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The role of CME dynamics in production of -10 MEV protons

  • Authors: Kocharov, L.; Torsti, J.; St. Cyr, O. C.
  • Publication: Proceedings of the 27th International Cosmic Ray Conference. 07-15 August, 2001. Hamburg, Germany. Under the auspices of the International Union of Pure and Applied Physics (IUPAP)., p.3435, 2001
  • Solar events between January 1997 and June 1998
  • Statistical study
  • ADS link
  • Abstract: During January 1997 - June 1998, the Large Angle Spectroscopic Coronagraph (LASCO) aboard the Solar and Heliospheric Observatory spacecraft (SOHO) registered 670 coronal mass ejections (CMEs). We compare two groups of the 300-800 km s‑1 CMEs: (i) (very) gradually accelerating CMEs with acceleration below 10 m s‑2 , and (ii) impulsively accelerating CMEs with acceleration a > 20 m s‑2 near the Sun, continuing then with the constant speed across the LASCO field of view. An association of those CMEs with solar energetic particle (SEP) events is studied using the data of the energetic particle experiment ERNE also aboard SOHO. There were no SEP events registered in association with the first group CMEs, whereas about 8% of the second group CMEs produced an enhancement in the ~10 MeV proton flux at SOHO. This result along with a number of additional tests supports an idea that production of SEPs by the moderate speed CMEs depends not only on the final speed but also on the magnitude of acceleration that CME experiences during its liftoff. The SEP-producing CMEs are typified by impulsively accelerating CMEs accompanied by soft X-ray flares and coronal shocks.

Created by mevali. Last Modification: Wednesday 23 of May, 2007 08:57:36 UTC by mevali.