Якутск, Россия
с 01.01.2001 по 01.01.2023
Якутск, Россия
The paper analyzes experimental data on the position of the polar wall of the main ionospheric trough under low geomagnetic activity at Kr=0–1 from measurements made at the Yakutsk chain of vertical and oblique sounding ionosondes. The northern boundary of the trough under these conditions shifts to high magnetic latitudes 67–70°. This corresponds to the position of the geophysical structure “contracted oval” or compressed oval. Critical frequencies at the polar wall of the trough have high values of about 6–8 MHz. At this time, the DMSP satellite records intense 200–300 eV electron precipitation that can create the observed ionization in the F-region of the ionosphere.
ionosonde, meridional chain, main ionospheric trough, polar wall, magnetically quiet conditions, contracted oval, electron density
1. Aisenberg G.Z. Korotkovolnovye antenny [Short-wave antennas]. Moscow, Svyazizdat, 1962, 110 p. (In Russian).
2. Bates H.F., Belon A.E., Romick G.J., Stringer W.J. On the correlation of optical and radio auroras. J. Atmos. Terr. Phys. 1966, vol. 28, pp. 439–442. DOI:https://doi.org/10.1016/0021-9169(66)90053-5.
3. Belinskaya S.I., Khalipov V.L. Some aeronomic effects in the aurora diffuse zone. Issledovaniya po geomagnetizmu, aeronomii i fizike Solntsa [Research on Geomagnetism, Aeronomy and Solar Physics]. 1983, vol. 63, pp. 116–124. (In Russian).
4. Benkova N.P., Zikrach E.K., Kozlov E.F., Mamrukov A.P., Osipov N.K., Samorokin N.I., Filippov L.D. Main ionospheric trough from data of meridional probe chains. Ionosfernye issledovaniya [Ionospheric studies]. 1983, vol. 35, pp. 5–12. (In Russian).
5. Cummock J.A., Blomberg L.G., Kullen A., Karlsson T., Sunberg K.A. Small-scale characteristics of a extremely high latitude aurora. Ann. Geophys. 2009, vol. 27, pp. 3335–3341. DOI:https://doi.org/10.5194/angeo-27-3335-2009.
6. Despirak I.V., Lubchich A.A., Kleimenova N.G. High-latitude substorm dependence on space weather conditions in solar cycle 23 and 24 (SC23 and SC24). J. Atmos. Solar-Terr. Phys. 2018, vol. 177, pp. 54–62. DOI:https://doi.org/10.1016/j.jastp.2017.09.011.
7. Galperin Yu.I., Cranier J., Lissakov Yu.V., Nikolaenko L.M., Sinitsyn V.M., Sauvaud J.-A., Khalipov V.L. Diffuse auroral zone. I. Model of the equatorial boundary of the diffuse zone of auroral electron invasion in the evening and near-midnight sectors. Kosmicheskie issledovaniya [Cosmic Res.]. 1977, vol. 15, no. 3, pp. 421–434. (In Russian).
8. Farley D.T., Jr. A plasma instability resulting in field-aligned irregularities in the ionosphere. J. Geophys. Res. 1963, vol. 68, pp. 6083–6097. DOI:https://doi.org/10.1029/JZ068i022p06083.
9. Gjerloev J.W. A Global Ground-Based Magnetometer Initiative. EOS. 2009, vol. 90, pp. 230–231. DOI:https://doi.org/10.1029/2009EO270002.
10. Gjerloev J.W. The SuperMAG data processing technique. J. Geophys. Res. 2012, vol. 117, A09213.DOI:https://doi.org/10.1029/2012JA017683.
11. Instruktsiya po obrabotke ionogramm naklonnogo zondirovaniya [Instructions for processing oblique sounding ionograms]. Ed. Vinogradova Yu.V. Leningrad, Gidrometeoizdat, 1985,127 p. (In Russian).
12. Khalipov V.L., Galperin Yu.I., Lissakov Yu.V., Cranier J., Nikolaenko L.M., Sinitsyn V.M., Sauvaud J.-A. Diffuse auroral zone. II. Formation and dynamics of the polar edge of the subauroral ionospheric trough in the evening sector. Kosmicheskie issledovaniya [Cosmic Res.]. 1977, vol. 15, no. 5, pp. 708–724. (In Russian).
