Feasibility and usefulness of steady-state calculations of the mean circulation in the vicinity of the Ebro mouth. Model tests against field data

摘要

A steady-state quasi-3D finite element model is forced with in situ measured wind conditions in order to obtain an estimate of the mean circulation off the Ebro delta and to assess its consequences upon water fluxes. The model is spectral in the vertical direction and is run with a reduced number of vertical degrees of freedom (modes). The boundary conditions prescribed on the ocean contours account for the existence of a slope jet. The hypothesis is that the direct wind forcing on the upper layer and the shelf mesoscale circulation are the main mechanisms driving the flow in the area and that it should be possible to reproduce the main current features even in the vicinity of the Ebro river mouth with this relatively simple model setup, as the usual river freshwater discharge rates are rather low. This is clearly different from the case of other region of freshwater influence systems, in which the river plume dynamics and the related density currents play relevant roles. The model results are compared with surface drifter trajectories obtained during field campaigns. (C) 2002 Elsevier Science Ltd. All rights reserved. [References: 24]