The solar particle event of Friday, July 14, 2000

A large solar particle event took place on Friday, July 14, commencing at 1012 UT with a X5.7/3B flare near the central meridian at N22W07. The event was in active region 9077. This event was the largest observed in 8 years of SAMPEX operations, surpassing the October/November 1992 events. Two shocks passed by Earth during the period of enhanced flux levels; one had come from an earlier event, the other from the July 14 event.

Overview plots of the event:

• Proton count rates
• Proton count rates compared to the October 31, 1992 events:
  > 0.5 MeV:
  > 4 MeV:
  19-28 MeV:
  > 85 MeV:
• Direct observation of particle cutoffs using low energy Iron ions. The plot also shows the Dst values, which correlate well with changes in cutoff. These cutoffs go to lower latitudes than the strong shock that occurred in April of this year.
• Display of magnetospheric response using L-sort plot. Note the deep penetration of electrons during the peak of the storm late on July 15 (day 197).

Contributed by Glenn Mason, Shri Kanekal, and Joe Mazur