SIMPLIFIED NORMAL MODE TREATMENT OF LONG-PERIOD ACOUSTIC-GRAVITY WAVES IN THE ATMOSPHERE

Abstract

A discussion of the effects of geometric dispersion due to stratification of the atmosphere on low-frequency mechanical waves generated by nuclear explosions. It is found that the pressure signal can be divided naturally into an early-arriving acoustic-gravity portion and a later acoustic portion, both portions being inversely proportional to the range (geometric spreading included). At very great ranges, however, portions of the gravity wave fall off faster by r(1/6); the effect of dispersion is to reduce the signal by r(-1/2). Most of the signal is composed of many propagating modes which, at a given range and time, will each demonstrate a characteristic frequency. A simplified treatment of the model picture is presented, along with the argument that a ray treatment for the high-frequency portion is appropriate.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1965
Accession Number
AD0625232

Entities

People

  • W. C. Meecham

Organizations

  • RAND Corporation

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Acoustic Signals
  • Acoustic Waves
  • Altitude
  • Atmospheric Motion
  • Crystal Lattice Vibrations
  • Detection
  • Explosions
  • Frequency
  • Gravity Waves
  • Group Velocity
  • Mechanical Waves
  • Nuclear Explosions
  • Phase Velocity
  • Power Spectra
  • Scattering
  • Two Dimensional
  • Waves

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Seismology