Wave Breaking and Dissipation in the Nearshore

The difficult problem of understanding wave dissipation in the nearshore is approached through field observations made across a variety of beach profiles and under a wide range of wave conditions. Data are obtained remotely from video recordings of the surf zone and inner continental shelf, and image processing techniques are used to detect and quantify wave breaking over spatial and temporal scales ranging 10-1000 meters and 10-10000 seconds. The observed spatial distributions of ensemble-averaged wave breaking distributions are used to improve numerical dissipation estimates, and subsequently applied to parametric models of incident wave energy transformation and mean current forcing within the surf zone. The forcing of low-frequency oscillatory motion through spatial and temporal variations of the point at which a wave breaks is being approached through a combination of theory and observation. The relationship of wave breaking to sediment transport is being pursued through co-located video observations and collaborative in situ measurements of sediment concentration, turbulence, and void fraction (air concentration).