Observations of a Large-Amplitude Internal Wave Train and Its Reflection off a Steep Slope

Abstract

Remote and in situ field observations documenting the reflection of a normally incident, short, and large-amplitude internal wave train off a steep slope are presented and interpreted with the help of the Dubreil?Jacotin?Long theory. Of the seven remotely observed waves that composed the incoming wave train, five were observed to reflect. It is estimated that the incoming wave train carried Ei = (24 ± 4) ? 104 J m?1 to the boundary. The reflection coefficient, defined as the ratio of reflected to incoming wave train energies, is estimated to be R = 0.5 ± 0.2. This is about 0.4 lower than parameterizations in the literature, which are based on reflections of single solitary waves, would suggest. It is also shown that the characteristics of the wave-boundary situation observed in the field are outside the parameter space examined in previous laboratory and numerical experiments on internal solitary wave reflectance. This casts doubts on extrapolating current laboratory-based knowledge to fjord-like systems and calls for more research on internal solitary wave reflectance.