Revisiting the Malvinas Current

Although the Malvinas Current (MC) plays a key role over the Patagonian shelf in sustaining an extremely rich ecosystem it remains rather undocumented. In this thesis, we combined in situ, satellite data, and operational model outputs to study the MC. The MC is an offshoot of the Antarctic Circumpol...

Full description

Bibliographic Details
Main Author: Artana, Camila
Other Authors: Austral, Boréal et Carbone (ABC), 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)-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)), 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, Christine Provost
Format: Doctoral or Postdoctoral Thesis
Language:English
Published: HAL CCSD 2018
Subjects:
Online Access:https://theses.hal.science/tel-03275315
https://theses.hal.science/tel-03275315/document
https://theses.hal.science/tel-03275315/file/these_artana_camila_1_2018.pdf
Description
Summary:Although the Malvinas Current (MC) plays a key role over the Patagonian shelf in sustaining an extremely rich ecosystem it remains rather undocumented. In this thesis, we combined in situ, satellite data, and operational model outputs to study the MC. The MC is an offshoot of the Antarctic Circumpolar Current (ACC). It flows northward up to 38°S where it turns southward forming the Malvinas Return Flow (MRF). We show that a substantial portion of the mesoscale activity from the ACC is dissipated over the Malvinas Plateau. We discovered the occurrence of recurrent blocking events cutting the MC from its source, the ACC. However, the MC does not collapse as a recirculation cell is established. Criteria in potential density and dynamic topography were defined to study the MC system fronts (Polar Front, Subantarctic Front and Brazil Current Front). Waters from the South of the Polar Front (PF) are recurrently injected into the MC as pulses or feeding events. Polar waters accumulate in the recirculation region between the MC and the MRF. Variations in the water characteristics of the recirculation region are consistent with changes in the occurrence of blocking and feeding events. Combining mooring and satellite altimetric data, a 24-year long time series of the MC transport at 41 ° S was constructed. Maxima and minima of the Malvinas current transport at 41 ° S are not associated with the ACC, rather with eddies coming from the Argentine Basin. Transport maxima appear to be related with cyclonic eddied detached from the Polar Front and transport minima with large anticyclonic anomalies from the Brazil Current. Bien que le Courant des Malouines (CM) soit le principal soutien de la productivité élevée qui caractérise l’Atlantique Sud-Ouest il reste encore peu documenté. Cette thèse combine des données in situ et satellitaires et des sorties de modèles opérationnels, pour étudier le CM. Le CM est une émanation du courant Antarctique Circumpolaire (ACC). Il s’écoule vers le nord jusqu’à 38°S puis il retourne vers le ...