Computer Simulation of Acoustic Fluctuations Due to Finescale Temperature Perturbations Measured by Thermistor Chain

Abstract

Finescale temperature features the oceanic mixed layer (OML) modify acoustic propagation by perturbing the index of refraction. A thermistor chain measures temperature from the surface to 250 m with 2 m vertical resolution and 1.85 m horizontal resolution. Thermistor data is converted to high resolution sound velocity profiles for input to an implicit finite difference parabolic equation (IFD-PE) model. The control case is a surface duct with a horizontally averaged sound velocity profile. The IFD-PE model is run with monofrequency sources from 500 Hz to 10 kHz. The acoustic fluctuations and average acoustic pressure are computed each 20 km to a range of 100 km. Acoustic propagation through the temperature varying OML is contrasted with acoustic propagation through the temperature invariant OML. Finescale temperature randomly alters the average acoustic pressure by up to a factor of two and the acoustic fluctuations by up to a factor of five.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1992
Accession Number
ADA252709

Entities

People

  • Gregory D. Crabtree

Organizations

  • Naval Postgraduate School

Tags

Communities of Interest

  • Energy and Power Technologies
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Acoustic Propagation
  • Acoustic Waves
  • Acoustics
  • Computational Science
  • Computer Simulations
  • Doppler Effect
  • Equations
  • High Resolution
  • Oceanography
  • Refraction
  • Refractive Index
  • Seabed
  • Second World War
  • Simulations
  • Statistical Analysis
  • United States
  • Wave Propagation

Readers

  • Acoustical Oceanography.
  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Computational Modeling and Simulation