Observations of the latitudinal structure of plasmaspheric convection plumes by
IMAGE-RPI and EUV

Leonard N. Garcia, Shing F. Fung, James L. Green, Scott A. Boardsen, 
Bill R. Sandel, Bodo W. Reinisch


Recent IMAGE Extreme Ultraviolet Imager (EUV) observations showed the first
global images of plasmaspheric convection plumes, which have been interpreted as
the plasmaspheric tails predicted theoretically 3 decades earlier. Using
observations by the IMAGE Radio Plasma Imager (RPI), we show that these
convection plumes have large latitudinal extent. These results complement those
recently made by others in correlating IMAGE EUV data with measurements of total
electron content in the ionosphere. By correlating in situ RPI density
measurements with global plasmaspheric EUV images, we have shown that apparently
detached plasma structures, as appear in RPI dynamic spectrograms, are in many
cases plasmaspheric convection plumes. The temporal separation between the RPI
and EUV observations help constrain the interpretation of one data set in the
context of the other, thereby enabling an examination of the three-dimensional
plasma density structures outside the core plasmasphere. The data sets are
mutually reinforcing because the data are collected within a few hours of one
another. We used the EUV data to provide unambiguous identification of density
enhancements in the region outside the plasmasphere and used the RPI data to
obtain accurate number densities and extend information from the EUV data set by
measuring densities below the EUV sensitivity threshold. 

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Journal of Geophysical Research, 108(A8), 1321, doi:10.1029/2002JA009496, 2003