We present the results of fully nonlinear numerical simulations of the geostrophic adjustment of a pressure front over topography, represented by an escarpment with a linear slope. The results of earlier simulations in the linear regime are confirmed and new essentially nonlinear effects are found. Topography influences both fast and slow components of motion. The fast unbalanced motion corresponds to inertia-gravity waves (IGW). The IGW emitted during initial stages of adjustment break and form the localized dissipation zones. Due to topography, the IGW activity is enhanced in certain directions. The slow balanced motion corresponds to topographic Rossby waves propagating along the escarpment. As shown, at large enough nonlinearities they may trap fluid/tracer and carry it on. There are indications that nonlinear topographic waves form a soliton train during the adjustment process. If the coastal line is added to the escarpment at the shallow side (continental shelf), secondary fronts related to the propagation of the coastal Kelvin waves appear.
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Note, however, that the exact value of the amplitude of the perturbation is not given in Ref. 3.
Due to their above-mentioned balanced character, we find this name more appropriate than the double Kelvin waves.
The diagnostic of transport with the help of potential vorticity frequently used in literature is not well suited for the present study because initial potential vorticity takes four different (constant) values out of the slope plus a continuous spectrum of values in the region of the slope.
