Observations of the Inner Magnetospheric and Radiation Belt Processes by Radio 
Plasma Imager on IMAGE

B. W. Reinisch, P. Song, and X. Huang
Center for Atmospheric Research, Department of Environmental, Earth and 
Atmospheric Sciences, University of Massachusetts Lowell, 600 Suffolk Street,
Lowell, Massachusetts, USA

J. L. Green
Goddard Space Flight Center, NASA, Greenbelt, Maryland, USA


Using the sounding measurements from the radio plasma image on IMAGE, and a
plasma density inversion algorithm, we derive the plasma density profiles
along the magnetic field from one hemisphere to the other in less than 2
minutes. In each satellite orbit, several such measurements are possible,
providing a tool to measure two-dimensional plasma density distributions in a
meridian plane. When the satellite revisits the same region in different
orbits, the temporal variations of the density in this plane can be measured.
We are using such measurements to develop the plasma density distribution
models and to study the depletion, refilling, and other dynamical processes.
These dynamical changes in the plasma conditions may affect the lifetime of
the radiation belt. Passive plasma wave measurements are also made by the
same instrument. We have conducted a comprehensive survey of the whistler
wave observed in the magnetosphere. Enhanced wave power is observed in good
correlation with the magnetic footprint and the operating frequencies of
ground VLF transmitters. These waves appear to have substantial effects on
the lifetime of the radiation belt particles.  The amplitude and the
effective area of the transmitters will be evaluated. 

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Presentation at URSI National Radio Science meeting, 
Boulder, Colorado, USA, 4-8 January 2004