摘要：We present multi-spacecraft observations of four solar electron events using measurements
from the Solar Electron Proton Telescope (SEPT) and the Electron Proton Helium INstrument
(EPHIN) on board the STEREO and SOHO spacecraft, respectively, occurring between 11
October 2013 and 1 August 2014, during the approaching superior conjunction period of the
two STEREO spacecraft. At this time the longitudinal separation angle between STEREO-A
(STA) and STEREO-B (STB) was less than 72°. The
parent particle sources (flares) of the four investigated events were situated close to,
in between, or to the west of the STEREO’s magnetic footpoints. The STEREO measurements
revealed a strong difference in electron peak intensities (factor ≤12) showing unexpected intensity
distributions at 1 AU, although the two spacecraft had nominally nearly the same angular
magnetic footpoint separation from the flaring active region (AR) or their magnetic
footpoints were both situated eastwards from the parent particle source. Furthermore, the
events detected by the two STEREO imply a strongly unexpected onset timing with respect to
each other: the spacecraft magnetically best connected to the flare detected a later
arrival of electrons than the other one. This leads us to suggest the concept of a rippled
peak intensity distribution at 1 AU formed by narrow peaks (fingers) superposed on a
quasi-uniform Gaussian distribution. Additionally, two of the four investigated solar
energetic particle (SEP) events show a so-called circumsolar distribution and their
characteristics make it plausible to suggest a two-component particle injection scenario
forming an unusual, non-uniform intensity distribution at 1 AU.
关键词：Sun: flares;Sun: particle emission;acceleration of particles
