Breaking surface waves were observed during the Surface Wave Processes
Program with a novel acoustical instrument that makes use of underwat
er ambient sound to track individual breaking events. The spatial and
temporal statistics of breaking waves such as duration, velocity, spac
ing, and breaking probability were determined under various wind and w
ave conditions. Statistical models are developed to assess and where a
ppropriate, correct for any bias resulting from limitations of the mea
surement approach. Empirical relations of these with wind speed are ob
tained. Comparison of the observed distributions with simultaneously m
easured directional wave spectra suggests that wave breaking occurs at
multiple scales and that the mean scale of breaking is substantially
smaller than the scale associated with the dominant wind wave componen
t. Preliminary analysis indicates that the dependence of breaking prob
ability on the fourth moment of the wave spectrum is consistent with a
linear statistical model.