CLUSTER measurements of energetic electron bursts in the context of global
multispacecraft  observations: The telescope-microscope combination

D.N. Baker, N.L. Farr, J.C. Green, S.P. Monk, and T.A. Fritz


The space research community has long sought the capability to view the
Sun-Earth system in a global way and concurrently to probe the microphysical
details of key physical regions. This objective has now been substantially
realized with the use of the CLUSTER and IMAGE missions in combination with ACE,
FAST, POLAR, and geostationary orbit spacecraft. Using such multispacecraft data
with appropriate radial positioning, there is a powerful ability to apply both
'telescopic' and 'microscopic' principles. Many recent examples from the 2001,
2002 and 2003 CLUSTER tail seasons serve to illustrate the observational power
of these new tools. In the case of the 31 March 2001 superstorm, we observed a
strong geomagnetic storm and saw a powerful compression of the magnetosphere and
a concomitant particle injection event. In another event on 27 August  2001,
CLUSTER observed a clear substorm sequence of events in the mid-magnetotail
region (X~-19RE) while the other spacecraft in the constellation saw the
near-Earth substorm consequences. In these examples, CLUSTER data revealed
microphysical details while IMAGE and other spacecraft showed the global,
macroscopic substorm context. We present in this paper our analyses of several
substorm events (analogous to the 27 August 2001 case) in order to understand
the radial propagation of substorm expansion phase processes.

_______________ 
Presentation, Fall A.G.U. Meeting, San Francisco, CA, 13-17 December 2004