Solnechno-Zemnaya Fizika Solnechno-Zemnaya Fizika Солнечно-земная физика 2712-9640 103600 10.12737/szf-113202513 15-я Российско-Китайская конференция по космической погоде, 9 - 13 сентября 2024 г., Институт солнечно-земной физики СО РАН, Иркутск, Россия The 15th Russian-Chinese Workshop on Space Weather, September 9–13, 2024, Institute of Solar-Terrestrial Physics SB RAS, Irkutsk, Russia 15-я Российско-Китайская конференция по космической погоде, 9 - 13 сентября 2024 г., Институт солнечно-земной физики СО РАН, Иркутск, Россия The Rayleigh—Taylor instability as a trigger of solar flares Неустойчивость Рэлея—Тейлора как триггер солнечных вспышек Степанов Александр Владимирович Stepanov Aleksandr Vladimirovich stepanov@gaoran.ru

доктор физико-математических наук;

doctor of physical and mathematical sciences;

 Зайцев Валерий Васильевич Zaitsev Valeriy Vasilyevich za130@ipfran.ru

доктор физико-математических наук;

doctor of physical and mathematical sciences;

 Главная (Пулковская) астрономическая обсерватория РАН Санкт-Петербург Россия Central Astronomical Observatory at Pulkovo St. Petersburg Russian Federation Физико-технический институт им. А.Ф. Иоффе Санкт-Петербург Россия Ioffe Institute St. Petersburg Russian Federation Институт прикладной физики им. А.В. Гапонова-Грехова РАН Нижний Новгород Россия Institute of Applied Physics RAS Nizhny Novgorod Russian Federation 22 09 2025 22 09 2025 11 3 125 131 04 03 2025 03 04 2025 https://zh-szf.ru/en/nauka/article/103600/view

Обзор работ авторов посвящен фундаментальной роли неустойчивости Рэлея—Тейлора (НРТ) как триггера вспышечного энерговыделения. Исследованы два случая НРТ: вблизи оснований корональной магнитной петли и в ее вершине. В первом случае требуется предварительный нагрев хромосферной плазмы, который может быть вызван джоулевой диссипацией в частично ионизированной плазме при сопротивлении Каулинга. НРТ в вершине петли обусловлена расположенным над ней протуберанцем. Определены условия развития НРТ как триггера вспышки в этих двух случаях. Показано, что НРТ возбуждает сверхдрайсеровское электрическое поле в хромосферных основаниях петли. Этим можно объяснить громадное количество ускоренных во вспышке частиц. Неустойчивость Рэлея—Тейлора является также причиной появления быстрых (~10 c) предвестников вспышек.

The review of authors’ papers is devoted to the essential role of the Rayleigh—Taylor instability (RTI) as a trigger of flare energy release. We have analyzed two cases of RTI: near coronal loop footpoints and at the loop top. RTI near loop footpoints requires pre-heating of chromospheric plasma. This pre-heating can be realized due to Joule dissipation in partially ionized plasma under condition of the Cowling resistivity. RTI at the loop top arises in current-carrying coronal loop loaded by prominence. We have determined the conditions of RTI as a flare trigger in both cases. It is shown that RTI generates super-Dreicer electric field in the chromospheric parts of a loop. This is the promising solution of longstanding “number problem” of particle acceleration. RTI can be also a cause of prompt (~10 s) hot onset precursor events (HOPE).

 Солнце триггер вспышек джоулева диссипация ускорение частиц Sun flare trigger Joule dissipation particle acceleration Работа выполнена при поддержке гранта РНФ № 22-12-00308-П The work was financially supported by RSF (Grant No. 22-12-00308-P)

