Parametric Studies of Field Aligned Echoes Observed by RPI/IMAGE

Jayanti, V., W. W. Taylor, J. L. Green, R. F. Benson, S. F. Fung, 
B. W. Reinisch, I. Galkin

Density gradients along the magnetic field lines in the magnetosphere
can cause radio waves to be guided along the field lines. Indeed
plasmagrams from the Radio Plasma Imager (RPI) on the IMAGE satellite
often show occurrences of field aligned echoes. These echoes are
normally seen within the plasmasphere and sometimes at the plasmapause
boundary. We have cataloged all the events from 01/01/01 to 06/30/01
when field aligned echoes are observed from both hemispheres. In this
paper we will present the results of parametric studies on the
dependence of field aligned echoes on L shell values, MLT (magnetic
local time) and Dst. For the observed echoes, we will determine density
profiles using field aligned tracing technique.

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To be presented at the Magnetospheric Imaging Workshop, 
Yosemite National Park, California, U.S.A., Feb. 5-8, 2002.