RADIO PHYSICS AND RADIO ASTRONOMY

Subject and Purpose. This work examines eff ects of the November 3, 2013 solar eclipse, in particular the atypical increases in the level of radio interference and scintillations of the radio sources 3C 123 and Cas-A that were observed at 25 MHz. These phenomena might owe to the enhanced wave activity in the ionosphere during the eclipse and a reduced radio wave absorption.

Methods and Methodology. The observations were conducted with the use of the low-frequency radio telescope URAN-4 (operative range 10—30 MHz). The observational data concerning radiation from cosmic radio sources and the accompanying interference are presented, for further analysis, in the form of time series. Wavelet analysis has been applied to the data arrays to identify the dominant periods of radio source scintillation.

Results. A significant increase in interference intensity was observed on the day of the eclipse climax, as well as the next day. The radio source Cas-A exhibited quasi-periodic variations of intensity on a timescale of 3 to 7 minutes. The scintillation analysis performed for the source 3C 123 before and aft er the eclipse failed to provide conclusive evidence of eclipse-related effects.

Conclusions. Despite the fact that the solar eclipse of November 3, 2013, was not optically visible in Ukraine (because the nearest visibility zone for the partial eclipse lay farther toward the South of the Crimea and further on toward Turkey), an anomalous rise in the level of interference was still recorded over the time window of observations from October 31 to November 7, 2013. No similar enhancements were observed either before or after the eclipse. This is likely the result of a combined effect involving reduced absorption in the ionospheric D-layer, the noticeable shift in the F-layer’s location (which leads to appearance of distant reflections), and appearance of active agents like TIDs. All of these together brought forth a sharp increase in interference levels at 25 MHz. Despite the fact that the eclipse stayed optically invisible, its generated ionospheric disturbances proved capable of reaching the
URAN-4 facility, manifesting themselves through a strong burst of interference during zenith-oriented reception.

Keywords: radio scintillations, ionosphere, ionospheric storm, geomagnetic storm, solar eclipse manifestations in the ionosphere, decameter-wavelength radio astronomy

Manuscript submitted  25.02.2025

Radio phys. radio astron. 2025, 30(4): 217-231

REFERENCES

1. Galanin, V.V., Komendant, V.H., Yasinski, V.V., 2021. Observation control device for the Uran-4 decameter radio telescope. Odessa Astronomical Publscations, 34, pp. 74—75. DOI: 10.18524/1810-4215.2021.34.244382

2. Chernogor, L.F., 2013. Physical effects of solar eclipses in atmosphere and geospace. Monograph. Kharkiv: V.N. Karazin Kharkiv National University Publ. 480 p.

3. Lion, E.F., Bridge, H.S., Binsack, J.H., 1967. Explorer-35 Plasma Measurements in Vicinity of the Moon. J. Geophys. Res., 72(23), pp. 6113—6117. DOI: 10.1029/JZ072i023p06113

4. Ness, N.F., 1970. Interaction of the Solar Wind with the Moon. Preprint NASA-GSFC, X-692 70-141, Maryland

5. Interaction of the Solar Wind with the Terrestrial Planets. Section: The Solar Wind in the Near-Earth Environment. Studies of the Solar Wind Flow around the Moon. 1988. Adv. Sci. Technol. Ser. Astronomy, 35.

6. Chernogor, L.F., Barabash, V.V., 2011. The response of the middle ionosphere to the solar eclipse of 4 January 2011 in Kharkiv: some results of vertical sounding. Kosm. nauka tehnol., 17(4), pp. 41—52. DOI: 10.15407/knit2011.04.041

7. Typinski, D., Greenman, W., 2015. Things That Go Hump in the Night — A Fun Experiment [pdf]. NASA RadioJove Project. Available from: https://radiojove.gsfc.nasa.gov/radio_telescope/observing/observing_galactic_bkg.pdf

8. Mertsch, P., Sarkar, S., 2013. Loops and spurs: the angular power spectrum of the Galactic synchrotron background. J. Cosmol. Astropart. Phys., 06, 041. DOI: 10.1088/1475-7516/2013/06/041

