Numerical simulation of the barotropic tides in the Tunisian Shelf and the Strait of Sicily

Abstract

We have investigated the barotropic tides in the Tunisian shelf and the Strait of Sicily using the Regional Ocean Modelling System (ROMS) with very high-resolution. Model performance was evaluated with respect to tide gauge, satellite data, and current meter measurements. The model fields faithfully reproduced the major feature of the barotropic tidal currents and agreed well with existing tidal elevation and phase observations. General features for the various semidiurnal constituents are nearly similar to each other with maximum amplitude in the Gulf of Gabes. The larger tidal currents occur over the continental shelves. In the Adventure Bank, the current is essentially of diurnal type whereas in the Gulf of Gabes it is of semidiurnal type. Tidal energy lost, which is primarily due to bottom stress dissipation, is predominantly in the Gulf of Gabes (∼ 61%), the Strait of Sicily, and the Strait of Messina. The forcing function for internal tides shows for both M 2 and K 1 constituents, significant spatial variability in the Strait of Sicily. This suggests that some internal tides will be generated in these regions and could thus explain the observed strong diurnal internal waves in the Adventure Bank.