Rogue SEP events: observational aspects
Abstract
About once in a solar cycle, a SEP event occurs whose fluence dominates that for the entire cycle. We refer to such events as 'rogue' events, in analogy to rogue ocean waves having unusually large amplitudes. Well-known examples of rogue SEP events at Earth occurred on 14 July 1959, 4 August 1972, 19 October 1989, and 14 July 2000. Rogue events also have been observed in the inner heliosphere (with Helios 1 on 4 November 1980 at 0.5 AU) and with Ulysses in March 1991 at 2.5 AU. In this paper we review the solar (multiple CMEs) and interplanetary circumstances (converging shocks) that give rise to these rare but, if observed at Earth, geophysically important events.
- Publication:
-
International Cosmic Ray Conference
- Pub Date:
- August 2001
- Bibcode:
- 2001ICRC....8.3314K