Modification of Internal Wave Generation and Energy Conversion in the Nearshore Due To Tide‐Tide and Tide‐Wind Interactions

Abstract

AbstractInternal wave generation due to semi‐diurnal tides (M2) through the acceleration of barotropic tidal flow over sloped topography has received considerable attention over the past several decades. However, the contribution of other tidal constituents and their interactions with M2 have not been as extensively evaluated. Moreover, on the inner shelf, the cross‐shore wind, which is often neglected in the energy conversion studies, dominates the cross‐shore transport and can also affect the energy conversion process. This study addresses this gap by including a diurnal (K1) tidal component and a shoreward diurnal sea breeze in an idealized model of southern Monterey Bay as it represents a highly stratified system that experiences active surface and internal tides. Our simulations demonstrate the role of the K1 tide and its interaction with M2, which is constructive and insensitive to the initial phase lag. Wind‐induced perturbations grow with the wind speed and enhance M2 conversion. On the other hand, the wind interaction with the K1 and M2K1 tides highly depends on the timing with constructive (destructive) conversion occurring when the shoreward wind intensifies during the ebb (flood) tide. Interactions among tides and winds lead to highly variable conversion rates, changes in timing and location of peak conversion, and a range of internal wave frequencies. Such a dynamic alone can be responsible for the complex internal wave environments often observed in the nearshore.