Андреев Г.В. Расчет сечения ионизации электронным ударом для атомов водорода и азота. Физико-химическая кинетика в газовой динамике. 2010, т. 9, с. 1–2. Alfvén H., Carlqvist P. Currents in the solar atmosphere and a theory of solar flares. Solar Phys. 1967, vol. 1, p. 220–228. DOI: 10.1007/BF00150857. Зайцев В.В., Степанов А.В. К природе быстрых рентгеновских предвестников солнечных вспышек. Письма в Астрономический журнал. 2025, т. 51, № 1. (В печати). Andreev G.V. Calculation of ionization cross-section by electron shock for hydrogen and nitrogen atoms. Physical-Chemical Kinetics in Gas Dynamics. 2010, vol. 9, pp. 1–2. (In Russian). Мешалкина Н.С., Алтынцев А.Т. Проявления нагрева в начале вспышки 29 июня 2012. Солнечно-земная физика. 2024, т. 10, № 3, с. 13–20. DOI: 10.12737/szf-103202402 // Meshalkina N.S., Altyntsev A.T. Heating manifestations at the onset of the 29 June 2012 flare. Sol.-Terr. Phys. 2024, vol. 10, iss. 3. DOI: 10.12737/stp-103202402. Awasthi A.K., Jain R. Multi-wavelength diagnostics of precursor phase in solar flares. First Asia-Pacific Solar Physics Meeting. Astron. Soc. India Conf. 2011, vol. 2, pp. 297–305. Степанов А.В., Зайцев В.В. Магнитосферы активных областей Солнца и звезд. М.: Физматлит, 2018, 387 с. Battaglia A.F., Hudson H., Warmuth A., et al. The existence of hot X-ray onsets in solar flares. Astron. Astrophys. 2023, vol. 679, article number A139. DOI: 10.1051/0004-6361/202347706. Струминский А.Б., Садовский А.М., Григорьева И.Ю. Критерии для предсказания протонных событий по солнечным наблюдениям в реальном времени. Геомагнетизм и аэрономия. 2024, т. 64, № 2, с. 163–174. DOI: 10.31857/S0016794024020019. Brown J.C. On the ionization of hydrogen in optical flares. Solar Phys. 1973, vol. 29, pp. 421–427. DOI: 10.1007/BF00150822. Alfvén H., Carlqvist P. Currents in the Solar Atmosphere and a Theory of Solar Flares. Solar Phys. 1967, vol. 1, p. 220–228. DOI: 10.1007/BF00150857. da Silva D. F., Hui L., Simoes P.J.A., et al. Statistical analysis of the onset temperature of solar flares in 2010–2011. Monthly Notices of the Royal Astronomical Society. 2023, vol. 525, iss. 3, pp. 4143–4148. DOI: 10.1093/mnras/stad2244. Awasthi A.K., Jain R. Multi-wavelength diagnostics of precursor phase in solar flares. First Asia-Pacific Solar Physics Meeting. Astron. Soc. India Conf. 2011, vol. 2, pp. 297–305. Emslie A.G., Henoux J.-C. The electrical current structure associated with solar flare electrons accelerated by large-scale electric fields. Astrophys. J. 1995, vol. 446, p. 371. DOI: 10.1086/175796. Battaglia A.F., Hudson H., Warmuth A., et al. The existence of hot X-ray onsets in solar flares. Astron. Astrophys. 2023, vol. 679, article number A139. DOI: 10.1051/0004-6361/202347706. Fritzová-Švestková L., Švestka Z. Electron density in flares. II Results of measurement. Solar Phys. 1967, vol. 2, pp. 87–97. DOI: 10.1007/BF00155894. Brown J.C. On the Ionization of Hydrogen in Optical Flares. Solar Phys. 1973, vol. 29, pp. 421–427. DOI: 10.1007/BF00150822. Giovanelli R.G. A theory of chromospheric flares. Nature. 1946, vol. 158, pp. 81–82. DOI: 10.1038/158081a0. da Silva D. F., Hui L., Simoes P.J.A., et al. Statistical analysis of the onset temperature of solar flares in 2010–2011. Monthly Notices of the Royal Astronomical Society. 