Air bubbles produced by breaking wind waves: a laboratory study.

Abstract

Air bubbles produced by breaking wind waves are measured in a laboratory tank to study bubble clouds produced in freshwater under various wind and wave conditions. Vertical entrainment of bubbles and their size compositions are found to be influenced greatly by wave structures. The significant wave height appears to be the appropriate scaling length for the vertical distribution of bubble concentrations. Their horizontal distribution, on the other hand, correlates well with the group characteristics of waves. Bubble populations on the water surface are influenced by both wind stress and surface wave height; more specifically, they are governed by the Reynolds number incorporating both effects. Other reported field and laboratory data are shown to follow well the functional variations deduced herewith. (A)