On the short-scale spatial variability of electron inflows in electron-only magnetic reconnection in the turbulent magnetosheath observed by MMS
Presentation Type
Talk
Presenter Format
In Person Meeting Talk
Topic
Dayside Science
Start Date
10-5-2022 3:30 PM
Abstract
In the Earth’s turbulent magnetosheath downstream of the quasiparallel bow shock region, magnetic reconnection without ion coupling was observed with bi-directional super-Alfvénic 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 less than 7 electron skin depth, the amplitudes of the inflows differed by as much as a factor of 5 among all MMS probes. Furthermore, the two inflow velocities for a given MMS probe were highly asymmetric away from the X-line and this asymmetry reversed on the opposite sides of the X-line. 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.
On the short-scale spatial variability of electron inflows in electron-only magnetic reconnection in the turbulent magnetosheath observed by MMS
In the Earth’s turbulent magnetosheath downstream of the quasiparallel bow shock region, magnetic reconnection without ion coupling was observed with bi-directional super-Alfvénic 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 less than 7 electron skin depth, the amplitudes of the inflows differed by as much as a factor of 5 among all MMS probes. Furthermore, the two inflow velocities for a given MMS probe were highly asymmetric away from the X-line and this asymmetry reversed on the opposite sides of the X-line. 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.
