Excitation of acoustic-gravity waves In an isothermal atmosphere

C. H. Liu; K. C. Yeh

doi:10.3402/tellusa.v23i2.10375

Excitation of acoustic-gravity waves In an isothermal atmosphere

Tellus

Volume 23 (1971): Issue 2

By: C. H. Liu and K. C. Yeh

Open Access

|Jan 1971

Abstract

The excitation of acoustic-gravity waves in an isothermal atmosphere is considered in this paper. It is shown that the excitation due to mass production, momentum production and heat production can be discussed by examining the same differential equation. The sources are assumed to be extended and vary both in time and in space. Asymptotic methods are used to obtain analytic expressions for the radiation field for all times, from the arrival of precursors to any time thereafter. It is found that the transient response results from contributions from one, two or all three modes depending on the times from the arrival of precursors. The three modes are the high frequency acoustic mode, the intermediate frequency buoyancy mode and the low frequency gravity mode. Additional features of the transient behavior depend on the temporal as well as spatial variation of the sources. An example is given for which numerical computations are made. Possible applications of the results to geophysical problems are duscussed and certain extensions of the results are proposed.

References

Baker , D. M. & Davies , K . 1969 . F2-region acoustic waves from severe weather . J. Atmos. Terr. Phys . 31 , 1345 – 1352 .
Search in Google Scholar Back to article
Bleistein, Norman , 1967 . Uniform asymptotic expansions of integrals with many nearby station-ary points and algebraic singularities . J. Math. and Mech . 17 , 533 – 560 .
Search in Google Scholar Back to article
Chirnonas , G. & Hines , C. O. 1970. Atmospheric gravity waves induced by a solar eclipse. J. Geo-phys. Res. 75, 875.
Search in Google Scholar Back to article
Chimonas , G. & Hines , C. O. 1970. Atmospheric gravity waves launched by auroral currents. Planet. Space Sci. 18 , 565 - 582.
Search in Google Scholar Back to article
Cole , J. D. & Greifinger , C . 1969 . Acoustic-gravity waves from an energy source at the ground in an isothermal atmosphere . J. Geophys. Res . 74 , 3693 – 3703 .
Search in Google Scholar Back to article
Davies , K. & Baker , D. M . 1965 . Ionospheric effects observed around the time of the Alaskan earthquake of March 28, 1964 . J. Geophys. Res . 70 , 2251 – 2253 .
Search in Google Scholar Back to article
Davies , M. J. & da Rosa , A. V . 1969 . Traveling ionospheric disturbances originating in the auroral oval during polar substorms . J. Geophys. Res . 74 , 5721 – 5735 .
Search in Google Scholar Back to article
Dieminger , W. & Hohl , H . 1962 . Effects of nuclear explosions on the ionosphere , Nature 193 , 953 – 964 .
Search in Google Scholar Back to article
Dickinson , R. E . 1969 . Propagators of atmospheric motions 1 and 2 . Rev. Geophys . 7 , 483 – 538 .
Search in Google Scholar Back to article
Donn , W. L. & Shaw , D. M . 1967 . Exploring the atmosphere with nuclear explosions . Rev. Geophys . 5 , 53 – 82 .
Search in Google Scholar Back to article
Felsen , L. B . 1969 . Transients in dispersive media . IEEE Trans. on Antenna and Propagation AP- 17 , 191 – 200 .
Search in Google Scholar Back to article
Georges , T. M . 1969 . HF Doppler studies of travel-ing ionospheric disturbances . J. Atmos. Terr. Phys . 30 , 735 – 746 .
Search in Google Scholar Back to article
Hines , C. O . 1968 . A possible source of waves in noctilucent clouds. J. Atmos. Sc i . 25 , 937 – 942 .
Search in Google Scholar Back to article
Hines , C. O . 1960 . Internal atmospheric gravity waves at ionospheric heights . Can J. Phys . 38 , 1441 – 1481 .
Search in Google Scholar Back to article
Jones , W. L . 1970 . A theory for quasi-periodic oscillations observed in the ionosphere . J. Atmos. Terr. Phys . 32 , 1555 – 1566 .
Search in Google Scholar Back to article
Kato , S . 1967 . The response of an unbounded atmos-phere to point disturbances, 2, Impulsive disturb-ances . Astrophys. J . 144 , 326 – 336 .
Search in Google Scholar Back to article
Leonard , R. S. & Barnes , R. A. , Jr , 1965. Observa-tion of ionospheric disturbances following the Alaskan earthquake. J. Geophys. Res . 70 , 1250-125 3 .
Search in Google Scholar Back to article
Lighthill , M. J . 1967 . On waves generated in disper-sive systems by traveling forcing effects, with applications to the dynamics of rotating fluids . J. Fluid Mech . 27 , 725 – 752 .
Search in Google Scholar Back to article
Lighthill , M. J . 1960 . Studies on magneto-hydro-dynamic waves and other anisotropic wave mo-tions . Phil. Trans. Roy. Soc. (London), ser. A. , 252 , 397 – 430 .
Search in Google Scholar Back to article
Mowbray , D. E. & Rarity , B . 1967 . A theoretical and experimental investigation of the phase configuration of internal waves of small amplitude in a density stratified liquid . J. Fluid Me,ch , 28 , 1 – 16 .
Search in Google Scholar Back to article
Obayashi , T . 1962 . Widespread ionospheric distur-bances due to nuclear explosions during October 1961. Rept. Ionosphere Space Res ., Japan , 16 , 334 – 340 .
Search in Google Scholar Back to article
Pierce , A. D . 1963 . Propagation of acoustic-gravity waves from a small source above the ground in an isothermal atmosphere . J. Acoustical Soc. Am . 35 , 1798 – 1807 .
Search in Google Scholar Back to article
Pierce , A. D . 1968. Theoretical source models for the generation of acoustic-gravity waves by nuclear explosions. Symposium proceedings, Acoustic. gravitywaves in the atmosphere. T. M. Georges. ( Ed.), Supt. of Documents. U.S. Govt. Printing Office, Washington, D.C., 9 - 24.
Search in Google Scholar Back to article
Row , R. V . 1967 . Acoustic-gravity waves in the upper atmosphere due to a nuclear detonation and an earthquake . J. Ge,ophys. Res . 12 , 1599 – 1610 .
Search in Google Scholar Back to article
Wickersham , A. F . 1966 . Identification of acoustic. gravity wave modes from ionospheric range-time observations . J. Geophys. Res . 71 , 4551 – 4555 .
Search in Google Scholar Back to article
Wilson , C. R . 1969 . Infrasonic waves from moving auroral electrojets . Planetary and Space Sci . 17 , 1107 – 1120 .
Search in Google Scholar Back to article
Yuen , P. C. , Weaver , P. F. , Suzuka R. K. & Furu-moto , A. S . 1969 . Continuous, traveling coupling between seismic waves and the ionosphere evident in May, 1968 Japan earthquake data . J. Geophys. Res . 74 , 2 256-2 264 .
Search in Google Scholar Back to article