Accession Number : ADA117682

Title :   Doppler Spectra of Sea-Surface Backscatter at High Acoustic Frequencies.

Descriptive Note : Technical document,

Corporate Author : NAVAL UNDERWATER SYSTEMS CENTER NEW LONDON CT NEW LONDON LAB

Personal Author(s) : Konrad,W. L. ; Browning,D. G. ; Mellen,R. H.

Report Date : 01 JUL 1982

Pagination or Media Count : 14

Abstract : The initial transfer of energy from atmospheric wind to the ocean surface, which would be a significant factor in ambient noise, may occur via the so-called Cat's Paw phenomena. To study this effect, an experiment was conducted at Seneca Lake for a moderately disturbed (no whitecaps) air-water interface. Doppler spectrum measurements of high-frequency acoustic waves backscattered from the wind-driven water surface indicate the presence of small-scale roughness that is convected downward by surface drift. For a slightly rippled surface, there is a sharp resonant peak corresponding to a convection velocity of approximately 0.4 m/s which is nearly independent of wind speed. The spectrum is broadened by phase modulation due to the orbital motion of large-scale gravity waves but remains skewed in the downwind direction. (Author)

Descriptors :   *Ocean surface, *Ambient noise, Backscattering, Doppler effect, Acoustic waves, Wave propagation, Sea breeze, Wind, Transducers, Angle of incidence

Subject Categories : Physical and Dynamic Oceanography
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE