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Related papers: Spectropolarimetric Fluctuations in a Sunspot Chro…

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The formation of shocks within the solar atmosphere remains one of the few observable signatures of energy dissipation arising from the plethora of magnetohydrodynamic waves generated close to the solar surface. Active region observations…

High-resolution spectropolarimetry has opened new avenues for understanding how chromospheric waves shape coronal plasma composition. All modeling efforts so far highlight wave activity and, in particular, the ponderomotive force associated…

Solar and Stellar Astrophysics · Physics 2026-05-14 M. Murabito , M. Stangalini

Magnetohydrodynamic (MHD) turbulence in the solar wind is observed to show the spectral behavior of classical Kolmogorov fluid turbulence over an inertial subrange and departures from this at short wavelengths, where energy should be…

Space Physics · Physics 2009-11-11 S. D. Bale , P. J. Kellogg , F. S. Mozer , T. S. Horbury , H. Reme

In \citet{Stangalini20} and \citet{Deb20}, magnetic oscillations were detected in the chromosphere of a large sunspot and found to be linked to the coronal locations where a First Ionization Potential (FIP) effect was observed. In an…

Magnetic fluctuations in the solar wind are often observed to maintain constant magnitude of the magnetic field in a manner consistent with spherically-polarized large-amplitude Alfv\'en waves. We investigate the effect of spherical…

Solar and Stellar Astrophysics · Physics 2023-11-17 Corina Dunn , Trevor Bowen , Alfred Mallet , Samuel Badman , Stuart Bale

Magneto-hydrodynamic (MHD) Alfv\'en waves have been a focus of laboratory plasma physics and astrophysics for over half a century. Their unique nature makes them ideal energy transporters, and while the solar atmosphere provides…

Sunspots are intense regions of magnetic flux that are rooted deep below the photosphere. It is well established that sunspots host magnetohydrodynamic waves, with numerous observations showing a connection to the internal acoustic (or…

Solar and Stellar Astrophysics · Physics 2025-01-07 Hemanthi Miriyala , Richard J. Morton , Elena Khomenko , Patrick Antolin , Gert J. J. Botha

Elemental abundances in the solar corona differ from those in the photosphere, with low first ionization potential (FIP) elements being enhanced, a phenomenon known as the FIP effect. This enhancement is attributed to ponderomotive forces…

Solar and Stellar Astrophysics · Physics 2025-04-23 Kyoung-Sun Lee , Jongchul Chae , Hannah Kwak , Kyuhyoun Cho , Kyeore Lee , Juhyung Kang , Eun-Kyung Lim , Donguk Song

In this study, we investigate the spatial distribution of highly varying plasma composition around one of the largest sunspots of solar cycle 24. Observations of the photosphere, chromosphere, and corona are brought together with magnetic…

Solar and Stellar Astrophysics · Physics 2021-01-27 D. Baker , M. Stangalini , G. Valori , D. H. Brooks , A. S. H. To , L. van Driel-Gesztelyi , P. Demoulin , D. Stansby , D. B. Jess , S. Jafarzadeh

Elemental abundance variations in the solar corona, commonly characterised by First Ionisation Potential (FIP) bias, provide crucial diagnostics of chromospheric processes. The ponderomotive force model, which attributes fractionation to…

Solar and Stellar Astrophysics · Physics 2026-04-16 Andy S. H. To , J. Martin Laming , Jeffrey Reep , Adam J. Finley

Sunspots are transient, magnetically intense features that host oscillations linked to magnetohydrodynamic (MHD) waves. These waves may contribute to plasma heating and drive mass flows in the solar wind. Beyond their energetic role, they…

Solar and Stellar Astrophysics · Physics 2026-05-20 Kartika Sangal , A. K. Srivastava , Libo Fu , Ding Yuan , Song Feng , Yuandeng Shen

Solar chromospheric observations of sunspot umbrae offer an exceptional view of magneto-hydrodynamic wave phenomena. In recent years, a wealth of wave signatures related to propagating magneto-acoustic modes have been presented, which…

A model for element abundance fractionation between the solar chromosphere and corona is further developed. The ponderomotive force due to Alfven waves propagating through, or reflecting from the chromosphere in solar conditions generally…

Solar and Stellar Astrophysics · Physics 2015-05-30 J. Martin Laming

We present results derived from the analysis of spectropolarimetric measurements of active region AR12546, which represents one of the largest sunspots to have emerged onto the solar surface over the last $20$ years. The region was observed…

Solar and Stellar Astrophysics · Physics 2018-12-26 M. Stangalini , S. Jafarzadeh , I. Ermolli , R. Erdélyi , D. B. Jess , P. H. Keys , F. Giorgi , M. Murabito , F. Berrilli , D. Del Moro

The effects of acoustic wave absorption, mode conversion and transmission by a sunspot on the helioseismic inferences are widely discussed, but yet accounting for them has proved difficult for lack of a consistent framework within…

Solar and Stellar Astrophysics · Physics 2012-06-26 S. P. Rajaguru

In November 2021, Solar Orbiter started its nominal mission phase. The remote-sensing instruments on board the spacecraft acquired scientific data during three observing windows surrounding the perihelion of the first orbit of this phase.…

We review our state of knowledge of coronal element abundance anomalies in the Sun and stars. We concentrate on the first ionization potential (FIP) effect observed in the solar corona and slow-speed wind, and in the coronae of solar-like…

Solar and Stellar Astrophysics · Physics 2015-09-30 J. Martin Laming

The ponderomotive force is suggested to be the main mechanism to produce the so-called first ionization potential (FIP) effect - the enrichment of low FIP elements observed in the outer solar atmosphere. It is well known that the ionization…

Solar and Stellar Astrophysics · Physics 2023-06-14 Juan Martínez-Sykora , Bart De Pontieu , Viggo H. Hansteen , Paola Testa , Q. M. Wargnier , Mikolaj Szydlarski

Context. Large-amplitude inversions of the solar wind's interplanetary magnetic field have long been documented; however, observations from the Parker Solar Probe (PSP) mission have renewed interest in this phenomenon as such features,…

The fast solar wind shows a wide spectrum of transverse magnetic and velocity field perturbations. These perturbations are strongly correlated in the sense of Alfv\'en waves propagating mostly outward, from the Sun to the interplanetary…

Solar and Stellar Astrophysics · Physics 2023-04-12 Réville Victor , Tenerani Anna , Velli Marco
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