Numerical modeling results for mode propagation in a wedge

A PE (parabolic equation) code is used to study propagation in a shallow water wedge with a penetrable bottom. Particular attention is given to ‘‘wedge modes’’ that have wave fronts that are arcs of circles centered on the wedge apex. For downslope propagation and for upslope propagation before cutoff, the wedge modes propagate independently without coupling. For upslope propagation through cutoff, there is a small amount of coupling to the next lower mode and a trace of coupling to the next higher mode. The wedge modes can be considered the natural modes of the wedge.