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Related papers: Spectropolarimetric Fluctuations in a Sunspot Chro…

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We present three-dimensional magnetic power spectra in wavevector space to investigate anisotropy and scalings of sub-Alfv\'enic solar wind turbulence at magnetohydrodynamic (MHD) scale using the Magnetospheric Multiscale spacecraft. The…

Solar and Stellar Astrophysics · Physics 2022-11-29 S. Q. Zhao , Huirong Yan , Terry Z. Liu , Mingzhe Liu , Huizi Wang

Sunspots are crucial for exploring how magnetic fields and plasma flows interact in the solar atmosphere, spanning from the stable photosphere to the shock-dominated chromosphere. To determine the thermal, magnetic, and kinematic properties…

Solar and Stellar Astrophysics · Physics 2026-04-29 A. Vicente Arevalo , J. M. Borrero , I. Milic , A. Pastor Yabar , I. Kontogiannis , A. G. M. Pietrow

Parker Solar Probe (PSP) entered a region of the sub-Alfvenic solar wind during encounter 8 and we present the first detailed analysis of low-frequency turbulence properties in this novel region. The magnetic field and flow velocity vectors…

Solar and Stellar Astrophysics · Physics 2022-02-08 G. P. Zank , L. -L. Zhao , L. Adhikri , D. Telloni , J. C. Kasper , M. Stevens , A. Rahmati , S. D. Bale

We find evidence for the first observation of the parametric decay instability (PDI) in the lower solar atmosphere. Specifically, we find that the power spectrum of density fluctuations near the solar transition region resembles the power…

Solar and Stellar Astrophysics · Physics 2022-07-20 Michael Hahn , Xiangrong Fu , Daniel Wolf Savin

Sunspots have played a key role in aiding our understanding of magnetohydrodynamic (MHD) wave phenomenon in the Sun's atmosphere, and it is well known they demonstrate a number of wave phenomenon associated with slow MHD modes. Recent…

Solar and Stellar Astrophysics · Physics 2021-01-20 R. J. Morton , K. Mooroogen , V. M. J. Henriques

Using numerical simulations of the magnetised solar photosphere carried out with the radiative magneto-hydrodynamic code, MURaM, and detailed spectro-polarimetric diagnostics of the simulated photospheric 6302A FeI line,…

Solar and Stellar Astrophysics · Physics 2015-06-19 S. Shelyag , D. Przybylski

The plasma composition of the solar corona is different from that of the solar photosphere. Elements that have a low first ionisation potential (FIP) are preferentially transported to the corona and, therefore, show enhanced abundances in…

The Coronal Multi-channel Polarimeter (CoMP) has previously demonstrated the presence of Doppler velocity fluctuations in the solar corona. The observed fluctuations are thought to be transverse waves, i.e. highly incompressible motions…

Solar and Stellar Astrophysics · Physics 2016-09-21 R. J. Morton , S. Tomczyk , R. F. Pinto

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…

Alfv\'enic fluctuations are very common features in the solar wind and are found especially within the main portion of fast wind streams while the slow wind usually is less Alfv\'enic and more variable. In general, fast and slow wind show…

Space Physics · Physics 2018-12-19 Raffaella D'Amicis , Lorenzo Matteini , Roberto Bruno

This paper reviews the latest observational evidence for the existence of propagating waves in the open magnetic flux tubes of the solar corona. SOHO measurements have put tentative limits on the fluxes of various types of…

Astrophysics · Physics 2007-05-23 Steven R. Cranmer

We report the observations of the magneto-hydrodynamic waves propagating along magnetic flux tubes in the solar photosphere. We identified 20 isolated strong peaks (8 peaks for pores and 12 peaks for inter-granular magnetic structure) in…

Solar and Stellar Astrophysics · Physics 2015-05-13 Daisuke Fujimura , Saku Tsuneta

In this paper we investigate spectral and phase coherence properties of magnetic fluctuations in the vicinity of the spectral transition from large, magnetohydrodynamic (MHD) to sub-ion scales using in-situ measurements of the Wind…

Solar and Stellar Astrophysics · Physics 2016-06-15 Sonny Lion , Olga Alexandrova , Arnaud Zaslavsky

The temperature and density conditions in the magnetized photosphere and chromosphere of the Sun lead to a very small degree of atomic ionization. In addition, at particular height, the magnetic field may be strong enough to give rise to a…

Solar and Stellar Astrophysics · Physics 2015-04-08 Elena Khomenko

How do magnetohydrodynamic waves travel from the fully ionized corona, into and through the underlying partially ionized chromosphere, and what are the consequences for solar flares? To address these questions, we have developed a 2-fluid…

Solar and Stellar Astrophysics · Physics 2013-02-22 Alexander J. B. Russell , Lyndsay Fletcher

The twist of the magnetic field above a sunspot is an important quantity in solar physics. For example, magnetic twist plays a role in the initiation of flares and coronal mass ejections (CMEs). Various proxies for the twist above the…

Solar and Stellar Astrophysics · Physics 2022-08-31 C. Baumgartner , A. C. Birch , H. Schunker , R. H. Cameron , L. Gizon

The First Ionization Potential (FIP) effect is the by now well known enhancement in abundance over photospheric values of Fe and other elements with first ionization potential below about 10 eV observed in the solar corona and slow speed…

Solar and Stellar Astrophysics · Physics 2015-06-04 Cara E. Rakowski , J. Martin Laming

Plasma ions heating (especially minor heavy ions preferential heating) in fast solar wind and solar corona is an open question in space physics. However, Alfv\'en waves have been always considered as a candidate of energy source for corona…

Plasma Physics · Physics 2021-08-17 Peng He

The Parker Solar Probe (PSP) spacecraft is performing the first in situ exploration of the solar wind within 0.2 au of the Sun. Initial observations confirmed the Alfv\'enic nature of aligned fluctuations of the magnetic field B and…

During Parker Solar Probe's first orbit, the solar wind plasma has been observed in situ closer than ever before, the perihelion on November 6th 2018 revealing a flow that is constantly permeated by large amplitude Alfv\'enic fluctuations.…

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