3.2. Configuration of the hydrodynamic operational system
3.2.1. Impact of initial density profile
In Fig. 8, the time series of velocity and temperature extracted at
the surface and at the bottom (z= −9.1 m) of the Channel
Monitoring Point (MP) for the three experiments (i.e. DEN-1, DEN-2
and DEN-3) are shown. At the beginning of the run, when the wind
forcing is weak, the three solutions follow the same trajectory,
although differences of 2–3 cm/s between them are present. Velocities
under linear stratification are the largest, while velocities without
stratification are the smallest. Later, during the wind gust at hour 42,
surface velocities in all the experiments are similar. Finally, after the
wind gust, the experiments with stratification converge to the same
solution while the experiment without stratification has more inertia
maintaining larger velocities. In the deeper layers, the behaviour at
the beginning is the same as at the surface. However, later on, the
velocities in the linear stratification experiment are significantly
larger, suggesting that the energy transfer from the wind is more
effective with that density profile. The strong density gradient in the
bilayer profile inhibits the energy transfer from the wind to the
deeper layers, so the behaviour near the bottom is similar to that of
the homogeneous case.