How efficient are coronal mass ejections at accelerating solar energetic particles?

R. A. Mewaldt, C. M.S. Cohen, G. M. Mason, D. K. Haggerty, M. D. Looper, A. Vourlidas, M. I. Desai, J. Giacalone, A. W. Labrador, R. A. Leske, J. E. Mazur

Research output: Contribution to journalConference articlepeer-review

10 Scopus citations


The largest solar energetic particle (SEP) events are thought to be caused by shocks driven by fast coronal mass ejections (CMEs). We study the efficiency of this process by comparing the energy content of energetic particles in large SEP events to the kinetic energy of the associated CMEs. The SEP observations are from 17 events observed by ACE, SAMPEX, and GOES during 1998-2003 and the CME observations are from SOHO. In situ solar-wind data show that CME kinetic energy estimates from SOHO/LASCO for the October 28, 2003 event are much more accurate than those from SMEI. The ratio of SEP to CME kinetic energies is found to range from ∼0.1% to ∼20%. The largest SEP events have an average SEP/CME kinetic-energy ratio of ∼10%, similar to that estimated for cosmic-ray acceleration by supernova shocks.

Original languageEnglish (US)
Pages (from-to)67-70
Number of pages4
JournalEuropean Space Agency, (Special Publication) ESA SP
Issue number592
StatePublished - 2005
EventSolar Wind 11/SOHO 16 - Connecting Sun and Heliosphere - Whistler, Canada
Duration: Jun 12 2005Jun 17 2005

ASJC Scopus subject areas

  • Aerospace Engineering
  • Space and Planetary Science


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