Spatial variation of energy transport mechanisms within solar flare ribbons

Solar flares release a tremendous amount of magnetic energy that subsequently manifests in several forms; the bulk of this energy is transported through the Sun’s atmosphere and explosively heats the chromosphere. While hard X-ray observations have pointed to flare-accelerated electrons as a primary means by which energy is transported following flares, alternative processes undoubtedly act alongside, or even instead of, those energetic electrons. To shed light on this we analysed flare-optimized, high-cadence Solar Orbiter observations. Footpoints from two flare ribbons were observed by the Spectral Imaging of the Coronal Environment (SPICE) instrument. Curiously, those footpoints exhibited contrasting behaviour: one had short-lived yet strong decreases in the Lyman β/Lyman γ line intensity ratio, whereas the other exhibited a more prolonged, moderate dip in that ratio. These observations were compared to synthetic spectra from radiation hydrodynamic simulations of flares driven by various energy transport mechanisms. This revealed that one footpoint was driven by energetic particle precipitation, while the other was driven by enhanced thermal heat flux. The implication is that energetic particles do not dominate along the entirety of flare ribbons. Critically, we must now focus on understanding where, when and why different mechanisms dominate in solar flare energy transport.

Keywords

Subject (DDC)

520 - Astronomie, Kartografie

Project

Event

Exhibition start date

Exhibition end date

Conference start date

Conference end date

Date of the last check

ISBN

ISSN

2397-3366

Language

English

Created during FHNW affiliation

Yes

Strategic action fields FHNW

Publication status

Published

Review

Peer review of the complete publication

Open access category

Hybrid

License

Citation

Kerr, G. S., Krucker, S., Allred, J. C., Rodriguez-Gomez, J. M., Inglis, A. R., Ryan, D. F., Hayes, L. A., Milligan, R. O., Kowalski, A. F., Plowman, J., Young, P. R., Kucera, T. A., & Brosius, J. W. (2026). Spatial variation of energy transport mechanisms within solar flare ribbons. Nature Astronomy. https://doi.org/10.1038/s41550-025-02747-9

Full item page