The Halloween 2003 Storm's Effect on Trapped Electron Populations

We have investigated the effects of the October and November 2003 solar energetic particle (SEP) events on trapped electron populations using data from the Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) in conjunction with the findings from the Solar, Anomalous, Magnetospheric Particle Explorer (SAMPEX). Immediately after the Halloween storm, RHESSI, saw an order of magnitude increase in the electron population in its low particle energy bin (less than 600 KeV); the population lingered for more than thirty days at L=1.9-2.2. The increase is caused by an inward transportation of trapped magnetospheric electrons from higher L values, and the decay is produced by pitch angle diffusion. Similar effects were seen by SAMPEX. However, the appearance of SEP's, whose energies are much greater and range up to 20 MeV, does not occur until months later, as these electrons are not pitch angle diffused as quickly as the lower energy population.