A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
Freely propagating flanks of wide coronal-mass-ejection-driven shocks: Modelling and observational insights
Tekijät: Wijsen, N.; Jebaraj, I. C.; Dresing, N.; Kouloumvakos, A.; Palmerio, E.; Rodriguez-Garcia, L.
Kustantaja: EDP Sciences
Kustannuspaikka: LES ULIS CEDEX A
Julkaisuvuosi: 2025
Journal: Astronomy and Astrophysics
Tietokannassa oleva lehden nimi: Astronomy & Astrophysics
Lehden akronyymi: ASTRON ASTROPHYS
Artikkelin numero: A51
Vuosikerta: 699
Sivujen määrä: 13
ISSN: 0004-6361
eISSN: 1432-0746
DOI: https://doi.org/10.1051/0004-6361/202453598
Verkko-osoite: https://doi.org/10.1051/0004-6361/202453598
Rinnakkaistallenteen osoite: https://research.utu.fi/converis/portal/detail/Publication/499282610
Context. Widespread solar energetic particle (SEP) events remain poorly understood phenomena in space weather. These events are often linked to coronal mass ejections (CMEs) and their shocks, but the mechanisms governing their global particle distribution remain debated. The 13 March 2023 event is particularly notable as a widespread SEP event associated with an exceptionally fast interplanetary shock. With speeds of up to 3000 km/s, it is one of the most extreme shocks observed in recent years.
Aims. We aim to investigate whether the flanks of a wide CME-driven shock can decouple from the CME and continue propagating as freely propagating shock waves. If shocks are the primary SEP source, such a mechanism could help explain some of the widest SEP events.
Methods. Using EUHFORIA, a 3D magnetohydrodynamic heliospheric model, we simulated the evolution of wide CME-driven shocks. We modified the model to allow direct shock injection at the inner boundary, upstream of the CME ejecta. Applying this to the 13 March 2023 event, we modelled two simultaneous CMEs whose shocks form a single, wide shock envelope that spans 280 degrees in longitude. We then compared our results to in situ observations.
Results. Our simulations show that the flanks of wide CME shocks can persist as freely propagating waves beyond 2 au. For the 13 March 2023 event, the modelled shock arrival times and amplitudes of associated plasma parameters (e.g. speed and density) show good agreement with observations from various spacecraft distributed across different radial distances and longitudes. Furthermore, the combined shock structure expands into a quasi-circumsolar wave as it propagates outwards.
Conclusions. These findings indicate that the shock flanks of fast CMEs can persist for a long time, supporting the idea that such freely propagating shock flanks play a key role in the global distribution of SEPs in widespread events.
Ladattava julkaisu This is an electronic reprint of the original article. |  |
Julkaisussa olevat rahoitustiedot:
N.W. acknowledges funding from the Research Foundation - Flanders (FWO - Vlaanderen, fellowship no. 1184319N) and from the KU Leuven project 3E241013. Computational resources used for the EUHFORIA simulations presented in this work were provided by the VSC (Flemish Supercomputer Center), funded by FWO - Vlaanderen and the Flemish Government - department EWI. Work in the University of Turku was performed under the umbrella of Finnish Centre of Excellence in Research of Sustainable Space (FORESAIL) funded by the Research Council of Finland (grant No. 352847). I.C.J. and N.D. are grateful for support by the Research Council of Finland (SHOCKSEE, grant No. 346902). We thank the members of the data analysis working group at the Space Research Laboratory of the University of Turku, Finland for useful discussions. We acknowledge funding by the European Union's Horizon 2020/orizon Europe research and innovation program under grant agreement No. 101004159 (SERPENTINE) and No. 101134999 (SOLER). The paper reflects only the authors' view and the European Commission is not responsible for any use that may be made of the information it contains. I.C.J. also acknowledges support from the International Space Science Institute (ISSI) in Bern through ISSI International Team project No. 23-575, "Collisionless Shock as a Self-Regulatory System". A.K. acknowledges financial support from NASA's NNN06AA01C (80MSFC19F0002 SO-SIS Phase-E and Parker Solar Probe EPI-Lo) contract. E.P. acknowledges support from NASA's PSP-GI (grant No. 80NSSC22K0349), HGI (grant No. 80NSSC23K0447), LWS (grant No. 80NSSC19K0067), and LWS-SC (grant No. 80NSSC22K0893) programmes, as well as NSF's PREEVENTS (grant No. ICER-1854790) programme.
