Quantifying Vertical Vorticity Generation from Breaking Waves in Deep Water

It has long been theorized that breaking waves cause an increase in the local vertical vorticity field. However, few measurements in the field have corroborated this assumption. A two-dimensional power spectral density technique was applied to video recorded by a stationary quadcopter that hovered over the Gulf of Mexico. The results show an increase in the local vertical vorticity field around individual breaking waves in deep water. The magnitude of the generated vorticity is comparable with previous field measurements in shallow water. It is further observed that the resulting coherent structures persist for some time after the wave breaks.