CORRELATIONS BETWEEN AMBIENT NOISE AND THE OCEAN SURFACE-WAVE FIELD

Measurements of the ambient noise spectrum level N with simultaneous, coincident wind and wave measurements were made from RP FLIP in fall 1 991. The measurements were designed to investigate the correlation bet ween the ambient noise and relevant surface wave parameters. The resul ts suggest that wave parameters related to the incidence of wave break ing correlated well with the ambient noise level. The correlation betw een N and the rms wave amplitude a was found to be poor but that betwe en N and the rms amplitude of the local wind sea a(w) was comparable t o that between wind speed U and N. Similar good correlations were foun d between the rms wave slope s and N, and the higher frequency surface wave spectral levels and N. Correlations between the surface wave dis sipation estimates D based on the Hasselmann and Phillips models and t he ambient noise were comparable to those between the wind speed and t he ambient noise. The mean square acoustic pressure was found to be pr oportional to D-n with n in the range 0.5-0.8. The implications of the se results for monitoring surface waves and air-sea fluxes are discuss ed.