Drift turbulence, particle transport, and anomalous dissipation at the reconnecting magnetopause

Using fully kinetic 3D simulations, the reconnection dynamics of asymmetric current sheets observed by NASA’s MMS spacecraft at Earth’s magnetopause are studied [1]. Drift-wave fluctuations are observed in the lower-hybrid frequency range at the steep density gradient across the magnetospheric separatrix. These fluctuations induce cross-field particle transport in agreement with quasi-linear theory and enhanced electron parallel heating compared to 2D simulations. We study three different methods of quantifying the associated anomalous dissipation, based on spatial and temporal averaging, and temporal averaging followed by integration along magnetic field lines. The anomalous dissipation appears weak for each case, and the reconnection rates observed in 3D are nearly the same as in 2D. The 3D simulations show new features consistent with the observations including cold beams of magnetosheath electrons that penetrate into the hotter magnetospheric inflow.

[1] Le et al., PoP 25 (6), 062103 (2018) and GRL 44 (5), 2096-2104 (2017)