Transition to turbulence in nonuniform coronal loops driven by torsional Alfven waves

Abstract

Both observations and numerical simulations suggest that Alfvenic waves may carry sufficient energy to sustain the hot temperatures of the solar atmospheric plasma. However, the thermalization of wave energy is inefficient unless very short spatial scales are considered. Phase mixing is a mechanism that can take energy down to dissipation lengths, but it operates over too long a timescale. Here, we study how turbulence, driven by the nonlinear evolution of phase-mixed torsional Alfven waves in coronal loops, is able to take wave energy down to the dissipative scales much faster than the theory of linear phase mixing predicts. We consider a simple model of a transversely nonuniform cylindrical flux tube with a constant axial magnetic field. The flux tube is perturbed by the fundamental mode of standing torsional Alfven waves. We solved the three-dimensional (3D) ideal magnetohydrodynamics equations numerically to study the temporal evolution. Initially, torsional Alfven waves undergo the process of phase mixing because of the transverse variation of density. After only few periods of torsional waves, azimuthal shear flows generated by phase mixing eventually trigger the Kelvin-Helmholtz instability (KHi), and the flux tube is subsequently driven to a turbulent state. Turbulence is very anisotropic and develops transversely only to the background magnetic field. After the onset of turbulence, the effective Reynolds number decreases in the flux tube much faster than in the initial linear stage governed by phase mixing alone. We conclude that the nonlinear evolution of torsional Alfven waves, and the associated KHi, is a viable mechanism for the onset of turbulence in coronal loops.

arXiv commentAccepted in A&A

References in corpus (53)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• PLUTO: a Numerical Code for Computational Astrophysics
• A weak turbulence theory for incompressible MHD
• The PLUTO Code for Adaptive Mesh Computations in Astrophysical Fluid Dynamics
• On the Generation, Propagation, and Reflection of Alfven Waves from the Solar Photosphere to the Distant Heliosphere
• Alfven Waves in the Lower Solar Atmosphere
• Heating of the Solar Chromosphere and Corona by Alfven Wave Turbulence
• Ubiquitous torsional motions in type II spicules
• Multiwavelength studies of MHD waves in the solar chromosphere: An overview of recent results
• Nonlinear Instability of kink oscillations due to shear motions
• Alfven Waves in the Solar Atmosphere
• On the prevalence of small-scale twist in the solar chromosphere and transition region
• Fine strand-like structure in the solar corona from MHD transverse oscillations
• Surface Alfven waves in solar flux tubes
• Resonant Absorption of Transverse Oscillations and Associated Heating in a Solar Prominence. II- Numerical aspects
• SDO/AIA Observation of Kelvin-Helmholtz Instability in the Solar Corona
• Connecting the Sun and the Solar Wind: The First 2.5 Dimensional Self-consistent MHD Simulation under the Alfvén Wave Scenario
• Heating by transverse waves in simulated coronal loops
• Stability of rotating magnetized jets in the solar atmosphere. I. Kelvin-Helmholtz instability
• Damping of nonlinear standing kink oscillations: a numerical study
• Magnetohydrodynamic kink waves in nonuniform solar flux tubes: phase mixing and energy cascade to small scales
• A self-consistent model of the coronal heating and solar wind acceleration including compressible and incompressible heating processes
• Heating effects from driven transverse and Alfvén waves in coronal loops
• Observation of coronal loop torsional oscillation
• Kelvin-Helmholtz instability in coronal magnetic flux tubes due to azimuthal shear flows
• Transverse Oscillations in Slender Ca II H Fibrils Observed with Sunrise/SuFI
• Energy transport and heating by torsional Alfvén waves propagating from the photosphere to the corona in the quiet Sun
• Generation of Magnetohydrodynamic Waves in Low Solar Atmospheric Flux Tubes by Photospheric Motions
• Mechanisms for MHD Poynting flux generation in simulations of solar photospheric magneto-convection
• The Heating of Solar Coronal Loops by Alfven Wave Turbulence
• First direct observation of a torsional Alfvén oscillation at coronal heights
• Evidence for Wave Heating of the Quiet Sun Corona
• Energetics of the Kelvin-Helmholtz instability induced by transverse waves in twisted coronal loops
• Simulations of fully deformed oscillating flux tubes
• Understanding uniturbulence: self-cascade of MHD waves in the presence of inhomogeneities
• Wave heating in gravitationally stratified coronal loops in the presence of resistivity and viscosity
• On Kelvin-Helmholtz and parametric instabilities driven by coronal waves
• Phase mixing and wave heating in a complex coronal plasma
• Magnetohydrodynamic kink waves in two-dimensional non-uniform prominence threads
• Observations of the Kelvin-Helmholtz instability driven by dynamic motions in a solar prominence
• Multi-fluid approach to high-frequency waves in plasmas. III. Nonlinear regime and plasma heating
• Nonlinear evolution of short-wavelength torsional Alfven waves
• Enhanced phase mixing of Alfvén waves propagating in stratified and divergent coronal structures
• An Analytical Model of the Kelvin-Helmholtz Instability of Transverse Coronal Loop Oscillations
• Weak Alfven-Wave Turbulence Revisited
• Phase mixing of nonlinear Alfven waves
• Contribution of phase-mixing of Alfvén waves to coronal heating in multi-harmonic loop oscillations
• Statistical Evidence for the Existence of Alfvénic Turbulence in Solar Coronal Loops
• Estimating the energy dissipation {from Kelvin-Helmholtz instability induced} turbulence in oscillating coronal loops}
• Chromospheric evaporation and phase mixing of Alfvén waves in coronal loops
• Torsional Alfvénic Oscillations Discovered in the Magnetic Free Energy During Solar Flares
• Phase Mixing of Kink MHD Waves in the Solar Corona: Viscous Dissipation and Heating

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• Transverse kink oscillations of inhomogeneous prominence threads: numerical analysis and H$\alpha$ forward modelling
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