The Role of Waves and Heat Exchange in the Hydrodynamics of Multi‐Basin Bays: The Example of Cádiz Bay (Southern Spain)

Abstract

Abstract Multi‐basin bays constitute one of the most complex coastal environments, as tides, waves, freshwater discharges and air‐water heat exchange often coexist in basins with very different characteristics, ranging from low‐friction open water bodies directly connected to the open sea to narrow, highly frictional shallow creek systems with no connection to the open sea. Although the influence of tides and baroclinic gradients in these areas is relatively well known, the role of waves in the hydrodynamics and distributions of density, salinity and temperature has received less attention. The aim of this research is to evaluate the effects of waves and heat exchange on the hydrodynamics of multiple basins through numerical modeling. The model is calibrated and tested in a mesotidal bay in Southern Spain with five different basins; the results are used to analyze the momentum balance equation and the salinity, temperature and density distributions for simulations with and without consideration of waves. The results show that baroclinic density gradients often dominate the hydrodynamics in highly frictional, shallow basins of the bay where the air‐water heat exchange is more efficient. Waves can also modify the hydrodynamics of basins directly connected to open sea by increasing flow velocities and causing deviations of baroclinic density gradients, increasing the importance of tidal stresses in low frictional basins, while increasing baroclinic density gradients in narrow, highly frictional basins.

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