Ionospheric Signatures of Plasmaspheric Tails

J. C. Foster (1), P. J. Erickson (1), A. J. Coster (2), J. Goldstein (3), 
and F. J. Rich (4)

1) MIT Haystack Observatory, Westford, MA
2) MIT Lincoln Laboratory, Lexington, MA
3) Rice University, Houston, TX
4) Air Force Research Laboratory, Hanscom AFB, MA

We make direct comparisons between GPS maps of total electron content (TEC) over the 
North American continent, Millstone Hill radar observations of storm enhanced density, 
and low and high-altitude satellite measurements of the perturbation of the outer 
plasmasphere during the March 31, 2001 geomagnetic storm. We find that storm enhanced 
density (SED) and plumes of greatly-elevated TEC are associated with the erosion of 
the outer plasmasphere by strong sub-auroral polarization electric fields. The SED/TEC 
plumes identified at low altitude map closely onto the magnetospheric determination of 
the boundaries of the plasmapause and plasmaspheric tail determined by EUV imaging 
from the IMAGE spacecraft. Characteristics of the SED/TEC plumes/tails for the March 31, 
2001 event are: TEC ~100 TECu; F region sunward velocity ~1000 m/s; sunward flux 
~5 x 10^24 ions s^-1; total transport to dayside magnetopause/merging region 
(3-hr event) ~5 x 10^28 ions. 

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Geophys. Res. Lett., 29(13), 10.1029/2002GL015067, 2002