On the short-scale spatial variability of electron inflows in electron-only magnetic reconnection in the turbulent magnetosheath observed by MMS

<p>In the Earth&#8217;s turbulent magnetosheath downstream of the quasiparallel bow shock region, magnetic reconnection without ion coupling was observed with bi-directional super-Alfv&#233;nic electron jets. The lack of ion coupling was attributed to the small-scale sizes of the current sheets. In an electron-only reconnection event that occurred on 26 December 2016, we examine the detailed properties of electron inflows observed by all 4 MMS spacecraft. Even though the farthest MMS probe in the outflow direction from the X-line was no more than 8 electron skin depth, the electron inflows have significant asymmetry and highly variable amplitudes. We compare MMS observations with 2D-kinetic PIC simulation and find that the asymmetry in the inflow stems directly from the tilt of the out-of-plane (guide) magnetic field structure in the reconnection plane, with inflow asymmetry enhanced in the downstream region.</p>