The North-western part Mediterranean basin is characterised by an anticlockwise (cyclonic) gyre. The current is relatively strong (about 0.25 to 0.5 m/s) and the surface water masses (incoming from the Atlantic Ocean trough the Strait of Gibraltar) flow from Corsica Island towards Spain along the French coast and following the Shelf break in the Gulf of Lion. This permanent current is called the Ligurian current or the North current. The wind, the evaporation, the seasonal cooling and warming of the sea can generate perturbation of this mean motion.
The equations of the water motion due to all physical processes are approximated using a computer. This kind of calculation is called numerical modelling and modellers are able to evaluate at each position the velocity, the temperature and the salinity of a water particle.
Obviously, numerical models are not perfect and don’t reproduce exactly the behaviour of a water parcel at each position and at any time. You will certainly find differences between the simulation and the actual state of the Sea. Nevertheless this kind of modelling can efficiently help you to understand and forecast the sea motions.