What Does 2D Coronal Seismology Measure?
Abstract
Two-dimensional (2D) coronal seismology based on coronagraphic imaging spectroscopy has emerged as a promising method for mapping the coronal magnetic field, but the physical meaning of its inferred quantities under optically thin line-of-sight (LOS) integration remains uncertain. We investigate this problem by synthesizing coronagraphic observables from a global wave-driven magnetohydrodynamic model with a long LOS extent and a structured corona, and by applying the same analysis procedures used for observations. We compare the diagnosed density, wave propagation direction, phase speed, and magnetic-field strength with different LOS-weighted reference quantities from the model. We find that the measured density and the wave propagation direction are both well represented by LOS emissivity-weighted quantities. In contrast, the phase speed is not controlled by emissivity weighting alone: the LOS distribution of wave velocity amplitude also plays an important role. As a result, the inferred magnetic field is better represented by combining the emissivity-weighted density with an amplitude-dependent effective speed. Emissivity weighting nevertheless remains a reasonable approximation, and a useful baseline, over much of the field of view, especially where the LOS does not cross strongly structured plasma-sheet-like regions. These results clarify the physical interpretation of 2D coronal seismology and provide guidance for future coronal magnetic-field tomography and model-constrained applications.
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BibTeX
@misc{yang2026what,
title = {{What Does 2D Coronal Seismology Measure?}},
author = {Zihao Yang and Yuhong Fan and Giuliana de Toma and Sarah Gibson and Matthias Rempel},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.17433},
eprint = {2610.17433},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.17433},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - What Does 2D Coronal Seismology Measure?
AU - Zihao Yang
AU - Yuhong Fan
AU - Giuliana de Toma
AU - Sarah Gibson
AU - Matthias Rempel
PY - 2026
DA - 2026/10/12
PB - arXiv
DO - 10.48550/arxiv.2610.17433
UR - https://arxiv.org/abs/2610.17433
AB - Two-dimensional (2D) coronal seismology based on coronagraphic imaging spectroscopy has emerged as a promising method for mapping the coronal magnetic field, but the physical meaning of its inferred quantities under optically thin line-of-sight (LOS) integration remains uncertain. We investigate this problem by synthesizing coronagraphic observables from a global wave-driven magnetohydrodynamic model with a long LOS extent and a structured corona, and by applying the same analysis procedures used for observations. We compare the diagnosed density, wave propagation direction, phase speed, and magnetic-field strength with different LOS-weighted reference quantities from the model. We find that the measured density and the wave propagation direction are both well represented by LOS emissivity-weighted quantities. In contrast, the phase speed is not controlled by emissivity weighting alone: the LOS distribution of wave velocity amplitude also plays an important role. As a result, the inferred magnetic field is better represented by combining the emissivity-weighted density with an amplitude-dependent effective speed. Emissivity weighting nevertheless remains a reasonable approximation, and a useful baseline, over much of the field of view, especially where the LOS does not cross strongly structured plasma-sheet-like regions. These results clarify the physical interpretation of 2D coronal seismology and provide guidance for future coronal magnetic-field tomography and model-constrained applications.
ER -