Effects of atmospheric gravity waves on the propagation of VLF signal

Heading: 
Space Physics
Zhao, G-G, Niu, Y-tian, Zhang, A-Q, Ding, Y-L, Yang, S
Kinemat. fiz. nebesnyh tel (Online) 2025, 41(2):31-46
https://doi.org/10.15407/kfnt2025.01.031
Language: Ukrainian
Abstract: 

During typhoon activity, the atmospheric gravity waves (AGWs) will cause the Earth’s ionosphere to fluctuate, causing the equivalent reflection height of the ionosphere to change, resulting in an abnormal change in the phase of the VLF signal received by the receiving station. Therefore, This paper analyses the response of phase the VLF signal to atmospheric gravity waves, using the VLF monitoring system to study the VLF signal data received by the Xinxiang receiving station during typhoon Dan in October 1999, which was transmitted from the Novosibirsk launching station of the Russian Alpha navigation system. Then the effect of the atmospheric gravity wave on the VLF signal propagation is studied based on the waveguide mode theory. It is calculated that when the frequency of the VLF signal is 14.9 kHz on 9 October 1999, the phase change is 5.12 cec, and the phase change on 12 and 13 October is 4.36 cec and 3.34 cec respectively. Space weather conditions, and solar flare data released by the GOES satellite were then analyzed and their effect on the phase of the VLF signal was excluded. The results show that the phase anomaly of the VLF signal is caused by the atmospheric gravity wave excited by the typhoon. Therefore, the effect of atmospheric gravity waves on VLF signal propagation studied in this paper could predict and correct the phase of VLF signals, ensure the accuracy of the VLF navigation system as GPS backup, and have great significance for improving the accuracy of VLF navigation and positioning.
Keywords: AGWs, phase changes, VLF signal, waveguide mode theory

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References: 

1. Bauer S. J. (1958) An apparent ionospheric response to the passage of hurricanes. J. Geophys. Res. 63, 265-269.
https://doi.org/10.1029/JZ063i001p00265

2. Chernogor L. F., Garmash K. P., Guo Q., et al. (2021) Supertyphoon Hagibis action in the ionosphere on 6-13 October 2019: Results from multi-frequency multiple path sounding at oblique incidence. Adv. in Space Res., 67(8), 2439-2469.
https://doi.org/10.1016/j.asr.2021.01.038

3. Davies K., Jones J. E. (1971) Ionospheric disturbances in the F2 region associated with severe thunderstorms. Atmos. Sci. 28, 254-262.
https://doi.org/10.1175/1520-0469(1971)0282.0.CO;2

4. Field E. C., et al. (1989) An aerostat-supported ELF/VLF transmitter. Radio Sci. 24. 02, 235-246.
https://doi.org/10.1029/RS024i002p00235

5. Hines C. O. (1960) Internal atmospheric gravity waves at ionospheric heights. Can. J. Phys. 38, 1441-1481.
https://doi.org/10.1139/p60-150

6. Hu D.-X. (2007) An inaudible sound - Infrasound wave. Modern Physics. Knowledge. 9-11.

7. Kong J., Yao Y., Xu Y., et al. (2017) A clear link connecting the troposphere and ionosphere: Ionospheric response to the 2015 typhoon Dujuan. J. Geodesy. 91, 1087-1097.
https://doi.org/10.1007/s00190-017-1011-4

8. Latovika J. (2006) Forcing of the ionosphere by waves from below. J. Atmos. and Solar-Terr. Phys., 68(3-5), 479-497.
https://doi.org/10.1016/j.jastp.2005.01.018

9. Liu W.-T. (1987) Analysis of the correlation between sudden VLF phase anomalies and solar X-ray events. J. Space Sci. 7.003, 185-189.
https://doi.org/10.11728/cjss1987.03.185

10. Nemec F., Santolk O., Parrot M. (2021) Doppler shifted Alpha transmitter signals in the conjugate hemisphere: DEMETER spacecraft observations and raytracing modeling. J. Geophys. Res. Space Phys. 126, JA029017.
https://doi.org/10.1029/2020JA029017

11. Niu Y.-T., Bi Y.-X. (2016) VLF method prospecting receiver based on software radio. J. Henan. Norm. Univ. Nat. Sci. 44, 70-73.

12. Niu Y.-T., Chen J.-F., Hao H.-Z., Zhang Z.-Y. (2009) Observation and analysis of total solar eclipse of 1997 March 9 using VLF signal. J. Henan. Norm. Univ. Nat. Sci. 37, 64-66.

13. Niu Y.-T., Li L., Zhao X.-Z., Li D.-D., Wei S.-J., Bi Y.-X. (2014) Correlation between extra-large solar flare and phase of VLF on February 25 1991 in the Antarctic. Prog. Geophys. 29, 2526.

14. Niu Y.-T., Zhang Y.-X., Xie Y.-T., Li D.-D., Li L. (2014) Forecast on solar activity during the launch of ShenzhouII by the VLF method. Prog. Geophys. 29, 1426.

15. Prasad S. S., Schneck L. J., Davies K. (1975) Ionospheric disturbances by severe tropospheric weather storms. Atmos. and Terr. Phys. 37, 1357-1363.
https://doi.org/10.1016/0021-9169(75)90128-2

16. Rice D. D., Sojka J. J., Eccles J. V., et al. (2012) Typhoon Melor and ionospheric weather in the Asian sector: A case study. Radio Sci. 47, RS0L05.
https://doi.org/10.1029/2011RS004917

17. Rishbeth H. (2006) F-region links with the lower atmosphere. J. Atmos. and Solar-Terr. Phys. 68(3-5), 469-478.
https://doi.org/10.1016/j.jastp.2005.03.017

18. Singh B., Kushwah V., Singh V., Tomar M., Hayakawa M. (2005) Simultaneous ULF/VLF amplitude anomalies observed during moderate earthquakes in Indian region. Indian J. Radio and Space Phys. 2005, 34. 221-232.

19. Song F. J., Zhang C., Wang R. P., et al. Application of Leica-TS30 on astronomic surveying system. J. Geomatics Sci. and Technol. 2015, 32 (2), 135-139

20. Wait J. R. (1959) Diurnal change of ionospheric heights deduced from phase velocity measurements at VLF. Proc. IRE. 47, 998.

21. Wang R. P., Zhang C., Li C. H. (2018) Principles and methods of geodetic astronomy. Beijing: Surveying and Mapping Press. 90.

22. Xiao S.-G., Hao Y.-Q., Zhang D.-H., et al. (2006) A case study on whole response processes of the ionosphere to typhoons. Chin. J. Geophys. 49, 623-628.
https://doi.org/10.1002/cjg2.867

23. Xiao S.-G., Zhang D. H., Xiao Z. (2007) Study on the detectability of Typhoon- generated atmospheric gravity waves. Chin. J. Space Sci. 27, 35-40.
https://doi.org/10.11728/cjss2007.01.035

24. Xiao Z., Xiao S., Hao Y., et al. (2007) Morphological features of the ionospheric response to typhoon. J. Geophys. Res. Space Phys., 112(A4).
https://doi.org/10.1029/2006JA011671

25. Zhao X.-Z. (1990) Very low frequency propagation effects during solar eclipses. Chin. J. Radio Sci. 23-31 (01) (in Chinese).

26. Zhao X.-Z., Wang X.-J. (1990) The study of the correlation between VLF phase anomalies and solar X-Ray fluxes during solar flares. Chin. J. Radio Sci. 05, 35 (in Chinese).