Transverse Wave Induced Kelvin-Helmholtz Rolls in Spicules

Abstract

In addition to their jet-like dynamic behaviour, spicules usually exhibit strong transverse speeds, multi-stranded structure and heating from chromospheric to transition region temperatures. In this work we first analyse \textit{Hinode} \& \textit{IRIS} observations of spicules and find different behaviours in terms of their Doppler velocity evolution and collective motion of their sub-structure. Some have a Doppler shift sign change that is rather fixed along the spicule axis, and lack coherence in the oscillatory motion of strand-like structure, matching rotation models or long wavelength torsional Alfvén waves. Others exhibit a Doppler shift sign change at maximum displacement and coherent motion of their strands, suggesting a collective MHD wave. By comparing with an idealised 3-D MHD simulation combined with radiative transfer modelling, we analyse the role of transverse MHD waves and associated instabilities in spicule-like features. We find that Transverse Wave Induced Kelvin-Helmholtz (TWIKH) rolls lead to coherence of strand-like structure in imaging and spectral maps, as seen in some observations. The rapid transverse dynamics and the density and temperature gradients at the spicule boundary lead to ring-shaped \ion{Mg}{2} k and \ion{Ca}{2} H source functions in the transverse cross-section, potentially allowing IRIS to capture the KHI dynamics. Twists and currents propagate along the spicule at Alfvénic speeds, and the temperature variations within TWIKH rolls produce sudden appearance / disappearance of strands seen in Doppler velocity and in \ion{Ca}{2} H intensity. However, only a mild intensity increase in higher temperature lines is obtained, suggesting there is an additional heating mechanism at work in spicules.

Accepted for publication in The Astrophysical Journal

References in corpus (46)

• The Interface Region Imaging Spectrograph (IRIS)
• The Solar Optical Telescope for the Hinode Mission: An Overview
• A Tale Of Two Spicules: The Impact of Spicules on the Magnetic Chromosphere
• MHD Waves and Coronal Seismology: an overview of recent results
• Prevalence of Small-scale Jets from the Networks of the Solar Transition Region and Chromosphere
• Observing the Roots of Solar Coronal Heating - in the Chromosphere
• The formation of IRIS diagnostics II. The formation of the Mg II h&k lines in the solar atmosphere
• Ubiquitous torsional motions in type II spicules
• On the generation of solar spicules and Alfvénic waves
• Quantifying Spicules
• Solar fine-scale structures. I. Spicules and other small-scale, jet-like events at the chromospheric level: observations and physical parameters
• Nonlinear Instability of kink oscillations due to shear motions
• The formation of IRIS diagnostics I. A quintessential model atom of Mg II and general formation properties of the Mg II h&k lines
• An Interface Region Imaging Spectrograph first view on Solar Spicules
• Fine strand-like structure in the solar corona from MHD transverse oscillations
• Resonant Absorption of Transverse Oscillations and Associated Heating in a Solar Prominence. II- Numerical aspects
• Wave Heating of the Solar Atmosphere
• RH 1.5D: a massively parallel code for multi-level radiative transfer with partial frequency redistribution and Zeeman polarisation
• Resonant Absorption of Transverse Oscillations and Associated Heating in a Solar Prominence. I- Observational aspects
• Interplay of three kinds of motion in the disk counterpart of type II spicules: up-flow, transversal and torsional motions
• Three-dimensional Magnetohydrodynamic Simulation of the Formation of Solar Chromospheric Jets with Twisted Magnetic Field Lines
• Heating by transverse waves in simulated coronal loops
• Heating signatures in the disk counterparts of solar spicules in IRIS observations
• Stability of rotating magnetized jets in the solar atmosphere. I. Kelvin-Helmholtz instability
• The Dynamics of Rapid Redshifted and Blueshifted Excursions in the Solar Halpha line
• Generalized phase mixing: Turbulence-like behaviour from unidirectionally propagating MHD waves
• Fast approximation of angle-dependent partial redistribution in moving atmospheres
• The Origin of Type I Spicule Oscillations
• Kelvin-Helmholtz instability in coronal magnetic flux tubes due to azimuthal shear flows
• The effects of resistivity and viscosity on the Kelvin-Helmholtz instability in oscillating coronal loops
• Observations and numerical models of solar coronal heating associated with spicules
• Kelvin-Helmholtz instability in solar chromospheric jets: theory and observation
• What causes the high apparent speeds in chromospheric and transition region spicules on the Sun?
• Energetics of the Kelvin-Helmholtz instability induced by transverse waves in twisted coronal loops
• Large-scale flow generation by inhomogeneous helicity
• Statistical study of network jets observed in the solar transition region: A comparison between coronal holes and quiet sun regions
• The Appearance of Spicules in High Resolution Observations of Ca II H and H-alpha
• The instability and non-existence of multi-stranded loops, when driven by transverse waves
• On the multi-threaded nature of solar spicules
• A Detailed Comparison Between The Observed and Synthesized Properties of a Simulated Type ii Spicule
• Helical motions of fine-structure prominence threads observed by Hinode and IRIS
• High--cadence observations of spicular-type events on the Sun
• Signatures of quiet Sun reconnection events in Ca~{\sc ii}, H$\alpha$ and Fe~{\sc i}
• Kelvin-Helmholtz instability in solar H-alpha surges
• The Possibility of Kelvin-Helmholtz Instability in Solar Spicules
• Effect of magnetic twist on nonlinear transverse kink oscillations

