Dynamics of three‐dimensional ionospheric plasma clouds

In this paper we will present the first fully three‐dimensional analytic study of plasma cloud dynamics, as well as computational results based upon a recently developed three‐dimensional electrostatic code. We derive a stability criterion for the large‐scale structuring of an ionospheric cloud based on a water bag model for the special case L z = r c (σ ‖ /σ ⊥ ) 1/2 (here, L z is the half length of the cloud along the magnetic field, r c is the radius of the cloud, and σ ‖,⊥ are the parallel and perpendicular cloud conductivities, respectively). We also present preliminary numerical results of three‐dimensional plasma cloud behavior. We examine the self‐consistent pressure‐induced plasma flow that results from a realistic plasma cloud in a realistic atmosphere in two‐dimensional cylindrical geometry, and the evolution of fully three‐dimensional perturbations of such a cloud.