Multiply coupled oscillations of field lines in the magnetosphere: Modulation of trapped particles and ionospheric currents
| Autor: | John B. Cladis |
|---|---|
| Rok vydání: | 1971 |
| Předmět: |
Physics
Atmospheric Science Drift velocity Ecology Field (physics) Field line Paleontology Soil Science Magnetosphere Forestry Aquatic Science Oceanography Standing wave symbols.namesake Geophysics Space and Planetary Science Geochemistry and Petrology Van Allen radiation belt Earth and Planetary Sciences (miscellaneous) symbols Phase velocity Atomic physics Ring current Earth-Surface Processes Water Science and Technology |
| Zdroj: | Journal of Geophysical Research. 76:2345-2356 |
| ISSN: | 0148-0227 |
| DOI: | 10.1029/ja076i010p02345 |
| Popis: | A new field-line resonance is proposed to explain some coherent modulations of trapped proton and electron fluxes with correlated magnetic-field variations that have been observed in the outer magnetosphere. The resonance is excited by the ▽B drift of energetic trapped particles that have an inhomogeneous distribution in the direction of the drift motion. The field lines oscillate as standing waves in the meridional plane and form a wave pattern in the azimuthal direction that moves with a phase velocity equal to the mean azimuthal drift velocity of the particles. Particles that drift near the phase velocity become bunched in the potential wells of the wave; other trapped particles undergo radial motions, tending to follow the motions of the field lines. Analytical solutions based on a simplified model of the magnetosphere are used to interpret experimental observations. The characteristics of the wave field that appear at the surface of the earth are discussed, and an experiment involving ground measurements of the field is suggested as a means of obtaining spatial information on particle-injection processes. |
| Databáze: | OpenAIRE |
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