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Ocean Dynamics

, Volume 66, Issue 4, pp 589–603 | Cite as

Unstructured-mesh modeling of the Congo river-to-sea continuum

  • Yoann Le Bars
  • Valentin Vallaeys
  • Éric Deleersnijder
  • Emmanuel HanertEmail author
  • Loren Carrere
  • Claire Channelière
Article
Part of the following topical collections:
  1. Topical Collection on the 47th International Liège Colloquium on Ocean Dynamics, Liège, Belgium, 4-8 May 2015

Abstract

With the second largest outflow in the world and one of the widest hydrological basins, the Congo River is of a major importance both locally and globally. However, relatively few studies have been conducted on its hydrology, as compared to other great rivers such as the Amazon, Nile, Yangtze, or Mississippi. The goal of this study is therefore to help fill this gap and provide the first high-resolution simulation of the Congo river-estuary-coastal sea continuum. To this end, we are using a discontinuous-Galerkin finite element marine model that solves the two-dimensional depth-averaged shallow water equations on an unstructured mesh. To ensure a smooth transition from river to coastal sea, we have considered a model that encompasses both hydrological and coastal ocean processes. An important difficulty in setting up this model was to find data to parameterize and validate it, as it is a rather remote and understudied area. Therefore, an important effort in this study has been to establish a methodology to take advantage of all the data sources available including nautical charts that had to be digitalized. The model surface elevation has then been validated with respect to an altimetric database. Model results suggest the existence of gyres in the vicinity of the river mouth that have never been documented before. The effect of those gyres on the Congo River dynamics has been further investigated by simulating the transport of Lagrangian particles and computing the water age.

Keywords

Multi-scale modelling Congo river-to-sea continuum Tides Water age Satellite altimetry 

Notes

Acknowledgments

The financial support of Total ep Recherche Développement and cls (under contract cls-dos-13-003) is gratefully acknowledged. Slim is developed under the auspices of the Action de Recherche Concertée “Taking up the challenges of multi-scale marine modelling” funded by the Communauté frana̧ise de Belgique under contract arc 10/15-028. Some of the computational resources were provided by the Consortium des Équipements de Calcul Intensif (céci), funded by the f.r.s.-fnrs under Grant No. 2.5020.11. Yoann Le Bars is indebted to Christopher Thomas for his comments and constructive criticism during the preparation of the present manuscript. Éric Deleersnijder is an honorary Research associate with the f.r.s.-fnrs.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  • Yoann Le Bars
    • 1
  • Valentin Vallaeys
    • 1
  • Éric Deleersnijder
    • 2
    • 3
  • Emmanuel Hanert
    • 4
    Email author
  • Loren Carrere
    • 5
  • Claire Channelière
    • 6
  1. 1.Institute of Mechanics, Materials, and Civil Engineering (IMMC)Université catholique de LouvainLouvain-la-NeuveBelgium
  2. 2.Institute of Mechanics, Materials, and Civil Engineering (IMMC), Earth and Life Institute (ELI)Université catholique de LouvainLouvain-la-NeuveBelgium
  3. 3.Delft Institute of Applied Mathematics (DIAM)Delft University of TechnologyDelftThe Netherlands
  4. 4.Earth and Life Institute (ELI)Université catholique de LouvainLouvain-la-NeuveBelgium
  5. 5.Collecte Localisation Satellites (CLS)Ramonville Saint-AgneFrance
  6. 6.Total S.A.,EP/DEV/TEC/GEOTour NewtonCourbevoieFrance

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