Advertisement

Measurements of Wind Dependent Acoustic Transmission Loss in Shallow Water under Breaking Wave Conditions

  • P. Wille
  • D. Geyer
  • L. Ginzkey
  • E. Schunk

Abstract

The enhancement of transmission loss induced by breaking waves in shallow water of 30 m depth, measured at a fixed 10 km-range under isothermal conditions rather depends on wind speed than on wave height. The attenuation coefficient, growing weakly at low wind speeds increases after a thresholdlike transition by the third to the fifth power of the wind speed, probably due to air bubble suspension. The transition wind speed around 10 m/s decreases with increasing frequency. The time lag between changing wind speed and attenuation is of the order of minutes. The loss differs at increasing and decreasing fetch. The close relation between wave height and attenuation at low sea states and predominating rough boundary scattering disappears at high sea states.

Keywords

Wind Speed Wave Height Breaking Wave Transmission Loss High Wind Speed 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Wille, P.C. and Geyer, D. “Measurements on the Origin of the Wind-dependent Ambient Noise Variability in Shallow Water”, J. Acoust. Soc. Am. 25 (1), 173–185 (1984).ADSCrossRefGoogle Scholar
  2. 2.
    Wu, J. “Bubble Populations and Spectra in Near-Surface Ocean: Summary and Review of Field Measurements”, J. Geophys. Res. 86, 457–463 (1981).ADSCrossRefGoogle Scholar
  3. 3.
    Clay, C.S. and Medwin, H. Acoustical Oceanography, John Wiley & Sons, New York (1977).Google Scholar
  4. 4.
    Thorpe, S.A. “On the Determination of KV in the Near-Surface Ocean from Acoustic Measurements of Bubbles”, J. Phys. Oceanogr. 14(5), 841–854 (1984) or “A Model of Turbulent Diffusion of Bubbles below the Sea Surface”, J. Phys. Oceanogr. 14(5), 841–854 (1984) - (I don t know which, - Ed.)Google Scholar
  5. 5.
    Schellstede, G. and Wille, P.C. “Measurements of Sound Attenuation in Standard Areas of the North Sea and Baltic” SACLANTCEN Conference Proceedings No. 14, Vol II (Conference on Sound Propagation in Shallow Water 23–27 Sept 1974 ) 52–68 (1974).Google Scholar
  6. 6.
    Schneider, H.G. “Modelling Wind Dependent Acoustic Transmission Loss Due to Bubbles in Shallow Water” presented at 12 ICA Associated Symposium on Underwater Acoustics, Halifax 16–18 July 1986. Published in this book, next paper.Google Scholar
  7. 7.
    Stolte, S. Fwg Internal Report 1985–4.Google Scholar
  8. 8.
    Ginzkey, L., Kroll, W., Scholz, B. and Wille, P. “Temporal and Spatial Variability of Transmission Loss Measured in Shallow Water and Breaking Wave Conditions” (in progress).Google Scholar

Copyright information

© Plenum Press, New York 1987

Authors and Affiliations

  • P. Wille
    • 1
  • D. Geyer
    • 1
  • L. Ginzkey
    • 1
  • E. Schunk
    • 1
  1. 1.Forschungsanstalt der Bundeswehr für Wasserschall-und GeophysikKiel 14Germany

Personalised recommendations