Effect of Shallow Water Internal Waves on Ocean Acoustic Striation Patterns

Abstract

Contour plots of underwater acoustic intensity, mapped in range and frequency, often exhibit striations. It has been claimed that a scalar parameter 'beta', defined in terms of the slope of the striations, is invariant to the details of the acoustic waveguide. In shallow water, the canonical value for beta is one. In the present paper, the waveguide invariant is modeled as a distribution rather than a scalar. The effects of shallow water internal waves on the distribution are studied by numerical simulation. Realizations of time-evolving shallow water internal wave fields are synthesized and acoustic propagation simulated using the parabolic equation method. The waveguide invariant distribution is tracked as the internal wave field evolves in time. Both random background internal waves and more event-like solitary internal waves are considered.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 2001
Accession Number
ADA391869

Entities

People

  • Daniel Rouseff

Organizations

  • University of Washington

Tags

Communities of Interest

  • Energy and Power Technologies
  • Space

DTIC Thesaurus Topics

  • Acoustic Propagation
  • Acoustic Waveguides
  • Acoustics
  • Bottom Loss
  • Crystal Lattice Vibrations
  • Deep Water
  • Equations
  • Frequency
  • Frequency Shift
  • Group Velocity
  • Physics Laboratories
  • Shallow Water
  • Simulations
  • Solitons
  • Water
  • Waveguides
  • Waves

Fields of Study

  • Physics

Readers

  • Acoustical Oceanography.
  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Plasma Physics / Magnetohydrodynamics