Initial duct growth determined from cold-start plasma-line data recorded at Arecibo

Journal Article · Fri Jan 03 04:00:00 EST 1992 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/91GL02870· OSTI ID:5306013

Muldrew, D B ^[1]

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1. Communications Research Centre, Ottawa, Ontario (Canada)

Recent high-resolution height observations of the HF-induced plasma line have been made by Djuth et al. The plasma line is first observed after 3 ms very close to the HF-reflection height and not at the height expected from weak-turbulence theory in a uniformly varying ionosphere. Natural field-aligned ducts exist in the ionosphere. Those with a diameter of a few meters or more can trap Langmuir waves (L waves) generated by the parametric decay instability and propagating nearly parallel to the magnetic field B. The ponderomotive force of the trapped L waves near the highest HF interference maximum causes electrons to be expelled parallel to B and ions to be expelled perpendicular to B. The ion gyroradius is comparable to the smallest duct diameter that can trap L waves. Since it only takes a few milliseconds to a level where L waves capable of backscattering the Arecibo radar can be trapped. Duct growth is eventually limited by Landau damping and/or escape of the ducted L waves. These control the lower-height limit of the plasma line and terminate the overshoot.

• OSTI ID: 5306013
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Journal Name: Geophysical Research Letters (American Geophysical Union); (United States) Vol. 19:1; ISSN 0094-8276; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

661320* -- Auroral
Ionospheric
& Magnetospheric Phenomena-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BACKSCATTERING
DECAY INSTABILITY
DIMENSIONS
EARTH ATMOSPHERE
HEATING
HEIGHT
INSTABILITY
IONOSPHERE
PARAMETRIC INSTABILITIES
PLANETARY IONOSPHERES
PLASMA HEATING
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
PLASMA WAVES
PONDEROMOTIVE FORCE
REFLECTION
SCATTERING
WAVE PROPAGATION