Laboratory air-entraining breaking waves: Imaging visible foam signatures to estimate energy dissipation

TitleLaboratory air-entraining breaking waves: Imaging visible foam signatures to estimate energy dissipation
Publication TypeJournal Article
Year of Publication2016
AuthorsCallaghan AH, Deane GB, Stokes MD
JournalGeophysical Research Letters
Volume43
Pagination11320-11328
Date Published2016/11
Type of ArticleArticle
ISBN Number0094-8276
Accession NumberWOS:000389305000032
Keywordsdependence; whitecaps
Abstract

Oceanic air-entraining breaking waves fundamentally influence weather and climate through bubble-mediated ocean-atmosphere exchanges, and influence marine engineering design by impacting statistics of wave heights, crest heights, and wave loading. However, estimating individual breaking wave energy dissipation in the field remains a fundamental problem. Using laboratory experiments, we introduce a new method to estimate energy dissipation by individual breaking waves using above-water images of evolving foam. The data show the volume of the breaking wave two-phase flow integrated in time during active breaking scales linearly with wave energy dissipated. To determine the volume time-integral, above-water images of surface foam provide the breaking wave timescale and horizontal extent of the submerged bubble plume, and the foam decay time provides an estimate of the bubble plume penetration depth. We anticipate that this novel remote sensing method will improve predictions of air-sea exchanges, validate models of wave energy dissipation, and inform ocean engineering design.

DOI10.1002/2016gl071226
Student Publication: 
No