9. Rapoport, Yu.G., Cheremnykh, O.K., Koshovyy, V.V, Melnik, M.O., Ivantyshyn, O.L., Nogach, R.T., Selivanov, Yu.A., Grimalsky, V.V., Mezentsev, V.P., Karataeva, L.M., Ivchenko, V.M., Milinevsky, G.P., Fedun, V.N., Tkachenko, Ye.N., 2017, Ground-based acoustic parametric generator impact on the atmosphere and ionosphere in an active experiment. Ann. Geophys., 35(1), pp. 53—70. DOI: 10.5194/angeo-35-53-2017

10. Galanin, V.V., Inyutin, G.A., Kvasha, I.M., Panishko, S.K., Pisarenko, Ya.V., Rashkovskij, S.L., Ryabov, M.I., Serokurova, N.G., Tsesevich, V.P., Sharykin, N.K., 1989. URAN-4 radio telescope as an element of VLBI system. Kinematika i Fizika
Nebesnykh Tel, 5, pp. 87—90.

11. Lytvynenko, O.A., Panishko, S.K., Derevyagin, V.G., 2023. The Long-Term Observations of the Power Cosmic Radio Sources on the Radio Telescope URAN-4 at the Decameter Wave Range. Odessa Astronomical Publications, 36, pp. 118—121. DOI: 10.18524/1810-4215.2023.36.290139

12. Sukharev, A., Orlyuk, M., Ryabov, M., Sobitniak, L., Bezrukovs, V., Panishko, S., Romenets, A., 2022. Results of comparison of fast variations of geomagnetic field and ionospheric scintillations of 3C 144 radio source in the area of Odessa geomagnetic anomaly. Astron. Astrophys. Trans., 33(1), pp. 67—88. DOI: 10.17184/eac.6481
13. Madden, H.H., 1978. Comments on the Savitzky-Golay convolution method for least-squares-fi t smoothing and differentiation of digital data. Anal. Chem., 50(9), pp. 1383—1386. DOI: 10.1021/ac50031a048

14. Breaz, N., 2004. The cross-validation method in the smoothing spline regression. Acta Universitatis Apulensis 7. Research Gate. Available from: https://www.researchgate.net/publication/237262065_THE_CROSS-VALIDATION_METHOD_IN_THE_SMOOTHING_SPLINE_REGRESSION
15. Garimella, R.V., 2017. A Simple Introduction to Moving Least Squares and Local Regression Estimation. Report number: LA-UR-17-24975. United States, DOI: 10.2172/1367799

16. Tipton, C., 2022. Basics of Fourier Analysis of Time Series Data. Johnson Matthey Technol. Rev., 66(2), pp. 169—176. DOI: 10.1595/205651322X16433652085975

17. Popinski, W., Kosek, W., 1995. The Fourier transform band pass filter and its application for polar motion analysis. Artif. Satell., Planet. Geod., 24 (30(1)), pp. 9—25.

18. Allen, J., 1977. Short term spectral analysis, synthesis, and modification by discrete Fourier transform. IEEE Trans. Acoust. Speech Signal Process., 25(3), pp. 235—238. DOI: 10.1109/TASSP.1977.1162950

19. Wang, Yun, He, Ping, 2023. Comparisons between fast algorithms for the continuous wavelet transform and applications in cosmology: the 1D case. RAS Tech. Instrum., 2(1), pp. 307—323. DOI: 10.1093/rasti/rzad020

20. Scholl, S., 2021. Fourier, Gabor, Morlet or Wigner: Comparison of Time-Frequency Transforms. DOI: 10.48550/arX-iv.2101.06707

21. NOAA Weekly Highlights and 27-Day Forecast. Available from: https://www.swpc.noaa.gov/products/weekly-highlights-and-27-day-forecast; Users Guide to The Preliminary Report and Forecast of Solar Geophysical Data. Available from:
https://www.swpc.noaa.gov/sites/default/files/images/u2/Usr_guide.pdf

22. Esaenwi, S., Ofodum, C.N, Okere, B.I., Opara, F.E, Sigalo, F.B., Omaliko, K.C., Wali, C.B., Sigalo, M.B., Suraju, S., Eze, E.J., Okonkwo, H., Osuji, U., Omowa, E., Ogbonda, C., and Anuforom, A., 2016. The 3 November 2013 partial solar eclipse: the
effect of Nigeria media popularization. Nig. J. Space Res., 14(1), 5 p.

