Breaking Waves in Deep and Intermediate Waters

Since time immemorial, surface water waves and their subsequent breaking have been studied. Herein we concentrate on breaking surface waves in deep and intermediate water depths. Progress has been made in several areas, including the prediction of their geometry, breaking onset, and especially energy dissipation. Recent progress in the study of geometric properties has evolved such that we can identify possible connections between crest geometry and energy dissipation and its rate. Onset prediction based on the local wave-energy growth rate appears robust, consistent with experiments, although the application of criteria in phase-resolving, deterministic prediction may be limited as calculation of the diagnostic parameter is nontrivial. Parameterization of the dissipation rate has benefited greatly from synergistic field and laboratory investigations, and relationships among the dynamics, kinematics, and the parameterization of the dynamics using geometric properties are now available. Field efforts continue, and although progress has been made, consensus among researchers is limited, in part because of the relatively few studies. Although direct numerical simulations of breaking waves are not yet a viable option, simpler models (e.g., implementation of an eddy viscosity model) have yielded positive results, particularly with regard to energy dissipation.