English
Related papers

Related papers: Spectropolarimetric Fluctuations in a Sunspot Chro…

200 papers

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

We present a model of magnetohydrodynamic (MHD) turbulence in the extended solar corona that contains the effects of collisionless dissipation and anisotropic particle heating. Measurements made by UVCS/SOHO have revived interest in the…

Astrophysics · Physics 2009-11-07 S. R. Cranmer , A. A. van Ballegooijen

We present an examination of the First Ionization Potential (FIP) fractionation scenario invoking the ponderomotive force in the chromosphere, and its implications for the source(s) of slow speed solar winds by using observations from The…

Solar and Stellar Astrophysics · Physics 2020-05-25 Natsuha Kuroda , J. Martin Laming

Magnetohydrodynamic (MHD) waves have been considered as energy sources for heating the solar chromosphere and the corona. Although MHD waves have been observed in the solar atmosphere, there are a lack of quantitative estimates on the…

Solar and Stellar Astrophysics · Physics 2016-11-01 Ryuichi Kanoh , Toshifumi Shimizu , Shinsuke Imada

Alfv\'enic fluctuations of various scales are ubiquitous in the corona; their non-linear interactions and eventual turbulent cascade result in an important heating mechanism that accelerates the solar wind. These fluctuations may be…

Solar and Stellar Astrophysics · Physics 2023-11-08 Chaitanya Prasad Sishtla , Jens Pomoell , Rami Vainio , Emilia Kilpua , Simon Good

We use images of high spatial and temporal resolution, obtained using both ground- and space-based instrumentation, to investigate the role magnetic field inclination angles play in the propagation characteristics of running penumbral waves…

Solar and Stellar Astrophysics · Physics 2015-06-17 D. B. Jess , V. E. Reznikova , T. Van Doorsselaere , P. H. Keys , D. H. Mackay

Waves are thought to play a significant role in the heating of the solar atmosphere and the acceleration of the wind. Among the many types of waves observed in the Sun, the so-called p-modes with a 3 mHz frequency peak dominate the lower…

Since the advent of X-ray and EUV spectroscopy, the discovery of the First Ionization Potential (FIP) effect--where coronal elemental compositions diverge from their photospheric values based on the element's FIP--has remained a key puzzle…

Solar and Stellar Astrophysics · Physics 2025-10-03 Biswajit Mondal , Amy R. Winebarger

The solar atmosphere is known to contain many different types of wavelike oscillation. Waves and other fluctuations (e.g., turbulent eddies) are believed to be responsible for at least some of the energy transport and dissipation that heats…

Solar and Stellar Astrophysics · Physics 2023-08-09 Steven R. Cranmer , Momchil E. Molnar

The composition of the solar corona differs from that of the photosphere, with the plasma thought to fractionate in the solar chromosphere according to the First Ionisation Potential (FIP) of the different elements. This produces a FIP…

Active regions often host large-scale gas flows in the chromosphere presumably directed along curved magnetic field lines. Spectropolarimetric observations of these flows are critical to understanding the nature and evolution of their…

Solar and Stellar Astrophysics · Physics 2011-01-05 Tom Schad , Sarah Jaeggli , Haosheng Lin , Matthew Penn

Within the last decade, due to significant improvements in the spatial and temporal resolution of chromospheric data, magnetohydrodynamic (MHD) wave studies in this fascinating region of the Sun's atmosphere have risen to the forefront of…

Solar and Stellar Astrophysics · Physics 2016-03-09 G. Verth , D. B. Jess

We investigate the spectral shape, the anisotropy of the wave vector distributions and the anisotropy of the amplitudes of the magnetic fluctuations in the Earth's magnetosheath within a broad range of frequencies. We present the first…

Astrophysics · Physics 2015-05-13 Olga Alexandrova , Catherine Lacombe , Andre Mangeney

The importance of the chromosphere in the mass and energy transport within the solar atmosphere is now widely recognised. This review discusses the physics of magnetohydrodynamic (MHD) waves and instabilities in large-scale chromospheric…

We use fluctuating magnetic helicity to investigate the polarisation properties of Alfv\'enic fluctuations at ion-kinetic scales in the solar wind as a function of $\beta_p$, the ratio of proton thermal pressure to magnetic pressure, and…

Space Physics · Physics 2022-04-12 L. D. Woodham , R. T. Wicks , D. Verscharen , J. M. TenBarge , G. G. Howes

Coronal plumes are bright, narrow structures rooted in coronal holes that contribute to the solar wind. Their composition, particularly elemental fractionation as a function of first ionization potential (FIP), provides diagnostics of…

Solar and Stellar Astrophysics · Physics 2026-02-27 Slimane Mzerguat , Miho Janvier , Eric Buchlin , Deborah Baker , Andy S. H. To , David M. Long , Natalia Zambrana Prado

Plage regions are patches of concentrated magnetic field in the Sun's atmosphere where hot coronal loops are rooted. While previous studies have shed light on the properties of plage magnetic fields in the photosphere, there are still…

Solar and Stellar Astrophysics · Physics 2023-08-23 J. M. da Silva Santos , K. Reardon , G. Cauzzi , T. Schad , V. Martinez Pillet , A. Tritschler , F. Wöger , R. Hofmann , J. Stauffer , H. Uitenbroek

In the immediate sunspots' vicinity -- their superpenumbra -- 3-minute line-of-sight (LOS) velocity oscillations dominate in the photosphere and chromosphere. Oscillations of similar periods are also registered in the transition region and…

Solar and Stellar Astrophysics · Physics 2024-09-25 Andrei Chelpanov , Nikolai Kobanov

Sulphur, with a first ionisation potential (FIP) of 10.36 eV, lies at the boundary between low- and high-FIP elements, making it particularly sensitive to fractionation processes in the solar atmosphere. Sulphur exhibits variable behaviour…

Solar and Stellar Astrophysics · Physics 2026-05-26 Dominik Orlovskij , Andy S. H. To , David M. Long

We revisit in more detail a model for element abundance fractionation in the solar chromosphere, that gives rise to the "FIP Effect" in the solar corona and wind. Elements with first ionization potential below about 10 eV, i.e. those that…

Solar and Stellar Astrophysics · Physics 2014-11-18 J. Martin Laming