Tidal motions in the deep Mediterranean

Abstract

The Mediterranean Sea is known for its limited tidal motions. For example, surface barotropic tidal elevations have an amplitude of 0.1 m in the Northwestern Mediterranean. Nevertheless, these small tides are noticeable in temperature records at the 2500-m deep seafloor, but only under near-homogeneous conditions when buoyancy frequency N < f, the inertial frequency. After transfer of pressure to temperature units via the local adiabatic lapse rate, the observed internal-wave temperature signals may thus be corrected for 1.5x10-5-degrC amplitude semidiurnal barotropic tides. The remaining baroclinic tides are embedded in the broad and featureless inertio-gravity wave band, with some energy enhancement near its boundaries, also under tenfold-larger energetic stratified water conditions.