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Related papers: Magnetohydrodynamic Non-linearities in Sunspot Atm…

200 papers

We present numerical simulations of reduced magnetohydrodynamic (RMHD) turbulence in a magnetic flux tube at the center of a polar coronal hole. The model for the background atmosphere is a solution of the momentum equation, and includes…

Solar and Stellar Astrophysics · Physics 2016-04-27 A. A. van Ballegooijen , M. Asgari-Targhi

Physical processes which may lead to solar chromospheric heating are analyzed using high-resolution 1.5D non-ideal MHD modelling. We demonstrate that it is possible to heat the chromospheric plasma by direct resistive dissipation of…

Solar and Stellar Astrophysics · Physics 2016-02-03 T. D. Arber , C. S. Brady , S. Shelyag

The solar corona has been revealed in the past decade to be a highly dynamic nonequilibrium plasma environment. Both the loop-filled coronal base and the extended acceleration region of the solar wind appear to be strongly turbulent, but…

Astrophysics · Physics 2008-11-26 Steven R. Cranmer

Parker Solar Probe and Solar Orbiter data are used to investigate the radial evolution of magnetic turbulence between $0.06 ~ \lesssim R ~\lesssim 1$ au. The spectrum is studied as a function of scale, normalized to the ion inertial scale…

Within the coronae of stars, abundances of those elements with low first ionization potential (FIP) often differ from their photospheric values. The coronae of the Sun and solar-type stars mostly show enhancements of low-FIP elements (the…

Context. We address the heating of the solar chromosphere and the related generation of plasma inflows and outflows. Aims. We attempt to detect variations in ion temperature and vertical plasma flows, which are driven by impulsively excited…

Solar and Stellar Astrophysics · Physics 2021-07-27 M. Pelekhata , K. Murawski , S. Poedts

The observation of propagating magneto-hydrodynamic kink waves in magnetic structures and measurement of their properties (amplitude, phase speed) can be used to diagnose the plasma conditions in the neighbourhood of the magnetic structure…

Solar and Stellar Astrophysics · Physics 2016-08-03 R J Morton

We investigate possible links between the large-scale and small-scale features of solar wind fluctuations across the frequency break separating fluid and kinetic regimes. The aim is to correlate the magnetic field fluctuations polarization…

Space Physics · Physics 2017-01-26 D. Telloni , R. Bruno

The overshooting convective motions in the solar photosphere are frequently proposed as the source for the excitation of Alfv\'en waves. However, the photosphere is a) very weakly ionized, and, b) the dynamics of the plasma particles in…

Astrophysics · Physics 2009-11-13 J. Vranjes , S. Poedts , B. P. Pandey , B. De Pontieu

Recent high-resolution observations of sunspot oscillations using simultaneously operated ground- and space-based telescopes reveal the intrinsic connection between different layers of the solar atmosphere. However, it is not clear whether…

Solar and Stellar Astrophysics · Physics 2015-10-13 S. Krishna Prasad , D. B. Jess , Elena Khomenko

Poynting flux generated by random shuffling of photospheric magnetic footpoints is transferred through the upper atmosphere of the Sun where the plasma is heated to over 1 MK in the corona. High spatiotemporal resolution observations of the…

Solar and Stellar Astrophysics · Physics 2024-11-20 L. P. Chitta , M. van Noort , H. N. Smitha , E. R. Priest , L. H. M. Rouppe van der Voort

It is well-known that light bridges inside a sunspot produce small-scale plasma ejections and transient brightenings in the chromosphere, but the nature and origin of such phenomena are still unclear. Utilizing the high-spatial and high…

Solar and Stellar Astrophysics · Physics 2017-02-08 Donguk Song , Jongchul Chae , Vasyl Yurchyshyn , Eun-Kyung Lim , Kyung-Suk Cho , Heesu Yang , Kyuhyoun Cho , Hannah Kwak

We analyze the propagation of waves in sunspots from the photosphere to the chromosphere using time series of co-spatial Ca II H intensity spectra (including its line blends) and polarimetric spectra of Si I 10827 and the He I 10830…

Solar and Stellar Astrophysics · Physics 2015-05-19 T. Felipe , E. Khomenko , M. Collados , C. Beck

Certain solar flares exhibit a distinctive candle-flame or cusp-shaped feature above the bright flare arcade visible in extreme ultraviolet (EUV) and X-ray channels sensitive to high-temperature plasma. The presence of a cusp-like structure…

Solar and Stellar Astrophysics · Physics 2026-05-19 Ivan Oparin , Sabastian Fernandes , Bin Chen , Chengcai Shen , Xiaocan Li , Fan Guo , Sijie Yu

We examine spectropolarimetric data from the CoMP instrument, acquired during the evolution of the September 10th 2017 X8.2 solar flare on the western solar limb. CoMP captured linearly polarized light from two emission lines of Fe XIII at…

Solar and Stellar Astrophysics · Physics 2019-12-25 Ryan J. French , Philip G. Judge , Sarah A. Matthews , Lidia van Driel-Gesztelyi

The presence of the magnetic field is critical to transport energy through the solar atmosphere. The new generation of telescopes will provide new insight into how the magnetic field arrives into the chromosphere and its role in the energy…

Solar and Stellar Astrophysics · Physics 2022-11-17 Juan Martínez-Sykora , Alberto Sainz Dalda , Milan Gošić , Bart De Pontieu

Alfv\'en vortex is a multi-scale nonlinear structure which contributes to intermittency of turbulence. Despite previous explorations mostly on the spatial properties of the Alfv\'en vortex (i.e., scale, orientation, and motion), the plasma…

Collisionless shocks, that is shocks mediated by electromagnetic processes, are customary in space physics and in astrophysics. They are to be found in a great variety of objects and environments: magnetospheric and heliospheric shocks,…

We analyze a set of full Stokes profile observations of the flaring active region NOAA 10808 recorded with the Vector-Spectromagnetograph (VSM) of the SOLIS facility. We aim to quantify transient and permanent changes in the magnetic field…

Solar and Stellar Astrophysics · Physics 2015-06-11 C. E. Fischer , C. U. Keller , F. Snik , L. Fletcher , H. Socas-Navarro

Recent near-sun solar-wind observations from Parker Solar Probe have found a highly dynamic magnetic environment, permeated by abrupt radial-field reversals, or "switchbacks." We show that many features of the observed turbulence are…

Space Physics · Physics 2020-03-04 Jonathan Squire , Benjamin D. G. Chandran , Romain Meyrand