Evanescent acoustic-gravity wave modes in the non-isothermal atmosphere
| 1Cheremnykh, OK, 1Fedorenko, AK, Vlasov, DI, Melnychuk, SV 1Space Research Institute under NAS and National Space Agency of Ukraine, Kyiv, Ukraine |
| Kinemat. fiz. nebesnyh tel (Online) 2021, 37(4):3-17 |
| https://doi.org/10.15407/kfnt2021.04.003 |
| Start Page: Dynamics and Physics of Solar System Bodies |
| Language: Ukrainian |
Abstract: The propargation of evanescent acoustic-gravity waves in the atmosphere with a casual altitude temperature profile was researched. We found that two types of evanescent wave modes can exist in the vertically nonisothermal atmosphere. The first type is the f-mode which dispersion doesn’t depend from the altitude inhomogeneity of temperature so it is carried out at any altitude level of the nonisothermal atmosphere. The second type is a recently discovered γ-mode which dispertion depends from the altitude temperature gradient in a non-isothermal atmosphere so it can be performed only at certain altitude intervals. We investigated the possibility of realizing the f- and γ-mode(s) in the Earth’s atmosphere taking into account the model altitude temperature profile. In this paper was found that these modes can exist at the altitude of local temperature extremes in the atmosphere. Moreover these modes are realized only in a narrow range of spectral parameters for which the conditions of a decrease in the wave energy above and below the level of their propagation are satisfied. Recommendations regarding the possibility of observing these modes in the atmosphere of the Earth and the Sun are given. The f-mode can presumably be observed near the mesopause with a characteristic wavelength λx ≈ 75 km at the Earth’s atmosphere and at the heights of the chromosphere with wavelength λx ≈ 1600 km at the solar atmosphere. The period of the f-mode that propagates in the region of the minimum temperature should be slightly exceed the Brent-Vaisala period at this height. The γ-mode can be observed at the regions of maximum temperature (for example: at the height of the stratopause) with a characteristic wavelength λx ≈ 100 km in the Earth’s atmosphere. The period of γ-mode should be slightly longer than the period of Brent-Vaisala at the height of its implementation. |
| Keywords: acoustic gravity wave, evanescent wave mode, non-isothermal atmosphere |
References:
1.Fedorenko A. K., Kryuchkov E. I., Cheremnykh O. K., Rapoport Yu. G. (2020) Influence of vertical heterogeneity of atmospheric temperature on the propagation of acoustic-gravity waves. Kinematics Phys. Celestial Bodies. 36(6). 253—264.
https://doi.org/10.3103/S0884591320060033
2.Cheremnykh O. K., Selivanov Yu. A., Zakharov I. V. (2010) The influence of compressibility and non-isothermality of the atmosphere on the propagation of acoustic-gravity waves. Kosm. nauka tehnol. 16(1). 09—19.
https://doi.org/10.15407/knit2010.01.009
3.Antia H. M. (1998) Estimate of solar radius from f-mode. Astron. and Astrophys. 330. 336—340.
4.Beer T. (1974) Atmospheric Waves. John Wiley, New York, 300.
5.Bespalova A. V., Fedorenko A. K., Cheremnykh O. K., Zhuk I. T. (2016) Satellite observations of wave disturbances caused by moving solar terminator. J. Atmos. and Solar-Terr. Phys. 140. 79—85.
https://doi.org/10.1016/j.jastp.2016.02.012
6.Cheremnykh O. K., Fedorenko A. K., Kryuchko E. I., Selivanov Y. A. (2019) Evanescent acoustic-gravity modes in the isothermal atmosphere: systematization, applications to the Earth’s and Solar atmospheres. Ann. geophys. 37(3). 405—415.
https://doi.org/10.5194/angeo-37-405-2019
7.Cheremnykh O. K., Fedorenko A. K., Selivanov Y. A., Cheremnykh S. O. (2021) Continuous spectrum of evanescent acoustic-gravity waves in an isothermal atmosphere. Mon. Notic. Roy. Astron. Soc. 503(4). 5545—5553.
https://doi.org/10.1016/j.asr.2021.10.050
8.Fedorenko A. K., Kryuchkov E. I., Cheremnykh O. K., Klymenko Yu. O., Yampolski Yu. M. (2018) Peculiarities of acoustic-gravity waves in inhomogeneous flows of the polar thermosphere. J. Atmos. and Solar. Terr. Phys. 178. 17—23.
https://doi.org/10.1016/j.jastp.2018.05.009
9.Francis S. H. (1975) Global propagation of atmospheric gravity waves: A review. J. Atmos. and Terr. Phys. 37. 1011—1054.
https://doi.org/10.1016/0021-9169(75)90012-4
10.Ghosh P., Antia H. M., Chitre S. M. (1995) Seismology of the solar f-mode. I. Basic signatures of shearing velocity fields. Astrophys. J. 451. 851—858.
https://doi.org/10.1086/176271
11.Hines C. O. (1960) Internal gravity waves at ionospheric heights. Can. J. Phys. 38. 1441—1481.
https://doi.org/10.1139/p60-150
12.Jones W. L. (1969) Non-divergent oscillations in the Solar Atmosphere. Solar Phys. 7. 204—209.
https://doi.org/10.1007/BF00224898
13.Miles Alan J., Roberts B. (1992) Magnetoacoustic-gravity surface waves. I. Constant Alfven Speed. Solar Phys. 141. 205—234.
https://doi.org/10.1007/BF00155176
14.Nalesso G. F., Jacobson A. R. (1993) On a mechanism for ducting of acoustic and short-period acoustic-gravity waves by the upper atmospheric thermocline. Ann. geophys. 11. 372—376.
15.Rosental C. S., Gough D. O. (1994) The Solar f-mode as interfacial mode at the chromosphere-corona transition. Astrophys. J. 423. 488—495.
https://doi.org/10.1086/173826
16.Roy A., Roy S., Misra A. P. (2019) Dynamical properties of acoustic-gravity waves in the atmosphere. J. Atmos. and Solar-Terr. Phys. 186. 78—81.
https://doi.org/10.1016/j.jastp.2019.02.009
17.Simkhada D. B., Snively J. B., Taylor M. J., Franke S. J. (2009) Analysis and modeling of ducted and avanescent gravity waves observed in the Havaiian airglow. Ann. geophys. 27. 3213—3224.
https://doi.org/10.5194/angeo-27-3213-2009
18.Tolstoy I. (1963) The theory of waves in stratified fluids including the effects of gravity and rotation. Revs Mod. Phys. 35(1).
https://doi.org/10.1103/RevModPhys.35.207
19.Waltercheid R. L., Hecht J. H. (2003) A reexamination of evanescent acoustic-gravity waves: Special properties and aeronomical significance. J. Geophys. Res. 108, D11. 4340.
https://doi.org/10.1029/2002JD002421
20.Yeh K. S., Liu C. H. (1974) Acoustic-gravity waves in the upper atmosphere. Rev. Geophys. and Space Phys. 12. 193—216.
https://doi.org/10.1029/RG012i002p00193