Investigation of the interaction of internal solitary waves with the slope-shelf topography

Abstract

In this paper, internal solitary waves (ISWs) propagating over shelf topographies are studied based on numerical experiments conducted according to the lock-release method. The wave generation, propagation, and interactions with slope-shelf topography are investigated in a wave tank. The primary features of the propagation of ISWs on the slope are assessed. Shear and advection instabilities are observed in the current simulations in some cases with 1.29 < Bs < 1.75 (Bs is defined as the ratio of layer water depth on the shelf to the ISW amplitude). The induced density flow contributes to the growth of potential energy by dilution and stripping, primarily through its head, which is one of the factors used to enhance the mixing efficiency. In addition, the obtained results are compared with those of previous experiments conducted by other researchers, while considering the differences in local topography. The comparison reveals that local topography is a reason for the experimental differences of some research studies. ISW breaking on a slope is strongly influenced by the initial flow field of the slope, which may lead to differences in the prediction of the breaking point by using boundary layer separation as a criterion. As the incident wave amplitude increases, the location of the breaking point shifts downward and its magnitude gradually decreases.