11:00 AM - 11:15 AM
[PEM10-07] Macroscopic description of the anomalous dissipation to drive magnetic reconnection
Keywords:magnetic reconnection, particle-in-cell simulation, turbulence, Ohm’s law, anomalous dissipation
To address these issues, we have carried out large-scale 3D particle-in-cell simulations of magntic reconnection with no guide-field. The simulation results show that the flow shear instabilities drive intense electromagnetic turbulence in the thin current layer formed around the reconnection x-line. It is found that the turbulence gives rise to the magnetic dissipation and electron heating in the diffusion region (Fujimoto & Sydora, 2021). It is interesting to notice that the ions hardly react to the turbulence, indicating that the turbulence does not cause siginificant momentum exchange between electrons and ions resulting in the resistivity. It is demonstrated instead that the dissipation is mainly caused by the viscosity associated with electron momentum transport across the current layer. In other words, the electric field raised from the turbulence is proportional to the Laplacian of the current density rather than the current density itself. The present results suggest a fundamental modification of the MHD framework based on the anomalous resistivity to generate the dissipation. In this talk, we will present the generation mechanism of the turbulence at the x-line and the macroscopic description of the resultant anomalus dissipation to drive reconnection.
Ref. Fujimoto, K., & Sydora, R. D. 2021, ApJL, 909, L15