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“Electrostatic Shocks” and field-aligned currents are associated with discrete auroral arcs and low-altitude particle acceleration. We show that accounting for the two new elements with respect to the previous “static” and “Alfven wave” models, namely the transverse wave-guide for shear Alfven waves and plasma density dip in the center of the structure, is necessary in order to explain the basic features of this phenomenon. The characteristics dimensions of the structure correspond to the “stirring scales” of the auroral turbulence.

This report describes common features of natural (‘Enhanced’) aurora and ‘artificial aurora’ (AA) created by electron beams injected from sounding rockets. These features cannot be explained solely by col‐lisional degradation of energetic electrons, thereby pointing to collisionless plasma effects. The fundamental role in electron beam‐ionosphere interactions belongs to Langmuir turbulence. Its development in the (weakly‐ionized) ionosphere is significantly affected by electron‐neutral collisions, so that the heating and acceleration of plasma electrons proceed more efficiently than in collisionless plasmas. As a result, a narrow layer of enhanced auroral glow/ionization is formed above the standard collisional peak.