13. Khalipov V.L., Golenkov E.V., Molochushkin N.E., Stepanov A.E. Characteristic traces on oblique incidence-backscatter sounding ionograms during the appearance of auroral arcs. Byulleten nauchno-tekhnicheskoi informatsii. Problemy kosmofiziki i aeronomii [Bull. of Scientific Technology Information. Problems of Cosmophysics and Aeronomy]. Yakutsk, USSR SB SA Publ., 1984, pp. 33–35. (In Russian).
14. Khalipov V.L., Stepanov A.E., Novopashina E.Yu. Model of the position of the polar edge of the ionospheric trough in the morning sector. Geomagnetizm i aeronomiya [Geomagnetism and Aeronomy]. 1987, vol. 27, no. 5, pp. 842–843. (In Russian).
15. Kleimenova N.G., Gromova L.I., Despirak I.V., Malysheva L.M., Gromov S.V., Lubchich A.A. Features of polar substorms: An analysis of individual events. Geomagnetism and Aeronomy. 2023a, vol. 63, no. 3, pp. 288–299. DOI:https://doi.org/10.1134/S0016793223600042.
16. Kleimenova N.G., Despirak I.V., Malysheva L.M., Gromova L.I., Lubchich A.A., Roldugin A.V., Gromov S.V. Substorms on a contracted auroral oval. J. Atmos. Solar-Terr. Phys. 2023b, vol. 245, p. 106049. DOI:https://doi.org/10.1016/j.jastp.2023.106049.
17. Lui A.T.Y., Akasofu S.-I., Hones E.W., Bame S.J., McIlwain C.E. Observation of plasma sheet during a contracted oval substorm in a prolonged quiet period. J. Geophys. Res. 1976, vol. 81, pp. 1415–1419. DOI:https://doi.org/10.1029/JA081i007p01415.
18. Mamrukov A.P., Zikrach E.K. Morphology of subauroral F2s. Geomagnetizm i aeronomiya [Geomagnetism and Aeronomy]. 1973, vol. 13, pp. 433–436. (In Russian).
19. Mamrukov A.P., Filippov L.D. Yakutsk meridional chain of ionosondes for vertical and oblique incidence-backscatter sounding and round-the-clock observations of the main ionospheric failure. Effekty vysypaniya zaryazhennykh chastits v verkhnei atmosfere [Effects of charged particle ejection in the upper atmosphere]. Yakutsk, YaF SB AS USSR Publ., 1988, pp. 107–123. (In Russian).
20. Mamrukov A.P., Khalipov V.L., Filippov L.D. Calculation of ionograms for rakurs-sensitive reflections from the ionosphere. Geofizicheskie yavleniya v polyarnoi oblasti [Geophysical phenomena in the polar region]. Yakutsk, YaF SB AS USSR Publ., 1973, pp. 92–97. (In Russian).
21. Mamrukov A.P., Kiselev V.A., Neustroev E.M., Filippov L.D. Combined ionosonde for vertical and oblique incidence-backscatter sounding for diagnostics of the ionosphere at the latitudes of the plasmapause in Zhigansk. Byulleten nauchno-tekhnicheskoi informatsii. Problemy kosmofiziki i aeronomii [Bull. of Scientific Technology Information. Problems of Cosmophysics and Aeronomy]. Yakutsk, YaF SB AS USSR Publ., 1982, pp. 24–27. (In Russian).
22. Newell P.T., Gjerloev J.W. Local geomagnetic indices and the prediction of auroral power. J. Geophys. Res. 2014, vol. 119, pp. 9790–9803. DOI:https://doi.org/10.1002/2014JA020524.
23. Rees M.H. Auroral ionization and excitation by incident energetic electrons. Planetary and Space Science. 1963, vol. 11, no. 10, pp. 1209–1218. DOI:https://doi.org/10.1016/0032-0633(63)90252-6.
24. Rukovodstvo URSI po interpretatsii i obrabotke ionogramm [URSI Handbook of ionogram interpretation and reduction]. Trans. from English. Ed. N.V. Mednikova. Moscow, Nauka Publ., 1977, 342 p. (In Russian).
25. Vasiliev G.V., Vasiliev K.N., Goncharov L.P. Automatic panoramic ionospheric station of the AIS type. Geomagnetizm i aeronomiya [Geomagnetism and Aeronomy]. 1961, vol. 1, no. 1, pp. 120–125. (In Russian).
26. URL: http://wdc.kugi.kyoto-u.ac.jp (accessed September 3, 2025).
27. URL: https://supermag.jhuapl.edu/info/ (accessed Septembe 3, 2025).
