HR: 0830h
AN: SH21B-0129 [PDF]
TI: Spatial Structure of Solar Electron Bursts: Two-Point Observations using ACE and Genesis
AU: * Steinberg, J T
EM: jsteinberg@lanl.gov
AF: Los Alamos National Laboratory, Space and Atmospheric Sciences
MS D466, Los Alamos, NM 87545 United States
AU: de Koning, C A
AF: Los Alamos National Laboratory, Space and Atmospheric Sciences
MS D466, Los Alamos, NM 87545 United States
AU: Gosling, J T
AF: Los Alamos National Laboratory, Space and Atmospheric Sciences
MS D466, Los Alamos, NM 87545 United States
AU: Skoug, R M
AF: Los Alamos National Laboratory, Space and Atmospheric Sciences
MS D466, Los Alamos, NM 87545 United States
AU: Wiens, R C
AF: Los Alamos National Laboratory, Space and Atmospheric Sciences
MS D466, Los Alamos, NM 87545 United States
AB:
Recent ACE studies have found that solar electron bursts associated with solar type III radio bursts are commonly observed at
energies below 1.4 keV. Solar electron bursts are typically recognized by their characteristic energy-time and pitch
angle-time dispersion. Durations of burst events from onset to decay can vary from 1 hour to more than 30 hours, during
which time a single L1 halo-orbit spacecraft has swept across 0.5 to 17 degrees of solar longitude. The true spatial extent
of a solar burst event cannot be established from single spacecraft time-series measurements, because such measurements carry
an inherent spatial-temporal ambiguity.
In order to address spatial-temporal ambiguity, we examine solar burst events from two spatially separated spacecraft. We
compare measurements using Genesis GEM and ACE SWEPAM-E, which are nearly identical electron spectrometers. The Genesis and
ACE spacecraft both occupy L1 halo orbits and can be separated by up to 1 million km. Most burst events are strikingly
similar at both spacecraft, suggesting spatial extent much greater than the usual ACE-Genesis separation distances. However,
a number of events show different onset times and distinctly different rise-time/decay-time behavior, consistent with
spatially varying structure. We present analysis of several solar bursts in which the Genesis observations clearly differ
from the ACE observations, thereby giving evidence of spatial structure for those bursts.
DE: 2114 Energetic particles, heliospheric (7514)
DE: 2118 Energetic particles, solar
DE: 7514 Energetic particles (2114)
DE: 7519 Flares
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting