A contour-advective semi-Lagrangian numerical algorithm for the problem of interaction between a vortex and an isolated topographic feature on a $\beta$-plane

The main stages of a contour-advective semi-Lagrangian algorithm for the simulation of inviscid incompressible flows with variable depth on the rotating Earth are considered. The numerical results for the case when a vortex encounters an axisymmetric topographic feature on a $\beta$-plane are discussed. The accuracy of the method for different values of the its parameters is numerically estimated. The contour-advective method is compared with the finite-difference method. It is shown that the contour-advective semi-Lagrangian algorithm is very efficient to represent a fine-scale structures of potential vorticity fields.