Abstract
The spreading of the plume induced by the freshwater discharge from the Ebro River into northwestern Mediterranean coastal waters was modelled using two numerical codes. The coastal current field was obtained with a finite difference hydrodynamic model based on a steady-state version of the shallow-water equations, whereas the freshwater dispersion was calculated with a Lagrangian code that solves the 3D convection-diffusion equation and reproduces turbulent diffusion using a random-walk algorithm. The agreement obtained between numerical results, satellite observations and field measurements allows an analysis of the more relevant physical mechanisms and the corresponding tuning of the two models. The results show that local hydrodynamics near the river mouth, and consequently the spreading of the river plume, are highly dependent on the driving river discharge and wind field characteristics.
Highlights
SCIENTIA MARINAMARC MESTRES1, JOAN PAU SIERRA1, AGUSTÍN SÁNCHEZ-ARCILLA1, JULIO GONZÁLEZ DEL RÍO2, THOMAS WOLF3, ANDRÉS RODRÍGUEZ4 and SYLVAIN OUILLON5
One of the most common mesoscale features of continental and shelf seas are the estuary plumes produced by the continuous discharge of brackish or freshwater from a coastal buoyancy source, such as a river or estuary
The provisional computed velocity is corrected by adding the hydrodynamic pressure gradient, calculated after imposing that the resulting velocity field is divergence-free throughout the computational domain, which leads to a finite difference Poisson equation that is solved iteratively using the preconditioned conjugate gradient method
Summary
MARC MESTRES1, JOAN PAU SIERRA1, AGUSTÍN SÁNCHEZ-ARCILLA1, JULIO GONZÁLEZ DEL RÍO2, THOMAS WOLF3, ANDRÉS RODRÍGUEZ4 and SYLVAIN OUILLON5. The coastal current field was obtained with a finite difference hydrodynamic model based on a steady-state version of the shallow-water equations, whereas the freshwater dispersion was calculated with a Lagrangian code that solves the 3D convection-diffusion equation and reproduces turbulent diffusion using a “random-walk” algorithm. RESUMEN: MODELADO DEL PENACHO DEL RÍO EBRO. – Se presenta la simulación del penacho de agua dulce resultante de la descarga del río Ebro en el Mediterráneo mediante el uso secuencial de dos modelos numéricos. Los resultados muestran que la hidrodinámica local cerca de la desembocadura del río y, por consiguiente, la dispersión del penacho del río, dependen principalmente del volumen de descarga del río y de la características del viento dominante. Palabras clave: río Ebro, penacho de agua dulce, modelado numérico, hidrodinámica, dispersión
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call