{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,15]],"date-time":"2026-05-15T22:45:56Z","timestamp":1778885156793,"version":"3.51.4"},"reference-count":79,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2023,3,2]],"date-time":"2023-03-02T00:00:00Z","timestamp":1677715200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Institute of Physics Belgrade, University of Belgrade"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>The strongest X-class solar flare (SF) event in 24th solar cycle, X9.3, occurred on 6 September 2017, accompanied by earthward-directed coronal mass ejections (CMEs). Such space weather episodes are known to cause various threats to human activities ranging from radio communication and navigation disturbances including wave blackout to producing geomagnetic storms of different intensities. In this study, SFs\u2019 ionospheric impacts and effects of accompanied heliospheric disturbances on primary cosmic rays (CR) are investigated. This work offers the first detailed investigation of characteristics of these extreme events since they were inspected both from the perspective of their electromagnetic nature, through very low frequency (VLF) radio waves, and their corpuscular nature of CR by multi-instrumental approach. Aside data recorded by Belgrade VLF and CR stations, data from GOES and SOHO space probes were used for modeling and analysis. Conducted numerical simulations revealed a significant change of ionospheric parameters (sharpness and effective reflection height) and few orders of magnitude increase of electron density. We compared our findings with those existing in the literature regarding the ionospheric response and corresponding parameters. In addition, Forbush decrease (FD) magnitude, corrected for magnetospheric effect, derived from measurements, and one predicted from power exponents used to parametrize the shape of energetic proton fluence spectra at L1 were compared and found to be in good agreement. Presented findings could be useful for investigation of atmospheric plasma properties, particles\u2019 modeling, and prediction of extreme weather impacts on human activities.<\/jats:p>","DOI":"10.3390\/rs15051403","type":"journal-article","created":{"date-parts":[[2023,3,2]],"date-time":"2023-03-02T01:39:21Z","timestamp":1677721161000},"page":"1403","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":14,"title":["Impacts of Extreme Space Weather Events on September 6th, 2017 on Ionosphere and Primary Cosmic Rays"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4769-0152","authenticated-orcid":false,"given":"Aleksandra","family":"Kolarski","sequence":"first","affiliation":[{"name":"Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3373-2104","authenticated-orcid":false,"given":"Nikola","family":"Veselinovi\u0107","sequence":"additional","affiliation":[{"name":"Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7938-5748","authenticated-orcid":false,"given":"Vladimir A.","family":"Sre\u0107kovi\u0107","sequence":"additional","affiliation":[{"name":"Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7785-4456","authenticated-orcid":false,"given":"Zoran","family":"Miji\u0107","sequence":"additional","affiliation":[{"name":"Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4368-0248","authenticated-orcid":false,"given":"Mihailo","family":"Savi\u0107","sequence":"additional","affiliation":[{"name":"Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6934-0095","authenticated-orcid":false,"given":"Aleksandar","family":"Dragi\u0107","sequence":"additional","affiliation":[{"name":"Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,3,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"3853","DOI":"10.5194\/angeo-27-3853-2009","article-title":"Electrodynamical response of the Indian low-mid latitude ionosphere to the very large solar flare of 28 October 2003\u2014A case study","volume":"27","author":"Manju","year":"2009","journal-title":"Ann. Geophys."