Ionospheric Ion Upflows Associated with the Alfven Wave Heating

Abstract:

In this study we present the simulation results from a self-consistent inductive-dynamic ionosphere-thermosphere model. In a 2-D numerical simulation (noon-midnight meridian plane), we solve the continuity, momentum, and energy equations for multiple species of ions and neutrals and Maxwell’s equations. In particular, the model retains Faraday’s law, inertial term in the ion momentum equations and photochemistry. The code is based on an implicit algorithm and simulates a region from 80 km to 5000 km above the Earth. The system is driven by an antisunward motion at the upper boundary of the dayside cusp latitude in both hemispheres. We show that the frictional heating, which can produce upflows of the light (H+ and He+) and heave (O+) ions, is driven by the Alfven wave-induced ion motion relative to the neutrals. The variations of the upflows along a noon-midnight magnetic meridian are examined in association with given driving conditions imposed by the magnetosphere convection.