Papers on Ionosphere and Upper Atmosphere
Observations of inner plasmasphere irregularities with a satellite-beacon radio-interferometer array
Article first published online: 20 SEP 2012
Copyright 1996 by the American Geophysical Union.
Journal of Geophysical Research: Space Physics (1978–2012)
Volume 101, Issue A9, pages 19665–19682, 1 September 1996
How to Cite
1996), Observations of inner plasmasphere irregularities with a satellite-beacon radio-interferometer array, J. Geophys. Res., 101(A9), 19665–19682, doi:10.1029/96JA01253., , , , , and (
- Issue published online: 20 SEP 2012
- Article first published online: 20 SEP 2012
- Manuscript Accepted: 17 APR 1996
- Manuscript Received: 7 NOV 1995
A radio-interferometer array illuminated by 136-MHz beacons of several geosynchronous satellites has been used to study small (≥ 1013 m−2) transient disturbances in the total electron content along the lines of sight to the satellites. High-frequency (ƒ> 3 mHz) electron content oscillations are persistently observed, particularly during night and particularly during geomagnetically disturbed periods. The oscillations move across the array plane at speeds in the range 200–2000 m/s, with propagation azimuths that are strongly peaked in lobes toward the western half-plane. Detailed analysis of this azimuth behavior, involving comparison between observations on various satellite positions, indicates compellingly that the phase oscillations originate in radio refraction due to geomagnetically aligned plasma density perturbations in the inner plasmasphere. The motion of the phase perturbations across the array plane is caused by E × B drift of the plasma medium in which the irregularities are embedded. We review the statistics of 2.5 years of around-the-clock data on the local time, magnetic disturbance, seasonal, and line-of-sight variations of these observed irregularities. We compare the irregularities' inferred electrodynamic drifts to what is known about midlatitude plasma drift from incoherent scatter. Finally, we show in detail how the observation of these irregularities provides a unique and complementary monitor of inner plasmasphere irregularity incidence and zonal drift.