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Fu, H., Zheng, Y., Ye, Y., Feng, X., Liu, C., and Ma, H. (2021). Joint Geoeffectiveness and Arrival Time Prediction of CMEs by a Unified Deep Learning Framework. Remote Sens., 13.","DOI":"10.3390\/rs13091738"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2497","DOI":"10.5194\/angeo-25-2497-2007","article-title":"Unusual ionospheric effects observed during the intense 28 October 2003 solar flare in the Brazilian sector","volume":"25","author":"Sahai","year":"2007","journal-title":"Ann. Geophys."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"576","DOI":"10.1029\/2012JA017934","article-title":"Statistical analysis of ionospheric responses to solar flares in the solar cycle 23","volume":"118","author":"Le","year":"2013","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Sre\u0107kovi\u0107, V.A., \u0160uli\u0107, D.M., Ignjatovi\u0107, L., and Vuj\u010di\u0107, V. (2021). Low Ionosphere under Influence of Strong Solar Radiation: Diagnostics and Modeling. Appl. Sci., 11.","DOI":"10.3390\/app11167194"},{"key":"ref_6","unstructured":"Kelley, M.C. (2009). The Earth\u2019s Ionosphere: Plasma Physics and Electrodynamics, Academic Press."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"904335","DOI":"10.3389\/fenvs.2022.904335","article-title":"Multi-instrumental investigation of the solar flares impact on the ionosphere on 05\u201306 December 2006","volume":"10","author":"Barta","year":"2022","journal-title":"Front. Environ. Sci."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Kolarski, A., Sre\u0107kovi\u0107, V.A., and Miji\u0107, Z.R. (2022). Response of the Earths Lower Ionosphere to Solar Flares and Lightning-Induced Electron Precipitation Events by Analysis of VLF Signals: Similarities and Differences. Appl. Sci., 12.","DOI":"10.3390\/app12020582"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Nina, A. (2022). Modelling of the Electron Density and Total Electron Content in the Quiet and Solar X-ray Flare Perturbed Ionospheric D-Region Based on Remote Sensing by VLF\/LF Signals. Remote Sens., 14.","DOI":"10.3390\/rs14010054"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1604","DOI":"10.1029\/2018SW001933","article-title":"Ionospheric Response to the X9.3 Flare on 6 September 2017 and Its Implication for Navigation Services Over Europe","volume":"16","author":"Berdermann","year":"2018","journal-title":"Space Weather"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1013","DOI":"10.1029\/2018SW001932","article-title":"The 6 September 2017 X-Class Solar Flares and Their Impacts on the Ionosphere, GNSS, and HF Radio Wave Propagation","volume":"16","author":"Yasyukevich","year":"2018","journal-title":"Space Weather"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"De Paula, V., Segarra, A., Altadill, D., Curto, J.J., and Blanch, E. (2022). Detection of Solar Flares from the Analysis of Signal-to-Noise Ratio Recorded by Digisonde at Mid-Latitudes. Remote Sens., 14.","DOI":"10.5194\/egusphere-egu22-5482"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1007\/s10291-011-0217-9","article-title":"Ionospheric super-bubble effects on the GPS positioning relative to the orientation of signal path and geomagnetic field direction","volume":"16","author":"Demyanov","year":"2012","journal-title":"GPS Solut."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"233","DOI":"10.1017\/S1743921309029342","article-title":"Statistical relationship between solar flares and coronal mass ejections","volume":"4","author":"Yashiro","year":"2008","journal-title":"Proc. Int. Astron. Union"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1007\/s41116-016-0002-5","article-title":"Large gradual solar energetic particle events","volume":"13","author":"Desai","year":"2016","journal-title":"Living Rev. Sol. Phys."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"e2019JA027662","DOI":"10.1029\/2019JA027662","article-title":"Comparing the Properties of ICME-Induced Forbush Decreases at Earth and Mars","volume":"125","author":"Guo","year":"2020","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1023\/A:1026532125747","article-title":"Coronal Mass Ejections and Forbush Decreases","volume":"93","author":"Cane","year":"2000","journal-title":"Space Sci. Rev."