Radio Plasma Imager Observation of Magnetostorm Effects on the Plasmaspheric 
Density Distribution

Bodo Reinisch, Xueqin Huang, Paul Song, Gary Sales, Ivan Galkin
Environmental, Earth, and Atmospheric Sciences Department, Center for 
Atmospheric Research, University of Massachusetts Lowell, Lowell, MA 01854,USA

Robert Benson, Shing Fung, James Green
NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA


The Radio Plasma Imager (RPI) on the IMAGE spacecraft has conducted echo radio 
sounding experiments since April 2000. Our analysis shows that the strongest 
sharp echo traces observed by RPI in the plasmasphere are the result of 
field-aligned propagation. Therefore the entire electron density distribution 
along the magnetic field line through the spacecraft location is measured with 
one plasmagram. Consecutive Plasmagrams can then establish the plasma 
distribution as function of L value and magnetic latitude. The paper discusses 
the depletion and refilling of the plasmasphere as a result of the March 31, 
2001 magnetic storm.

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To be presented at the 27th General Assembly of International Union of 
Radio Science (URSI), Maastricht, The Netherlands, August 17-24, 2002.