Internal breather-like wave generation by the second mode solitary wave interaction with a step

The transformation of an internal second mode solitary wave over a bottom step in a computational tank filled with a three-layer stratified fluid was studied. The convex waveforms were generated by a collapse mechanism for stratification with a thin mid-layer. The wave transformation depends on the blocking parameter B which is a ratio of the amplitude of the incident wave to the thickness of the lower water layer over the step. Three regimes of second mode wave transformation over the step are identified. In regime I (2 6. In regime II (0.5 < B < 2) the mode-2 wave is permanently disintegrated, generating a chain of waves of mode-1 ahead of wave of mode-2 and tail of short waves of mode-1 behind the wave. In regime III (B < 0.5) only waves of elevation of mo...