Thèses (PHYSED)

Deux thèses en cours

• Delphine Fernandez Bruyère

  • PhD project : Eddy detection and tracking in the Northwestern Mediterranean sea and eddy modelling in MARS 3D
  • The general circulation in the North Western Mediterranean Basin is characterised by a large cyclonic circulation strongly perturbed by mesoscale processes. Eddies, upwelling filaments, horizontal stretches exhibit horizontal scales in the range of 10 to 50 km and a duration of a few days to weeks. They strongly influence the flux of buoyancy and energy and also impact biological processes. Such patterns are observable both on satellite pictures (AVHRR and MODIS/MERIS) and in-situ data (ECOLO campaigns, Tethys II measurements and SISMER/CORIOLIS data basis). However, their origin, dynamics and behaviour are not well known. Since they are now accessible to high resolution modelling, the aim of this project is firstly to identify and characterize mesoscale structures from different available data sets, and secondly to put into light, through an energy analysis, all the processes involved in their formation, development and decay.

  • Key-words : Eddy, mesoscale structure, North-Western Mediterranean sea.

• Iman KHOJASTEH POUR FARD

  • PhD project : Particle exchanges between the Loire estuary (France) and the adjacent coastal zone
  • The quantification of sediment exchanges between the Loire estuary and the adjacent sea is a main concern for end-users and stakeholders in the area of the Loire mouth, as it controls both the sediment equilibrium of the estuary and the mud sedimentation rate in the Bourgneuf Bay (South) and the Vilaine Bay (North).
  • This subject aims to build a model able to describe the sediment fluxes between the Loire estuary and the coastal sea. The model will be validated by existing field measurements (tidal gauges and ADCP moorings). Ocean colour images from satellite will also be used to validate surficial turbidity structures. The model should be able to account for the forcings variability during long periods (at least one year) and give answers to operational problems (optimization of dredging strategy…) as well as to scientific questions (contribution of density gradients and possible role of the deep artificial channel …). For reaching theses goals, the model MARS was used with a non-orthogonal curvilinear mesh which allows refinements in the areas of interest (especially inside and at mouth of the Loire estuary) with reasonable computing coasts thanks to larger meshes off shore. The model runs with all natural and anthropic forcings such as wind stresses, real tide, real river input, large-scale surge and semi-real boundary conditions exchanges.
  • Key-words : sediment dynamics, coastal hydrodynamics, estuary, Loire (France)

Thèses terminées

• Rôle des herbiers de Zostères (Zostera noltii) sur la dynamique sédimentaire du Bassin d'Arcachon (2011) Plus d'infos >

• Modélisation du transport particulaire dans le Golfe du Lion en vue d'une application au devenir des traceurs radioactifs issus du Rhône (2008)

• Etude de la circulation résiduelle lagrangienne en mer d'Iroise / Study of lagrangian residual circulation in the Iroise sea (2008) Plus d'infos >

• Echanges côte-large à moyenne échelle au niveau de la pente continentale du Golfe du Lion. Processus et Modélisation (2007) Plus d'infos >

• Caractérisation et dynamique des turbidités en zone côtière : L'exemple de la région marine Bretagne Sud (2006) Plus d'infos >

• Influence des ondes de Rossby sur le système biogéochimique de l'Océan Atlantique Nord : Utilisation des données satellites couleur de l'eau et d'un modèle couplé physique/biogéochimie (2005) Plus d'infos >

• Modélisation morphodynamique de l'embouchure de la seine (2005) Plus d'infos >