Abstract: Multi-point observations of energetic particle injection deep into the inner magnetosphere: Implications for the ring current and radiation belts (2014 AGU Fall Meeting)

Multi-point observations of energetic particle injection deep into the inner magnetosphere: Implications for the ring current and radiation belts

Geoffrey D Reeves¹, Brian Larsen², Reiner H W Freidel³, Michael G Henderson³, Ruth M Skoug³, Herbert O Funsten⁴, Seth G Claudepierre⁵, Joseph Fennell⁶, Weichao Tu¹, Gregory Cunningham³ and Harlan E Spence⁷, (1)Los Alamos National Laboratory, Los Alamos, United States, (2)The New Mexico Consortium, Los Alamos, NM, United States, (3)Los Alamos National Laboratory, Los Alamos, NM, United States, (4)Los Alamos National Laboratory, ISR-DO, Los Alamos, NM, United States, (5)The Aerospace Corporation, Los Angeles, CA, United States, (6)Aerospace Corporation, Los Angeles, CA, United States, (7)University of New Hampshire Main Campus, Space Science Center, Durham, NH, United States

Abstract:

For thirty years, the “injection boundary” model of substorm injections has provided a framework for studies of the impulsive transport of energetic electrons and ions into the inner magnetosphere. New, multi-satellite observations of substorm injections show signatures that require revision and rethinking of the classical picture. Recent observations by the LANL-GEO and GOES energetic particle instruments provide unprecedented coverage at geosynchronous orbit while the Van Allen Probes satellites provide simultaneous multi-point measurements inside geosynchronous orbit. With these satellites we can observe injections at three different radial distances and up to ten different local times - simultaneously. These observations reveal a complex and varied set of dynamics that have important implications for the development of the radiation belts and ring current.

In this study we look specifically at the radial penetration of energetic particle injections in storms and substorms. Radial alignments of satellites confirm and extend the CRRES/LANL-GEO observations of relatively slow inward propagation of the injection region inside geosynchronous orbit [1]. At the same time, synoptic Van Allen Probes observations show frequent storm-time “injection” of energetic (~50-500 keV) electrons to very low L-shells (L < 3) that have not previously been reported. The radial distribution of electrons and ions injected during storms and substorms have profound implications for the generation of waves, for the availability of a radiation belt “seed population”, and for the radial distribution of ring current ions. In this paper we will use multi-point satellite observations to understand the processes that inject energetic particles into the inner magnetosphere, the Earthward propagation of these injections, the conditions that control variation in Earthward extent of energetic particle injections, and how particles can be injected deep inside the plasmasphere and even through the slot region.

[1] Reeves, G. D., R. W. H. Friedel, M. G. Henderson, A. Korth, P. S. McLachlan, and R. D. Belian (1996), Radial propagation of substorm injections, proceedings of the 3rd International Conference on Substorms, ICS-3.

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