Remote-sensing and In Situ Study of Inner Magnetospheric Coupling During Storms
and Substorms

J. Goldstein, B.R. Sandel, P.C. Brandt, and J.L. Burch


During storms and substorms, the inner magnetosphere responds as a
globally-coupled system. The components of this system are the plasmasphere,
ring current, plasma sheet, and ionosphere. We present observations by IMAGE
(which provides global snapshots of the plasmasphere, ring current, and aurora),
by ground-based GPS receivers (which measure total electron content), and by in
situ spacecraft both at geosynchronous orbit (i.e., LANL) and at ionospheric
altitudes (i.e., DMSP). During mild storms with little or no substorm activity,
(e.g., 17-18 June 2001) the inner magnetosphere responds mainly to external
driving by the solar wind and IMF. During substorms (e.g., 17 April 2002) the
inner magnetosphere evolves under the influence of both external and internal
processes. We examine the coupling between the high-altitude equatorial
plasmapheric plasma, and the ionospheric plasma at the footpoints of the
magnetic field lines that pass through the plasmasphere. Weak coupling would
result in, among other things, an altitude-dependent L-value for the location of
the plasmapause. Strong coupling might occur especially during times when strong
region 1 and region 2 current systems are in place.

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