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  • Vorticity generation by sho...
    Clark, David B.; Elgar, Steve; Raubenheimer, Britt

    Geophysical research letters, 28 December 2012, Letnik: 39, Številka: 24
    Journal Article

    Eddies and vortices associated with breaking waves rapidly disperse pollution, nutrients, and terrestrial material along the coast. Although theory and numerical models suggest that vorticity is generated near the ends of a breaking wave crest, this hypothesis has not been tested in the field. Here we report the first observations of wave‐generated vertical vorticity (e.g., horizontal eddies), and find that individual short‐crested breaking waves generate significant vorticity O(0.01 s−1) in the surfzone. Left‐ and right‐handed wave ends generate vorticity of opposite sign, consistent with theory. In contrast to theory, the observed vorticity also increases inside the breaking crest, possibly owing to onshore advection of vorticity generated at previous stages of breaking or from the shape of the breaking region. Short‐crested breaking transferred energy from incident waves to lower frequency rotational motions that are a primary mechanism for dispersion near the shoreline. Key Points Short‐crested breaking waves generate vertical vorticity in the surfzone Breaking transfers wave motions into lower frequency vortical motions