Mixing Efficiency for Breaking Internal Solitary Waves

We propose a semi-analytic approach to estimate mixing induced by internal solitary waves (ISWs) breaking over a sloping boundary. The theoretical framework we develop describes the energetics of a stratified fluid flow during the interaction of ISWs with a slope. In particular, through both Ozmidov and Thorpe lengthscales we derive a heuristic expression for mixing efficiency, valid for plunging and plunging-collapsing breakers. On the other hand, we perform laboratory experiments that also provide mixing efficiency by estimating both changes of the background potential energy and the incident and reflected ISWs energy. We then compare those results with the ones derived by our theoretical model, obtaining a power law that relates the two quantities. This function allows to estimate mixing efficiency when the change in the background potential energy due to the ISWs breaking is unknown. We finally successfully apply our model to estimate the mixing efficiency under real field conditions.