Post-Impulsive-Phase Acceleration in a Wide Range of Solar Longitudes

  • Leon Kocharov
  • Jarmo Torsti
  • Timo Laitinen
  • Matti Teittinen
Chapter

Abstract

We have analyzed five solar energetic particle (SEP) events observed aboard the SOHO spacecraft during 1996–1997. All events were associated with impulsive soft X-ray flares, Type II radio bursts and coronal mass ejections (CMEs). Most attention is concentrated on the SEP acceleration during the first 100 minutes after the flare impulsive phase, post-impulsive-phase acceleration, being observed in eruptions centered at different solar longitudes. As a representative pattern of a (nearly) well-connected event, we consider the west flare and CME of 9 July 1996 (S10 W30). Similarities and dissimilarities of the post-impulsive-phase acceleration at large heliocentric-angle distance from the eruption center are illustrated with the 24 September 1997 event (S31 E19). We conclude that the proton acceleration at intermediate scales, between flare acceleration and interplanetary CMEdriven shock acceleration, significantly contributes to the production of ≳ 10 MeV protons. This post-impulsive-phase acceleration seems to be caused by the CME lift-off.

Keywords

Solar Phys Radio Burst Solar Energetic Particle Solar Energetic Particle Event Moreton Wave 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer Science+Business Media Dordrecht 2000

Authors and Affiliations

  • Leon Kocharov
    • 1
  • Jarmo Torsti
    • 1
  • Timo Laitinen
    • 1
  • Matti Teittinen
    • 1
  1. 1.Space Research Laboratory, Department of PhysicsUniversity of TurkuTurkuFinland

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