Acoustic-gravity Waves in the Atmosphere

Acoustic-gravity Waves in the Atmosphere PDF

Author: Stanford University. Stanford Electronics Laboratories

Publisher:

Published: 1965

Total Pages: 118

ISBN-13:

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The purpose of this research was to obtain a panoramic view of acoustic-gravity-wave motions throughout the atmosphere. A one-dimensional array of particles and springs, conceived by Newton to study sound waves in the atmosphere, was extended to two dimensions by means of 1500 particles interconnected by springs. Variations of density and pressure with altitude are represented by variations in mass and spring constants. This new model has provided means by which acoustic-gravity-wave motions in the atmosphere are solved on a high-speed digital computer, and a new animated-computer-output technique is used. A motion picture--automatically plotted by the computer, a frame at a time--provides greater detail and perspective of mechanical wave motions in the atmosphere than has ever been obtainable before. Ground-level and 100-km-high explosions were investigated with this computer model, and the resulting transient motions of the atmosphere were displayed by means of a motion picture produced by digital techniques. Computed ground-level barograms resulting from a ground-level explosion compare well with experimental barograms recorded during ground-level nuclear explosions. (Author).

Acoustic-gravity Waves in the Upper Atmosphere

Acoustic-gravity Waves in the Upper Atmosphere PDF

Author: Kung C. Yeh

Publisher:

Published: 1974

Total Pages: 108

ISBN-13:

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In this report we review the theory of acoustic-gravity waves, the interaction of such waves with the ionosphere, the experimental support for the existence of such waves in the upper atmosphere, and the role played by acoustic-gravity waves in thermospheric dynamics. After a thorough discussion on the properties of acoustic-gravity waves in an ideal isothermal atmosphere, the effects produced by horizontal winds, sharp boundary discontinuities, and dissipative processes are discussed. These discussions are followed by reviewing propagation effects in a realistic atmosphere for both free waves and guided waves. The propagation of these acoustic-gravity waves in the upper atmosphere may induce changes in the ionosphere sometimes known as traveling disturbances. The existing experimental data on traveling disturbances are then reviewed and found consistent, in most cases, with the acoustic-gravity wave interpretation.