The propagation of sub‐MeV solar electrons to heliolatitudes above 50°S

Abstract

On 27 February 1994 when the Ulysses spacecraft was at an heliolatitude of 54°S low energy electrons (∼50–400 keV) and high energy protons (14–31 MeV) were measured following a solar flare beyond the west limb. These measurements show that under favorable conditions energetic particles can be transported very rapidly across 60 degrees in heliocentric latitudes to radial distances beyond 35 AU. The interplanetary transport occurs inside a structure that was identified as a CME in interplanetary space by Gosling et al. [1994] and that was produced on 20 February. The flare associated with the interplanetary electron event was well documented by the Nancay radio heliograph and was located at 09°N 95°W in the same active region that can be associated with the earlier origin of the Gosling et al. event. This particle event presents many similarities with the June '93 interplanetary particle event observed at 32°S [Armstrong et al., 1994].