Journal of Geophysical Research: Oceans

Modeling the structure and variability of the southern Benguela upwelling using QuikSCAT wind forcing

Authors

  • Bruno Blanke,

    1. Laboratoire de Physique des Oceans, UMR 6523, Centre National de la Recherche Scientifique/Institut Français de Recherche pour l'Exploitation de la Mer/Université de Bretagne Occidentale, Brest, France
    2. Also at Institut de Recherche pour le Développement, Paris, France.
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  • Sabrina Speich,

    1. Laboratoire de Physique des Oceans, UMR 6523, Centre National de la Recherche Scientifique/Institut Français de Recherche pour l'Exploitation de la Mer/Université de Bretagne Occidentale, Brest, France
    2. Also at Institut de Recherche pour le Développement, Paris, France.
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  • Abderrahim Bentamy,

    1. Institut Français de Recherche pour l'Exploitation de la Mer, Plouzané, France
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  • Claude Roy,

    1. Institut de Recherche pour le Développement, Centre de Brest, Plouzané, France
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  • Bamol Sow

    1. Laboratoire de Physique de l'Atmosphère Siméon Fongang, Université Cheikh Anta Diop, Dakar, Senegal
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Abstract

[1] The structure and patterns of variability of the southern Benguela coastal upwelling system are investigated with a high-resolution regional model forced by QuikSCAT winds over 1999–2003. The relevance of this global wind product is tested, at first, for the specific nearshore southeast Atlantic; then, the wind products are spatially or temporally degraded from the original 0.5° daily fluxes and are used to diagnose the main scales of the surface dynamical forcing variability. Time resolution appears as a crucial factor in the wind stress to retrieve the patterns of interannual anomalies in sea surface temperatures in a good agreement with independent NASA Pathfinder observations. Various upwelling indices are also calculated in the model to study specific warm or cold coastal events whose circulation schemes are detailed from a Lagrangian interpretation of the model time-varying three-dimensional velocity field. Our study emphasizes the connections established between the Benguela upwelling and the large-scale circulation in relation with, for instance, the Agulhas Current retroflection and associated ring shedding.

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