Deep Water Acoustics

Abstract

A mechanism is presented by which the observed acoustic intensity is made to vary due to changes in the acoustic path that are caused by internal-tide vertical fluid displacements. The position in range and depth of large-scale caustic structure is determined by the background sound-speed profile. Internal tides cause a deformation of the background profile, which changes the positions of the caustic structuresintroducing slow intensity changes at a fixed position in depth and range. Parabolic equation and Hamiltonian ray-tracing calculations indicate that internal tides could cause enhanced variability in the intensity in the form of slow changes. Furthermore, the calculations demonstrate how large-scale perturbations to the index of refraction can result in intensity fluctuations--contrary to conclusions of previous theoretical work.

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Document Details

Document Type
Technical Report
Publication Date
Jun 28, 2016
Accession Number
AD1011438

Entities

People

  • Andrew Dickson White
  • James A. Mercer

Organizations

  • University of Washington

Tags

Communities of Interest

  • Ground and Sea Platforms
  • Materials and Manufacturing Processes
  • Space

DTIC Thesaurus Topics

  • Acoustic Measurement
  • Acoustic Propagation
  • Acoustics
  • Ambient Noise
  • Data Analysis
  • Deep Water
  • Displacement
  • Engineering
  • Equations
  • Intensity
  • Pacific Ocean
  • Philippine Sea
  • Physics
  • Physics Laboratories
  • Ray Tracing
  • Refractive Index
  • Signal Processing

Fields of Study

  • Physics

Readers

  • Coastal Oceanography
  • Wave Propagation and Nonlinear Chaotic Dynamics.