A Data-constrained Magnetohydrodynamic Simulation of the X1.0 Solar Flare of 2021 October 28

The solar active region NOAA 12887 produced a strong X1.0 flare on 2021 October 28, which exhibits X-shaped ribbons and circle-shaped erupting filament. To understand the eruption process with these characteristics, we conducted data-constrained magnetohydrodynamics simulation using nonlinear force-free field of about an hour before as initial condition. Our reproduces filament observed in Ha images GONG 304 angstrom SDO/AIA suggests that two mechanisms can possibly contribute to magnetic eruption. One is torus instability pre-existing flux rope (MFR), other upward pushing by loops newly formed below MFR via continuous reconnection between sheared arcades. presence this evidenced observations 1600 brightening footpoints arcades at onset. clarify more essential for eruption, performed experimental lines suppressed. In case too, could erupt, but much reduced rising speed. We interpret result indicating not only driven instability, additionally accelerated under reconnection.