23. Patel, D.B., Kotadia, K.M., Lele, P.D., Jani, K.G., 1986. Absorption of radio waves during a solar eclipse. Proc. Indian Acad. Sci. (Earth Planet. Sci.), 95(2), pp. 193—200. DOI: 10.1007/bf02871864

24. Bamford, R.A., 2001. The effect of the 1999 total solar eclipse on the ionosphere. Phys. Chem. Earth (C), 26(5), pp. 373—377. DOI: 10.1016/S1464-1917(01)00016-2
25. Knížova, K.P., Mošna, Z., 2011. Acoustic-Gravity Waves in the Ionosphere during Solar Eclipse Events. In: Beghi, M.G. ed., 2011. Acoustic Waves — From Microdevices to Helioseismology. ISBN: 978-953-307-572-3, InTech. Available from: http://www.intechopen.com/books/acoustic-waves-from-microdevices-to-helioseismology/acoustic-gravity-waves-in-the-ion-osphere-during-solar-eclipse-events

26. Kaladze, T.D., Pokhotelov, O.A., Shah, H.A., Khan, M.I., Stenflo, L., 2008. Acoustic-gravity waves in the Earth’s ionosphere. J. Atmos. Sol.-Terr. Phys., 70(13), pp. 1607—1616. DOI: 10.1016/j.jastp.2008.06.009

27. Nayak, Ch., Yiğit, E., 2018. GPS-TEC Observation of Gravity Waves Generated in the Ionosphere during 21 August 2017 Total Solar Eclipse. J. Geophys. Res. Space Phys., 123(1), pp. 725—738. DOI: 10.1002/2017JA024845

28. Sukharev, A.L., Ryabov, M.I., Galanin, V.V., Komendant, V.G., 2023. About research programs at the radio telescope "URAN-4" IRA NASU — monitoring of fluxes of powerful radio sources, study of the Sun’s supercorona, observations of
solar eclipse. Odessa Astronomical Publications, 36, pp. 135. DOI: 10.18524/1810-4215.2023.36.290143

29. Chernogor, L.F., 2016. Propagating waves and processes associated with the March 20, 2015 solar eclipse in the ionosphere over Europe. Kinemat. Phys. Celest. Bodies, 32(4), pp. 60—72.

30. Kaladze, T.D., Pokhotelov, O.A., Shah, H.A., Khan, M.I., Stenflo, L., 2008. Acoustic-gravity waves in the Earth’s ionosphere. J. Atmos. Terr. Phys., 70(13), pp. 1607—1616. DOI: 10.1016/j.jastp.2008.06.009

31. Crowley, G., Azeem, S.M.I., 2018. Extreme Ionospheric Storms and Their Effects on GPS Systems. In book: Buzulukova, N. ed., 2018. Extreme Events in Geospace. Elsevier, 2018, pp. 555—586. DOI: 10.1016/B978-0-12-812700-1.00023-6

32. Kozyreva, O., Kozlovsky, A., Pilipenko, V., Yagova, N., 2019. Ionospheric and geomagnetic Pc5 oscillations as observed by the ionosonde and magnetometer at Sodankylä. Adv. Space Res., 63(7), pp. 2052—2065. DOI: 10.1016/j.asr.2018.12.004

33. Eisenbeis, J., 2020. Ionospheric Dynamics by GNSS total electron content observations: the effect of Solar Eclipses and the mystery of Earthquake precursors. Doctoral thesis in Earth and Environmental Sciences. Université Paris Cité, 2020. English. NNT: 2020UNIP7027. Available from: https://theses.hal.science/tel-03181359v1/file/EISENBEIS_Julian_va2.pdf

34. Sun, Y.-Y., Shen, M.M., Tsai, Y.-L., Lin, C.-Y., Chou, M.-Y., Yu, T., Lin, K., Huang, Q., Wang, J., Qiu, L., Chen, C.-H, and Liu, J.-Y., 2021. Wave Steepening in Ionospheric Total Electron Density due to the 21 August 2017 Total Solar Eclipse.
J. Geophys. Res. Space Phys., 126(3), e2020JA028931. DOI: 10.1029/2020JA028931