Effect of Internal Waves on the Hydrodynamics of a Mediterranean Sea Strait

Abstract

In the present work, the effects of wind- and tide-induced internal waves in the Rio-Antirio Strait in western Greece were studied by using three-dimensional numerical simulations. For the wind-induced flow in the strait, it emerged that the internal waves’ initiation is associated with the direction of the wind. Tidal action, with or without the combined action of wind, also generates internal waves in the strait, with amplitudes higher than 20 m. The action of the internal waves causes a subsurface inflow of colder waters from the Gulf of Corinth to the Gulf of Patras, as has been also simulated for the case of the wind-induced flow, generating strong hypolimnetic currents. The exchange flowrate between the Gulf of Patras and the Gulf of Corinth appeared to undergo significant modification for the wind-induced flow and had little effect for the pure tidal flow (in windless conditions) due to the development and action of the internal waves at the strait. The combined action of the tide and the wind was found to marginally affect the exchange flowrate between the two gulfs compared to the pure tidal flow. The interaction between the Coriolis effect and internal waves, at least away from the strait, forms a characteristic horizontal structure of flow. The structure of turbulence in the near strait area under the action of internal waves generated by the wind and/or tide was also discussed and compared with the corresponding barotropic flow.

Studying the Internal Wave Generation Mechanism in the Northern South China Sea Using Numerical Simulation, Synthetic Aperture Radar, and In Situ Measurements

“…Internal waves occur within the density-stratified interiors of oceans, where the maximum amplitude is found within the ocean itself, and the wave frequency is between the inertial and buoyancy frequencies. Among them, high-frequency internal waves often exist in the form of rank-ordered solitary wave packages or solitary waves and are widely distributed across the continental shelves and marginal seas of the world's oceans, such as in the South China Sea (SCS) [1,2], Gulf of Mexico [3,4], Gibraltar Strait [5], Strait of Messina [6,7], Sulu Sea [8,9], Andaman Sea [10,11], Arctic Ocean [12], Black Sea [13,14], Lombok Strait [15,16], Georges Bank [17,18], and the Gulf of Maine [19]. They are often generated by the interaction between currents with varying bottom topographies.…”