Suspended matter dispersion in the Ebro ROFI: an integrated approach

River discharges represent the main source of telluric freshwater and suspended matter in coastal areas. Spatio-temporal complex mechanisms of exchanges in the river plume are investigated for successively highly stratified and mixed situations, using in situ measurements, satellite images and numerical modelling. The study, as part of the “fluxes across narrow shelves” research project, is focused on the Ebro river plume (Spain). Three specific situations encountered in the Ebro site, and for which in situ data, satellite images and numerical simulations are available, have been studied. Depending on the river flow and wind conditions, three-dimensional salinity, temperature and suspended matter fields exhibit weak to strong horizontal and vertical diffusion patterns leading to a challenging case for modelling. Occurrence of fronts at the plume boundaries is shown to inhibit exchanges near the river mouth but to enhance the region of mixing. Association of this latter process with wind effect influences the space scale of mixing and determines the occurrence of fluxes across the shelf break.