Gulf Stream Surface Front Displacement by the Local Wind Stress: A Two- Dimensional Numerical Model

The displacement of the surface front of the Gulf Stream due to normally short but intense wind events such as hurricanes is modelled. The model is a relatively simple extension of a one-dimensional bulk mixed-layer model to two dimensions to allow the representation of the cross section of the mixed layer in the frontal zone of a strong current such as the Gulf Stream. The wind event is assumed to be a rapidly moving (11 m/s) circularly symmetric cyclone. Three different storm paths are modelled. All generate net shifts of the surface front relative to the subsurface front with inertial oscillations superimposed. One path is designed to simulate the passage of Hurricane Dennis during a Gulf Stream survey (Horton 1982). The net shift of the surface front predicted by the model compares reasonably with that observed.