Solar activity proxies and the E layer

Cover Page

Cite item

Full Text

Open Access Open Access
Restricted Access Access granted
Restricted Access Subscription Access

Abstract

Analysis of the quality of description of the dependence of the E-layer critical frequency foE on solar activity by five solar activity proxies (F10.7, F30, MgII, Ly-α, and Rz) is performed. It is emphasized that interest to the problem of description of ionospheric parameters behavior by various SA proxies increased sharply during the recent years, and a brief review of the recent publications on that problem is given. The behavior with solar activity of the foE monthly medians based on observations at three European vertical sounding stations Juliusruh, Slough, and Rome in a period of 1957–1980 for two months of each season (winter, equinox, and summer) is considered. As a measure of the quality of that description, the determination coefficient R2 according to Fisher F-test is used, and the method used earlier for similar analysis of the foF2 data is applied. It is found that three proxies (F30, MgII, and Ly-α) provide similar quality of the description (almost coinciding values of R2 in the majority of cases above 0.9) for all considered situations. The F10.7 and Rz proxies describe the foE behavior worse than these three proxies, the Rz proxy being the worst.

About the authors

A. D Danilov

Fedorov Institute of Applied Geophysics

Email: adanilov99@mail.ru
Moscow, Russia

A. V Konstantinova

Fedorov Institute of Applied Geophysics

Moscow, Russia

N. A Berbeneva

M.V. Lomonosov Moscow State University

Moscow, Russia

References

  1. Данилов А.Д., Бербенева Н.А. Статистический анализ зависимости критической частоты foF2 от различных индексов солнечной активности // Геомагнетизм и аэрономия. Т. 63. № 5. С. 653–661. 2023. https://doi.org/10.31857/S0016794023600588
  2. Данилов А.Д., Бербенева Н.А. Зависимость foF2 от индексов солнечной активности по данным ионосферных станций Северного и Южного полушарий // Геомагнетизм и аэрономия. Т. 64. № 2. С. 253–264. 2024. https://doi.org/10.31857/S0016794024020083
  3. Данилов А.Д, Константинова А.В. Долговременные тренды критической частоты слоя E // Геомагнетизм и аэрономия. Т. 58. № 3. С. 356–365. 2018a. https://doi.org/10.7868/S0016794018030069
  4. Данилов А.Д., Константинова А.В. Дальнейший анализ трендов foE на станции Juliusruh // Гелиогеофизические исследования. Вып. 19. С. 41–46. 2018b.
  5. Данилов А.Д., Константинова А.В., Бербенева Н.А. Дальнейший детальный анализ зависимости foF2 от солнечной активности // Гелиогеофизические исследования. Вып. 40. С. 68–80. 2023. https://doi.org/10.5425/2304-7380_2023_40_68
  6. Деминов М.Г. Тренды ионосферных индексов солнечной активности // Геомагнетизм и аэрономия. Т. 64. № 5. С. 649–655. 2024. https://doi.org/10.31857/S0016794024050052
  7. Деминов М.Г. Связи между индексами солнечной активности в разные интервалы времени // Геомагнетизм и аэрономия. Т. 65. № 3. С. 335–342. 2025.
  8. Деминов М.Г., Деминова Г.Ф. Изменения со временем связи между индексами солнечной активности // Геомагнетизм и аэрономия. Т. 65. № 4. С. 345–342. 2025.
  9. Cnossen I., Emmert J.T. Garcia R.R., Elias A.G., Mlynczak M.G., Zhang Sh.R. A review of global long-term changes in the mesosphere, thermosphere and ionosphere: a starting point for inclusion in (semi-) empirical models // Adv. Space Res. V. 74. № 11. P. 5991–6011. 2024. https://doi.org/10.1016/j.asr.2024.10.00
  10. Danilov A.D., Berbeneva N.A. Statistical analysis of the critical frequency foF2 dependence on various solar activity indices // Adv. Space Res. V. 72. № 6. P. 2351–2361. 2023. https://doi.org/10.1016/j.asr.2023.05.012
  11. de Haro Barbas B.F., Zossi B.S., Jun G.T., Bravo M., Martinez-Ledesma M., Venchiarutti V., Gonzalez G., Medina F.D., Duran T., Elias A.G. Performance of the IRI-2016 and IRI-Plas 2020 considering Mg II as EUV solar proxy // Adv. Space Res. V. 72. № 6. P. 2406–2417. 2023. https://doi.org/10.1016/j.asr.2023.06.007
  12. Duran T., Zossi B.S., Melendi Y., de Haro Barbas B.F., Buezas F.S., Elias A.G. Impact of different solar EUV proxies and Ap index on hmF2 trend analysis // Preprint EGUSphere, ID 2479. 24 p. 2024. https://doi.org/10.5194/egusphere-2024-2479
  13. Elias A., Alberti T., Bravo M., et al. Long-term trends in the ionospheric equivalent slab thickness: Some evidences by Working Team #1 within IAGA WGII-F // Paper presented at the 12th International Workshop on Long-Term Changes and Trends in the Atmosphere, 6–10 May 2024, Ourense, Galicia, Spain. 2024.
