Eileen Emily Chollet

Observations of a 3He-rich SEP event over a broad range of heliographic longitudes: results from STEREO and ACE

Observations of energetic ions and electrons from STEREO and ACE have been used to investigate the longitudinal extent of particle emissions from 3He ‐rich solar energetic particle (SEP) events. In the event of 3–4 Nov 2008, ions and electrons were detected 20° ahead and behind the nominal connection from the source region to 1 AU, and electrons were also detected 60° ahead. The results are consistent with those of earlier studies that correlated data from near‐Earth spacecraft with Helios data or with observations of source regions on the Sun.

Reconnection and Disconnection: Observations of Suprathermal Electron Heat Flux Dropouts

Suprathermal electron heat flux dropouts (HFD) serve as a sensitive test of the magnetic topology of the inner heliosphere. Since the heat flux electron strahl always flows away from the Sun, a heat flux dropout should indicate either that the magnetic field line is completely disconnected from the Sun or that the heat flux strahl is scattered into other pitch angles. We present observations of two suprathermal electron heat flux dropout events observed by the Advanced Composition Explorer (ACE) spacecraft which occur simultaneously with impulsive energetic ion events. Since suprathermal electrons encompass the same velocity range as ions with energies of a few MeV/nucleon, the similarities and differences between them as observed at 1 AU probes the sources and transport of these two species. We compare the two events to show the difference between the signatures of a simple disconnection and a more complicated reconnection scenario. Comparing suprathermal electron modulations with energetic ion modulations is a powerful technique for determining the magnetic topology between particle injection at the Sun and observation at 1 AU.