Acoustics Remote Sensing Near the Air-Sea Interface

Abstract

At higher sea states the ocean surface layer presents some of the greatest challenges to observation. It is dynamic, imposes severe demands on in siru instrumentation and is subject to great variability over a wide range of space and time scales. Remote acoustical sensing can play a major role in resolving the physical properties of this environment, but the acoustical interpretations present interesting subtleties that must be understood before they can be used with con dence. Rather than attempt a summary of all the many new techniques being deployed in ocean surface research, this brief report focuses on a specific study directed at measurement of near surface velocities within wave Crests so as to illustrate some of the challenges involved. Attenuation and scattering of the acoustical signal by bubble clouds is an important factor in setting limits to the range ofconditions over which useful measurement can be achieved.