Storm-Time and Isolated Substorms Compared through Geosynchronous and 
ENA Measurements

G.D. Reeves, M.G. Henderson, R.M. Skoug, M.F. Thomsen, J.E. Borovsky, 
H.O. Funsten, J.-M. Jahn, C.J. Pollock, D. J. McComas, P.C:son Brandt, 
D.G. Mitchell, S.B. Mende


Isolated substorms have been studied extensively in part because it 
can reasonably be hoped that an understanding of relatively simple, 
isolated substorms would form the foundation for an understanding of 
more complex events. However, storm-time magnetospheric dynamics can 
often be so complex that the signatures which characterize isolated 
substorms can be difficult to identify. In recent years it has become 
possible to make quantitative comparisons between isolated and 
storm-time substorms using the powerful combination of global auroral 
imaging, multi-satellite magnetospheric measurements, ground based 
observations, and global energetic neutral atom (ENA) images. We have 
previously investigated particle injections in isolated substorms and 
the first substorm of a storm main phase showing that they are very 
similar in intensity, energetics, and spatial extent [Reeves and 
Henderson, 2001]. In this paper we further investigate storm-time 
substorms by examining substorms which occur throughout the duration 
of a storm. We show that the characteristic signatures of isolated 
substorms can also be observed for storm-time substorms. Those 
characteristics include auroral brightening with poleward.

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Presented at the Sixth International Conference on Substorms, ICS-6, 
Seattle, WA, March 25-29, 2002.