Simon Fraser University
Burnaby, British Columbia, Canada
In order to improve the representation of topographic variations, previous numerical circulation models use the $\sigma$-coordinate system which maps the varying topology into a regular domain and greatly simplifies the numerical computation. However, this linear mapping is not consistent with uniformly high resolution at the ocean surface. In this talk, we will introduce a more general coordinate system which is capable of simultaneously maintaining high resolution in the surface layer as well as dealing with steep topography. The motivation of using the general coordinate system steams from the boundary-layer-resolving spectral method. The convergence theory of this spectral method, which is useful in choosing appropriate coordinate systems, will be presented. Several numerical tests for ocean circulation are used to demonstrate the accuracy, stability and the applicability of the general coordinate system.