The Dynamical Generation of Current Sheets in Astrophysical Plasma Turbulence

Abstract

Turbulence profoundly affects particle transport and plasma heating in many astrophysical plasma environments, from galaxy clusters to the solar corona and solar wind to Earth's magnetosphere. Both fluid and kinetic simulations of plasma turbulence ubiquitously generate coherent structures, in the form of current sheets, at small scales, and the locations of these current sheets appear to be associated with enhanced rates of dissipation of the turbulent energy. Therefore, illuminating the origin and nature of these current sheets is critical to identifying the dominant physical mechanisms of dissipation, a primary aim at the forefront of plasma turbulence research. Here we present evidence from nonlinear gyrokinetic simulations that strong nonlinear interactions between counterpropagating Alfven waves, or strong Alfven wave collisions, are a natural mechanism for the generation of current sheets in plasma turbulence. Furthermore, we conceptually explain this current sheet development in terms of the nonlinear dynamics of Alfven wave collisions, showing that these current sheets arise through constructive interference among the initial Alfven waves and nonlinearly generated modes. The properties of current sheets generated by a strong Alfven wave collisions are compared to published observations of current sheets in the Earth's magnetosheath and the solar wind, and the nature of these current sheets leads to the expectation that Landau damping of the constituent Alfven waves plays a dominant role in the damping of turbulently generated current sheets.

arXiv comment7 pages, 5 figures, accepted to Astrophysical Journal Letters

References in corpus (18)

• A weak turbulence theory for incompressible MHD
• Spectrum of magnetohydrodynamic turbulence
• Astrophysical Gyrokinetics: Basic Equations and Linear Theory
• Statistical Analysis of Current Sheets in Three-Dimensional Magnetohydrodynamic Turbulence
• Magnetic Reconnection and Intermittent Turbulence in the Solar Wind
• Intermittent Dissipation and Local Heating in the Solar Wind
• Current Sheets and Collisionless Damping in Kinetic Plasma Turbulence
• Linearized model Fokker-Planck collision operators for gyrokinetic simulations. I. Theory
• Linearized model Fokker-Planck collision operators for gyrokinetic simulations. II. Numerical implementation and tests
• Alfven Wave Collisions, The Fundamental Building Block of Plasma Turbulence I: Asymptotic Solution
• Spectral scaling laws in MHD turbulence simulations and in the solar wind
• A Dynamical Model of Plasma Turbulence in the Solar Wind
• AstroGK: Astrophysical Gyrokinetics Code
• Structures in magnetohydrodynamic turbulence: detection and scaling
• Magnetic Discontinuities in Magnetohydrodynamic Turbulence and in the Solar Wind
• Toward Astrophysical Turbulence in the Laboratory
• Alfven Wave Collisions, The Fundamental Building Block of Plasma Turbulence II: Numerical Solution
• The scaling properties of dissipation in incompressible isotropic three-dimensional magnetohydrodynamic turbulence

Cited by in corpus (28)

• The multi-scale nature of the solar wind
• Black hole flares: ejection of accreted magnetic flux through 3D plasmoid-mediated reconnection
• A Dynamical Model of Plasma Turbulence in the Solar Wind
• Diagnosing collisionless energy transfer using field-particle correlations: gyrokinetic turbulence
• Magnetic Reconnection May Control the Ion-Scale Spectral Break of Solar Wind Turbulence
• Laboratory Space Physics: Investigating the Physics of Space Plasmas in the Laboratory
• Spatially Localized Particle Energization by Landau Damping in Current Sheets Produced by Strong Alfven Wave Collisions
• Kinetic Turbulence in Astrophysical Plasmas: Waves and/or Structures?
• Diagnosing collisionless energy transfer using field-particle correlations: Alfven-Ion Cyclotron Turbulence
• Local energy transfer rate and kinetic processes: the fate of turbulent energy in two-dimensional Hybrid Vlasov-Maxwell numerical simulations
• Role of reconnection in inertial kinetic-Alfven turbulence
• The Importance of Electron Landau Damping for the Dissipation of Turbulent Energy in Terrestrial Magnetosheath Plasma
• Multiscale Solar Wind Turbulence Properties inside and near Switchbacks measured by Parker Solar Probe
• Three-dimensional magnetic reconnection in particle-in-cell simulations of anisotropic plasma turbulence
• ViDA: a Vlasov-DArwin solver for plasma physics at electron scales
• Collisionless energy transfer in kinetic turbulence: field-particle correlations in Fourier space
• Weak Alfvénic turbulence in relativistic plasmas II: Current sheets and dissipation
• Nonlinear energy transfer and current sheet development in localized Alfven wavepacket collisions in the strong turbulence limit
• Identification of active magnetic reconnection using magnetic flux transport in plasma turbulence
• The Velocity-Space Signature of Transit-Time Damping
• Free energy sources in current sheets formed in collisionless plasma turbulence
• The Alfvenic nature of energy transfer mediation in localized, strongly nonlinear Alfven wavepacket collisions
• Importance of accurate consideration of the electron inertia in hybrid-kinetic simulations of collisionless plasma turbulence: 1. The 2D limit
• The Development of Magnetic Field Line Wander by Plasma Turbulence
• Electron-to-ion bulk speed ratio as a parameter reflecting the occurrence of strong electron-dominated current sheets in the solar wind
• Scale Statistics of Current Sheets in Relativistic Collisionless Plasma Turbulence
• Machine-Learning Characterization of Intermittency in Relativistic Pair Plasma Turbulence: Single and Double Sheet Structures
• Heating of Magnetically Dominated Plasma by Alfvén-Wave Turbulence