Ryan French | Research

Scientific Research

My research primarily investigates explosive phenomena in the atmosphere of the Sun called solar flares. Solar flares a fundamental part of space weather, the impact of the Sun's activity on Earth and near-Earth environment - it is therefore important to understand the behaviour of solar flares and ultimately how to predict them.

My research uses observations from telescopes on the ground and in space, including the NSF'S Inouye Solar Telescope, NASA's IRIS & SDO spacecraft, ESA's Solar Orbiter and JAXA's Hinode.

Below is a list of my publications, updated twice a year. Lists are also managed on ResearchGate and Google Scholar.

Image: The day of my PhD viva/defence, sat infront of the engineering model of the Hinode Extreme-ultraviolet Imaging Spectrometer (EIS), an instrument I used in my PhD research.

Research Publications

2025

Tamburri, C.A., Kazachenko, M.D., Cauzzi, G., Kowalski, A.F., French, R.J., ... et al, "Unveiling Unprecedented Fine Structure in Coronal Flare Loops with the DKIST", The Astrophysical Journal Letters, vol. 990, no. 1, 2025. doi: 10.3847/2041-8213/adf95e
Yadav, R., Kazachenko, M.D., Cauzzi, G., Tamburri, C.A., Corchado, M., French, R.J., "Multiline Spectropolarimetric Observation of Flare Ribbon Fine Structures with ViSP/DKIST", The Astrophysical Journal, vol. 989, no. 2, 2025. doi: 10.3847/1538-4357/adf4c1
French, R.J., Kazachenko, M.D., Mihailescu, T., Reeves, K.K., "Spectroscopic Observations of Supra-arcade Downflows", The Astrophysical Journal Letters, vol. 986, no. 1, 2025. doi:10.3847/2041-8213/adde59

2024

French, R.J., Ben, T., Corchado Albelo, M., Kazachenko, M.D., ... et al, “Visible Eclipses through Clouds — a Challenge of Outreach Messaging”, Bulletin of the AAS, vol. 56, no. 9, 2024. doi:10.3847/25c2cfeb.555fdbad
Kazachenko, M.D., Perez-Gallego, J., ... French, R.J., ... et al, “Eagle Pass, TX: The First American City on the Path of Totality: Organizing an Eclipse Party in the Stadium", Bulletin of the AAS, vol. 56, no. 9, 2024. doi:10.3847/25c2cfeb.5baa13ea
French, R.J., Hayes, L., Kazachenko, M.D., Reeves, K.K., ... et al, “X-ray and Spectral UV Observations of Periodic Pulsations in a Solar Flare Fan/Looptop”, The Astrophysical Journal, vol. 907, no. 2, 2024. doi:10.3847/1538-4357/ad8ed1
To, A.S.H., Brooks, D.H., Imada, S., French, R.J.,... et al, “Spatially Resolved Plasma Composition Evolution in a Solar Flare – The Effect of Reconnection Outflow”, Astronomy & Astrophysics, vol. 691, A95, 2024. doi:10.1051/0004-6361/202449246
French, R.J., Yu, S., Chen, B., Shen, S., Matthews, S.A., “Doppler signature of a possible termination shock in an off-limb solar flare”, Monthly Notices of the Royal Astronomical Society, vol. 528, no. 4, pp. 6836-6844, 2024. doi:10.1093/mnras/stae430
French, R.J., “Eclipse Outreach via TikTok – 270 Personal Reflections on the 2017 Eclipse”, Bulletin of the AAS, vol. 56, no. 3, 204. doi:10.3847/25c2cfeb.f8d607d2

2023

Yardley, S.L., Owen, C.J., Long, D.M., ... French, R.J., ... et al, “Slow Solar Wind Connection Science during Solar Orbiter’s First Close Perihelion Passage”, The Astrophysical Journal Supplement, vol. 267, no. 11, 2023. doi:10.3847/1538-4365/acd24b
Wibisono, A.D., Branduardi-Raymont, G., Coates, A.J., Dunn, W. French, R.J., “Jupiter’s equatorial X-ray emissions over two solar cycles”, Monthly Notices of the Royal Astronomical Society, vol. 521, no. 4, pp. 5596–5603, 2023. doi:10.1093/mnras/stad905.
Baker, D., Demoulin, P., Yardley, S.L., ... French, R.J., ... et al, “Observational Evidence of S-web Source of the Slow Solar Wind”, The Astrophysical Journal, vol. 950, no. 1, 2023. doi:10.3847/1538-4357/acc653.
Ledvina, V., Brandt, L., MacDonald, E., ... French, R.J., ... et al, “Agile collaboration: Citizen science as a transdisciplinary approach to heliophysics”, Frontiers in Astronomy and Space Sciences, vol. 10, 2023. doi:10.3389/fspas.2023.1165254.
French, R.J., Bogdan, T.J., Casini, R., de Wijn, A.G., and Judge, P.G., “First Observation of Chromospheric Waves in a Sunspot by DKIST/ViSP: The Anatomy of an Umbral Flash”, The Astrophysical Journal, vol. 945, no. 2, 2023. doi:10.3847/2041-8213/acb8b5.

2022

French, R.J., “Five years on: the monster flare of 2017”, Astronomy and Geophysics, vol. 63, no. 5, pp. 5.38–5.40, 2022. doi:10.1093/astrogeo/atac069.
French, R.J., “Spectroscopic and Spectropolarimetric Insights into Reconnection Dynamics in Solar Flares”, PhD thesis. 2022.

2021

French, R.J., Matthews, S.A., Rae, J.I., and Smith, A.W., “Probing Current Sheet Instabilities from Flare Ribbon Dynamics”, The Astrophysical Journal, vol. 922, no. 2, 2021. doi:10.3847/1538-4357/ac256f.
Stansby, D., Bercic, L., Matteini, L., Owen, C.J., French, R.J.,... et al, “Sensitivity of solar wind mass flux to coronal temperature”, Astronomy and Astrophysics, vol. 650, 2021. doi:10.1051/0004-6361/202039789.

2020

French, R.J., James, A.W., Baker, D., ... et al, “Opening pupils’ eyes to the Sun”, Astronomy and Geophysics, vol. 61, no. 6, pp. 6.22–6.23, 2020. doi:10.1093/astrogeo/ataa085.
French, R.J., Matthews, S.A., van Driel-Gesztelyi, L., Long, D.M., and Judge, P.G., “Dynamics of Late-stage Reconnection in the 2017 September 10 Solar Flare”, The Astrophysical Journal, vol. 900, no. 2, 2020. doi:10.3847/1538-4357/aba94b.

2019

French, R.J., Judge, P.G., Matthews, S.A., and van Driel-Gesztelyi, L., “Spectropolarimetric Insight into Plasma Sheet Dynamics of a Solar Flare”, The Astrophysical Journal Letters, vol. 887, no. 2, 2019. doi:10.3847/2041-8213/ab5d34.