# Magnetohydrodynamic Simulations for Studying Solar Flare Trigger Mechanism

## TL;DR

This study uses 3D magnetohydrodynamic simulations based on Hinode satellite data to identify magnetic bipoles that can trigger solar flares, enhancing understanding of flare mechanisms and aiding space weather prediction.

## Contribution

It demonstrates that small emerging bipoles with specific orientations can effectively trigger solar flares, confirmed through data-constrained simulations of active region NOAA 10930.

## Key findings

- Certain small bipoles trigger flares when emerging into sheared magnetic fields
- Opposite polarity and reversed shear bipoles are key trigger structures
- Data-constrained simulations help identify flare-productive regions

## Abstract

In order to understand the flare trigger mechanism, we conducted three-dimensional magnetohydrodynamic simulations using a coronal magnetic field model derived from data observed by the Hinode satellite. Several types of magnetic bipoles were imposed into the photospheric boundary of the Non-linear Force-Free Field (NLFFF) model of Active Region NOAA 10930 on 2006 December 13 to investigate what kind of magnetic disturbance may trigger the flare. As a result, we confirm that certain small bipole fields, which emerge into the highly sheared global magnetic field of an active region, can effectively trigger a flare. These bipole fields can be classified into two groups based on their orientation relative to the polarity inversion line: the so called opposite polarity (OP) and reversed shear (RS) structures as it was suggested by Kusano et al. (2012). We also investigated the structure of the footpoints of reconnected field lines. By comparing the distribution of reconstructed field lines and the observed flare ribbons, the trigger structure of the flare can be inferred. Our simulation suggests that the data-constrained simulation taking into account both the large-scale magnetic structure and the small-scale magnetic disturbance such as emerging fluxes is a good way to find out a flare productive active region for space weather prediction.