Reconnection in a weakly stochastic field

  title={Reconnection in a weakly stochastic field},
  author={Alexander Lazarian and Ethan T. Vishniac},
  journal={The Astrophysical Journal},
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 for reconnection flows and by allowing many independent flux reconnection events to occur simultaneously. Allowing only for the first effect and using Goldreich & Sridhar's model of strong turbulence in a magnetized plasma with negligible intermittency, we find a lower limit for the reconnection… 

Figures from this paper

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
Fast Magnetic Reconnection with Turbulence in High Lundquist Number Limit
We use extensive 3D resistive MHD simulations to study how large-scale current sheets will undergo fast reconnection in the high Lundquist number $S$ limit (above $\sim 10^4$), when the system is
Three-dimensional Spontaneous Magnetic Reconnection
Magnetic reconnection is best known from observations of the Sun where it causes solar flares. Observations estimate the reconnection rate as a small, but non-negligible fraction of the Alfven speed,
Fast Reconnection in a Two‐Stage Process
Magnetic reconnection plays an essential role in the generation and evolution of astrophysical magnetic fields. The best tested and most robust reconnection theory is that of Parker and Sweet.
Reconnection in weakly stochastic B -fields in 2D
We study two-dimensional turbulent magnetic reconnection in a compressible fluid in the gas pressure dominated limit. We use open boundary conditions and start from a Harris current sheet
Stochastic Reconnection for Large Magnetic Prandtl Numbers
We consider stochastic magnetic reconnection in high-β plasmas with large magnetic Prandtl numbers, Pr m > 1. For large Pr m , field line stochasticity is suppressed at very small scales, impeding
Faster Form of Electron Magnetic Reconnection with a Finite Length X-Line.
A new form of 3D electron-only reconnection spontaneously develops where the magnetic X-line is localized in the out-of-plane (z) direction, resulting in an enhancement of the reconnection rate compared with two dimensions, which results from differential mass flux out of the diffusion region along z, enabling a faster inflow velocity and thus a larger reconnections rate.
Sub-Grid-Scale Description of Turbulent Magnetic Reconnection in Magnetohydrodynamics
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
Magnetic Field Structure and Stochastic Reconnection in a Partially Ionized Gas
We consider stochastic reconnection in a magnetized, partially ionized medium. Stochastic reconnection is a generic effect that results from field line wandering, in which the speed of reconnection
Magnetic Reconnection and Turbulent Mixing: From ISM to Clusters of Galaxies
Magnetic reconnection, or the ability of the magnetic field lines that are frozen in plasma to change their topology, is a fundamental problem of magnetohydrodynamics (MHD). Webriefly examine the


Reconnection in the Interstellar Medium
We discuss the role of ambipolar diffusion for simple reconnection in a partially ionized gas, following the reconnection geometry of Parker and Sweet. When the recombination time is short, the
Reconnection rates of magnetic fields including the effects of viscosity
The Sweet–Parker and Petschek scalings of the magnetic reconnection rate are modified to include the effect of the viscosity. The modified scalings show that the viscous effect can be important in
Fast magnetic reconnection and sudden enhancement of current sheets due to inward boundary flows
Magnetic reconnection is widely believed to be involved in dynamical phenomena such as solar flares or magnetospheric substorms. The Sweet–Parker model of magnetic reconnection in a Y‐type geometry
The Rate of Magnetic Reconnection Observed in the Solar Atmosphere
The structure of the solar corona is often observed to evolve in a manner that is generally attributed to the process of magnetic field line reconnection. The spatial and temporal scales for a
Turbulent magnetic reconnection
The effects of turbulence on magnetic reconnection are investigated by two‐dimensional spectral method magnetohydrodynamic computations. The nonlinear evolution of the periodic sheet pinch
Magnetic Reconnection via Current Sheets
A general picture of magnetic reconnection in the framework of 2‐D incompressible resistive magnetohydrodynamic theory is presented. Numerical studies of (quasi‐) steady‐state driven reconnection
Two-fluid theory of collisionless magnetic reconnection
Theoretical studies of collisionless reconnection in the framework of two-fluid theory are presented. In the high-β case (β≳1) reconnection is controlled by the whistler mode, leading to decoupling
Structure of the dissipation region during collisionless magnetic reconnection
Collisionless magnetic reconnection is studied using a 2 1/2-dimensional hybrid code including Hall dynamics and electron inertia. The simulations reveal that the dissipation region develops a
Role of photospheric footpoint shear in the impulsive dynamics of the solar corona
A frequently observed feature of a solar flare is its impulsive growth from a relatively quiescent background. This imposes a significant constraint on magnetic reconnection models which propose to
Can the turbulent galactic dynamo generate large-scale magnetic fields?
Large-scale magnetic fields in galaxies are thought to be generated by a turbulent dynamo. However, the same turbulence also leads to a small-scale dynamo which generates magnetic noise at a more