Impulsive Solar Energetic Particle Events: Extreme-Ultraviolet Waves and Jets

Frontiers in Astronomy and Space Sciences ◽

10.3389/fspas.2021.807961 ◽

2022 ◽

Vol 8 ◽

Author(s):

Radoslav Bučík

Keyword(s):

Energetic Particle ◽

Large Scale ◽

Extreme Ultraviolet ◽

Solar Energetic Particle ◽

Power Laws ◽

Heavy Ion ◽

Energetic Ions ◽

Solar Energetic Particle Events ◽

System Composition ◽

Low Energies

Impulsive solar energetic particle (ISEP) events show peculiar elemental composition, with enhanced 3He and heavy-ion abundances, markedly different from our Solar System composition. Furthermore, the events are characterized by a wide variety of energy spectral shapes from power laws to rounded spectra toward the low energies. Solar sources of the events have been firmly associated with coronal jets. Surprisingly, new observations have shown that events are often accompanied by so-called extreme-ultraviolet (EUV) coronal waves–a large-scale phenomenon compared to jets. This paper outlines the current understanding of the linkage of EUV waves with jets and energetic ions in ISEP events.

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Geomagnetic transmission disturbances and heavy-ion fluences observed in low Earth orbit during the solar energetic particle events of October 1989

Advances in Space Research ◽

10.1016/0273-1177(95)00522-g ◽

1996 ◽

Vol 17 (2) ◽

pp. 121-125 ◽

Cited By ~ 2

Author(s):

P.R Boberg ◽

A.J Tylka ◽

J.H Adams ◽

L.P Beahm ◽

E.O Flückiger ◽

...

Keyword(s):

Energetic Particle ◽

Solar Energetic Particle ◽

Heavy Ion ◽

Low Earth Orbit ◽

Earth Orbit ◽

Solar Energetic Particle Events

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SOURCE REGIONS OF THE INTERPLANETARY MAGNETIC FIELD AND VARIABILITY IN HEAVY-ION ELEMENTAL COMPOSITION IN GRADUAL SOLAR ENERGETIC PARTICLE EVENTS

The Astrophysical Journal ◽

10.1088/0004-637x/776/2/92 ◽

2013 ◽

Vol 776 (2) ◽

pp. 92 ◽

Cited By ~ 12

Author(s):

Yuan-Kuen Ko ◽

Allan J. Tylka ◽

Chee K. Ng ◽

Yi-Ming Wang ◽

William F. Dietrich

Keyword(s):

Magnetic Field ◽

Interplanetary Magnetic Field ◽

Elemental Composition ◽

Energetic Particle ◽

Solar Energetic Particle ◽

Heavy Ion ◽

Source Regions ◽

Solar Energetic Particle Events

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Spectroscopic EUV observations of impulsive solar energetic particle event sources

Astronomy and Astrophysics ◽

10.1051/0004-6361/201833120 ◽

2018 ◽

Vol 617 ◽

pp. A40 ◽

Cited By ~ 1

Author(s):

R. Bučík ◽

A. Fludra ◽

R. Gómez-Herrero ◽

D. E. Innes ◽

B. Kellett ◽

...

Keyword(s):

Energetic Particle ◽

Extreme Ultraviolet ◽

Solar Energetic Particle ◽

Impulsive Phase ◽

Ion Acceleration ◽

Solar Energetic Particle Event ◽

Energetic Ions ◽

Theoretical Predictions ◽

Ion Production ◽

Field Lines

Context. Remote observations of solar flare ion acceleration are rather limited. Theoretical predictions for signatures of ion acceleration in extreme ultraviolet (EUV) line profiles have been made. Previous tests involve observations of flares with no evidence for energetic ions. Aims. We aim to examine a source flare of impulsive (or 3He-rich) solar energetic particle events with EUV line spectroscopy. Methods. We inspected all (more than 90) reported 3He-rich flares of the previous solar cycle 23 and found only 4 (recurrent) jets in the field of view of the Coronal Diagnostic Spectrometer (CDS) on board the Solar and Heliospheric Observatory (SOHO). The jet with the most suitable spatial and temporal coverage was analyzed in detail. Results. Two enhanced (nonthermal) line broadenings are observed in the cooler chromospheric and transition-region lines, and they are localized near the site where the closed magnetic loops reconnect with the open magnetic field lines. The enhanced broadenings are both found at the sites with redshifts in the lines, surrounded by the region with blueshifts. One enhanced line broadening is associated with a small flare without energetic particle signatures, while another occurs just after the particle acceleration signatures of the main flare terminated. Conclusions. The observed excess broadening does not appear to be directly related to the energetic ion production and motions. Further investigations are required that cover the critical impulsive phase of the flare, ideally with high-resolution spectrometers that are specifically pointed to the 3He-rich solar energetic particle source.

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