Guided Infrasonic Modes in a Temperature‐ and Wind‐Stratified Atmosphere
作者:
Allan D. Pierce,
期刊:
The Journal of the Acoustical Society of America
(AIP Available online 1967)
卷期:
Volume 41,
issue 3
页码: 597-611
ISSN:0001-4966
年代: 1967
DOI:10.1121/1.1910386
出版商: Acoustical Society of America
数据来源: AIP
摘要:
The propagation of infrasonic waves in a realistic model atmosphere which includes a variable wind profile as well as a variable temperature profile is discussed quantitatively for wave periods between 1–10 min. The numerical method used for the computation of phase and group velocity curves and other characteristic quantities associated with the possible guided modes is an extension of the multilayer method used previously by Press and Harkrider and by Pfeffer and Zarichny for atmospheres without winds. The effects of winds on the propagation are assessed by examining computations carried out for various fixed directions of the horizontal group velocity and from the computation of deviations of the phase‐velocity direction from group‐velocity direction for the case of propagation crosswind. Pressure height profiles of various frequencies propagating in various modes are exhibited and excitation amplitudes for ground level sources (excluding the frequency spectrum of the source) are plotted versus frequency for various modes and various group‐velocity directions. Qualitative explanations of the computed results are given, and the implications of the results to actual waveforms are discussed.
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