High-power high-frequency-induced Langmuir turbulence in the smooth ionosphere at Arecibo. I. Theoretical predictions for altitude-resolved plasma line radar spectra

This is the first of two papers comprising a theoretical and observational study of new, altitude-resolved, observations at Arecibo of Langmuir turbulence induced in the ionosphere by a powerful high-frequency (hf) heater operated at very low duty cycles. As shown in paper II [Cheung et al., Phys. Plasmas 8, 802 (2001)], higher power enabled the first observation at Arecibo of the well-developed decay-cascade features in the Thomson scatter radar power spectrum at the unmodified matching altitudes. New theoretical predictions are presented here for the parameters of these observations emphasizing the altitude and pump power dependence of the radar spectra and the time dependence of the spectra from the decaying spectra following heater switch-off. Further details of the strong turbulence signatures from higher altitudes are also presented. At the lower matching altitudes the increase, with hf power, of the angular width of the well-developed decay-cascade spectrum allows these spectral features to come into the view of the Arecibo radar. The favorable comparison of the simulation predictions and observations is discussed in the second paper.