Description
Magnetic reconnection and plasma turbulence are deeply interlinked processes. The turbulent evolution of magnetic structures lead to the onset of reconnection events and turbulence is present in different regions associated with the reconnection dynamics, e.g., inflow region, exhaust, Ion diffusion region and Electron diffusion region. Plasma turbulence plays a fundamental role because it transports energy across spatial scales from the large energy injection scales down to small-scales at which energy is dissipated. A key challenge is understanding how the small-scale turbulent dynamics couple into and influences the large-scale behaviour of the system, this is particularly important to assess the importance of anomalous effects on the reconnection dynamics. In this work we tackle this challenge using Vlasov-Hybrid and fully kinetic Paritcle-in-Cell (PIC) simulations modelling conditions similar to the turbulence in Earth’s magnetosheath and employing a scale filtering analysis to estimate the contribution from small-scale terms in the generalised Ohm’s law, such as the anomalous transport and anomalous resistivity, to the total electric field. We also establish the dependence of the small-scale terms on large-scale quantities such as the mean magnetic field, mean current density and mean plasma vorticity. This is highly relevant to produce Sub-Grid-Scale (SGS) models that can be used to perform Large-Eddy-Simulations (LES) of plasma turbulence and magnetic reconnection in astrophysical systems where the plasma conditions make it unfeasible to perform direct numerical simulations due to the scale separation between the system size scale and the dissipation scale.
