Profile Evolution and Energy Dissipation for Internal Soliton Transmitting over Different Submarine Ridges

Fundamental experiments were carried out in a wave flume on internal solitary wave (ISW) of depression-type propagating over a submerged ridge. The seabed ridge included either triangular or semicircular shape- regarded as topographic obstacles. Influenced by the submarine ridge, the transmitted waves were found to always consist of a leading pulse (a solitary wave) followed by a dispersive wave train. The wave profile propagating over a triangular ridge was similar to that caused by a semicircular obstacle. Apparently, the smooth face of a semicircular ridge produced time lag of wave propagation. From experimental results available, the reduction in wave energy induced by a semicircular ridge was larger than that by a triangular one. The events of wave distortion, strong breaking, internal bolus, and stratification mixing happened in case that the crest of an ISW was great enough to interact with the topographic obstacle. The reduction in wave energy was induced by strong breaking, and it depended on the ridge height rather than the geometric shape of the ridge.