Numerical simulation of circulation in Gulf St Vincent due to an idealized storm.

Abstract

A three-dimensional model was developed using the primitive equation of motion and continuity equation and allowing for vertical surface displacements to occur. Actual depths were used and observed values for the temperature and salinity were used to calculate the density. Four vertical grid layers were used in the numerical simulation of the circulation. The wind speed and directions were based on a theoretical form for the wind stream function. This form was similar to that for observed storm patterns in the gulf area.

The simulation was carried out over a period of about 60 h and displays of mass transports, horizontal velocities at each layer and surface elevations were produced at regular intervals throughout the simulation.

In the wake of the storm there was a complete reversal of the directions of the flow after the first 6 h followed by a return to the original directions after the next 6 h and then a return to the initial steady state during the next 12 h. The elevations were found to increase rapidly with the increase in the wind velocity in the shallow parts of the gulf and the lines of constant elevations settled to a direction perpendicular to the wind direction.