Apparent magnetic field decay in a solar flare from Zeeman splitting of the Mg 12.32 microns observations

@misc{deng2026apparent,
  title = {{Apparent magnetic field decay in a solar flare from Zeeman splitting of the Mg 12.32 microns observations}},
  author = {Yuanyong Deng and Xianyong Bai and Jie Hong and Wenxian Li and Jinliang Wang and Yuyang Ye and Kaifan Ji and Jiangtao Su and Yongliang Song and Yuliang Shen and Ziyao Hu and Xiao Yang and Dongguang Wang and Jiaben Lin and Junfeng Hou and Xiaoming Zhu and Xing Hu and Zhiwei Feng and Wei Duan and Biyuan Gao and Liyue Tong and Yang Bai and Jianwen Hua and Lianwei Zhao and Songbo Xu and Shoulin Wei},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.33502},
  eprint = {2610.33502},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.33502},
  note = {CC0},
}

TY  - UNPB
TI  - Apparent magnetic field decay in a solar flare from Zeeman splitting of the Mg 12.32 microns observations
AU  - Yuanyong Deng
AU  - Xianyong Bai
AU  - Jie Hong
AU  - Wenxian Li
AU  - Jinliang Wang
AU  - Yuyang Ye
AU  - Kaifan Ji
AU  - Jiangtao Su
AU  - Yongliang Song
AU  - Yuliang Shen
AU  - Ziyao Hu
AU  - Xiao Yang
AU  - Dongguang Wang
AU  - Jiaben Lin
AU  - Junfeng Hou
AU  - Xiaoming Zhu
AU  - Xing Hu
AU  - Zhiwei Feng
AU  - Wei Duan
AU  - Biyuan Gao
AU  - Liyue Tong
AU  - Yang Bai
AU  - Jianwen Hua
AU  - Lianwei Zhao
AU  - Songbo Xu
AU  - Shoulin Wei
PY  - 2026
DA  - 2026/10/24
PB  - arXiv
DO  - 10.48550/arxiv.2610.33502
UR  - https://arxiv.org/abs/2610.33502
AB  - The magnetic field is the most fundamental observable in solar physics, while solar flares are the most violent, rapid magnetic energy-release events in the solar atmosphere. Decades of observations and theory have sketched the framework of flare evolution and magnetic-field-related physical process, yet the actual magnetic field variations during flares remained poorly understood. The main obstacle is that magnetic-diagnostic spectral lines are distorted by transient flare activity, making traditional spectro-polarimetry inversions complicated. Using a mid-infrared solar telescope, we investigate spectroscopic evolution of the Mg 12.32 microns line during an X1.5-class flare. Owing to the exceptionally large Zeeman sensitivity of this line, magnetic field strength can be directly determined from the measured line separation. Our analysis reveals apparent magnetic field weakening beneath flare ribbons in the impulsive phase. Radiative-hydrodynamic simulations and atmospheric inversions confirm that the formation height of the Mg 12.32 microns line increases during the flare. We suggest this apparent field change probably originates either from elevated line-formation altitude or magnetic-field redistribution. Additional observations and modeling are needed to clarify these two contributions. This study demonstrates the capability of mid-infrared wavelengths to trace magnetic-field evolution during flares.
ER  -