Data-driven MHD Simulation of Successive Solar Plasma Eruptions

Solar flares and plasma eruptions are sudden releases of magnetic energy stored in the plasma atmosphere. To understand the physical mechanisms governing their occurrences, three-dimensional magnetic fields from the photosphere up to the corona must be studied. The solar photospheric magnetic fields are observable, whereas the coronal magnetic fields cannot be measured. One method for inferring coronal magnetic fields is performing data-driven simulations, which involves time-series observational data of the photospheric magnetic fields with the bottom boundary of magnetohydrodynamic simulations. We developed a data-driven method in which temporal evolutions of the observational vector magnetic field can be reproduced at the bottom boundary in the simulation by introducing an inverted velocity field. This velocity field is obtained by inversely solving the induction equation and applying an appropriate gauge transformation. Using this method, we performed a data-driven simulation of successive small eruptions observed by the Solar Dynamics Observatory and the Solar Magnetic Activity Telescope in 2017 November. The simulation well reproduced the converging motion between opposite-polarity magnetic patches, demonstrating successive formation and eruptions of helical flux ropes.

Automated summary

Solar flares and plasma eruptions are sudden releases of magnetic energy from the plasma atmosphere, and to better understand the physical mechanisms behind these events, studying three-dimensional magnetic fields from the photosphere up to the corona is crucial. As coronal magnetic fields are unmeasurable directly, a data-driven simulation approach utilizing observational data of photospheric magnetic fields is employed to infer the coronal magnetic fields, leading to a better reproduction of phenomena such as helical flux ropes formation and eruptions.