MODELING WIND AND TIDE-INDUCED CURRENTS IN THE EASTERN IONIAN SEA: PATRAIKOS GULF (GREECE)

The Gulf of Patras is a shallow embayment, in the western Greece, leading into the Ionian Sea on the west, and through the straits of Rio-Antirio into the Gulf of Corinth, on the east. The three-dimensional code MIKE 3 FM (HD) has been applied to simulate the barotropic response which develops in the complex bathymetry of the Gulf of Patras due to tidal and wind forcing. Numerical simulations were conducted for the dominant wind directions and wind speeds up to 15 m/s. In addition, the tidal forcing was applied at the domain boundaries to simulate tidal currents in the Gulf. Based on the simulations, the hydraulic exchange flow rate at the Rio-Antirio straits was calculated, for different tidal and wind forcing scenarios. The numerical study corroborated that the simulated tidal currents at the Rio-Antirio straits are among the strongest in Greece and stronger than wind-driven circulation at spring tides. At neap tides, however, wind induced exchange may be dominant, if forced by a sufficiently strong wind. Wind-induced, barotropic residence time is estimated to be of the order of a month.