Ionospheric flow structures associated with auroral beading at substorm auroral onset

Abstract Auroral observations have shown that brightening at substorm auroral onset often consists of azimuthally propagating beads forming along a preexisting arc. However, the ionospheric flow structure related to this wavy auroral structure has been poorly understood. We investigated ionospheric flow patterns associated with auroral onset beads using line‐of‐sight flow observations from the Super Dual Auroral Radar Network (SuperDARN) and …