Sensitivity study of an upper ocean model in a coastal bay

An upper layer ocean model, with primitive equation dynamics and embedded with a mixed layer model at the top, is developed. Entrainment and detrainment in the mixed layer are determined from wind and buoyancy turbulent kinetic energy, as well as the effect of shear instability at the base of the mixed layer. The model parameterised the processes of convection and deep ocean diffusion, as well as mass entrainment at a subsurface layer due to strong upwelling. It was applied to the Baie des Chaleurs (Gulf of St. Lawrence, Canada). The model was forced by observed winds, atmospheric heat fluxes, river runoff and a remote coastal jet. The simulations in the main run reproduced well the observational fields in both time and space. Sensitivity runs are conducted to study the effects of external forcing, important physical processes and the internal physical parameterisation on the model results and to compare these with the main run.