The role of oceanic and atmospheric dynamics in the North Atlantic on the functioning of West African upwelling
The southern end of the Canary current system comprises of an original upwelling center that has so far received little attention. This Ph.D. Thesis focuses on the dynamical functioning of the Southern Senegal-Gambia Upwelling Center (SSUC). We are interested in the upwelling circulation and thermoh...
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Other Authors: | , , , , , , , |
Format: | Doctoral or Postdoctoral Thesis |
Language: | French |
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HAL CCSD
2019
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Online Access: | https://theses.hal.science/tel-03363982 https://theses.hal.science/tel-03363982/document https://theses.hal.science/tel-03363982/file/KOUNTA_DIOP_Lala_2019.pdf |
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ftepunivpsaclay:oai:HAL:tel-03363982v1 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
École Polytechnique, Université Paris-Saclay: HAL |
op_collection_id |
ftepunivpsaclay |
language |
French |
topic |
West African upwelling Current Wind Coastal wave Ocean circulation Atmospheric circulation Upwelling ouest africain Courant Vent Onde côtière Circulation océanique Circulation atmosphérique [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere |
spellingShingle |
West African upwelling Current Wind Coastal wave Ocean circulation Atmospheric circulation Upwelling ouest africain Courant Vent Onde côtière Circulation océanique Circulation atmosphérique [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere Kounta Diop, Lala The role of oceanic and atmospheric dynamics in the North Atlantic on the functioning of West African upwelling |
topic_facet |
West African upwelling Current Wind Coastal wave Ocean circulation Atmospheric circulation Upwelling ouest africain Courant Vent Onde côtière Circulation océanique Circulation atmosphérique [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere |
description |
The southern end of the Canary current system comprises of an original upwelling center that has so far received little attention. This Ph.D. Thesis focuses on the dynamical functioning of the Southern Senegal-Gambia Upwelling Center (SSUC). We are interested in the upwelling circulation and thermohaline structure on the shelf between the coastline and 100-200 km offshore. Our focus is on the upwelling period (November to May). The main originality of the SSUC compared to other upwelling centers stems from its conti-nental shelf that is broad and shallow (20–30 m over tens of kilometers). The normal state of the system comprises the classical upwelling front but also a well-defined inner-shelf front that separates cold upwelled waters from nearshore warmer waters. We investigate its dynamical functioning using analysed satellite images, in situ data and state-of-the- art 3D numerical simulations. Through a fine-scale analysis of the physical conditions of the SSUC, this work poses the basis of an integrated approach to the Senegalese marine environment functioning. A first part of results is based on the careful examinations and analysis of over 1500 satellite images of sea surface temperature scenes contextualized with respect to wind conditions. Analysis confirm the regularity and stability of the SSUC dynamical functioning (as manifested by the recurrence and persistence of particular SST patterns). The analyses also reveal subtle aspects of its upwelling structure : shelf break cooling of surface waters consistent with internal tide breaking/mixing complex interplay between local upwelling and the Mauritanian current off the Cape Verde headland complexity of the inner-shelf/mid shelf frontal transition. The amplitude of the diurnal cycle suggests that large uncertainties exist in the SSUC heat budget. The studies limitations underscore the need for continuous in situ measurement in the SSUC, particularly of winds. The dynamical functioning of SSUC is also investigated by means of numerical simulations, ... |
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)-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)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité) Sorbonne Université Université Cheikh Anta Diop (Dakar) Xavier Capet |
format |
Doctoral or Postdoctoral Thesis |
author |
Kounta Diop, Lala |
author_facet |
Kounta Diop, Lala |
author_sort |
Kounta Diop, Lala |
title |
The role of oceanic and atmospheric dynamics in the North Atlantic on the functioning of West African upwelling |
title_short |
The role of oceanic and atmospheric dynamics in the North Atlantic on the functioning of West African upwelling |
title_full |
