1pAO9. Preliminary characterization and modeling of ambient noise due to high surf during DUCK94.

Session: Monday Afternoon & Evening, May 13

Time: 3:45

Author: J. Paquin-Fabre
Location: Neptune Sciences, Inc., 150 Cleveland Ave., Slidell, LA 70458
Author: James H. Wilson
Location: Neptune Sciences, Inc., San Diego, CA 92123


Broadband noise due to surf that propagates kilometers out to sea with little transmission loss has been observed for many years, but rarely directly measured and characterized. In October of 1994 a coastal research experiment, DUCK94, was conducted off the coast of Duck, North Carolina. Neptune Sciences, Inc., under Naval Research Laboratory sponsorship, participated in that experiment with the objectives of obtaining ambient noise data at offshore positions for investigations of nearshore acoustic noise generated by waves and surf. Measurements were taken, using modified Navy standard sonobuoys, primarily during high surf events (wave heights of 1.7 to 2.4 Hmo,m). Preliminary analysis of the data indicates a broadband noise maxima between 400 and 600 Hz. In order to characterize ambient noise due to surf for modeling purposes, source level densities for heavy surf are currently being developed using the measured AN data and a finite element parabolic equation transmission loss model.

from ASA 131st Meeting, Indianapolis, May 1996