Direct auroral precipitation from the magnetotail during substorms
Author/Creator ORCID
Date
Type of Work
Department
Program
Citation of Original Publication
Ashour-Abdalla, M., Schriver, D., Alaoui, M. E., Richard, R., Walker, R., Goldstein, M. L., Donovan, E., and Zhou, M. (2013), Direct auroral precipitation from the magnetotail during substorms, Geophys. Res. Lett., 40, 3787–3792, doi:10.1002/grl.50635.
Rights
This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.
Public Domain Mark 1.0
Public Domain Mark 1.0
Subjects
Abstract
In this study, we examine the causes of electron precipitation during a substorm on 15 February 2008 that lead to auroral brightening. We use global kinetic simulations along with spacecraft and ground-based data. We find ~keV electrons in the region modeled in the simulation precipitate into the premidnight sector at latitudes between 71° and 75° due to two distinct physical processes: (1) higher latitude precipitation due to electrons that undergo relatively rapid non-adiabatic pitch angle scattering into the loss cone just earthward of a reconnection region, and (2) lower latitude precipitation due to electrons that are more gradually accelerated primarily parallel to the geomagnetic field by Fermi acceleration. These latter electrons enter the loss cone much closer to Earth at ~−15 to −10 Rᴇ. The electron precipitation due to the combination of these two mechanisms coincides spatially with observed auroral brightening during the disturbed event.