Observations of High Frequency Ambient Sound Generated by Wind

Observations of ambient sound generated by wind waves provide a basis for studying the structure, distribution and properties of breaking events. The sound detected by a hydrophone represents a spatially filtered average over an area of the ocean surface that increases with increasing measurement depth. Measurements at shallow depths can detect individual breaking events. Observations show great variability in spectral structure with multiple peaks and well defined minima; this structure appears persistent during a particular experimental period (of a few hours) and location but can be quite different at other times and places. The recorded signal fluctuations can be used to infer properties of the distribution of breaking events, in particular their density on the ocean surface.