A unified breaking onset criterion for surface gravity water waves in arbitrary depth

TL;DR

This paper validates and extends a wave breaking prediction criterion to all water depths, demonstrating its effectiveness in detecting and predicting wave breaking in various wave types and bathymetries, including shallow water.

Contribution

The study confirms the applicability of the Barthelemy et al. (2018) criterion across all water depths and shows it outperforms existing criteria in predicting wave breaking onset.

Findings

The criterion accurately detects breaking in shallow, intermediate, and deep water.

It predicts single and multiple breaking events in space and time.

It improves prediction skill over previous kinematic and geometric criteria.

Abstract

We investigate the validity and robustness of the Barthelemy et al. (2018) breaking wave onset prediction framework for surface gravity water waves in arbitrary water depth, including shallow water breaking over varying bathymetry. We show that the Barthelemy et al. (2018) breaking onset criterion, which they validated for deep and intermediate water depths, also segregates breaking crests from non-breaking crests in shallow water, with subsequent breaking always following the exceedance of their proposed generic breaking threshold. We consider a number of representative wave types, including regular, irregular, solitary, and focused waves, shoaling over idealized bed topographies including an idealized bar geometry and a mildly- to steeply-sloping planar beach. Our results show that the new breaking onset criterion is capable of detecting single and multiple breaking events in time and space in arbitrary water depth. Further, we show that the new generic criterion provides improved skill for signaling imminent breaking onset, relative to the available kinematic or geometric breaking onset criteria in the literature. In particular, the new criterion is suitable for use in wave-resolving models that cannot intrinsically detect the onset of wave breaking.