2023, vol. 525, iss. 3, pp. 4143–4148. DOI: 10.1093/mnras/stad2244. Hoyng P., Brown J.C., van Beek H.F. High time resolution analysis of solar hard X-ray flares observed on board the ESRO TD-1A satellite, Solar Phys. 1976, vol. 48, P.197–254. DOI: 10.1007/BF00151992. Emslie A.G., Henoux J.-C. The electrical current structure associated with solar flare electrons accelerated by large-scale electric fields. Astrophys. J. 1995, vol. 446, p. 371. DOI: 10.1086/175796. Hudson H., Simoes P.J.A., Fletcher L., et al. Hot X-ray onsets of solar flares. Monthly Notices of the Royal Astronomical Society. 2021, vol. 501, iss. 1, pp. 1273–1281. DOI: 10.1093/mnras/staa3664. Fritzová-Švestková L., Švestka Z. Electron density in flares. II Results of measurement. Solar Phys. 1967, vol. 2, pp. 87–97. DOI: 10.1007/BF00155894. Kane S.R., Hurley K., McTiernan J.M., et al. Energy release and dissipation during giant solar flares. Astrophys. J. Lett. 1995, vol. 446, p. L47. DOI: 10.1086/187927. Giovanelli R.G. A theory of chromospheric flares. Nature. 1946, vol. 158, pp. 81–82. DOI: 10.1038/158081a0. Kumar P., Srivastava A.K., Somov, B.V., et al. Evidence of solar flare triggering due to loop-loop interaction caused by footpoint shear motion. Astrophys. J. 2010, vol. 723, pp. 1651–1664. DOI: 10.1088/0004-637X/723/2/1651. Hoyng P., Brown J.C., van Beek H.F. High time resolution analysis of solar hard X-ray flares observed on board the ESRO TD-1A satellite, Solar Phys. 1976, vol. 48, P.197–254. DOI: 10.1007/BF00151992. Kusano K., Bamba Y., Yamamoto T.T. Magnetic field structures triggering solar flares and coronal mass ejections. Astrophys. J. 2012, vol. 760, no. 1, p. 31. DOI: 10.1088/0004-637X/760/1/31. Hudson H., Simoes P.J.A., Fletcher L., et al. Hot X-ray onsets of solar flares. Monthly Notices of the Royal Astronomical Society. 2021, vol. 501, iss. 1, pp. 1273–1281. DOI: 10.1093/mnras/staa3664. Ledentsov L. Thermal trigger for solar flares I: Fragmentation of the preflare current layer. Solar Phys. 2021, vol. 296, article number 74. DOI: 10.1007/s11207-021-01817-1. Kane S.R., Hurley K., McTiernan J.M., et al. Energy release and dissipation during giant solar flares. Astrophys. J. Lett. 1995, vol. 446, p. L47. DOI: 10.1086/187927. Masuda S., Kosugi T., Hara H., et al. A loop-top hard X-ray source in a compact solar flare as evidence for magnetic reconnection. Nature. 1994, vol. 371, pp. 495–497. DOI: 10.1038/371495a0. Kumar P., Srivastava A.K., Somov, B.V., et al. Evidence of solar flare triggering due to loop-loop interaction caused by footpoint shear motion. Astrophys. J. 2010, vol. 723, pp. 1651–1664. DOI: 10.1088/0004-637X/723/2/1651. Meshalkina N.S., Altyntsev A.T. Heating manifestations at the onset of the 29 June 2012 flare. Solar-Terrestrial Physics. 2024, vol. 10, iss. 3, pp/ 1–17. DOI: 10.12737/stp-103202402. Kusano K., Bamba Y., Yamamoto T.T. Magnetic field structures triggering solar flares and coronal mass ejections. Astrophys. J. 2012, vol. 760, no. 1, p. 31. DOI: 10.1088/0004-637X/760/1/31. Melrose D.B. Neutralized and unneutralized current patterns in the solar corona. Astrophys. J. 1991, vol. 381, p. 306. DOI: 10.1086/170652. Ledentsov L. Thermal trigger for solar flares I: Fragmentation of the preflare current layer. Solar Phys. 2021, vol. 296, article number 74. DOI: 10.1007/s11207-021-01817-1. Miller J.A., Cargill P.J., Emslie A.G., et al. Critical issues for understanding particle acceleration in impulsive solar flares. J. Geophys. Res. 1997, vol. 102, pp. 14631–14659. DOI: 10.1029/97JA00976. Masuda S., Kosugi T., Hara H., et al. A loop-top hard X-ray source in a compact solar flare as evidence for magnetic reconnection. Nature. 