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"625","DOI":"10.1016\/S0273-1177(01)00095-3","article-title":"What determines the magnitude of forbush decreases?","volume":"27","author":"Belov","year":"2001","journal-title":"Adv. Space Res."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"101","DOI":"10.3847\/1538-4357\/ab6bd1","article-title":"Interplanetary Coronal Mass Ejections as the Driver of Non-recurrent Forbush Decreases","volume":"890","author":"Papaioannou","year":"2020","journal-title":"Astrophys. J."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Belov, A., Shlyk, N., Abunina, M., Belova, E., Abunin, A., and Papaioannou, A. (2022). Solar Energetic Particle Events and Forbush Decreases Driven by the Same Solar Sources. Universe, 8.","DOI":"10.3390\/universe8080403"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1002\/2016SW001470","article-title":"Extreme geomagnetic storms: Probabilistic forecasts and their uncertainties","volume":"15","author":"Riley","year":"2017","journal-title":"Space Weather"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"206","DOI":"10.1111\/risa.12765","article-title":"The Economic Impact of Space Weather: Where Do We Stand?","volume":"37","author":"Eastwood","year":"2017","journal-title":"Risk Anal."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Kumar, A., Kashyap, Y., and Kosmopoulos, P. (2023). Enhancing Solar Energy Forecast Using Multi-Column Convolutional Neural Network and Multipoint Time Series Approach. Remote Sens., 15.","DOI":"10.3390\/rs15010107"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2663","DOI":"10.1038\/s41598-018-20932-x","article-title":"Long-Term Study of Heart Rate Variability Responses to Changes in the Solar and Geomagnetic Environment","volume":"8","author":"Alabdulgader","year":"2018","journal-title":"Sci. Rep."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"419","DOI":"10.1029\/2018SW002085","article-title":"Spectral Analysis of the September 2017 Solar Energetic Particle Events","volume":"17","author":"Bruno","year":"2019","journal-title":"Space Weather"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1470","DOI":"10.1029\/2018SW001866","article-title":"Solar Ultraviolet Irradiance Observations of the Solar Flares During the Intense September 2017 Storm Period","volume":"16","author":"Chamberlin","year":"2018","journal-title":"Space Weather"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Pikulina, P., Mironova, I., Rozanov, E., and Karagodin, A. (2022). September 2017 Solar Flares Effect on the Middle Atmosphere. Remote Sens., 14.","DOI":"10.3390\/rs14112560"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Vankadara, R.K., Panda, S.K., Amory-Mazaudier, C., Fleury, R., Devanaboyina, V.R., Pant, T.K., Jamjareegulgarn, P., Haq, M.A., Okoh, D., and Seemala, G.K. (2022). Signatures of Equatorial Plasma Bubbles and Ionospheric Scintillations from Magnetometer and GNSS Observations in the Indian Longitudes during the Space Weather Events of Early September 2017. Remote Sens., 14.","DOI":"10.3390\/rs14030652"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"e2021SW002806","DOI":"10.1029\/2021SW002806","article-title":"Multi-Instrument Investigation of the Impact of the Space Weather Events of 6\u201310 September 2017","volume":"19","author":"Amaechi","year":"2021","journal-title":"Space Weather"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1709","DOI":"10.1029\/2018SW001927","article-title":"Analysis of the Solar Flare Effects of 6 September 2017 in the Ionosphere and in the Earth\u2019s Magnetic Field Using Spherical Elementary Current Systems","volume":"16","author":"Curto","year":"2018","journal-title":"Space Weather"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1","DOI":"10.5194\/ars-16-1-2018","article-title":"IRI the International Standard for the Ionosphere","volume":"16","author":"Bilitza","year":"2018","journal-title":"Adv. Radio Sci."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"299","DOI":"10.1007\/s11214-011-9819-3","article-title":"Cosmic-Ray Modulation Equations","volume":"176","author":"Moraal","year":"2013","journal-title":"Space Sci. Rev."