Quiet Sun magnetic fields: an observational view

Rubio, L. R. Bellot; Suárez, D. Orozco

doi:10.1007/s41116-018-0017-1

Cited by 124 publications

(77 citation statements)

References 339 publications

(545 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Active regions refer to areas of strong kilogauss magnetic fields composed of sunspots, pores and plages. In addition, we also recognise the so-called quiet Sun regions which are composed of network (NE) and internetwork (IN) areas (Bellot Rubio & Orozco Suárez 2019). Photospheric NE outlines the supergranular cell boundaries, whereas the IN represents the interior of supergranular cells.…”

Section: Introductionmentioning

confidence: 99%

Supergranular turbulence in the quiet Sun: Lagrangian coherent structures

Chian

Silva²,

Rempel

et al. 2019

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

ABSTRACT The quiet Sun exhibits a wealth of magnetic activities that are fundamental for our understanding of solar magnetism. The magnetic fields in the quiet Sun are observed to evolve coherently, interacting with each other to form prominent structures as they are advected by photospheric flows. The aim of this paper is to study supergranular turbulence by detecting Lagrangian coherent structures (LCS) based on the horizontal velocity fields derived from Hinode intensity images at disc centre of the quiet Sun on 2010 November 2. LCS act as transport barriers and are responsible for attracting/repelling the fluid elements and swirling motions in a finite time. Repelling/attracting LCS are found by computing the forward/backward finite-time Lyapunov exponent (FTLE), and vortices are found by the Lagrangian-averaged vorticity deviation method. We show that the Lagrangian centres and boundaries of supergranular cells are given by the local maximum of the forward and backward FTLE, respectively. The attracting LCS expose the location of the sinks of photospheric flows at supergranular junctions, whereas the repelling LCS interconnect the Lagrangian centres of neighbouring supergranular cells. Lagrangian transport barriers are found within a supergranular cell and from one cell to other cells, which play a key role in the dynamics of internetwork and network magnetic elements. Such barriers favour the formation of vortices in supergranular junctions. In particular, we show that the magnetic field distribution in the quiet Sun is determined by the combined action of attracting/repelling LCS and vortices.

show abstract

Section: Introductionmentioning

confidence: 99%

Supergranular turbulence in the quiet Sun: Lagrangian coherent structures

Chian

Silva²,

Rempel

et al. 2019

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

show abstract

“…The MANCHA3D [17][18][19] model used here is from a local dynamo simulation with a mean magnetic field in the range of typical quiet Sun values [30,31]: B z = 0 G, |B z | ≈ 67 G, |B| ≈ 110 G and B RMS ≈ 140 G at z = 0 km. While these fields should not have a significant influence on the dynamics, the wave speeds may be modified slightly and there might be additional dissipation.…”

Section: (C) Mancha3dmentioning

confidence: 99%

Acoustic-gravity wave propagation characteristics in three-dimensional radiation hydrodynamic simulations of the solar atmosphere

Fleck¹,

Carlsson

Khomenko

et al. 2020

Phil. Trans. R. Soc. A.

View full text Add to dashboard Cite

There has been tremendous progress in the degree of realism of three-dimensional radiation magneto-hydrodynamic simulations of the solar atmosphere in the past decades. Four of the most frequently used numerical codes are Bifrost, CO5BOLD, MANCHA3D and MURaM. Here we test and compare the wave propagation characteristics in model runs from these four codes by measuring the dispersion relation of acoustic-gravity waves at various heights. We find considerable differences between the various models. The height dependence of wave power, in particular of high-frequency waves, varies by up to two orders of magnitude between the models, and the phase difference spectra of several models show unexpected features, including ±180° phase jumps. This article is part of the Theo Murphy meeting issue ‘High-resolution wave dynamics in the lower solar atmosphere’.

show abstract

“…Small-scale magnetic fields are ubiquitous in such quiet regions (recent review by Bellot Rubio & Orozco Suárez 2019). Such magnetic fields are the energy source of coronal heating and solar wind acceleration (see Cranmer & Winebarger 2019 and references therein).…”

Section: Introductionmentioning

confidence: 99%

Study of the Dynamics of Convective Turbulence in the Solar Granulation by Spectral Line Broadening and Asymmetry

Ishikawa

Katsukawa

Oba

et al. 2020

ApJ

View full text Add to dashboard Cite

In the quiet regions on the solar surface, turbulent convective motions of granulation play an important role in creating small-scale magnetic structures, as well as in energy injection into the upper atmosphere. The turbulent nature of granulation can be studied using spectral line profiles, especially line broadening, which contains information on the flow field smaller than the spatial resolution of an instrument. Moreover, the Doppler velocity gradient along a line-of-sight (LOS) causes line broadening as well. However, the quantitative relationship between velocity gradient and line broadening has not been understood well. In this study, we perform bisector analyses using the spectral profiles obtained using the Spectro-Polarimeter of the Hinode/Solar Optical Telescope to investigate the relationship of line broadening and bisector velocities with the granulation flows. The results indicate that line broadening has a positive correlation with the Doppler velocity gradients along the LOS. We found excessive line broadening in fading granules, that cannot be explained only by the LOS velocity gradient, although the velocity gradient is enhanced in the process of fading. If this excessive line broadening is attributed to small-scale turbulent motions, the averaged turbulent velocity is obtained as 0.9 km/s.

show abstract

Quiet Sun magnetic fields: an observational view

Cited by 124 publications

References 339 publications

Supergranular turbulence in the quiet Sun: Lagrangian coherent structures

Supergranular turbulence in the quiet Sun: Lagrangian coherent structures

Acoustic-gravity wave propagation characteristics in three-dimensional radiation hydrodynamic simulations of the solar atmosphere

Study of the Dynamics of Convective Turbulence in the Solar Granulation by Spectral Line Broadening and Asymmetry

Contact Info

Product

Resources

About