We have studied the properties of impulsive geomagnetic disturbances, which are observed synchronously at the network of induction magnetometers of the Institute of Solar-Terrestrial Physics (ISTP SB RAS) and Canadian stations of the CARISMA project [Mann, et al., 2008]. A feature of the pulses we detected is that their frequency range (f~5–30 Hz) lies at the junction of the ranges of two known classes of electromagnetic oscillations: ultra-low-frequency (ULF) oscillations (f<5–10 Hz), or geomagnetic pulsations, and extra-low frequency (ELF) oscillations (f~30–300 Hz); therefore, the 5–30 Hz range is poorly studied. The work is of undoubted interest for physics of processes in the magnetosphere–ionosphere–atmosphere system. Morphological analysis of the pulses detected has been carried out using data from ISTP stations. As a result, we obtained statistical characteristics of the pulses, plotted their dynamic spectra, and determined a number of unusual properties that distinguish them, on the one hand, from geomagnetic pulsations of the pulsed type (irregular pulsations of the Pi1B type), and, on the other hand, from higher frequency ELF and VLF signals (atmospherics, whistlers, etc.). On the basis of the results, we have made an assumption that a source of the pulses under study can be electrical sprites caused by powerful thunderstorms at middle and low latitudes. Using the results obtained by Wang, et al. in 2019 on spatial and temporal fixation of sprites in North China, we have confirmed that ultra-short-period pulses occur following the emergence of sprites. Thunderstorm activity, both local and global, is considered to be one of the main sources of excitation of the ionospheric Alfvén resonator (IAR), which plays an important role in coupling the ionosphere and the magnetosphere. The pulsed oscillations of interest may be one of the agents through which the energy of thunderstorms is transferred to IAR, thereby including the atmosphere in the system considered.
geomagnetic pulsations, magnetosphere, ULF-ELF frequency range, red sprites, lightning, Alfvén resonator
1. Allcock G.McK. Propagation of Whistlers to Polar Latitudes. Nature. 1960, vol. 188, pp. 732–733. DOI: 10.1038/188732a0.
2. Belyaev P.P., Polyakov S.V., Rapoport V.O., Trakhtengerts V.Y. Theory for the formation of resonance structure in the spectrum of atmospheric electromagnetic background noise in the range of short-period geomagnetic pulsations. Radiophys. Quantum Electron. 1989, vol. 32, no. 7, pp. 594–601.
3. Blakeslee R.J., Mach D.M., Bateman M.G., Bailey J.C. Seasonal variations in the lightning diurnal cycle and implications for the global electric circuit. Atmos. Res. 2014, vol. 135-136, pp. 22–243. DOI: 10.1016/j.atmosres.2012.09.023.
4. Cagniard L. Basic theory of the magnetotelluric method of geophysical prospecting. Geophys. 1953, vol. 18, no. 3, pp. 605–635.
5. Christian H.J., Blakeslee R.J., Boccippio D.J., Boeck W.L., Buechler D.E., Driscoll K.T., et al. Global frequency and distribution of lightning as observed from space by the optical transient detector. J. Geophys. Res. 2003, vol. 108, iss. D1, pp. ACL4-1–ACL4-15. DOI: 10.1029/2002JD002347.
6. Encyclopedia of World Climatology. Springer, 2005, 854 p. DOI: 10.1007/1-4020-3266-8.
7. Fedorov E., Schekotov A.Ju., Molchanov O.A., Hayakawa M., Surkov V.V., Gladichev V.A. An energy source for the mid-latitude IAR: World thunderstorm centers, nearby discharges or neutral wind fluctuations? Physics and Chemistry of the Earth. 2006, vol. 31, pp. 462–468. DOI: 10.1016/j.pce.2006.02.001.
8. Fukunishi H., Takahashi Y., Kubota M., Sakanoi K., Inan U.S., Lyons W.A. Lower ionospheric flashes induced by lightning discharges. EOS Suplemment. 1995, vol. 46, p. F114.
9. Gershman B.N., Ugarov V.A. Propagation and generation of low-frequency electromagnetic waves in the upper atmosphere. Physics-Uspekhi [Advances in Physical Sciences]. 1960, vol. 72, pp. 235–271. (In Russian). DOI: 10.1070/PU1961v003n05ABEH005809.
10. Huang E., Williams E., Boldy R., Heckman S., Lyons W., Taylor M., et al. Criteria for sprites and elves based on Schumann resonance observations. J. Geophys. Res.: Atmos. 1999, vol. 104, no. D14, pp. 16943–16964. DOI: 10.1029/1999JD900139.
11. Lu G., Cummer S.A., Li J., Zigoneanu L., Lyons W.A., Stanley M.A., et al. Coordinated observations of sprites and in-cloud lightning flash structure. J. Geophys. Res.: Atmos. 2013, vol. 118, no. 12, pp. 6607–6632. DOI: 10.1002/jgrd.50459.
12. Lysak R.L., Yoshikawa A. Resonant cavities and wave-guides in the ionosphere and atmosphere. Geophysical Monograph Series. 2006, vol. 169, pp. 289–306. DOI: 10.1029/169GM19.
