A primitive equation ocean model is applied to the process study of the Gaspé Current and cyclonic circulation over the northwestern Gulf of St. Lawrence (NWG). The model is driven by river discharge and barotropic boundary flows. Two types of model domains are used: an idealized basin with a flat bottom and piecewise coastline, and a realistic basin with model-resolved NWG bathymetry. The model domains are initially filled with horizontally uniform but vertically stratified waters. The river discharge is expressed in terms of lower salinity and a weak barotropic inflow in the upper waters at the estuary head. The early developments of the estuarine plume and coastal current system driven by the river discharge are qualitatively similar in both basins. After a short-period adjustment, a buoyant plume is developed near the estuary mouth, with a surface-intensified coastal current advecting the estuarine water seaward in the direction of Kelvin wave propagation. The coastal current initially follow... Abstract A primitive equation ocean model is applied to the process study of the Gaspé Current and cyclonic circulation over the northwestern Gulf of St. Lawrence (NWG). The model is driven by river discharge and barotropic boundary flows. Two types of model domains are used: an idealized basin with a flat bottom and piecewise coastline, and a realistic basin with model-resolved NWG bathymetry. The model domains are initially filled with horizontally uniform but vertically stratified waters. The river discharge is expressed in terms of lower salinity and a weak barotropic inflow in the upper waters at the estuary head. The early developments of the estuarine plume and coastal current system driven by the river discharge are qualitatively similar in both basins. After a short-period adjustment, a buoyant plume is developed near the estuary mouth, with a surface-intensified coastal current advecting the estuarine water seaward in the direction of Kelvin wave propagation. The coastal current initially follow...

In this study an individual-based numerical model with three-dimensional (3D) and time-dependent fields of circulation and hydrography is used to examine the effects of the physical environment and various biological behaviours on the distribution and movement of particles in the Gulf of St. Lawrence and adjacent waters. The 3D circulation and hydrographic fields are simulated by a numerical ocean circulation model. The model domain covers the St. Lawrence Estuary (SLE), the Gulf of St. Lawrence (GSL), the Scotian Shelf, the Gulf of Maine, and their adjacent waters. The basis of the individual-based model is a numerical scheme that tracks the movement of particles carried by ocean currents. Several swimming behaviours of marine animals are considered with efficient seaward migration in the GSL as the goal. Electronic tagging data for the American eel (Anguilla rostrata) are used as guidance in specifying the behaviours. It is demonstrated that particles that undergo an observed behaviour, known as selective tidal stream transport, are able to exit the SLE more efficiently than particles that are carried passively by the 3D ocean currents. Outside the SLE, particles that search for and swim towards higher salinity move further downstream than those that have a preference for deeper water or swim in random directions.

A three-dimensional ocean circulation model is used to study circulation and month-to-month variability in the western Caribbean Sea. The domain covers the area between 72° and 90°W and between 8° and 24°N, with a horizontal resolution of roughly 18 km. The western Caribbean Sea model is forced by the monthly mean Comprehensive Ocean–Atmosphere Data Set (COADS) wind stress and surface heat flux and monthly mean volume transports through the model open boundaries calculated by a (1/3)° Atlantic Ocean model. The model sea surface salinity is restored to the monthly mean climatology. The semiprognostic method suggested by Sheng et al. is used to reduce the model errors by assimilating the hydrographic data into the momentum equations. The model reproduces many well-known circulation features in the region, including the warm and persistent throughflow known as the Caribbean Current, the highly variable Panama–Colombia Gyre, and moderate seasonal variations of temperature and salinity in the surface ...