Exploring if a coronal dimming event can produce coronal hole-like properties
Rattachement africain : ch, ca, jp, in, us, gb, de, ar. Niveau de preuve : code pays fourni par la source.
Le résumé fourni par la source
Context . Coronal dimmings, or transient coronal holes, are manifested as a sudden reduction in extreme ultraviolet (EUV) and X-ray emission, often following solar eruptions. Aims . We investigate whether a dimming event can produce coronal hole-like plasma characteristics in the initially quiet Sun. Methods . On 17 and 18 March 2022, Solar Orbiter, Hinode, IRIS, and SDO observed a coronal dimming event that occurred after a quiescent filament eruption. We analysed imaging and spectroscopic data to compare the chromospheric and coronal response prior to and during the coronal dimming. Results . The SDO/AIA 193 Å emission intensity in the dimming region was reduced to the same level as the neighbouring coronal hole within 11 hours. The Doppler velocity measured with Fe XII (corona) decreased from −0.34 +0.37 −0.27 km s −1 towards a predominant upflow of −3.2 +0.4 −0.6 km s −1 . The first ionisation potential (FIP) bias was reduced towards photospheric values. We found an increase in the number of automatically detected EUV brightenings near the dimming boundary in SDO/AIA 193 Å , which could be a sign of magnetic reconnection. In the cooler SDO/AIA 171 Å or Solar Orbiter HRI EUV 174 Å channel, we did not observe such an increase. Coronal bright points (CBPs) appeared relatively unaffected by the formation of the dimming. The Mg II k 3 (chromosphere) Doppler velocities were unchanged, except for a small reduction in the dimming upflows in areas with weak magnetic fields ( < 20 G). Conclusions . We find that the dimming only shows partial coronal hole-like properties; specifically, in the coronal emission lines and at temperatures of > 1 MK. We suggest that this is due to the dimming resulting from plasma depletion only at higher altitudes. Since the CBPs were not significantly impacted by the dimming, we used their magnetic loop heights (∼10 Mm) as the lower limit to the dimming height. Our findings provide new insights into the atmospheric structure of coronal dimmings.
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Le contrôle bibliographique ouvert
DOI retrouvé dans Crossref DOI retrouvé ; titre concordant.
- Titre Crossref
- Exploring if a coronal dimming event can produce coronal hole-like properties
- Date Crossref
- 01/09/2026
- Éditeur
- EDP Sciences
- Type
- journal-article
Ce recoupement confirme des métadonnées liées au DOI. Il ne confirme ni la méthode ni les conclusions de l’étude, et il ne compte pas comme une seconde source scientifique indépendante.
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ETH Zurich pays non établi dans la noticeUniversité ou école supérieure
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Institute of Particle Physics pays non établi dans la noticeOrganisation à but non lucratif
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Institute for Particle Physics and Astrophysics ETH Zurich pays non établi dans la noticeStructure de recherche
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National Institutes of Natural Sciences pays non établi dans la noticeStructure de recherche
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Department of Space pays non établi dans la noticeOrganisme public
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Computational Physics (United States) pays non établi dans la noticeEntreprise
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National Astronomical Observatory of Japan pays non établi dans la noticeStructure de recherche
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University College London pays non établi dans la noticeUniversité ou école supérieure
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Max Planck Institute for Solar System Research pays non établi dans la noticeStructure de recherche
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FHNW University of Applied Sciences and Arts Northwestern Switzerland pays non établi dans la noticeUniversité ou école supérieure
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Institute of Astronomy and Space Physics pays non établi dans la noticeStructure de recherche
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University of St Andrews pays non établi dans la noticeUniversité ou école supérieure
ETH Zurich, Institute of Particle Physics et ETH Zurich — Institute for Particle Physics and Astrophysics, avec 9 autres affiliations.
Une affiliation ne permet pas de déduire la nationalité d’un auteur.