A NESTED PRIMITIVE EQUATION MODEL OF THE ICELAND-FAEROE FRONT

A fully two-way interactive nested primitive equation model of the Ice land-Faeroe region is described. The model consists of a fine grid (ap proximately 3 km resolution) model nested 3:1 within a coarse grid (ap proximately 9 km resolution) larger area model. The fine grid model ha s increased resolution in both the horizontal and vertical directions. This allows better representation of coastlines and bottom topography , as well as of the ocean fields and dynamics. The model nesting techn ique used is suitable for relatively short-term applications, for exam ple, ocean forecasting or studies of mesoscale ocean processes. The ne sting technique is found to be robust, with little noise or distortion produced at the interfaces between the model regions. Results from th e nested model are compared with those from a coarse grid only model. Introduction of the nested fine grid model is seen to produce benefits in the form of tightened frontal gradients, increased meandering, and increased eddy activity; greater overflow of cold bottom water southw ard over the Iceland-Faeroe ridge is also observed in the nested model . Calculations of the heat and volume transports through the Iceland-F aeroe-Shetland region show significant differences between the nested model and the coarse grid reference model. When the nested model is ru n in one-way interactive mode, with no feedback from the fine grid mod el to the coarse grid model, increased noise is generated at the bound aries of the fine grid model.