Sub-Grid-Scale Description of Turbulent Magnetic Reconnection in Magnetohydrodynamics

  title={Sub-Grid-Scale Description of Turbulent Magnetic Reconnection in Magnetohydrodynamics},
  author={F. Widmer and Jorg Buchner and N. Yokoi},
  journal={arXiv: Plasma Physics},
Magnetic reconnection requires, at least locally, a non-ideal plasma response. In collisionless space and astrophysical plasmas, turbulence could permit this instead of the too rare binary collisions. We investigated the influence of turbulence on the reconnection rate in the framework of a single fluid compressible MHD approach. The goal is to find out, whether unresolved, sub-grid for MHD simulations, turbulence can enhance the reconnection process in high Reynolds number astrophysical plasma… 
Magnetohydrodynamic Simulation of Reconnection in Turbulent Astrophysical Plasmas
Turbulence is ubiquitous at large-Reynolds-number astrophysical plasmas like in the Solar corona. In such environments, the turbulence is thought to enhance the energy conversion rate by magnetic
Characterizing plasmoid reconnection by turbulence dynamics
In weakly dissipative plasmas, the plasmoid instability may lead, in principle, to fast magnetic reconnection through long current sheets. On the other hand, it is well known that weakly dissipative
Turbulent Plasmoid Reconnection
The plasmoid instability may lead to fast magnetic reconnection through long current sheets(CS). It is well known that large-Reynolds-number plasmas easily become turbulent. We address the question
Analysis of fast turbulent reconnection with self-consistent determination of turbulence timescale
We present results of Reynolds-averaged turbulence model simulation on the problem of magnetic reconnection. In the model, in addition to the mean density, momentum, magnetic field, and energy
Electron acceleration by turbulent plasmoid reconnection
In space and astrophysical plasmas, like in planetary magnetospheres, as that of Mercury, energetic electrons are often found near current sheets, which hint at electron acceleration by magnetic
Magnetic reconnection in the era of exascale computing and multiscale experiments
Astrophysical plasmas have the remarkable ability to preserve magnetic topology, which inevitably gives rise to the accumulation of magnetic energy within stressed regions including current sheets.
A nonlinear structural subgrid-scale closure for compressible MHD. I. Derivation and energy dissipation properties
Compressible magnetohydrodynamic (MHD) turbulence is ubiquitous in astrophysical phenomena ranging from the intergalactic to the stellar scales. In studying them, numerical simulations are nearly
Turbulence, Transport and Reconnection
  • N. Yokoi
  • Physics
    Topics in Magnetohydrodynamic Topology, Reconnection and Stability Theory
  • 2019
Turbulence is a multi-scale phenomenon that is ubiquitous in our universe. Strong nonlinearity in a system enhances coupling among modes, leading to a very broad spectrum in the spatial domain which
Electromotive force in strongly compressible magnetohydrodynamic turbulence
  • N. Yokoi
  • Physics
    Journal of Plasma Physics
  • 2018
Fully compressible magnetohydrodynamic (MHD) turbulence is investigated in the framework of the multiple-scale direct-interaction approximation. With the aid of the propagators (correlation and
A nonlinear structural subgrid-scale closure for compressible MHD. II. A priori comparison on turbulence simulation data
Even though compressible plasma turbulence is encountered in many astrophysical phenomena, its effect is often not well understood. Furthermore, direct numerical simulations are typically not able to


Nonlinear closures for scale separation in supersonic magnetohydrodynamic turbulence
Turbulence in compressible plasma plays a key role in many areas of astrophysics and engineering. The extreme plasma parameters in these environments, e.g. high Reynolds numbers, supersonic and
We study the effects of turbulence on magnetic reconnection using three-dimensional direct numerical simulations. This is the first attempt to test a model of fast magnetic reconnection in the
Reconnection in a weakly stochastic field
We examine the effect of weak, small-scale magnetic field structure on the rate of reconnection in a strongly magnetized plasma. This affects the rate of reconnection by reducing the transverse scale
Collisionless magnetic reconnection in the presence of a guide field
The results of kinetic simulations of magnetic reconnection in Harris current sheets are analyzed. A range of guide fields is considered to study reconnection in plasmas characterized by different β
Magnetic reconnection in the partially ionized solar chromosphere is studied in 2.5 dimensional magnetohydrodynamic simulations including radiative cooling and ambipolar diffusion. A Harris current
Kinetic simulations of collisionless magnetic reconnection in presence of a guide field
The results of kinetic simulations of magnetic reconnection in Harris current sheets are analyzed. A range of guide fields is considered to study reconnection in plasmas characterized by different
Flow-turbulence interaction in magnetic reconnection
Roles of turbulence in the context of magnetic reconnection are investigated with special emphasis on the mutual interaction between flow (large-scale inhomogeneous structure) and turbulence. In
Astrophysical reconnection and collisionless dissipation
Magnetic reconnection and collisionless dissipation are common phenomena of astrophysical and fusion plasmas. While reconnection is responsible for disruptions of a fusion confinement, it causes
A turbulence model for magnetohydrodynamic plasmas
The statistical theory of inhomogeneous turbulence is applied to develop a system of model equations for magnetohydrodynamic (MHD) turbulence. The statistical descriptors of MHD turbulence are taken
Geospace Environmental Modeling (GEM) magnetic reconnection challenge
The Geospace Environmental Modeling (GEM) Reconnection Challenge project is presented and the important results, which are presented in a series of companion papers, are summarized. Magnetic