Parallel Propagation Effects on the Type I Electrojet Instability.
Abstract
The Farley-Buneman instability has been extended to consider higher frequency, shorter wavelength modes (thus including finite Debye length effects) while allowing these modes to propagate with a component parallel to the magnetic field (k parallel not = 0). By driving the current sufficiently hard (drift speeds in the range 2-3 times the ion thermal velocity, vi) the growth rates of these modes maximize slightly away from the perpendicular to the magnetic field showing the importance of k parallel not = 0. Although the wavelengths of these maximum growing modes are in the regime of several to tens of centimeters, the phase velocities are near the ion thermal velocity. This suggests that a nonlinear coupling of these off angle modes may be responsible for the observed radar spectrum with maximum intensity near vi and wavelengths in the 1-10 meter regime. Maximum growth rates of off angle propagation while varying the densities and collision frequencies are shown. Also, growth rates of unstable waves in the radar regime (1-10 meters) are shown for drift velocities 1.5 and 3 times vi. (Modified author abstract)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1974
- Accession Number
- AD0775596
Entities
People
- Joseph H. Orens
- Konstantinos Papadopoulos
- Sidney L. Ossakow
- Timothy P. Coffey
Organizations
- United States Naval Research Laboratory