The role of oceanic and atmospheric dynamics in the North Atlantic on the functioning of West African upwelling |
title_fullStr |
The role of oceanic and atmospheric dynamics in the North Atlantic on the functioning of West African upwelling |
title_full_unstemmed |
The role of oceanic and atmospheric dynamics in the North Atlantic on the functioning of West African upwelling |
title_sort |
role of oceanic and atmospheric dynamics in the north atlantic on the functioning of west african upwelling |
publisher |
HAL CCSD |
publishDate |
2019 |
url |
https://theses.hal.science/tel-03363982 https://theses.hal.science/tel-03363982/document https://theses.hal.science/tel-03363982/file/KOUNTA_DIOP_Lala_2019.pdf |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
https://theses.hal.science/tel-03363982 Océan, Atmosphère. Sorbonne Université; Université Cheikh Anta Diop (Dakar), 2019. Français. ⟨NNT : 2019SORUS649⟩ |
op_relation |
NNT: 2019SORUS649 tel-03363982 https://theses.hal.science/tel-03363982 https://theses.hal.science/tel-03363982/document https://theses.hal.science/tel-03363982/file/KOUNTA_DIOP_Lala_2019.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1799485652096516096 |
spelling |
ftepunivpsaclay:oai:HAL:tel-03363982v1 2024-05-19T07:45:34+00:00 The role of oceanic and atmospheric dynamics in the North Atlantic on the functioning of West African upwelling Le rôle de la dynamique océanique et atmosphérique en Atlantique Nord sur le fonctionnement de l'upwelling ouest-africain Kounta Diop, Lala 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)-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)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité) Sorbonne Université Université Cheikh Anta Diop (Dakar) Xavier Capet 2019-07-05 https://theses.hal.science/tel-03363982 https://theses.hal.science/tel-03363982/document https://theses.hal.science/tel-03363982/file/KOUNTA_DIOP_Lala_2019.pdf fr fre HAL CCSD NNT: 2019SORUS649 tel-03363982 https://theses.hal.science/tel-03363982 https://theses.hal.science/tel-03363982/document https://theses.hal.science/tel-03363982/file/KOUNTA_DIOP_Lala_2019.pdf info:eu-repo/semantics/OpenAccess https://theses.hal.science/tel-03363982 Océan, Atmosphère. Sorbonne Université; Université Cheikh Anta Diop (Dakar), 2019. Français. ⟨NNT : 2019SORUS649⟩ West African upwelling Current Wind Coastal wave Ocean circulation Atmospheric circulation Upwelling ouest africain Courant Vent Onde côtière Circulation océanique Circulation atmosphérique [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere info:eu-repo/semantics/doctoralThesis Theses 2019 ftepunivpsaclay 2024-04-25T00:42:25Z The southern end of the Canary current system comprises of an original upwelling center that has so far received little attention. This Ph.D. Thesis focuses on the dynamical functioning of the Southern Senegal-Gambia Upwelling Center (SSUC). We are interested in the upwelling circulation and thermohaline structure on the shelf between the coastline and 100-200 km offshore. Our focus is on the upwelling period (November to May). The main originality of the SSUC compared to other upwelling centers stems from its conti-nental shelf that is broad and shallow (20–30 m over tens of kilometers). The normal state of the system comprises the classical upwelling front but also a well-defined inner-shelf front that separates cold upwelled waters from nearshore warmer waters. We investigate its dynamical functioning using analysed satellite images, in situ data and state-of-the- art 3D numerical simulations. Through a fine-scale analysis of the physical conditions of the SSUC, this work poses the basis of an integrated approach to the Senegalese marine environment functioning. A first part of results is based on the careful examinations and analysis of over 1500 satellite images of sea surface temperature scenes contextualized with respect to wind conditions. Analysis confirm the regularity and stability of the SSUC dynamical functioning (as manifested by the recurrence and persistence of particular SST patterns). The analyses also reveal subtle aspects of its upwelling structure : shelf break cooling of surface waters consistent with internal tide breaking/mixing complex interplay between local upwelling and the Mauritanian current off the Cape Verde headland complexity of the inner-shelf/mid shelf frontal transition. The amplitude of the diurnal cycle suggests that large uncertainties exist in the SSUC heat budget. The studies limitations underscore the need for continuous in situ measurement in the SSUC, particularly of winds. The dynamical functioning of SSUC is also investigated by means of numerical simulations, ... Doctoral or Postdoctoral Thesis North Atlantic École Polytechnique, Université Paris-Saclay: HAL |