Cited by in corpus (35)

• Coronal heating by MHD waves
• Kink oscillations of coronal loops
• Probing the physics of the solar atmosphere with the Multi-slit Solar Explorer (MUSE): I. Coronal Heating
• Heating effects from driven transverse and Alfvén waves in coronal loops
• Impact of Type II Spicules in the Corona: Simulations and Synthetic Observables
• Amplitudes and energy fluxes of simulated decayless kink oscillations
• Wave heating in gravitationally stratified coronal loops in the presence of resistivity and viscosity
• On Kelvin-Helmholtz and parametric instabilities driven by coronal waves
• High Frequency Waves in Chromospheric Spicules
• Coronal cooling as a result of mixing by the nonlinear Kelvin--Helmholtz instability
• Estimating the energy dissipation {from Kelvin-Helmholtz instability induced} turbulence in oscillating coronal loops}
• Novel data analysis techniques in coronal seismology
• Observations of instability-driven nanojets
• The impact of multi-fluid effects in the solar chromosphere on the ponderomotive force under LTE and NEQ ionization conditions
• The chromosphere underneath a Coronal Bright Point
• Effect of Coronal Loop Structure on Wave Heating by Phase Mixing
• Evidence of multithermal nature of spicular downflows. Impact on solar atmospheric heating
• Small-scale solar jet formation and their associated waves and instabilities
• Investigating the damping rate of phase-mixed Alfven waves
• The dynamic chromosphere: pushing the boundaries of observations and models
• Kink instability of triangular jets in the solar atmosphere
• Simulations of the Biermann battery mechanism in two-fluid partially ionised plasmas
• Implications of spicule activity on coronal loop heating and catastrophic cooling
• Statistical properties of Hα jets in the polar coronal hole and their implications in coronal activities
• Response of the solar atmosphere to flux emergence: With emergence-driven prominence formation
• Evolution of Kelvin-Helmholtz Instability in the Fan-Spine Topology
• Dynamic kink instability and transverse motions of solar spicules
• Solar H-alpha features with hot onsets. IV. Network fibrils
• Solar Atmosphere Radiative Transfer Model Comparison based on 3D MHD simulations
• Damping of coronal oscillations in self-consistent 3D radiative MHD simulations of the solar atmosphere
• Transverse oscillations in 3D along Ca II K bright fibrils in the solar chromosphere
• A new view of the solar interface region from the Interface Region Imaging Spectrograph (IRIS)
• ALMA Observations of Solar Spicules in a Polar Coronal Hole
• Concurrent Kink and Sausage Waves in A Crescent Shaped Structure Over A Limb Prominence
• Magnetic reconnection and the Kelvin-Helmholtz instability in the solar corona