1994, vol. 371, pp. 495–497. DOI: 10.1038/371495a0. Pustil’nik L.A. Instability of quiescent prominences and the origin of solar flares. Soviet Astronomy. 1974, vol. 17, p. 763. Melrose D.B. Neutralized and Unneutralized current patterns in the solar corona. Astrophys. J. 1991, vol. 381, p. 306. DOI: 10.1086/170652. Sharykin I.N., Kosovichev A.G. Dynamics of electric currents, magnetic field topology, and helioseismic response of a solar flare. Astrophys. J. 2015, vol. 808, no.1. DOI: 10.1088/0004-637X/808/1/72. Miller J.A., Cargill P.J., Emslie A.G., et al. Critical issues for understanding particle acceleration in impulsive solar flares. J. Geophys. Res. 1997, vol. 102, pp. 14631–14659. DOI: 10.1029/97JA00976. Somov B.V. Magnetic reconnection and topological trigger in physics of large solar flares. ?2008, vol. 17, no. 2-3, pp. 421–454. DOI: 10.48550/arXiv.0901.4697. Pustil’nik L.A. Instability of quiescent prominences and the origin of solar flares. Soviet Astronomy. 1974, vol. 17, p. 763. Stepanov A.V., Zaitsev V.V. Magnetospheres of Active Regions of the Sun and Stars. Moscow, Fizmatlit Publ., 2018, 387 p. (In Russian). Sharykin I.N., Kosovichev A.G. Dynamics of electric currents, magnetic field topology, and helioseismic response of a solar flare. Astrophys. J. 2015, vol. 808, no. 1. DOI: 10.1088/0004-637X/808/1/72. Stepanov A.V., Zaitsev V.V., Kupriyanova E.G. Features of electric current dissipation in the solar atmosphere. Geomagnetism and Aeronomy. 2024, vol. 64, pp. 1203–1214. DOI: 10.1134/S001679322470030. Somov B.V. Magnetic reconnection and topological trigger in physics of large solar flares. Asian J. Phys. 2008, vol. 17, no. 2-3, pp. 421–454. DOI: 10.48550/arXiv.0901.4697. Struminsky A.B. Sadovsky A.M., Grogoryeva I.Yu. Criteria for forecasting proton events from real time solar observations. Geomagnetism and Aeronomy. 2024, vol. 64, no. 2, pp. 139–149. DOI: 10.1134/S0016793223600984. Stepanov A.V., Zaitsev V.V., Kupriyanova E.G. Features of electric current dissipation in the solar atmosphere. Geomagnetism and Aeronomy. 2024, vol. 64, pp. 1203–1214. DOI: 10.1134/S001679322470030. Syrovatskii S.I. Current sheet characteristics and thermal trigger of solar flares. Soviet Astronomy Letters. 1976, vol. 2, p. 13. Syrovatskii S.I. Current sheet characteristics and thermal trigger of solar flares. Soviet Astronomy Lett. 1976, vol. 2, p. 13. Verner D.A., Ferland C.J. Atomic data for astrophysics. I. Radiative recombination rates for H-like, He-like, Li-like, and Na-like ions over a broad range of temperature. Astrophys. J. Suppl. Ser. 1996, vol. 103, no. 2, pp. 467–473. DOI: 10.1086/192284. Verner D.A., Ferland C.J. Atomic data for astrophysics. I. Radiative recombination rates for H-like, He-like, Li-like, and Na-like ions over a broad range of temperature. Astrophys. J. Suppl. Ser. 1996, vol. 103, no. 2, pp. 467–473. DOI: 10.1086/192284. Veronig A., Vršnak B., Dennis B.R., et al. Investigation of the Neupert effect in solar flares. I. Statistical properties and the evaporation model. Astron. Astrophys. 