  Electron heating and mixing during asymmetric reconnection are studied with a
3D 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 2D simulation. The transport of particles across the
separatrix in 3D is attributed to lower-hybrid drift turbulence excited at the
steep density gradient near the magnetopause. In the 3D simulation (and not the
2D 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.
