Cyclotron harmonic effect on the thermal oscillating two-stream instability in the high latitude ionosphere

Journal Article · Tue Feb 01 04:00:00 EST 1994 · Journal of Geophysical Research

DOI:https://doi.org/10.1029/93JA02668· OSTI ID:28485

Huang, J; Kuo, S P ^[1]

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1. Polytechnic Univ., Farmingdale, NY (United States)

A thermal oscillating two-stream instability as the generation mechanism of electron Bernstein/upper hybrid waves by the o-mode HF heater wave in the high-latitude ionosphere is investigated. The purely growing decay mode is described by the fluid equations, while the kinetic equations are employed to derive the coupled mode equations of the electron Bernstein/upper hybrid sidebands. It is found that the instability can be excited in the altitude regions both above and below the upper hybrid resonance layer. The parametric excitation of electron Bernstein waves is in general not effective. On the other hand, the upper hybrid sidebands of the instability excited in the {open_quotes}below{close_quotes} region have been considered by Leyser to be the pumps for the parametric excitation of downshifted maximum (DM) lines of the stimulated electromagnetic emissions (SEEs) observed in the ionospheric heating experiments. The detail analysis of the proposed work shows that the instability zone of upper hybrid waves below the upper hybrid resonance layer becomes very small when the heater frequency f{sub o} is operated near three times of the local electron cyclotron frequency f{sub c}. Thus the source wave of the DM lines is effectively suppressed. This result explains the phenomenon of quenching of the DM feature in the SEE spectrum as f{sub o} is adjusted near 3f{sub c} in the ionospheric modification experiments. 27 refs., 4 figs.

• OSTI ID: 28485
• Journal Information: Journal of Geophysical Research, Journal Name: Journal of Geophysical Research Journal Issue: A2 Vol. 99; ISSN JGREA2; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BERNSTEIN MODE
ELECTRON CYCLOTRON-RESONANCE
HIGH-FREQUENCY HEATING
IONOSPHERE
MODE CONVERSION
SHORT WAVE RADIATION
TWO-STREAM INSTABILITY