2002, vol. 392, no. 2, pp. 699–712. DOI: 10.1051/0004-6361:20020947. Veronig A., Vršnak B., Dennis B. R., et al. Investigation of the Neupert effect in solar flares. I. Statistical properties and the evaporation model. Astron. Astrophys. 2002, vol. 392, no. 2, pp. 699–712. DOI: 10.1051/0004-6361:20020947. Wang H., Liu Ch., Ahn K., et al. High-resolution observations of flare precursors in the low solar atmosphere. Nature Astronomy. 2017, vol. 1, article number 0085. DOI: 10.1038/s41550-017-0085. Wang H., Liu Ch., Ahn K., et al. High-resolution observations of flare precursors in the low solar atmosphere. Nature Astronomy. 2017, vol. 1, article number 0085. DOI: 10.1038/s41550-017-0085. Zaitsev V.V. Ultrafine magnetic structures in the chromosphere. Geomagnetism and Aeronomy. 2015, vol. 55, pp. 846–849. DOI: 10.1134/S0016793215070294. Zaitsev V.V. Ultrafine magnetic structures in the chromosphere. Geomagnetism and Aeronomy. 2015, vol. 55, pp. 846–849. DOI: 10.1134/S0016793215070294. Zaitsev V.V., Stepanov A.V. Towards the circuit theory of solar flares. Solar Phys. 1992, vol. 139, pp. 343–356. DOI: 10.1007/BF00159158. Zaitsev V.V., Stepanov A.V. Towards the circuit theory of solar flares. Solar Phys. 1992, vol. 139, pp. 343–356. DOI: 10.1007/BF00159158. Zaitsev V.V., Urpo S., Stepanov A.V. Temporal dynamics of Joule heating and DC-electric field acceleration in single flare loop. Astron. Astrophys. 2000, vol. 357, pp. 1105–1114. Zaitsev V.V., Urpo S., Stepanov A.V. Temporal dynamics of Joule heating and DC-electric field acceleration in single flare loop. Astron. Astrophys. 2000, vol. 357, pp. 1105–1114. Zaitsev V.V., Stepanov A.V. Particle acceleration and plasma heating in the chromosphere. Solar Phys. 2015, vol. 290, pp. 3559–3572. DOI: 10.1007/s11207-015-0731-y. Zaitsev V.V., Stepanov A.V. Particle acceleration and plasma heating in the chromosphere. Solar Phys. 2015, vol. 290, pp. 3559–3572. DOI: 10.1007/s11207-015-0731-y. Zaitsev V.V., Stepanov A.V. On the nature of fast X-ray precursors of solar flares. Astronomy Lett. 2025, vol. 51, no. 1. (In print). Zaitsev V.V., Kronshtadtov P.V., Stepanov A.V. Rayleigh — Taylor instability and excitation of super-Dreicer electric fields in the solar chromosphere. Solar Phys. 2016, vol. 291, pp. 3451–3459. DOI: 10.1007/s11207-016-0983-1. Zaitsev V.V., Kronshtadtov P.V., Stepanov A.V. Rayleigh — Taylor instability and excitation of super-Dreicer electric fields in the solar chromosphere. Solar Phys. 2016, vol. 291, pp. 3451–3459. DOI: 10.1007/s11207-016-0983-1. Zaitsev V.V., Stepanov A.V., Kronshtadtov P.V. On the possibility of heating the solar corona by heat fluxes from coronal magnetic structures. Solar Phys. 2020, vol. 295, article number 166. DOI: 10.1007/s11207-020-01732-x. Zaitsev V.V., Stepanov A.V., Kronshtadtov P.V. On the possibility of heating the solar corona by heat fluxes from coronal magnetic structures. Solar Phys. 2020, vol. 295, article number 166. DOI: 10.1007/s11207-020-01732-x. Zimovets I.V., Sharykin I.N., Gan W.Q. Relationships between photospheric vertical electric currents and hard X-ray sources in solar flares: Statistical study. Astrophys. J. 2020, vol. 891, no. 2. DOI: 10.3847/1538-4357/ab75be. Zimovets I.V., Sharykin I.N., Gan W.Q. Relationships between photospheric vertical electric currents and hard X-ray sources in solar flares: Statistical study. Astrophys. J. 2020, vol. 891, no. 2. DOI: 10.3847/1538-4357/ab75be.