Nueva doctora: Sloane Bertin

El 4 de noviembre, Sloane Bertin defendió su tesis doctoral en la Université du Littoral Côte d’Opale en Wimereux, Francia. La tesis, titulada “Amélioration de la prévisibilité de la dispersion du matériel en dérive en zone côtière par fusion d’informations numériques et observationnelles,” fue supervisada por Alexei Sentchev y Anna Rubio. Este trabajo se centró en el estudio de la dispersión y la identificación de estructuras de convergencia costera en el este del Canal de la Mancha y el sureste del Golfo de Vizcaya, y se llevó a cabo con el apoyo del proyecto LAMARCA, en el que participa AZTI (PID2021-123352OB-C33), financiado por MCIN/AEI/10.13039/501100011033 y “FEDER Una manera de hacer Europa.”

Resumen (en inglés)

Transport and dispersion processes in the ocean are crucial, as they determine the fate of biological and chemical quantities drifting with ocean currents. Coastal zones, located between the continent and the open ocean, are subject to numerous anthropogenic pressures causing pollution, toxic algal blooms and invasive species. Undersatnding the transport and dispersion processes of particulate matter in these areas is essential to preserve these environments and enable their sustainable management. Numerical circulation models and observation systems have a significant potential to study dispersion processes. However, they are limited by the complexity of the coastal ocean environment and by the lack of spatio-temporal resolution. This thesis aims to contribute to the improvement of the realistic representation and characterization of coastal current convergence structures using fusion of heterogeneous data. This method consists to optimallu interpolate in space and time surface current velocities derived from Lagrangian drifter deployments to constrain different regular surface current fields (modeled, observed by high-frequency radar). In order to test the capabilities of this techniquen it is applied in two very different study regions – the Eastern English Channel and the southeastern Bay of Biscay. The proposed optimization significantly improves the reconstruction of surface current fields, reducing by 50% the Lagrangian error, thus enhancing our understanding of particulate matter transport and dispersion processes. By calculating various Lagrangian quantities such as dispersion, Lyapunov exponents and Lagrangian divergence, it is possible to identify areas of high turbulence and map the spatial distribution of coastal current convergence structures. Hence, thanks to optimization, the identification of coastal current convergence structures is more precise, enabling a better understanding of the transport of particulate matter at the surface of coastal zones.