Electron Trapping in Magnetic Mirror Structures at the Edge of Magnetopause Flux Ropes

Flux ropes are a proposed site for particle energization during magnetic reconnection, with several mechanisms proposed. Here, Magnetospheric Multiscale mission observations of mirror structures on the edge two ion-scale magnetopause flux presented. Donut-shaped features in electron pitch angle distributions provide evidence trapping structures. Furthermore, both events show extended 3D structure along body rope. Potential formation mechanisms, such as instability, examined and evolutionary states compared. Pressure force analysis suggest that could an important acceleration mechanism ropes, reconnection more generally.