Study of an upwelling event in the Portuguese coast -  Upwelling Filaments in Aveiro region

Paulo Filipe Alexandre Correia

Key information

Authors:

Paulo Filipe Alexandre Correia (Paulo Filipe Alexandre Correia)

Supervisors:

Aires José Pinto dos Santos (Aires José Pinto dos Santos); Lígia Laximi Machado de Amorim Pinto (Lígia Laximi Machado de Amorim Pinto)

Published in

10/03/2017

Abstract

This work is about coastal upwelling in the region of Aveiro, aiming to understand and simulate the generation of filaments during an upwelling event in the summer of 2011. The main issue addressed is whether the existence of the Western Iberian Buoyant Plume (WIBP) due to river discharges, affects the formation of the so-called Aveiro filament. To verify the influence of the plume on the filament formation, numerical simulations were performed using the hydrodynamic 3D model MOHID, in two distinct scenarios. In the first scenario, the model was initialized with the known values of temperature and salinity, whereas in the second scenario the coastal fresher water was replaced by saltwater with a salinity equal to 35.9 psu. Comparing both scenarios, the main conclusion of this work is that the plume, considering only the contribution of the salinity, does not affect the filament extension but rather its direction, since there is a southward displacement. In terms of filament extension, MOHID model was compared with an analytical model, the Lentz's model. The comparison confirmed that the replacement of coastal fresher water by saltwater does not affect the filament extension, which is about 150 km in both cases. However, Lentz’s model shows that without the salinity signature of the WIBP the buoyant plume reaches a distance of 122 km, while without the temperature signature the offshore distance is 127 km. These reductions in the filament extension were not observed with the MOHID model.