Breaking threshold and energy dissipation in solitary waves in a depth transition

Energy dissipation due to the breaking of surface waves remains an important open topic in both the open ocean and in coastal waters. Here we will discuss similarities between the deep- and shallow-water regimes. To do this, we first present data from direct numerical simulations of shoaling and breaking solitary waves in bathymetric depth transition. In an abrupt depth transition, we investigate the influence of the severity of the depth transition on whether the incident wave will break, finding good agreement with experimental data of Losada et al. (1988). We next investigate the energy dissipation rate in a gradual, linear depth transition. The resulting dataset is compared with an array of existing physics-based scaling arguments, and finds especially good agreement with an inertial model of Mostert & Deike (2020). We then discuss possible scaling approaches for understanding breaker dissipation in shallow water and draw comparisons with deep-water data and models. We will conclude with some insights towards a potential universal breaking parametrisation.