Frequency asymmetry in the upshifted and downshifted plasma lines induced by an HF wave at Arecibo

Journal Article · Fri Jun 01 04:00:00 EDT 1979 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA084iA06p02705· OSTI ID:6093213

Muldrew, D B

The Langmuir waves responsible for the HF-wave-induced plasma lines observed during ionospheric heating experiments at Arecibo are generated and propagate to the point of detection in field-aligned ionization ducts. These Langmuir waves grow parametrically in the ducts at the height in the ionosphere at which the HF wave electric field is strongest. If it is assumed that there is a positive density gradient upward along the duct, then the observed ion acoustic frequency asymmetry between the upshifted and downshifted plasma lines can be explained. Agreement can be obtained between experimental and theoretical values for the frequency asymmetry and for the growth rates of the plasma line for a scale length along the magnetic field direction of about 40 km. A 40-km-scale length is less than that which would be expected during the day in the ambient plasma. However, it is probably not an unreasonable value for a duct under the influence of HF heating. A 40-km scale length also leads to a height differential of about 55 m between the points at which the waves responsible for the upshifted and downshifted plasma lines are detected by the Arecibo radar. The model also implies that the intensity of the upshifted plasma line would be greater than that for the downshifted plasma line.

• Research Organization: Communications Research Centre, Department of Communications, Ottawa, Canada K2H 8S2
• OSTI ID: 6093213
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 84:A6; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ASYMMETRY
EARTH ATMOSPHERE
ELECTRON DENSITY
HEATING
INSTABILITY GROWTH RATES
IONOSPHERE
LANGMUIR FREQUENCY
PLANETARY IONOSPHERES
PLASMA HEATING
PLASMA WAVES
WAVE PROPAGATION