Enhanced electron mixing and heating in 3‐D asymmetric reconnection at the Earth's magnetopause

Electron heating and mixing during asymmetric reconnection are studied with a 3‐D kinetic simulation that matches plasma parameters from Magnetospheric Multiscale (MMS) spacecraft observations of a magnetopause diffusion region. The mixing and heating are strongly enhanced across the magnetospheric separatrix compared to a 2‐D simulation. The transport of particles across the separatrix in 3‐D is attributed to lower hybrid drift turbulence excited at the steep density gradient near the magnetopause. In the 3‐D simulation (and not the 2‐D simulation), the electron temperature parallel to the magnetic field within the mixing layer is significantly higher than its upstream value in agreement with the MMS observations.