11:45 〜 12:00
[PEM11-09] A Data-Constrained Magnetohydrodynamic Simulation of the X7.1 Solar Flare on 2024 October 1
キーワード：Solar Flares、Solar active region magnetic fields、Magnetohydrodynamics、Magnetohydrodynamical simulations
The solar active region 13842 produced two large X flares in 2024. The first one is an X7.1-class solar flare on 2024 October 01. To understand the initiation and early evolution of the X7.1 flare, we performed data-constrained magnetohydrodynamic (MHD) simulations. In this simulation, a nonlinear force-free field (NLFFF), which was extrapolated from the photospheric magnetic field 1 hour before the flare, was used as the initial condition of the MHD simulation.
The NLFFF reproduced highly sheared field lines that captured a sigmoidal structure, which was well seen in extreme ultraviolet observation. As a result, our simulation showed that the tether-cutting reconnection occurred between the sheared field lines at the strong current region, resulting in highly twisted magnetic flux ropes (MFRs). Eventually, they showed a complex eruption with couple of the magnetic reconnection and the torus instability. From our detailed analysis, we found that the magnetic reconnection in the pre-eruption phase is crucial in the subsequent eruption driven by the torus instability. This result indicates that the magnetic reconnection in the pre-eruption phase impacts the torus instability.
Furthermore, the magnetic reconnection was found to help accelerate the MFR even in the eruptive phase after the MFR had already become unstable to the torus instability. These results indicate that reconnection is not only a byproduct of the eruption but plays a significant role in accelerating the MFR in the eruption. In this paper, we will also compare the simulation results with observations and discuss the reliability of the simulation.
The NLFFF reproduced highly sheared field lines that captured a sigmoidal structure, which was well seen in extreme ultraviolet observation. As a result, our simulation showed that the tether-cutting reconnection occurred between the sheared field lines at the strong current region, resulting in highly twisted magnetic flux ropes (MFRs). Eventually, they showed a complex eruption with couple of the magnetic reconnection and the torus instability. From our detailed analysis, we found that the magnetic reconnection in the pre-eruption phase is crucial in the subsequent eruption driven by the torus instability. This result indicates that the magnetic reconnection in the pre-eruption phase impacts the torus instability.
Furthermore, the magnetic reconnection was found to help accelerate the MFR even in the eruptive phase after the MFR had already become unstable to the torus instability. These results indicate that reconnection is not only a byproduct of the eruption but plays a significant role in accelerating the MFR in the eruption. In this paper, we will also compare the simulation results with observations and discuss the reliability of the simulation.