The characteristics of tides and their effects on the general circulation of the Mediterranean Sea

The effects of tides on the Mediterranean Sea’s general circulation, with a particular focus on the horizontal and vertical currents, are investigated using twin simulations with and without tides. Amplitudes of tides in the region are typically low, but an analysis of the kinetic energy demonstrates that tides have effects across many spatial and temporal scales in the basin, including nonlinear effects at short periods (less than one day) with high kinetic energy peaks at near-inertial, basin modes and tidal frequencies. Internal tidal waves are also revealed below 100 m. Tides are found to amplify several basin modes of the Mediterranean Sea, broaden several tidal frequency energy spectra bands, as well as interact energetically with near-inertial waves. Tides are found to increase the mixed layer depth in the Mediterranean Sea, particularly in the deep and intermediate water formation areas of the Western and Eastern basins. It is confirmed that the net mass transport through the Gibraltar Strait is unchanged by tides, but both inflow and outflow increase.