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Dorman, L.I. (2004). Cosmic Rays in the Earth\u2019s Atmosphere and Underground, Springer.","DOI":"10.1007\/978-1-4020-2113-8"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1030","DOI":"10.1016\/j.nima.2010.08.091","article-title":"The Yangbajing Muon\u2013Neutron Telescope","volume":"Volume 623","author":"Zhang","year":"2010","journal-title":"Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1016\/j.nima.2017.09.008","article-title":"An underground laboratory as a facility for studies of cosmic-ray solar modulation","volume":"Volume 875","author":"Banjanac","year":"2017","journal-title":"Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"e2020SW002712","DOI":"10.1029\/2020SW002712","article-title":"Modeling Meteorological Effects on Cosmic Ray Muons Utilizing Multivariate Analysis","volume":"19","author":"Banjanac","year":"2021","journal-title":"Space Weather"},{"key":"ref_37","unstructured":"Ferguson, J. (1998). Computer Programs for Assessment of Long-Wavelength Radio Communications, Version 2.0: User\u2019s Guide and Source Files, Space and Naval Warfare Systems Center."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Mitra, A.P. (1974). Lonospheric Effects of Solar Flares, Springer.","DOI":"10.1007\/978-94-010-2231-6"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Wait, J.R., and Spies, K.P. (1964). Characteristics of the Earth-Ionosphere Waveguide for VLF Radio Waves.","DOI":"10.6028\/NBS.TN.300"},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Sre\u0107kovi\u0107, V.A., \u0160uli\u0107, D.M., Vuj\u010di\u0107, V., Miji\u0107, Z.R., and Ignjatovi\u0107, L.M. (2021). Novel Modelling Approach for Obtaining the Parameters of Low Ionosphere under Extreme Radiation in X-Spectral Range. Appl. Sci., 11.","DOI":"10.3390\/app112311574"},{"key":"ref_41","unstructured":"(2022, December 14). AR12673 History. Available online: http:\/\/helio.mssl.ucl.ac.uk\/helio-vo\/solar_activity\/arstats\/arstats_page4.php?region=12673."},{"key":"ref_42","unstructured":"(2022, January 22). Space Weather Prediction Center (IZMIRAN). Available online: http:\/\/spaceweather.izmiran.ru\/eng\/dbs.html."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"A17","DOI":"10.1051\/swsc\/2018005","article-title":"Verification of real-time WSA\u2212ENLIL+Cone simulations of CME arrival-time at the CCMC from 2010 to 2016","volume":"8","author":"Wold","year":"2018","journal-title":"J. Space Weather Space Clim."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"295","DOI":"10.1007\/s11038-008-9282-7","article-title":"The SOHO\/LASCO CME Catalog","volume":"104","author":"Gopalswamy","year":"2009","journal-title":"Earth Moon Planets"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"357","DOI":"10.1029\/2018SW001993","article-title":"Modeling the Multiple CME Interaction Event on 6\u20139 September 2017 with WSA-ENLIL+Cone","volume":"17","author":"Werner","year":"2019","journal-title":"Space Weather"},{"key":"ref_46","unstructured":"(2022, November 10). SPDF - OMNIWeb Service, Available online: https:\/\/spdf.gsfc.nasa.gov\/pub\/data\/omni\/low_res_omni\/."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"505","DOI":"10.1007\/BF00733438","article-title":"Energetic particle experiment ERNE","volume":"162","author":"Torsti","year":"1995","journal-title":"Sol. Phys."},{"key":"ref_48","unstructured":"(2022, October 25). Multi-Source Spectral Plots (MSSP) of Energetic Particle, Available online: https:\/\/omniweb.gsfc.nasa.gov\/ftpbrowser\/flux_spectr_m.html."},{"key":"ref_49","first-page":"2006","article-title":"New insights from cross-correlation studies between solar activity indices and cosmic-ray flux during Forbush decrease events","volume":"71","author":"Banjanac","year":"2022","journal-title":"Adv. Space Res."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1086\/172995","article-title":"BATSE Observations of Gamma-Ray Burst Spectra. I. Spectral Diversity","volume":"413","author":"Band","year":"1993","journal-title":"Astrophys. J."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"400","DOI":"10.1086\/163623","article-title":"Shock acceleration of electrons and ions in solar flares","volume":"298","author":"Ellison","year":"1985","journal-title":"Astrophys. J."