On the plasma flow inside magnetic tornadoes on the Sun

Abstract

High-resolution observations with the Swedish 1-m Solar Telescope (SST) and the Solar Dynamics Observatory (SDO) reveal rotating magnetic field structures that extend from the solar surface into the chromosphere and the corona. These so-called magnetic tornadoes are primarily detected as rings or spirals of rotating plasma in the Ca II 854.2 nm line core (also known as chromospheric swirls). Detailed numerical simulations show that the observed chromospheric plasma motion is caused by the rotation of magnetic field structures, which again are driven by photospheric vortex flows at their footpoints. Under the right conditions, two vortex flow systems are stacked on top of each other. We refer to the lower vortex, which extends from the low photosphere into the convection zone, as intergranular vortex flow (IVF). Once a magnetic field structure is co-located with an IVF, the rotation is mediated into the upper atmospheric layers and an atmospheric vortex flow (AVF, or magnetic tornado) is generated. In contrast to the recent work by Shelyag et al., we demonstrate that particle trajectories in a simulated magnetic tornado indeed follow spirals and argue that the properties of the trajectories decisively depend on the location in the atmosphere and the strength of the magnetic field.

7 pages, 3 figures; Accepted for publication in PASJ

References in corpus (2)

• Convectively driven vortex flows in the Sun
• Numerical simulation of excitation of solar oscillation modes for different turbulent models

Cited by in corpus (15)

• The European Solar Telescope
• Three-dimensional Magnetohydrodynamic Simulation of the Formation of Solar Chromospheric Jets with Twisted Magnetic Field Lines
• A solar coronal loop in a box: Energy generation and heating
• Solar Vortex Tubes: Vortex Dynamics in the Solar Atmosphere
• Reconstruction of a helical prominence in 3D from IRIS spectra and images
• Stirring the Base of the Solar Wind: On Heat Transfer and Vortex Formation
• Magnetic Tornado Properties: A Substantial Contribution to the Solar Coronal Heating via Efficient Energy Transfer
• Unveiling the magnetic nature of chromospheric vortices
• Non-magnetic photospheric bright points in 3D simulations of the solar atmosphere
• Evidence for the two fluid scenario in solar prominences
• New approach for analysing dynamical processes on the surface of photospheric vortex tubes
• Spectro-polarimetric simulations of the solar limb: absorption-emission FeI $6301.5\mathring{\mathrm{A}}$ and $6302.5\mathring{\mathrm{A}}$ line profiles and torsional flows in the intergranular magnetic flux concentrations
• The non-ideal finite Larmor radius effect in the solar atmosphere
• A persistent quiet-Sun small-scale tornado. II. Oscillations
• Spectral Characteristics of a Rotating Solar Prominence in Multiple Wavelengths