Speed of Sound in Atmosphere of the Earth

DOI: 10.4236/oja.2012.22009   PDF   HTML     5,542 Downloads   11,065 Views   Citations

Abstract

It is demonstrated that contemporary conception on adiabaticity of sound in the Earth atmosphere is fair in sufficient approximation only for altitudes z ≤ 103 m. At higher altitudes adiabaticity of sound is violated and essential dependence of its speed on altitude is revealed which is related to heterogeneity of the atmosphere in gravitation field of the Earth. It became possible to reveal the factor of gravity field due to the fact that in the equation of the state of atmosphere considered to be ideal gas, the entropy s is taken into consideration and is written down as ρ = (p, s) instead of generally accepted ρ = ρ(p) which is fair only for isentropic media and is not applicable to the Earth. Such approach enabled to determine that apart from adiabatic mechanism of generation of sound wave there exists isobaric one and exactly this mechanism leads to dependence of sound speed on altitude which is the same as dependence on density.

Share and Cite:

V. Kirtskhalia, "Speed of Sound in Atmosphere of the Earth," Open Journal of Acoustics, Vol. 2 No. 2, 2012, pp. 80-85. doi: 10.4236/oja.2012.22009.

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1] U.S. Standard Atmosphere, National Aeronautics and Space Administration, 1976.
[2] http://www.digitaldutch.com/atmoscalc
[3] G. S. K. Wang, “Speed of Sound in Standard Air,” Journal of the Acoustical Society of America, Vol. 79, No. 5, 1986, pp. 1359-1366. doi:10.1121/1.393664
[4] G. Santostasi, et al., “A Student Designed Experiment Measuring the Speed of Sound as a Function of Altitude,” McNeese State University, Lake Charles, 2008.
[5] L. D. Landau and E. N. Lifshitz, “Nauka,” Theoretikal Physics, Hydrodynamics, Vol. 6, Moscow, 1988.
[6] A. D. Pirce, “Acoustics: An Introduction to Its Physical Principles and Applications,” Acoustical Society of America, New York, 1989.
[7] E. E. Gossard and W. H. Hooke, “Waves in the Atmosphere,” Elsevier, New York, 1975.
[8] L. M. B. C. Campos, “On Three-Dimensional Acoustic Gravity Waves in Model Non-Isothermal Atmospheres,” Wave Motion, Vol. 5, No. 1, 1983, pp. 1-14. doi:10.1016/0165-2125(83)90002-1
[9] M. J. Lighthill, “Waves in Fluids,” Cambridge University Press, Cambridge, 2002.

  
comments powered by Disqus

Copyright © 2020 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.