 |
| Titel |
The local-time variation of the quiet plasmasphere: geosynchronous observations and kinetic theory |
| VerfasserIn |
M. A. Reynolds, G. Ganguli, Y.-J. Su, M. F. Thomsen |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
0992-7689
|
| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 21, no. 11 ; Nr. 21, no. 11, S.2147-2154 |
| Datensatznummer |
250014706
|
| Publikation (Nr.) |
 copernicus.org/angeo-21-2147-2003.pdf |
|
|
|
|
|
| Zusammenfassung |
The quiet-time structure
of the plasmaspheric density was investigated using observations of the Los
Alamos geosynchronous satellites, and these observations were compared with
theoretical predictions of the quasi-static local-time variation by a kinetic
model. It was found that the coupling to the ionosphere (via the local-time
variation of the exobase) played a key role in determining the density
structure at 6.6 RE . The kinetic model predicts that most of
the local-time variation at geosynchronous orbit is due to the variation of the
exobase parameters. During quiet times, when the convection electric field is
dominated by the corotation field, the effects due to flux-tube convection are
less prominent than those due to the exobase variation. In addition, the
kinetic model predicts that the geosynchronous plasmaspheric density level is
at most only 25% of saturation density, even when geomagnetic activity is low.
The low night-time densities of the ionospheric footpoints, and the subsequent
long trapping time scales, prevent the equatorial densities from reaching
saturation.
Key words. Magnetospheric physics
(magnetosphere-ionosphere interactions; plasma convection; plasmasphere) |
| |
|
| Teil von |
|
|
|
|
|
|
|
|