The Origin and Evolution of Deep Plasmaspheric Notches

D. Gallagher (NASA/MSFC, Huntsville, AL 35805), M. Adrian, and M. Liemohn

Deep plasmaspheric notches can extend over more than 2 RE in radial distance
and 3 hours MLT in the magnetic equatorial plane.  They appear to be among
the largest evacuated features in the exterior plasmaspheric boundary.  They
can last for days and exhibit varying structure.  In this presentation, the
low L-shell portion of the recovery-time plasmaspheric convection plume will
be explored as the source for these deep evacuations in density.  Notch
lifetime variations in profile, filling, and circulation rates are found
with changing conditions and MLT.  These properties will be presented for
notches observed by the IMAGE Extreme Ultraviolet imager in 2000 and 2001. 
Localized interactions with the ring current will be explored as the source
of some features observed in these density depletions.

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Presentation at the Yosemite Conference of Inner Magnetospheric Interactions,
3 - 6 February 2004, Yosemite, California, USA