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"1191","DOI":"10.1063\/1.1358071","article-title":"Energy spectra of high-energy SEP event protons derived from statistical analysis of experimental data on a large set of events","volume":"552","author":"Mottl","year":"2001","journal-title":"AIP Conf. Proc."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"62","DOI":"10.3847\/0004-637X\/821\/1\/62","article-title":"Double power laws in the event-integrated solar energetic particle spectrum","volume":"821","author":"Zhao","year":"2016","journal-title":"Astrophys. J."},{"key":"ref_54","first-page":"99","article-title":"On the flux saturation of SOHO\/ERNE proton events","volume":"33","author":"Miteva","year":"2020","journal-title":"Bulg. Astron. J."},{"key":"ref_55","unstructured":"(2022, October 10). NOAA National Centers for Environmental Information, Available online: https:\/\/satdat.ngdc.noaa.gov\/sem\/goes\/data\/avg\/."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"775","DOI":"10.1016\/j.jastp.2007.01.012","article-title":"D-region electron density evaluated from VLF amplitude time delay during X-ray solar flares","volume":"69","author":"Grubor","year":"2007","journal-title":"J. Atmos. Sol.-Terr. Phys."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"1595","DOI":"10.1016\/j.asr.2014.02.022","article-title":"Sensing the Earth\u2019s low ionosphere during solar flares using VLF signals and goes solar X-ray data","volume":"53","author":"Kolarski","year":"2014","journal-title":"Adv. Space Res."},{"key":"ref_58","first-page":"105","article-title":"Monitoring solar activity during 23\/24 solar cycle minimum through VLF radio signals","volume":"52","author":"Kolarski","year":"2022","journal-title":"Contrib. Astron. Obs. Skaln. Pleso"},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"1029","DOI":"10.1016\/j.asr.2015.12.025","article-title":"A study of VLF signals variations associated with the changes of ionization level in the D-region in consequence of solar conditions","volume":"57","author":"Mihajlov","year":"2016","journal-title":"Adv. Space Res."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"012070","DOI":"10.1088\/1742-6596\/1181\/1\/012070","article-title":"Investigation of exceptional solar activity in September 2017: GLE 72 and unusual Forbush decrease in GCR","volume":"1181","author":"Dorman","year":"2019","journal-title":"J. Phys. Conf. Ser."},{"key":"ref_61","unstructured":"(2022, October 20). Neutron Monitor Database. Available online: https:\/\/www.nmdb.eu\/."},{"key":"ref_62","unstructured":"Kojima, H., Shibata, S., Oshima, A., Hayashi, Y., Antia, H., Dugad, S., Fujii, T., Gupta, S.K., Kawakami, S., and Minamino, M. (2013, January 2\u20139). Rigidity Dependence of Forbush Decreases. Proceedings of the 33rd International Cosmic Ray Conference, Rio de Janeiro, Brazil."},{"key":"ref_63","unstructured":"(2022, October 15). Near-Earth Interplanetary Coronal Mass Ejections Since January 1996. Available online: https:\/\/izw1.caltech.edu\/ACE\/ASC\/DATA\/level3\/icmetable2.htm."},{"key":"ref_64","unstructured":"(2022, November 10). Soho Lasco Cme Catalog Cdaw Data Center, Available online: https:\/\/cdaw.gsfc.nasa.gov\/CME_list\/."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"21","DOI":"10.3847\/1538-4365\/ab6216","article-title":"CME\u2013CME Interactions as Sources of CME Geoeffectiveness: The Formation of the Complex Ejecta and Intense Geomagnetic Storm in 2017 Early September","volume":"247","author":"Scolini","year":"2020","journal-title":"Astrophys. J. Suppl. Ser."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"487","DOI":"10.1029\/2018SW001941","article-title":"Forbush Decreases and Geomagnetic Storms During a Highly Disturbed Solar and Interplanetary Period, 4\u201310 September 2017","volume":"17","author":"Badruddin","year":"2019","journal-title":"Space Weather"},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"579","DOI":"10.1007\/s11207-012-0195-2","article-title":"Solar Energetic Particle Events in the 23rd Solar Cycle: Interplanetary Magnetic Field Configuration and Statistical Relationship with Flares and CMEs","volume":"282","author":"Miteva","year":"2013","journal-title":"Sol. Phys."