The electron edge of low latitude boundary layer during accelerated flow events

Abstract

Magnetosheath plasma entering the Earth's magnetosphere to populate the low latitude boundary layer, LLBL, is often accelerated to speeds considerably greater than are observed in the adjacent magnetosheath. Measurements made during such accelerated flow events separate electron and ion edges to the LLBL, with the electron edge being found earthward of the ion edge, electron velocity distributions observed at the edge of the LLBL are often highly structured, exhibiting large asymmetries parallel and antiparallel, as perpendicular, to the local magnetic field. These can consistently be interpreted as time‐of‐flight effects on recently reconnected field lines, and thus are evidence in support of the reconnection interpretation of accelerated plasma flow events.