  14. Elias A.G., Zossi B.S., Medina F.D., Duran T. Selecting the best solar EUV proxy for long-term timescale applications // Adv. Space Res. V. 75. № 1. P. 856–863. 2025. https://doi.org/10.1016/j.asr.2024.07.023
  15. Emmert J.T., Dhadly M.S., Segerman A.M. A globally averaged thermospheric density dataset derived from two-line orbital element sets and special perturbations state vectors // J. Geophys. Res. – Space. V. 126. № 8. ID e2021JA029455. 2021. https://doi.org/10.1029/2021JA029455
  16. Laštovička J. What is the optimum solar proxy for long-term ionospheric investigations? // Adv. Space Res. V. 67. № 1. P. 2–8. 2021a. https://doi.org/10.1016/j.asr.2020.07.025
  17. Laštovička J. The best solar activity proxy for longterm ionospheric investigations // Adv. Space Res. V. 68. № 6. P. 2354–2360. 2021b. https://doi.org/10.1016/j.asr.2021.06.032
  18. Laštovička J. Long-term changes in ionospheric climate in terms of foF2 // Atmosphere. V. 13. № 1. ID 110. 2022. https://doi.org/10.3390/atmos13010110
  19. Laštovička J. Progress in investigating long–term trends in the mesosphere, thermosphere, and ionosphere // Atmos. Chem. Phys. V. 23. № 10. P. 5783–5800. 2023a. https://doi.org/10.5194/acp-23-5783
  20. Laštovička J. Dependence of long-term trends in foF2 at middle latitudes on different solar activity proxies // Adv. Space Res. V. 73. № 1. P. 685–689. 2024. https://doi.org/10.1016/j.asr.2023.09.047
  21. Laštovička J., Burešova D. Relationships between foF2 and various solar activity proxies // Space Weather. V. 21. № 4. ID e2022SW003359. 2023. https://doi.org/10.1029/2022SW003359
  22. Mursula K. Hale cycle in solar hemispheric radio flux and sunspots: Evidence for a northward shifted relic field // Astron. Astrophys. V. 674. ID A182. 2023. https://doi.org/10.1051/0004-636 6361/202345999
  23. Natali M.P., Urutti A., Castaco J.M., Zossi B.S., Duran T., Meza A., Elias A.G. Long term global ionospheric total electron content trend analysis // Geophys. Res. Lett. V. 51. № 21. ID e2024GL112248. 2024. https://doi.org/10.1029/2024GL112248
  24. Qian L., Mursula K. Evaluating F10.7 and F30 radio fluxes as long-term solar proxies of energy deposition in the thermosphere // Ann Geophys. V. 43. № 1. P. 175–182. 2025. https://doi.org/10.5194/angeo-43-175-2025
  25. Rios M.G.T.J., Borries C., Liu H., Mielich J. Long-term changes in the dependence of NmF2 on solar flux at Juliusruh // Ann Geophys. V. 43. № 1. P. 73–89. 2025. https://doi.org/10.5194/angeo-43-73-2025
  26. Sivakandan M., Mielich J., Renkwitz T., Chau J.L., Jaen J., Laštovička J. Long-term variations and trends in the E, F and sporadic E (Es) layer over Juliusruh, Europe // J. Geophys. Res. – Space. V. 128. № 4. ID e2022JA031097. 2023. https://doi.org/10.1029/2022JA031097
  27. Spogli L., Sabbagh D., Perrone L., Scotto C., Cesaroni C. Investigating the drivers of long-term trends in the upper atmosphere over Rome across four decades // J. Space Weather Spac. V. 15. ID 8. 2025. https://doi.org/10.1051/swsc/2024040
  28. Urbář J., Laštovička J. Global long-term trends in the total electron content // Preprint EGUsphere. ID 3021. 9 p. 2024. https://doi.org/10.5194/egusphere-2024-3021
  29. Zossi B.S., Medina F.D., Duran T., Elias A.G. The effect of mixing EUV proxies on the correlation with foF2 and on long-term trends estimations // Adv. Space Res. V. 74. № 10. P. 4930–4936. 2024. https://doi.org/10.1016/j.asr.2024.07.064
  30. Zossi B.S., Medina F.D., Duran T., Elias A.G. Selecting the best solar EUV proxy for long-term timescale applications // Adv. Space Res. V. 75. № 1. P. 856–863. 2025a. https://doi.org/10.1016/j.asr.2024.07.023
  31. Zossi B.S., Medina F.D., Duran T., de Haro Barbas B.F., Elias A.G. Revisiting sunspot number as an extreme ultraviolet (EUV) proxy for ionospheric F2 critical frequency // Ann. Geophys. V. 43. № 1. P. 91–98. 2025b. https://doi.org/10.5194/angeo-43-91-2025
  32. Zossi B.S., Medina F.D., Duran T., Vega Caro M.A., Blas F., de Haro Barbas D.F., Elias A.G. Non-conventional statistical approaches for ionospheric long-term trend analysis // Global Planet. Change. GLOPLACHA-D-25-00121. 2025c.

Supplementary files

Supplementary Files
Action
1. JATS XML
Download

Copyright (c) 2025 Russian Academy of Sciences

Согласие на обработку персональных данных

 

Используя сайт https://journals.rcsi.science, я (далее – «Пользователь» или «Субъект персональных данных») даю согласие на обработку персональных данных на этом сайте (текст Согласия) и на обработку персональных данных с помощью сервиса «Яндекс.Метрика» (текст Согласия).