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"A42","DOI":"10.1051\/0004-6361\/202037528","article-title":"Non-interacting coronal mass ejections and solar energetic particles near the quadrature configuration of Solar TErrestrial RElations Observatory","volume":"638","author":"Ravishankar","year":"2020","journal-title":"Astron. Astrophys."},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1007\/s10509-015-2279-6","article-title":"Solar flare induced ionospheric D-region perturbation as observed at a low latitude station Agra, India","volume":"357","author":"Pandey","year":"2015","journal-title":"Astrophys. Space Sci."},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"747","DOI":"10.1134\/S0016793220060043","article-title":"Reconstruction of the Parameters of the Lower Midlatitude Ionosphere in M- and X-Class Solar Flares","volume":"60","author":"Gavrilov","year":"2020","journal-title":"Geomagn. Aeron."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"1923","DOI":"10.18520\/cs\/v114\/i09\/1923-1926","article-title":"Extreme space-weather effect on D-region ionosphere in Indian low latitude region","volume":"114","author":"Venkatesham","year":"2018","journal-title":"Curr. Sci."},{"key":"ref_72","doi-asserted-by":"crossref","unstructured":"Thomson, N.R., Rodger, C.J., and Clilverd, M.A. (2005). Large solar flares and their ionospheric D region enhancements. J. Geophys. Res. Space Phys., 110.","DOI":"10.1029\/2005JA011008"},{"key":"ref_73","unstructured":"Grubor, D., \u0160uli\u0107, D., and \u017digman, V. (2007, January 2\u201313). The response of the Earth-ionosphere VLF waveguide to the January 15-22 2005 solar events. Proceedings of the IUGG XXIV General Assembly, Perugia, Italy."},{"key":"ref_74","unstructured":"Kolarski, A., and Grubor, D. (2020, January 13\u201317). Monitoring VLF signal perturbations induced by solar activity during January 2005. Proceedings of the The XIX Serbian Astronomical Conference, Belgrade, Serbia."},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"788","DOI":"10.1002\/2014JA020751","article-title":"Response of the low-latitude D region ionosphere to extreme space weather event of 14\u201316 December 2006","volume":"120","author":"Kumar","year":"2015","journal-title":"J. Geophys. Res. Space Phys."},{"key":"ref_76","first-page":"197","article-title":"Study of solar flare induced D-region ionosphere changes using VLF amplitude observations at a low latitude site","volume":"43","author":"Tan","year":"2014","journal-title":"Indian J. Radio Space Phys."},{"key":"ref_77","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1016\/j.jastp.2003.09.009","article-title":"Solar flare induced ionospheric D-region enhancements from VLF phase and amplitude observations","volume":"66","author":"McRae","year":"2004","journal-title":"J. Atmos. Sol.-Terr. Phys."},{"key":"ref_78","doi-asserted-by":"crossref","first-page":"13","DOI":"10.3847\/0004-637X\/827\/1\/13","article-title":"Transient galactic cosmic-ray modulation during solar cycle 24: A comparative study of two prominent forbush decrease events","volume":"827","author":"Zhao","year":"2016","journal-title":"Astrophys. J."},{"key":"ref_79","doi-asserted-by":"crossref","first-page":"1025","DOI":"10.1007\/s11207-016-0863-8","article-title":"Solar Activity Parameters and Associated Forbush Decreases During the Minimum between Cycles 23 and 24 and the Ascending Phase of Cycle 24","volume":"291","author":"Lingri","year":"2016","journal-title":"Sol. Phys."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/15\/5\/1403\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T18:45:43Z","timestamp":1760121943000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/15\/5\/1403"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,3,2]]},"references-count":79,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2023,3]]}},"alternative-id":["rs15051403"],"URL":"https:\/\/doi.org\/10.3390\/rs15051403","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,3,2]]}}}