3D Anisotropy of Solar Wind Turbulence, Tubes, or Ribbons?

Abstract

We study the anisotropy with respect to the local magnetic field of turbulent magnetic fluctuations at magnetofluid scales in the solar wind. Previous measurements in the fast solar wind obtained axisymmetric anisotropy, despite that the analysis method allows nonaxisymmetric structures. These results are probably contaminated by the wind expansion that introduces another symmetry axis, namely, the radial direction, as indicated by recent numerical simulations. These simulations also show that while the expansion is strong, the principal fluctuations are in the plane perpendicular to the radial direction. Using this property, we separate 11 yr of Wind spacecraft data into two subsets characterized by strong and weak expansion and determine the corresponding turbulence anisotropy. Under strong expansion, the small-scale anisotropy is consistent with the Goldreich & Sridhar critical balance. As in previous works, when the radial symmetry axis is not eliminated, the turbulent structures are field-aligned tubes. Under weak expansion, we find 3D anisotropy predicted by the Boldyrev model, that is, turbulent structures are ribbons and not tubes. However, the very basis of the Boldyrev phenomenology, namely, a cross-helicity increasing at small scales, is not observed in the solar wind: the origin of the ribbon formation is unknown.

arXiv commentPublished version with ERRATUM (fig7) attached

References in corpus (33)

• Spectrum of magnetohydrodynamic turbulence
• The Anisotropy of MHD Alfvénic Turbulence
• Compressible Magnetohydrodynamic Turbulence: mode coupling, scaling relations, anisotropy, new regime and astrophysical implications
• Anisotropic scaling of magnetohydrodynamic turbulence
• On the Spectrum of Magnetohydrodynamic Turbulence
• Dependence of solar wind power spectra on the direction of the local mean magnetic field
• Power and spectral index anisotropy of the entire inertial range of turbulence in the fast solar wind
• Dynamic Alignment in Driven Magnetohydrodynamic Turbulence
• Solar wind turbulent spectrum at plasma kinetic scales
• Weak compressible magnetohydrodynamic turbulence in the solar corona
• Radial Dependence of the Frequency Break Between Fluid and Kinetic Scales in the Solar Wind Fluctuations
• Three-Dimensional Structure of Solar Wind Turbulence
• Role of magnetic reconnection in MHD turbulence
• Residual Energy Spectrum of Solar Wind Turbulence
• Coherent events and spectral shape at ion kinetic scales in the fast solar wind turbulence
• Disruption of sheetlike structures in Alfvénic turbulence by magnetic reconnection
• Polarization intermittency in MHD and its influence on turbulent cascade
• Anisotropy of Imbalanced Alfvenic Turbulence in Fast Solar Wind
• Compressive Coherent Structures at Ion Scales in the Slow Solar Wind
• Comparison of spectral slopes of magnetohydrodynamic and hydrodynamic turbulence and measurements of alignment effects
• Magnetohydrodynamic turbulence mediated by reconnection
• A statistical model of three-dimensional anisotropy and intermittency in strong Alfvénic turbulence
• Numerical Measurements of the Spectrum in Magnetohydrodynamic Turbulence
• Spectra of strong MHD Turbulence from high-resolution simulations
• Refined critical balance in strong Alfvenic turbulence
• Plasma beta dependence of the ion-scale spectral break of solar wind turbulence: high-resolution 2D hybrid simulations
• Anisotropy of third-order structure functions in MHD turbulence
• Evolution of turbulence in the expanding solar wind, a numerical study
• Correlations at large scales and the onset of turbulence in the fast solar wind
• Measures of Three-Dimensional Anisotropy and Intermittency in Strong Alfvénic Turbulence
• Imprints of expansion onto the local anisotropy of solar wind turbulence
• Beyond the Maltese cross: geometry of turbulence between 0.2 and 1 AU
• The uncertainty of local background magnetic field orientation in anisotropic plasma turbulence

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• A local approach to the study of energy transfers in incompressible magnetohydrodynamic turbulence
• Observational quantification of three-dimensional anisotropies and scalings of space plasma turbulence at kinetic scales
• On the evolution of the Anisotropic Scaling of Magnetohydrodynamic Turbulence in the Inner Heliosphere
• Kinetic range spectral features of cross-helicity using MMS
• Isotropic Scaling Features Measured Locally in the Solar Wind Turbulence with Stationary Background Field
• Kinetic Scale Spectral Features of Cross Helicity and Residual Energy in the Inner Heliosphere
• Three-dimensional local anisotropy of velocity fluctuations in the solar wind
• Dependence of 3D Self-correlation Level Contours on the Scales in the Inertial Range of Solar Wind Turbulence
• 3-D feature of self-correlation level contours at $10^{10}\mathrm{cm}$ scale in solar wind turbulence
• De-Biasing Structure Function Estimates From Sparse Time Series of the Solar Wind: A Data-Driven Approach
• Statistical study of electron density turbulence and ion-cyclotron waves in the inner heliosphere: Solar Orbiter observations
• The influence of Parker spiral on the reflection-driven turbulence