131 and 304 Å Emission Variability Increases Hours Prior to Solar Flare Onset

Thermal changes in coronal loops are well studied, both in quiescent active regions and in flaring scenarios. However, relatively little attention has been paid to loop emission in the hours before the onset of a solar flare; here, we present the findings of a study of over 50 off-limb flares of Geo...

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Main Authors: Kara L. Kniezewski, E. I. Mason, Vadim M. Uritsky, Seth H. Garland
Format: Article
Language:English
Published: IOP Publishing 2024-01-01
Series:The Astrophysical Journal Letters
Subjects:
Online Access:https://doi.org/10.3847/2041-8213/ad94dd
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author Kara L. Kniezewski
E. I. Mason
Vadim M. Uritsky
Seth H. Garland
author_facet Kara L. Kniezewski
E. I. Mason
Vadim M. Uritsky
Seth H. Garland
author_sort Kara L. Kniezewski
collection DOAJ
description Thermal changes in coronal loops are well studied, both in quiescent active regions and in flaring scenarios. However, relatively little attention has been paid to loop emission in the hours before the onset of a solar flare; here, we present the findings of a study of over 50 off-limb flares of Geostationary Operational Environmental Satellite class C5.0 and above. We investigated the integrated emission variability for Solar Dynamics Observatory Atmospheric Imaging Assembly channels 131, 171, 193, and 304 Å for 6 hr before each flare and compared these quantities to the same time range and channels above active regions without proximal flaring. We find significantly increased emission variability in the 2–3 hr before flare onset, particularly for the 131 and 304 channels. This finding suggests a potential new flare prediction methodology. The emission trends between the channels are not consistently well correlated, suggesting a somewhat chaotic thermal environment within the coronal portion of the loops that disturbs the commonly observed heating and cooling cycles of quiescent active region loops. We present our approach and the resulting statistics and discuss the implications for heating sources in these preflaring active regions.
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series The Astrophysical Journal Letters
spelling doaj-art-73d543f26bd1450ca738e5ab2d957c302025-08-20T03:17:39ZengIOP PublishingThe Astrophysical Journal Letters2041-82052024-01-019771L2910.3847/2041-8213/ad94dd131 and 304 Å Emission Variability Increases Hours Prior to Solar Flare OnsetKara L. Kniezewski0https://orcid.org/0000-0003-3740-9240E. I. Mason1https://orcid.org/0000-0002-8767-7182Vadim M. Uritsky2https://orcid.org/0000-0002-5871-6605Seth H. Garland3https://orcid.org/0000-0002-9359-6776Air Force Institute of Technology , 2950 Hobson Way, Wright-Patterson AFB, OH 45433, USAPredictive Science Inc. , 9990 Mesa Rim Road, Suite 170 San Diego, CA 92121, USACatholic University of America , 620 Michigan Avenue, N.E. Washington, DC 20064, USA; NASA Goddard Space Flight Center , 8800 Greenbelt Avenue, Greenbelt, MD 20771, USAAir Force Institute of Technology , 2950 Hobson Way, Wright-Patterson AFB, OH 45433, USAThermal changes in coronal loops are well studied, both in quiescent active regions and in flaring scenarios. However, relatively little attention has been paid to loop emission in the hours before the onset of a solar flare; here, we present the findings of a study of over 50 off-limb flares of Geostationary Operational Environmental Satellite class C5.0 and above. We investigated the integrated emission variability for Solar Dynamics Observatory Atmospheric Imaging Assembly channels 131, 171, 193, and 304 Å for 6 hr before each flare and compared these quantities to the same time range and channels above active regions without proximal flaring. We find significantly increased emission variability in the 2–3 hr before flare onset, particularly for the 131 and 304 channels. This finding suggests a potential new flare prediction methodology. The emission trends between the channels are not consistently well correlated, suggesting a somewhat chaotic thermal environment within the coronal portion of the loops that disturbs the commonly observed heating and cooling cycles of quiescent active region loops. We present our approach and the resulting statistics and discuss the implications for heating sources in these preflaring active regions.https://doi.org/10.3847/2041-8213/ad94ddActive solar coronaSolar flaresSolar physicsSolar coronal loopsSolar coronaSolar coronal mass ejections
spellingShingle Kara L. Kniezewski
E. I. Mason
Vadim M. Uritsky
Seth H. Garland
131 and 304 Å Emission Variability Increases Hours Prior to Solar Flare Onset
The Astrophysical Journal Letters
Active solar corona
Solar flares
Solar physics
Solar coronal loops
Solar corona
Solar coronal mass ejections
title 131 and 304 Å Emission Variability Increases Hours Prior to Solar Flare Onset
title_full 131 and 304 Å Emission Variability Increases Hours Prior to Solar Flare Onset
title_fullStr 131 and 304 Å Emission Variability Increases Hours Prior to Solar Flare Onset
title_full_unstemmed 131 and 304 Å Emission Variability Increases Hours Prior to Solar Flare Onset
title_short 131 and 304 Å Emission Variability Increases Hours Prior to Solar Flare Onset
title_sort 131 and 304 a emission variability increases hours prior to solar flare onset
topic Active solar corona
Solar flares
Solar physics
Solar coronal loops
Solar corona
Solar coronal mass ejections
url https://doi.org/10.3847/2041-8213/ad94dd
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AT eimason 131and304aemissionvariabilityincreaseshourspriortosolarflareonset
AT vadimmuritsky 131and304aemissionvariabilityincreaseshourspriortosolarflareonset
AT sethhgarland 131and304aemissionvariabilityincreaseshourspriortosolarflareonset