A three-dimensional model of wind-driven circulation on the shelf: application to the storm of January 1993

A three-dimensional hydrodynamic model covering the NorthWest European Continental Shelf is used to examine the wind-induced circulation on the shelf during early January 1993, the time of the oil spill due to the grounding of the tanker Braer on the Shetlands. The model is used to study the response of the wind-driven currents on the shelf to changes in the wind stress which occurred on a number of time scales during this period. The sensitivity of the currents to various formulations of vertical eddy viscosity is considered in detail with particular emphasis on surface currents. Although the prime aim of the calculations is a study of the wind-driven flow over the whole shelf and not a study of oil movement, some of the flow fields in the vicinity of the Shetlands help to explain the movement and eventual fate of the oil in that region.