Convective Amplification of Type I Irregularities in the Equatorial Electrojet.
CALIFORNIA UNIV LOS ANGELES PLASMA PHYSICS GROUP
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Wave propagation and refraction of Type I irregularities in the equatorial electrojet are investigated. Quantitative calculation of wave refraction in a model electrojet shows that the direction of wave refraction must change sign at one altitude. Wave propagating with the electrons rotate their wave vectors upwards in the upper electrojet and downwards in the lower electrojet during the day, and vice versa at night. Furthermore, the altitude region of largest linear growth rate is also the one with the weakest refraction rate. Consequently computations of the ray-path integrated wave growth shows that this region would dominate the backscatter spectrum from the electrojet if linear were valid, and it is further noted that the maximum amplitude wave should have phase velocities exceeding the ion acoustic speed. The authors conclude that propagation alone, without inclusion of nonlinear effects, cannot explain backscatter observations of a constant Doppler frequency shift given by the ion acoustic speed. Author
- Atmospheric Physics