Coordinated Ground-Based and In-Situ Observations of Plasma Dynamics at L=2.5 

Menk, F.W., Clilverd, M.A., Mann, I.A., Carpenter, D.L., Sandel, B.R.    

We report preliminary results from a new multi-instrument study of plasma
dynamics in the inner plasmasphere. Three closely-spaced digital magnetometer
stations have been operating near Rothera, Antarctica, since December 2000.
Cross-phase analysis of daytime field line resonances observed by these
provides information on plasma mass density in the equatorial plane of the
magnetosphere near L=2.5. Ducted whistler mode VLF transmissions from the
conjugate point are received by co-located VLF receivers, providing
simultaneous electron density information for the same flux tubes. These
ground-based observations can be compared with global EUV images of
plasmaspheric helium, and in situ electron density measurements from the RPI
experiment on the IMAGE spacecraft. We present for illustration results from
two moderately disturbed days, showing the effect of heavy ions and dynamic
variations in particle populations in the inner plasmasphere. 

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To be presented at the Western Pacific Geophysical Meeting, 
Wellington, New Zealand, 9-12 July 2002.