A New Two-Way Nested-Grid Ocean Modeling Technique Applied to the Scotian Shelf and Slope

A nested-grid ocean circulation model is developed for the Scotian Shelf and adjacent slope. The nested model consists of a fine-resolution inner model embedded inside a coarse-resolution outer model. The inner model covers the Scotian Shelf and slope, with a resolution of approximate 7 km. The outer model is the northwest Atlantic Ocean model developed by Sheng et al., with a horizontal resolution of approximate 25 km. The unique feature of the nested-grid model is its use of the semi-prognostic method to exchange information between the two different grids. The nested-grid ocean model is forced by the monthly mean COADS (Comprehensive Ocean-Atmosphere Data Set) wind stress and surface heat flux. The model sea surface salinity is restored to the monthly mean climatology. The nested-grid model is integrated for two years and the model results in the second year are presented in this paper. The inner model produces not only large-scale circulation features which are consistent with observations and those produced by the outer model, but also more meso-scale features than those in the outer model.