Energetic-particle drift motions in the outer dayside magnetosphere
Models of the geomagnetic field predict that within a distance of approximately one earth radius inside the dayside magnetopause, magnetic fields produced by the Chapman-Ferraro magnetopause currents create high-latitude minimum-B pockets in the geomagnetic field. These pockets are theoretically capable of temporarily trapping azimuthally-drifting electrons and modifying electron directional distributions. The Lawrence Livermore National Laboratory's scanning electron spectrometer aboard the OGO-5 satellite provided detailed energetic (E > 70 keV) electron pitch-angle distributions throughout the magnetosphere. Distributions obtained in the outer dayside magnetosphere over a wide range of longitudes show unusual flux features. This study analyzes drift-shell branching caused by the minimum-B pockets, and interprets the observed flux features in terms of an adiabatic-shell branching and rejoining process. The author examines the shell-branching process for a static field in detail, using the Choe-Beard 1974 magnetospheric magnetic field mode. He finds that shell branching and rejoining conserves the particle mirror field B/sub M/, the fieldline integral invariant I, and the directional electron flux j. He also finds a good correlation between the itch angles that mark the transition from branched to unbranched shells in the model and the distinctive features of the OGO-5 distributions.
- Research Organization:
- California Univ., Davis, CA (USA)
- OSTI ID:
- 5508092
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
EARTH MAGNETOSPHERE
MAGNETOPAUSE
PLASMA DRIFT
ELECTRONS
GEOMAGNETIC FIELD
MINIMUM-B CONFIGURATIONS
SOLAR WIND
CHAPMAN-FERRARO PROBLEM
FUNCTIONAL MODELS
EARTH ATMOSPHERE
ELEMENTARY PARTICLES
FERMIONS
LEPTONS
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC FIELDS
OPEN CONFIGURATIONS
SOLAR ACTIVITY
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena