A Field Study of Breaking Waves in Developing Seas

Abstract

Breaking waves are the dominant pathway by which energy is dissipated at the ocean surface, yet their definition, dynamics, and energetics remain subjects of ongoing debate. Here, we present results from a six-week field campaign during the Coastal Land–Air–Sea Interaction project, where wave breaking was detected across scales using an array of Air–Sea Interaction Spar buoys. Application of the wavelet-based Liberzon phase-discontinuity method identified more than 3.2 million wave crests and over 269,000 breaking events from high-frequency wave-wire measurements. From these elevation records, we developed an observation-constrained, crest-resolved parameterized framework for estimating breaking-induced energy dissipation. We introduce a breaking-strength parameterization consistent with the inertial scaling in terms of locally measured nonlinear steepness and consistent with inertial scaling after application of a constant empirical correction. Breaking fraction and associated dissipation depend strongly on wind forcing, wave age, and effective fetch, deviating from traditional whitecap-coverage power-law formulations. During active wind–wave coupling, breaking accounts for approximately 20–50% of the local atmospheric reference energy flux, underscoring its dynamical significance. Together, these results provide a physically grounded, observation-constrained, and crest-resolved picture of breaking-wave energetics from small-scale spilling events to larger, energetic whitecaps—and offer new constraints for improving dissipation schemes in spectral wave models under developing sea conditions.