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Refilling of Geosynchronous Flux Tubes as Observed at the Equator by GEOS 2
Journal of Geophysical Research
  • Jan Josef Sojka, Utah State University
  • G. L. Wrenn
Document Type
American Geophysical Union
Publication Date

During periods of extended quiet geomagnetic activity the geosynchronous satellite orbit lies inside the plasmasphere. Five such periods were observed by the GEOS 2 satellite. During the initial 48 hours of such periods the equatorial plasma flux tube density increases at 30 to 50 cm−3/day. However, on reaching ∼100 cm−3 the refilling rate decreases, and refilling is limited. Only when the density reaches ∼100 cm−3 do the plasma characteristics and fluctuations appear to be plasmaspheric and the flow predominantly corotational. The “hot outer zone” of the plasmasphere is highly structured in density and temperature when viewed from a corotating satellite. This region also has a relatively dense population of warm subkilovolt electrons. These warm electrons whose density is ∼1% to 50% of the cold plasma may be the heat source for the hot outer zone ions.

Originally published by the American Geophysical Union. This article appears in the Journal of Geophysical Research: Space Science.
Citation Information
Sojka, J. J., and G. L. Wrenn (1985), Refilling of Geosynchronous Flux Tubes as Observed at the Equator by GEOS 2, J. Geophys. Res., 90(A7), 6379–6385, doi:10.1029/JA090iA07p06379.