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The chromosphere is a thin layer of the solar atmosphere that bridges the relatively cool photosphere and the intensely heated transition region and corona. Compressible and incompressible waves propagating through the chromosphere can…

Solar and Stellar Astrophysics · Physics 2015-03-12 D. B. Jess , R. J. Morton , G. Verth , V. Fedun , S. D. T. Grant , I. Giagkiozis

Acoustic waves are one of the primary suspects besides magnetic fields for the chromospheric heating process to temperatures above radiative equilibrium (RE). We derived the mechanical wave energy as seen in line-core velocities to obtain a…

Solar and Stellar Astrophysics · Physics 2015-05-13 C. Beck , E. Khomenko , R. Rezaei , M. Collados

It is well-known that the global acoustic oscillations of the Sun's atmosphere can excite resonance modes within large-scale magnetic concentrations. These structures are conduits of energy between the different layers of the solar…

Solar and Stellar Astrophysics · Physics 2025-05-14 M. Berretti , M. Stangalini , G. Verth , V. Fedun , S. Jafarzadeh , D. B. Jess , F. Berrilli

High frequency acoustic waves have been suggested as a source of mechanical heating in the chromosphere. In this work the radial component of waves in the frequency interval 22mHz to 1mHz are investigated. Observations were performed using…

Astrophysics · Physics 2008-11-07 Aleksandra Andic

We recently presented evidences (Rajaguru et al. 2012) that seismic halos around expanding magnetic structures in the lower solar atmosphere are related to the acoustic to magnetoacoustic wave conversions, using multi-height data from…

Solar and Stellar Astrophysics · Physics 2013-08-28 S. P. Rajaguru , Xudong Sun , K. Hayashi , S. Couvidat

Small-scale magnetic field concentrations (magnetic elements) in the quiet Sun are believed to contribute to the energy budget of the upper layers of the Sun's atmosphere, as they are observed to support a large number of MHD modes. In…

Solar and Stellar Astrophysics · Physics 2015-04-29 M. Stangalini , F. Giannattasio , S. Jafarzadeh

Gravity waves are generated by turbulent subsurface convection overshooting or penetrating locally into a stably stratified medium. While propagating energy upwards, their characteristic negative phase shift over height is a well-recognized…

Solar and Stellar Astrophysics · Physics 2023-07-26 Hirdesh Kumar , Brajesh Kumar , S. P. Rajaguru

High-resolution images of the solar surface show a granulation pattern of hot rising and cooler downward-sinking material -- the top of the deep-reaching solar convection zone. Convection plays a role for the thermal structure of the solar…

Solar and Stellar Astrophysics · Physics 2011-12-14 Bernd Freytag , Matthias Steffen , Hans-Günter Ludwig , Sven Wedemeyer-Böhm , Werner Schaffenberger , Oskar Steiner

We study vertical variations of wave-periods of magnetoacoustic two-fluid waves in the partially ionized lower solar atmosphere, consisting of ion (proton) + electron and neutral (atomic hydrogen) fluids, which are coupled by ion-neutral…

Solar and Stellar Astrophysics · Physics 2022-11-30 J. Kraśkiewicz , K. Murawski , Z. E. Musielak

We use the exact solutions for magnetoacoustic waves in a two dimensional isothermal atmosphere with uniform inclined magnetic field to calculate the wave reflection, transmission, and conversion of slow and fast waves incident from above…

Solar and Stellar Astrophysics · Physics 2016-01-27 Shelley Hansen , Paul Cally , Alina Donea

We characterize waves in small magnetic elements and investigate their propagation in the lower solar atmosphere from observations at high spatial and temporal resolution. We use the wavelet transform to analyze oscillations of both…

Solar and Stellar Astrophysics · Physics 2017-03-31 Shahin Jafarzadeh , S. K. Solanki , M. Stangalini , O. Steiner , R. H. Cameron , S. Danilovic

We present high-cadence observations and simulations of the solar photosphere, obtained using the Rapid Oscillations in the Solar Atmosphere imaging system and the MuRAM magneto-hydrodynamic code, respectively. Each dataset demonstrates a…

Solar and Stellar Astrophysics · Physics 2015-06-03 D. B. Jess , S. Shelyag , M. Mathioudakis , P. H. Keys , D. J. Christian , F. P. Keenan

Helioseismic and magnetohydrodynamic waves are abundant in and above sunspots. Through cross-correlating oscillation signals in the photosphere observed by the SDO/HMI, we reconstruct how waves propagate away from virtual wave sources…

Solar and Stellar Astrophysics · Physics 2015-08-19 Junwei Zhao , Ruizhu Chen , Thomas Hartlep , Alexander G. Kosovichev

Improving methods for determining the subsurface structure of sunspots from their seismic signature requires a better understanding of the interaction of waves with magnetic field concentrations. We aim to quantify the impact of changes in…

Solar and Stellar Astrophysics · Physics 2017-08-30 T. Felipe , D. C. Braun , A. C. Birch

From the analysis of Dopplergrams in the K I 7699 A and Na I 5890 A spectral lines observed with the Magneto-Optical filter at Two Heights (MOTH) experiment during the austral summer in 2002-03 we find upward traveling waves in magnetic…

Solar and Stellar Astrophysics · Physics 2010-01-29 M. Haberreiter , W. Finsterle , S. McIntosh , S. Wedemeyer-Boehm

Oscillations in sunspot umbrae exhibit remarkable differences between the photosphere and chromosphere. We evaluate two competing scenarios proposed for explaining those observations: a chromospheric resonant cavity and waves traveling from…

Solar and Stellar Astrophysics · Physics 2020-08-26 T. Felipe , C. Kuckein , S. J. González Manrique , I. Milic , C. R. Sangeetha

The propagation and dissipation of magnetohydrodynamic waves play a key role in transporting energy from the solar photosphere to the chromosphere. Using high-resolution three-dimensional radiative MHD simulations, we investigate the…

Solar and Stellar Astrophysics · Physics 2026-05-21 Nitin Yadav , Apanba Khuman

The propagation of solar waves through the sunspot of AR 9787 is observed using temporal cross-correlations of SOHO/MDI Dopplergrams. We then use three-dimensional MHD numerical simulations to compute the propagation of wave packets through…

Astrophysics · Physics 2009-11-13 R. Cameron , L. Gizon , T. L. Duvall

The chromosphere of the quiet Sun is a highly intermittent and dynamic phenomenon. Three-dimensional radiation (magneto-)hydrodynamic simulations exhibit a mesh-like pattern of hot shock fronts and cool expanding post-shock regions in the…

Astrophysics · Physics 2009-11-13 Sven Wedemeyer-Böhm , Friedrich Wöger

We report 2D time-dependent non-linear magneto-hydrodynamical simulations of waves in the atmospheres of roAp stars. We explore a grid of simulations in a wide parameter space. The aim of our study is to understand the influence of the…

Solar and Stellar Astrophysics · Physics 2009-11-13 E. Khomenko , O. Kochukhov