Erosion of the thermocline in the Gulf of Patras, due to a severe wind event

Three-dimensional numerical simulations, performed using the MIKE 3 FM (HD) code, have been used to study the effect of a severe wind event on the early stratification structure in the Gulf of Patras, Greece. Before the onset of the severe wind event thermocline was at an approximately mean depth of ~ 10 m. The wind action deepened the well mixed layer of the epilimnion at the surface and redistributed the thermal stratification to a new stable formation where tilt and erosion of the thermocline occurred. Under the effect of wind the thermocline was established in a new mean depth of ~ 60 m. Furthermore, strong wind - generated internal waves, in the area of Rio-Antirio straits, were found to affect the exchange flowrate at the straits. Comparison of the exchange flowrate between the barotropic and the baroclinic flow, under the same severe wind conditions, revealed a deviation of approximately 20% of the resulting flowrate, under steady wind conditions. The hydrodynamic response of the Gulf, under these wind conditions, i.e., wind-induced currents, turbulence structure in the water column, internal waves and flow patterns, has been simulated indicating basic, unique, flow characteristics for the baroclinic flow in contrast with the barotropic ones.