Solar-Terrestrial Physics Solar-Terrestrial Physics Solar-Terrestrial Physics 2500-0535 113878 10.12737/stp-121202609 frfuog Results of current research Results of current research Results of current research Thermospheric effects during the magnetic superstorms in May 2024 and October-November 2003 in the Northern Hemisphere and the ionospheric response to them Thermospheric effects during the magnetic superstorms in May 2024 and October-November 2003 in the Northern Hemisphere and the ionospheric response to them https://orcid.org/0000-0002-8927-5814 Черниговская Марина Артуровна Chernigovskaya Marina Arturovna cher@iszf.irk.ru

кандидат физико-математических наук;

candidate of physical and mathematical sciences;

 https://orcid.org/0009-0009-2857-4333 Хабитуев Денис Сергеевич Khabituev Denis Sergeevich khabituev@iszf.irk.ru

кандидат физико-математических наук;

candidate of physical and mathematical sciences;

 Сетов Артём Геннадьевич Setov Artem Gennadyevich artemsetov@gmail.com

кандидат физико-математических наук;

candidate of physical and mathematical sciences;

 https://orcid.org/0000-0002-0847-3553 Ратовский Константин Геннадьевич Ratovsky Konstantin Gennadyevich ratovsky@iszf.irk.ru

кандидат физико-математических наук;

candidate of physical and mathematical sciences;

 https://orcid.org/0000-0001-7299-6546 Калишин Алексей Сергеевич Kalishin Alexey Sergeevich askalishin@aari.ru

кандидат технических наук;

candidate of technical sciences;

 https://orcid.org/0000-0003-3661-4197 Долгачева Светлана Александровна Dolgacheva Svetlana Aleksandrovna dolgachyova2010@yandex.ru Степанов Александр Егорович Stepanov Aleksandr Egorovich a_e_stepanov@ikfia.ysn.ru https://orcid.org/0000-0003-2254-6138 Белинская Анастасия Юрьевна Belinskaya Anastasiya Yuryevna belinskayaay@ipgg.sbras.ru

кандидат физико-математических наук;

candidate of physical and mathematical sciences;

 Бычков Василий Валентинович Bychkov Vasily Valentinovich vasily.v.bychkov@gmail.com

кандидат физико-математических наук;

candidate of physical and mathematical sciences;

 Григорьева Светлана Анатольевна Grigorieva Svetlana Anatolyevna ion@arti.igfuroran.ru Панченко Валерий Алексеевич Panchenko Valery Alekseevich panch@izmiran.ru https://orcid.org/0000-0003-0576-5443 Тимченко Александр Владимирович Timchenko Aleksandr Vladimirovich aleksandr.timchenko77@gmail.com Институт солнечно-земной физики СО РАН Иркутск Россия Institute of Solar-Terrestrial Physics SB RAS Irkutsk Russian Federation Институт солнечно-земной физики СО РАН Иркутск Россия Institute of Solar-Terrestrial Physics SB RAS Irkutsk Russian Federation Институт солнечно-земной физики СО РАН Иркутск Россия Institute of Solar-Terrestrial Physics SB RAS Irkutsk Russian Federation Институт солнечно-земной физики СО РАН Иркутск Россия Institute of Solar-Terrestrial Physics SB RAS Irkutsk Russian Federation Арктический и антарктический научно-исследовательский институт Санкт-Петербург Россия Arctic and Antarctic Research Institute St. Petersburg Russian Federation Арктический и антарктический научно-исследовательский институт Санкт-Петербург Россия Arctic and Antarctic Research Institute St. Petersburg Russian Federation Институт космофизических исследований и аэрономии им. Ю.Г. Шафера СО РАН Якутск Россия Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy SB RAS Yakutsk Russian Federation Институт нефтегазовой геологии и геофизики им. А.А. Трофимука СО РАН Новосибирск Россия Trofimuk Institute of Petroleum Geology and Geophysics SB RAS Novosibirsk Russian Federation Институт космофизических исследований и распространения радиоволн ДВО РАН Паратунка Россия Institute of Cosmophysical Research and Radio Wave Propagation FEB RAS Paratunka Russian Federation Институт геофизики им. Ю.П. Булашевича УрО РАН Екатеринбург Россия Institute of Geophysics UB RAS Ekaterinburg Russian Federation Институт земного магнетизма, ионосферы и распространения радиоволн им. Н.В. Пушкова РАН Москва, Троицк Россия Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation RAS Moscow, Troitsk Russian Federation Калининградский филиал Института земного магнетизма, ионосферы и распространения радиоволн им. Н.В. Пушкова РАН Калининград Россия West Department of Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation RAS Kaliningrad Russian Federation 25 03 2026 25 03 2026 12 1 68 86 08 07 2025 06 10 2025 https://naukaru.ru/en/nauka/article/113878/view

