Journal cover Journal topic
Annales Geophysicae An open-access journal of the European Geosciences Union
Ann. Geophys., 15, 236-245, 1997
© European Geosciences Union 1997
28 Feb 1997
Improved analysis of plasmasphere motion using the VLA radio interferometer
G. W. Hoogeveen and A. R. Jacobson Space and Atmospheric Sciences Group, Mail Stop D466, Los Alamos National Laboratory, Los Alamos, NM 87545
Abstract. Observations using the very large (VLA) radio interferometer during the past five years have enabled the discovery of a new type of plasmasphere disturbance, the magnetic eastward-directed wave. Previous work indicated these disturbances were likely frozen to the geomagnetic field as determined from their azimuth distributions. This work provides a method to explain more accurately the azimuth distribution, thereby allowing the calculation of the disturbances' location in the plasmasphere independently of the measured velocity. The measurable velocity due to corotation is calculated and subtracted from the measured trace velocity. This difference, or deviation from corotation, is attributed to electrodynamic convection; the measurement of plasmaspheric convection may lead to the eventual monitoring of mid-latitude electric fields. Disturbances are seen convecting predominantly westward, with the fastest having angular velocities greater than the anticorotating VLA line of sight. The direction of convection and conditions of observations indicate that the disturbances are likely the same phenomenon seen by the Los Alamos satellite beacon array.

Citation: Hoogeveen, G. W. and Jacobson, A. R.: Improved analysis of plasmasphere motion using the VLA radio interferometer, Ann. Geophys., 15, 236-245, doi:10.1007/s00585-997-0236-6, 1997.
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