic water mass life cycle oceanic processes and air-sea interactions from meso to large scale seasonal to interannual variability Dynamique océanique aux moyennes latitudes cycle de vie des masses d’eau processus océaniques et d’interactions océan-atmosphère de méso à grande échelle variabilité saisonnière à interannuelle [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography info:eu-repo/semantics/other Habilitation à diriger des recherches 2020 ftccsdartic 2021-09-18T22:22:26Z The subtropical gyre is a large system of ocean currents and water masses stretching across each of the oceans at mid-latitudes. Primarily driven by winds, the upper ocean circulation tends to accumulate water masses in the center of the gyre. This accumulation drives: a specific stratification, a large scale equatorward circulation in the upper ocean and a compensating intense and narrow current flowing poleward along the western boundary of the ocean (eg: the Gulf Stream in the North Atlantic or the Kuroshio in the North Pacific). The gyre circulation is responsible for redistributing heat taken up by the ocean at low-latitudes to the higher latitudes and to the atmosphere, as well as for storing heat and anthropogenic carbon in its water masses at mid-latitudes. The gyre dynamic furthermore leads to a shallow (1000m) ventilation of the ocean on time scale ranging from 1 to 20 years that plays a role in climate by moderating ocean-atmosphere fluxes on these intermediate timescales.Over 14 years, my work has been centered on subtropical gyres with a focus on the North Atlantic gyre and its water masses. I provide a description of my research contributions to key physical oceanographic questions: what is, and what controls, the ocean stratification structure and variability on seasonal to decadal time-scales ? I answer these questions applied to the most important subtropical gyre water mass of the North Atlantic,the "Eighteen Degree water". I show how I used geophysical fluid dynamic principles of the ocean ventilation. A clear emphasis is made on the water-mass transformation process. I will furthermore present new analysis and diagnostic techniques I developed to objectively study the ocean stratification from ocean circulation numerical simulations, ocean state estimates based on data assimilation and direct ocean measurements. Last, I conclude with the main research axes I propose to investigate in the upcoming years: the past and future variability of western boundary currents. Le gyre subtropical est un ... Doctoral or Postdoctoral Thesis North Atlantic Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Pacific |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
Mid-latitude ocean dynamic water mass life cycle oceanic processes and air-sea interactions from meso to large scale seasonal to interannual variability Dynamique océanique aux moyennes latitudes cycle de vie des masses d’eau processus océaniques et d’interactions océan-atmosphère de méso à grande échelle variabilité saisonnière à interannuelle [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
spellingShingle |
Mid-latitude ocean dynamic water mass life cycle oceanic processes and air-sea interactions from meso to large scale seasonal to interannual variability Dynamique océanique aux moyennes latitudes cycle de vie des masses d’eau processus océaniques et d’interactions océan-atmosphère de méso à grande échelle variabilité saisonnière à interannuelle [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography Maze, Guillaume Structure and variability of the subtropical gyre |
topic_facet |
Mid-latitude ocean dynamic water mass life cycle oceanic processes and air-sea interactions from meso to large scale seasonal to interannual variability Dynamique océanique aux moyennes latitudes cycle de vie des masses d’eau processus océaniques et d’interactions océan-atmosphère de méso à grande échelle variabilité saisonnière à interannuelle [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography |
description |
The subtropical gyre is a large system of ocean currents and water masses stretching across each of the oceans at mid-latitudes. Primarily driven by winds, the upper ocean circulation tends to accumulate water masses in the center of the gyre. This accumulation drives: a specific stratification, a large scale equatorward circulation in the upper ocean and a compensating intense and narrow current flowing poleward along the western boundary of the ocean (eg: the Gulf Stream in the North Atlantic or the Kuroshio in the North Pacific). The gyre circulation is responsible for redistributing heat taken up by the ocean at low-latitudes to the higher latitudes and to the atmosphere, as well as for storing heat and anthropogenic carbon in its water masses at mid-latitudes. The gyre dynamic furthermore leads to a shallow (1000m) ventilation of the ocean on time scale ranging from 1 to 20 years that plays a role in climate by moderating ocean-atmosphere fluxes on these intermediate timescales.Over 14 years, my work has been centered on subtropical gyres with a focus on the North Atlantic gyre and its water masses. I provide a description of my research contributions to key physical oceanographic questions: what is, and what controls, the ocean stratification structure and variability on seasonal to decadal time-scales ? I answer these questions applied to the most important subtropical gyre water mass of the North Atlantic,the "Eighteen Degree water". I show how I used geophysical fluid dynamic principles of the ocean ventilation. A clear emphasis is made on the water-mass transformation process. I will furthermore present new analysis and diagnostic techniques I developed to objectively study the ocean stratification from ocean circulation numerical simulations, ocean state estimates based on data assimilation and direct ocean measurements. Last, I conclude with the main research axes I propose to investigate in the upcoming years: the past and future variability of western boundary currents. Le gyre subtropical est un ... |
author2 |
Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER) Université de Bretagne Occidentale, Brest Guillaume Roullet |
format |
Doctoral or Postdoctoral Thesis |
author |
Maze, Guillaume |
author_facet |
Maze, Guillaume |
author_sort |
Maze, Guillaume |
title |
Structure and variability of the subtropical gyre |
title_short |
Structure and variability of the subtropical gyre |
title_full |
Structure and variability of the subtropical gyre |
title_fullStr |
Structure and variability of the subtropical gyre |
title_full_unstemmed |
Structure and variability of the subtropical gyre |
title_sort |
structure and variability of the subtropical gyre |
publisher |
HAL CCSD |
publishDate |
2020 |
url |
https://hal.archives-ouvertes.fr/tel-03344568 https://hal.archives-ouvertes.fr/tel-03344568/document https://hal.archives-ouvertes.fr/tel-03344568/file/gmaze_hdr_jury_20200312_hal.pdf |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
https://hal.archives-ouvertes.fr/tel-03344568 Ocean, Atmosphere. Université de Bretagne Occidentale, Brest, 2020 |
op_relation |
tel-03344568 https://hal.archives-ouvertes.fr/tel-03344568 https://hal.archives-ouvertes.fr/tel-03344568/document https://hal.archives-ouvertes.fr/tel-03344568/file/gmaze_hdr_jury_20200312_hal.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1766128338629296128 |