We study the spatiotemporal variations of ionospheric parameters over the regions of Eurasia by analyzing data from chains of high- and mid-latitude ionosondes during the extreme magnetic storm in May 2024. The analysis of ionospheric parameters allowed us to note strong latitudinal and longitudinal differences in variations of the analyzed parameters under quiet conditions before the onset of the magnetic storm and during its development. Almost immediately after the onset of the storm at 17:00 UT on May 10, 2024, according to data from all ionosondes, a sharp drop in the electron density at the height of the F2-layer maximum was recorded, regardless of the local time at the measurement point. Ionosondes of the high-latitude chain showed a complete absence of data (radio signal blackout) during the main and early recovery phases of the storm until the evening of May 12, 2024, i.e. more than one and a half days. Additional bursts of geomagnetic activity during the recovery phase of the storm were also accompanied by significant and prolonged decreases in the electron density according to ionosonde measurements at all longitudes of Eurasia. The recovery of ionospheric ionization began on May 14–15 at all longitudes of the mid- and high-latitude regions of Eurasia. A long-term negative disturbance of electron density covering a huge territory of mid-latitude Eurasia was caused by an extraordinary, catastrophic drop in the [O]/[N2] ratio according to satellite measurements of GUVI TIMED during the superstorm for almost three days. The response of the thermospheric composition of neutral gas to the processes developing at high latitudes of the Northern Hemisphere on May 10–15, 2024 was global, with penetration of the thermospheric disturbance at almost all longitudes up to the equatorial latitudes (~10° N) and with very low values of the [O]/[N2] ratio ~0.1÷0.4. Significant differences in the spatiotemporal variations of the thermospheric composition of neutral gas were revealed during the most extreme geomagnetic storms of the current 21st century — in May 2024 and October–November 2003 (Halloween storms). The magnetic superstorm in May 2024 was much more geoeffective than the superstorms in October–November 2003, and caused a significantly different ionospheric response at different longitudes and latitudes of the Northern Hemisphere.

We study the spatiotemporal variations of ionospheric parameters over the regions of Eurasia by analyzing data from chains of high- and mid-latitude ionosondes during the extreme magnetic storm in May 2024. The analysis of ionospheric parameters allowed us to note strong latitudinal and longitudinal differences in variations of the analyzed parameters under quiet conditions before the onset of the magnetic storm and during its development. Almost immediately after the onset of the storm at 17:00 UT on May 10, 2024, according to data from all ionosondes, a sharp drop in the electron density at the height of the F2-layer maximum was recorded, regardless of the local time at the measurement point. Ionosondes of the high-latitude chain showed a complete absence of data (radio signal blackout) during the main and early recovery phases of the storm until the evening of May 12, 2024, i.e. more than one and a half days. Additional bursts of geomagnetic activity during the recovery phase of the storm were also accompanied by significant and prolonged decreases in the electron density according to ionosonde measurements at all longitudes of Eurasia. The recovery of ionospheric ionization began on May 14–15 at all longitudes of the mid- and high-latitude regions of Eurasia. A long-term negative disturbance of electron density covering a huge territory of mid-latitude Eurasia was caused by an extraordinary, catastrophic drop in the [O]/[N2] ratio according to satellite measurements of GUVI TIMED during the superstorm for almost three days. The response of the thermospheric composition of neutral gas to the processes developing at high latitudes of the Northern Hemisphere on May 10–15, 2024 was global, with penetration of the thermospheric disturbance at almost all longitudes up to the equatorial latitudes (~10° N) and with very low values of the [O]/[N2] ratio ~0.1÷0.4. Significant differences in the spatiotemporal variations of the thermospheric composition of neutral gas were revealed during the most extreme geomagnetic storms of the current 21st century — in May 2024 and October–November 2003 (Halloween storms). The magnetic superstorm in May 2024 was much more geoeffective than the superstorms in October–November 2003, and caused a significantly different ionospheric response at different longitudes and latitudes of the Northern Hemisphere.

 mid- and high-latitude ionosphere ionosonde chains geomagnetic storm variations of ionospheric parameters mid- and high-latitude ionosphere ionosonde chains geomagnetic storm variations of ionospheric parameters The research was financially supported by the Russian Science Foundation (Project No. 25-17-00187, https:// rscf.ru/en/project/25-17-00187/). The works on observations and data pre-processing were supported by the Ministry of Science and Higher Education of the Russian Federation. The works on observations and data pre-processing were partially carried out with the support from the Ministry of Science and Higher Education of the Russian Federation (Project FWZZ-2022-0019); under the Government assignment (State Registration Number 122011700182-1); under clause 6.2. of the plan of Roshydromet RTW "Development of Methods and Means of Ground-Based Monitoring of the Geophysical Conditions over the Arctic" The research was financially supported by the Russian Science Foundation (Project No. 25-17-00187, https:// rscf.ru/en/project/25-17-00187/). The works on observations and data pre-processing were supported by the Ministry of Science and Higher Education of the Russian Federation. The works on observations and data pre-processing were partially carried out with the support from the Ministry of Science and Higher Education of the Russian Federation (Project FWZZ-2022-0019); under the Government assignment (State Registration Number 122011700182-1); under clause 6.2. of the plan of Roshydromet RTW "Development of Methods and Means of Ground-Based Monitoring of the Geophysical Conditions over the Arctic"

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