STUDY OF THE PHYSICAL MECHANISM OF A SOLAR FLARE USING MHD MODELING OVER AN ACTIVE REGION: THE ONSET OF AN EXTENDED SURFACE OF MAGNETIC LINES PASSING THROUGH A CHAIN OF CURRENT DENSITY MAXIMA
Authors:
1.
Lebedev Physical Institute of the Russian Academy of Sciences
Moscow, Moscow, Russian Federation
Moscow, Moscow, Russian Federation
2.
Institute of Astronomy of the Russian Academy of Sciences
Type:
Сonference article
Published:
27.12.2024
Subject area:
UDK 52
UDK 53
UDK 520
UDK 521
UDK 523
UDK 524
UDK 52-1
UDK 52-6
GRNTI 41.00
GRNTI 29.35
GRNTI 29.31
GRNTI 29.33
GRNTI 29.27
GRNTI 29.05
OKSO 03.06.01
OKSO 03.05.01
OKSO 03.04.03
BBK 2
BBK 223
TBK 614
TBK 6135
BISAC SCI004000 Astronomy
BISAC SCI005000 Physics / Astrophysics
UDK 53
UDK 520
UDK 521
UDK 523
UDK 524
UDK 52-1
UDK 52-6
GRNTI 41.00
GRNTI 29.35
GRNTI 29.31
GRNTI 29.33
GRNTI 29.27
GRNTI 29.05
OKSO 03.06.01
OKSO 03.05.01
OKSO 03.04.03
BBK 2
BBK 223
TBK 614
TBK 6135
BISAC SCI004000 Astronomy
BISAC SCI005000 Physics / Astrophysics
Language:
English
Keywords:
solar flare; current sheet; MHD simulation; active region
Abstract (English):
The primary release of solar flare energy in the corona at altitudes of 15,000 — 70,000 km is explained by the physical mechanism of S.I. Syrovatsky, based on the rapid release of energy accumulated in the magnetic field of the current layer. The observed manifestations of the solar flare are explained by its electrodynamic model proposed by I.M. Podgorny. The model uses analogies with the electrodynamic model of a substorm, previously developed by its author. Since it is impossible to obtain the magnetic field configuration in the corona from observations, it is necessary to conduct MHD modeling. When setting the problem, no assumptions were made about the mechanism of the solar flare. For the numerical solution, an upwind absolutely implicit finite-difference scheme, conservative with respect to magnetic flux, was developed. The scheme is realized in the PERESVET computer program. A detailed study of the pre-flare state over the active region AR 10365 was conducted. The study revealed the emergence of an extended current sheet 50,000 km wide, which is a surface of magnetic lines passing through a chain of closely spaced current density maxima. The magnetic lines of the surface are in the form of arches located in the bright region of the flare emission. At the center of such a current sheet, a 3D maximum of current density does not necessarily have to be achieved. An appearance of a flare in such an arcade is explained by the fact that the main part of the surface of the magnetic arcs has properties that contribute to the development of flare instability.
The primary release of solar flare energy in the corona at altitudes of 15,000 — 70,000 km is explained by the physical mechanism of S.I. Syrovatsky, based on the rapid release of energy accumulated in the magnetic field of the current layer. The observed manifestations of the solar flare are explained by its electrodynamic model proposed by I.M. Podgorny. The model uses analogies with the electrodynamic model of a substorm, previously developed by its author. Since it is impossible to obtain the magnetic field configuration in the corona from observations, it is necessary to conduct MHD modeling. When setting the problem, no assumptions were made about the mechanism of the solar flare. For the numerical solution, an upwind absolutely implicit finite-difference scheme, conservative with respect to magnetic flux, was developed. The scheme is realized in the PERESVET computer program. A detailed study of the pre-flare state over the active region AR 10365 was conducted. The study revealed the emergence of an extended current sheet 50,000 km wide, which is a surface of magnetic lines passing through a chain of closely spaced current density maxima. The magnetic lines of the surface are in the form of arches located in the bright region of the flare emission. At the center of such a current sheet, a 3D maximum of current density does not necessarily have to be achieved. An appearance of a flare in such an arcade is explained by the fact that the main part of the surface of the magnetic arcs has properties that contribute to the development of flare instability.
Keywords:
solar flare; current sheet; MHD simulation; active region
solar flare; current sheet; MHD simulation; active region
1. Lin R.P., Krucker S., Hurford G.J., et al., 2003, Astrophysical Journal, 595, 2, p. L69
2. Syrovatskii S.I., 1966, Soviet physics, JETP, 23, 4, p. 754
3. Podgorny I.M., Balabin Y.V., Vashenyuk, et al., 2010, Astronomy Reports, 54, 7, p. 645
4. Podgorny I.M., Dubinin E.M., Israilevich P.L., et al., 1988, Geophysical Research Letters, 15, 13, p. 1538
5. Podgorny A.I. and Podgorny I.M., 2004, Computational Mathematics and Mathematical Physics, 44, 10, p. 1784
6. Podgorny A.I. and Podgorny I.M., 2013, Sun and Geosphere, 8, 2, p. 71