13. Mann I.R., Milling D.K., Rae I.J., Ozeke L.G., Kale A., Kale Z.C., et al. The upgraded CARISMA magnetometer array in the THEMIS era, Space Sci. Rev. 2008, vol. 141, pp. 413–451. DOI: 10.1007/s11214-008-9457-6.
14. Mishin V.V., Tsegmed B., Klibanova Y.Y., Kurikalova M.A. Burst geomagnetic pulsations as indicators of substorm expansion onsets during storms. J. Geophys. Res.: Space Phys. 2020, vol. 125, iss. 10, 15 p. DOI: 10.1029/2020JA028521.
15. Nose M., Uyeshima M., Kawai J., Hase H. Ionospheric Alfvén resonator observed at low-latitude ground station, Muroto. J. Geophys. Res.: Space Phys. 2017, vol. 122, no. 7, pp. 7240–7255. DOI: 10.1002/2017JA024204.
16. Paras M., Rai J. Electrical parameters of red sprites. Atmósfera. 2012, vol. 25, no. 4, pp. 371–380.
17. Parkhomov V.A., Rakhmatulin R.A. Localization of Pi1B source. Issledovaniya po geomagnetizmu, aeronomii i ﬁzike Solntsa [Research on Geomagnetism, Aeronomy and Solar Physics]. 1975, vol. 36, pp. 132–138. (In Russian).
18. Potapov A.S., Polyushkina T.N., Tsegmed B. Morphology and diagnostic potential of the ionospheric Alfvén resonator. Solar-Terr. Phys. 2021, vol. 7, no. 3, pp. 36–52. DOI: 10.12737/stp-73202104.
19. Price C. ELF electromagnetic waves from lightning: The Schumann resonances. Atmosphere. 2016, vol. 7, no. 116, 20 p. DOI: 10.3390/atmos7090116.
20. Price C., Asfur M., Lyons W., and Nelson T. An improved ELF/VLF method for globally geolocating sprite-producing lightning. Geophys. Res. Lett. 2002, vol. 29, no. 3, pp. 1-1–1-4. DOI: 10.1029/2001GL013519.
21. Rodger C.J. Red sprites, upward lightning, and VLF perturbations. Rev. Geophys. 1999, vol. 37, no. 3, pp. 317–336. DOI: 10.1029/1999RG900006.
22. Satori G., Mushtak V., Neska M., Nagy T., Barta V. Global lightning dynamics deduced from Schumann resonance frequency variations at two sites ∼550 km apart. Geophys. Res. Abstr. 2012, vol. 14, EGU2012-10647.
23. Schekotov A., Pilipenko V., Shiokawa K., Fedorov E. ULF impulsive magnetic response at mid-latitudes to lightning activity. Earth and Planetary Physics. 2011, vol. 63, no. 2, pp. 119–128. DOI: 10.5047/eps.2010.12.009.
24. Shvets A.V., Krivonos A.P., Serdiuk T.N., Goryshnya Y.V. Evaluating parameters of conductivity profile of the lower ionosphere by tweek-atmospherics. Radiofiz. elektron. 2015, vol. 20, pp. 40–47. (In Russian). DOI: 10.15407/rej2015.01.040.
25. Surkov V.V., Hayakawa M., Schekotov A.Y., Fedorov E.N., Molchanov O.A. Ionospheric Alfvén resonator excitation due to nearby thunderstorms. J. Geophys. Res. 2006, vol. 111, iss. A1, 13 p. DOI: 10.1029/2005JA011320.
26. Tikhonov A.N. On the determination of the electrical characteristics of the deep layers of the earth's crust. Doklady Akademii nauk SSSR [Proceedings of the USSR Academy of Sciences]. 1950, vol. 73, no. 2, pp. 295–297. (In Russian).
27. Wang Y., Lu G., Ming M., Zhang H., Fan Y., Liu G., et al. Triangulation of red sprites observed above a mesoscale convective system in North China. Earth and Planetary Physics. 2019, vol. 3, pp. 111–125. DOI: 10.26464/epp2019015.
28. Williams E., Downes E., Boldi R., Lyons W., Heckman S. Polarity asymmetry of sprite-producing lightning: A paradox? Radio Sci. 2007, vol. 42, no. 2, 15 p. DOI: 10.1029/2006 RS003488.
29. Winckler J.R. Further observations of cloud-ionosphere electrical discharges above thunderstorms. J. Geophys. Res.: Atmos. 1995, vol. 100, no. D7, pp. 14335–14345. DOI: 10.1029/ 95JD00082.
30. URL: http://lemisensors.com/wp-content/uploads/2018/ 03/LEMI-030_Datasheet.pdf (accessed March 30, 2022).
31. URL: http://www.carisma.ca/backgrounder/carisma-induction-coils (accessed March 30, 2022).
32. URL: https://docs.google.com/spreadsheets/d/1f10yd47JKR7FJ8HgUzIVI3bxfju2Utz0/edit?usp=sharing&ouid=108794281214343087703&rtpof=true&sd=true (accessed March 30, 2022).
33. URL: http://janto.ru/repository/008/annex-b.html (accessed March 30, 2022).