Impact of offshore eddies on shelf circulation and river plumes of the Sofala Bank, Mozambique Channel

Abstract : A high-resolution, two-way nested Regional Ocean Modeling System, forced with monthly climatologies, has been set up for the Sofala Bank and adjacent deeper ocean of the Mozambique Channel to investigate the role of offshore mesoscale eddies on the shelf circulation, hydrographic structures and river plumes. The model is shown in comparison with available observations and published studies. Most known oceanographic features are reproduced by our model. We applied Self-Organizing Maps and showed that offshore passing eddies, depending on their strength and proximity to the shelf, modulate the shelf circulation and river plume direction and spread. The presence of a strong cyclonic eddy close to the shelf induces northward surface shelf currents. In contrast, the presence of a strong anticyclonic eddy close to the shelf induces a strong southward current over most of the shelf, except off Beira. Our analyses confirm that the plume of the Zambezi River is bi-directional. The southward-directed plume patterns, opposite to the dominant northwards, occur in response to nearby offshore anticyclonic eddies (26% of occurrence). This behavior could have an influence on water dispersal, shelf ecosystems and important fisheries. Therefore, offshore mesoscale eddies should be taken into account when studying the ocean dynamics of the Sofala Bank.
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https://hal.umontpellier.fr/hal-02002359
Contributeur : Isabelle Vidal Ayouba <>
Soumis le : jeudi 31 janvier 2019 - 16:05:08
Dernière modification le : jeudi 22 août 2019 - 18:50:06

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  • HAL Id : hal-02002359, version 1

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Bernardino S. Malauene, Coleen L. Moloney, Christophe Lett, Michael J. Roberts, Francis Marsac, et al.. Impact of offshore eddies on shelf circulation and river plumes of the Sofala Bank, Mozambique Channel. Journal of Marine Systems, Elsevier, 2018, 185, pp.1-12. ⟨hal-02002359⟩

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