In-depth Analysis of the 2022 March 28 3He-rich Solar Energetic Particle Event
Year: 2025
Type: article
Abstract: On 2022 March 28, a solar eruption from active region AR 12975 produced a solar energetic particle (SEP) event observed by BepiColombo (BC; 0.57 au), STEREO-A (STA; 0.97 au), GOES (1.0 au), ACE (L1), and Wind (L1). The event was associated with an M4.0 soft X-ray flare peaking at 11:29 UTC, a Type III radio burst (0.1–16 MHz) at 11:24 UTC, a metric Type II radio burst (25–250 MHz) at 11:23 UTC, and a coronal mass ejection with a speed of 700 km s−1. BC and STA, magnetically aligned along the same Parker spiral and well connected to the flare site (footpoint separations of 19 . ° 8 and 16 . ° 5, respectively), detected a gradual SEP event with remarkable impulsive characteristics, including a high 3He/4He ratio (0.7 at 1 MeV), elevated Fe/O ratio (∼0.5 increasing with energy), a 3He spectrum harder than that of other ions, and particle dropouts at BC linked to intermittent magnetic connections. Near-Earth spacecraft (44 . ° 8 from the flare site) observed abundance ratios closer to coronal values, and more uniform proton/heavy-ion spectra. Our findings suggest both the contribution of particles accelerated by a quasi-parallel shock and a direct contribution from flare suprathermals, accelerated during postflare ongoing reconnection, at well connected spacecraft.
Source: The Astrophysical Journal
Authors: Mirko Stumpo, Monica Laurenza, Simone Benella, Anna Milillo, Christina Plainaki, Matthew J. West, Pietro Zucca, Stas Barabash, Daniel Heyner, Ali Varsani, Go Murakami, Shyama Narendranath, Alessandro Aronica, H. U. Auster, Lorenzo Biasiotti, Alessandro Brin, Luca Colasanti, D. Constantinescu, Elisabetta De Angelis, Pier Paolo Di Bartolomeo, D. Fischer, Stavro Ivanovski, Harald Jeszenszky, Adrian Kazakov, Gunter Laky, Valeria Mangano, Stefano Massetti, Martina Moroni, Alessandro Mura, Livio Narici, Hans Nilsson, Raffaella Noschese, Stefano Orsini, Grace Richards, I. Richter, Rosanna Rispoli, Beatriz Sanchez-Cano, Roberto Sordini, Srikar P. Tadepalli, Nello Vertolli, Martin Wieser, Hayley Williamson
Institutions: Institute for Space Astrophysics and Planetology, National Institute for Astrophysics, Agenzia Spaziale Italiana, Max Planck Institute for Solar System Research, European Space Agency, European Space Research and Technology Centre, Netherlands Institute for Radio Astronomy, Swedish Institute of Space Physics, Technische Universität Braunschweig, Space Research Institute, Japan Aerospace Exploration Agency, Indian Space Research Organisation, Trieste Astronomical Observatory, University of Rome Tor Vergata, University of Leicester
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
OpenAlex ID: W4411834171