Condor equatorial electrojet campaign: Radar results
A review of the experimental and theoretical background to the Condor equatorial electrojet compaign is followed by the presentation and discussion of VHF radar interferometer and HF radar backscatter data taken concurrently with two rocket in situ experiments reported in companion papers (Pfaff et al., this issue (a, b). Both experiments were conducted in strongly driven periods with the on-line radar interferometer displaying signatures of what has been interpreted in earlier radar work (Kudeki et al., 1982) as kilometer scale gradient drift waves. Low-frequency density fluctuations detected by in situ rocket sensors confirm the earlier interpretation. VHF radar/rocket data comparisons also indicate the existence of a turbulent layer in the upper portion of the daytime electrojet at about 108 km altitude driven purely by the two-stream instability. Nonlinear mode coupling of linearly growing two-stream waves to linearly damped 3-m vertical modes could account for the radar echoes scattered from this layer, which showed no indication of large-scale gradient drift waves. Nonlinear mode coupling may therefore compete with the wave-induced anomalous diffusion mechanism proposed recently by Sudan (1983) for the saturation of directly excited two-stream waves. Nighttime radar data show a bifurcated layer with the two parts having comparable echo strength but oppositely directed zonal drift velocities. The lower layer shows narrow backscatter spectra; the upper layer is characterized by kilometer scale waves and vertically propagating type 1 waves.
- Research Organization:
- Department of Electrical and Computer Engineering, University of Illinois, Urbana
- OSTI ID:
- 5647638
- Journal Information:
- J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 92:A12; ISSN JGREA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Long wavelength irregularities in the equatorial electrojet
Radar observations of two-dimensional turbulence in the equatorial electrojet, 2
Related Subjects
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CURRENTS
ELECTRIC CURRENTS
ELECTROJETS
INSTABILITY
INTERFEROMETRY
MEASURING INSTRUMENTS
PLASMA DENSITY
PLASMA DRIFT
PLASMA INSTABILITY
PLASMA MICROINSTABILITIES
PLASMA WAVES
RADAR
RANGE FINDERS
TURBULENCE
TWO-STREAM INSTABILITY