The present study investigates, via linear theory, how striations (treated as perturbations) created in a plasma cloud centered at 200 km will penetrate into the background inhomogeneous (real) ionosphere as a function of wavelength, integrated Pedersen conductivity ratio of the cloud to ionosphere (Σpb/Σpι), and ambient ionospheric conditions. The study is posed as an eigenvalue problem which while determining the potential variation (eigenmode) along magnetic field lines, self-consistently solves for the growth rate (eigenvalue) in the coupled cloud-inhomogeneous ionosphere system. Perturbed particle densities, fluxes parallel to the magnetic field B, and electrostatic potential are presented as a function of altitude. The results show the importance of the image transport parameter (kL⊥νι/ωcι)(1 + νι²/ωcι²)−1 (where k is the wave number transverse to B, L⊥ is the transverse dimension of the cloud, and νι and ωcι are the ionospheric ion-neutral collision frequency and ion cyclotron frequency, respectively) in determining the magnitude of imaging and aspect angle of striations with respect to B (i.e., striations take on a parallel component of wave number). Perturbations penetrate further down in the presence of the plasma cloud than was indicated in simple previous studies which neglected image transport and considered the perturbation mapping from one region of the ionosphere to another. Our results show that clouds with smaller conductivity ratios produce image striations further down into the background E region ionosphere with a more uniform coupling as a function of wavelength. It is further shown that there is a slight dependence of the E region coupling of the perturbations on the level of solar activity (solar maximum or minimum conditions) and also that this E region coupling shows a slight dependence on the extent of F region coupling above the cloud. Finally, with a fully self-consistent treatment of F region coupling, the growth rates show negligible short-wavelength damping due to ionospheric coupling for the Σpb/Σpι = 4 case.
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