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| Titel |
Understanding the Physical Links Between Energetic Storm Particle Events and large Gradual Solar Energetic Particle Events |
| VerfasserIn |
Mihir Desai, Maher Dayeh, Robert Ebert, Glenn Mason, Gang Li, Charles Smith |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250074655
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| Zusammenfassung |
| Fast coronal mass ejections or CMEs drive shock waves through the corona and the
interplanetary medium and are believed to produce both, the large gradual solar
energetic particle (SEP) events and the energetic storm particle (ESP) events observed
at 1 AU. While there is little doubt that the ESP events are accelerated by in-situ
CME shocks, evidence that the large SEP events are accelerated by the near-Sun
CME shocks is circumstantial. The primary candidate for accelerating energetic
particles at CME-driven shocks is the diffusive shock acceleration (DSA) theory,
comprising the first-order Fermi mechanism at quasi-parallel shocks and the shock-drift
mechanism at quasi-perpendicular shocks. However, major criticisms of the DSA
theory are: (1) ESP events rarely exhibit clear signatures consistent with theoretical
predictions, and (2) self-excited Alfvén waves that play a crucial role in scattering and
accelerating the particles are seldom observed upstream of IP shocks near Earth. In a
survey of observations from solar cycle 23, we identified ~10 ESP events with
clear signatures of the two types of DSA mechanisms. In addition, we find striking
similarities between particle properties during 6 of these ESP events and those
observed during many intense, large gradual SEP event in which the associated |
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