ANGEO Annales Geophysicae ANGEO Ann. Geophys. 1432-0576 Copernicus Publications Göttingen, Germany 10.5194/angeo-28-983-2010 Energetic electrons in the exterior cusp: identifying the source Walsh B. M. 1 Fritz T. A. 1 Klida M. M. 1 Chen J. 1 Center for Space Physics, Boston University, Boston, MA, USA 16 04 2010 28 4 983 992 Copyright: © 2010 B. M. Walsh et al. 2010 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://angeo.copernicus.org/articles/28/983/2010/angeo-28-983-2010.html The full text article is available as a PDF file from https://angeo.copernicus.org/articles/28/983/2010/angeo-28-983-2010.pdf

A case study is presented to test the role several different sources may play in populating the exterior cusp with energetic (<I>E</I>&gt;40 keV) electrons. The properties of the electrons measured in the exterior cusp are compared with the expected signatures of three sources in order to weigh the role each source may contribute in populating this region. The potential sources probed are: (1) solar energetic electrons entering the cusp from the solar wind; (2) an equatorial magnetospheric source with particles drifting to high latitudes on the dayside; and (3) a local source accelerating the electrons in situ. From the observations it is likely that local acceleration is the primary source of the energetic electrons in the exterior cusp during this event.

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