Field measurements and scaling of ocean surface wave-breaking statistics

TitleField measurements and scaling of ocean surface wave-breaking statistics
Publication TypeJournal Article
Year of Publication2013
AuthorsSutherland P., Melville W.K
JournalGeophysical Research Letters
Date Published2013/06
Type of ArticleArticle
ISBN Number0094-8276
Accession NumberWOS:000321951300035
Keywordsbreaking waves; deep-water; dissipation; energy-dissipation; infrared; range; stereo; upper ocean turbulence; whitecap; wind-waves

[1] Deep-water breaking waves provide a mechanism for mass, momentum, and energy transfer between the atmosphere and ocean. Microscale breaking is particularly important, but notoriously difficult to measure in the field. In this paper, measurements from a new technique, using a stereo pair of long-wave infrared cameras to reconstruct the sea surface shape and velocity field, are presented. Breakers are detected using an image texture-based algorithm and then tracked on the reconstructed surface. These waves range from large air-entraining breakers to microbreakers that are undetectable by traditional visible video-based techniques. This allows measurements of breaker length distributions, (c), that extend to velocities near the gravity-capillary transition. These distributions are compared with measurements from the literature and from visible video imagery. A nondimensional scaling is proposed which collapses (c). Finally, estimates of energy dissipation and stress based on (c) are found to agree well with wave energy dissipation and wind stress models.

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