Response of the Magnetosphere to Microscopic Effects in Auroral Arc Formation

Abstract

A process of quiet auroral arc formation, in particular, the response of the magnetosphere to the effect of auroral energetic electrons, is studied using a holistic auroral simulation code. It consists of a three-dimensional magnetohydrodynamic code for a dipole magnetosphere-ionosphere coupling system and a one-dimensional electrostatic plasma particle code for auroral energetic electron production. Results of the holistic auroral simulation indicate that drastic variation in the ionospheric electric field, which is induced by auroral energetic electrons and propagates into the magnetosphere, influences the magnetospheric field-aligned current distribution. Furthermore, the characteristic time scale of this process is investigated.

Linear analysis of cross-field dynamics with feedback instability on detached divertor plasmas

“…This difference of the current mechanism between the magnetosphere and the ionosphere can induce the instability called 'feedback instability' [22]. The field-aligned current (FAC) and the ionosphere plasma density grow locally by the feedback instability and auroral arcs are formed in the region where FAC is enhanced [23][24][25].…”