Electron cyclotron waves in the presence of parallel electric fields in the Earth's auroral plasma
The electron cyclotron waves that originate at low altitudes (<0.5 R<sub>E</sub>) and observed by ground facilities have been studied in the presence of a weak parallel electric field in auroral magnetoplasma consisting of trapped energetic auroral electrons and cold backgroun...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
1997-01-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/15/24/1997/angeo-15-24-1997.pdf |
| Summary: | The electron cyclotron waves that originate
at low altitudes (<0.5 R<sub>E</sub>) and observed by ground facilities have
been studied in the presence of a weak parallel electric field in auroral
magnetoplasma consisting of trapped energetic auroral electrons and cold
background electrons of ionospheric origin. The model distribution for auroral
trapped electrons is taken as Maxwellian ring distribution. An expression for
the growth rate has been obtained in the presence of parallel electric field
assuming that the real frequency in the whistler mode is not affected by the
presence of the electric field. The results show that waves grow (or damp) in
amplitude for a parallel (or antiparallel) electric field. The influence of the
electric field is more pronounced at a shorter wavelength spectrum. An increase
in population of energetic electrons increases the growth rate and thus, plays a
significant role in the wave excitation process in the auroral regions. |
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| ISSN: | 0992-7689 1432-0576 |