Analysis of short-period internal waves using wave-induced surface displacement: A three-dimensional model approach in Algeciras Bay and the Strait of Gibraltar

Abstract

A three-dimensional, nonlinear, high-resolution, sigma coordinate, hydrodynamic model was applied to study the sea surface manifestation of short-period internal waves measured in Algeciras Bay and the Strait of Gibraltar. Model results reproduce the tidally induced generation of the internal bore over the Camarinal Sill and its disintegration into wave trains as it moves eastward. While propagating along the Strait of Gibraltar toward the Mediterranean Sea, the wave trains partly penetrate into Algeciras Bay, with typical oscillation periods of 20 and 40 min. The modeled wave-induced surface train structures are compared with satellite images and in situ observational data obtained from two pressure sensors located inside the bay. Results demonstrate that wave-induced sea surface displacements are indicators of the presence of internal waves and may be used in the context of the internal wave analysis when surface oscillations are captured with sufficient precision.