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Related papers: High frequency waves in the solar atmosphere?

200 papers

The measurement of Doppler velocities in spectroscopic solar observations requires a reference for the local frame of rest. The rotational and radial velocities of the Earth and the rotation of the Sun introduce velocity offsets in the…

Solar and Stellar Astrophysics · Physics 2015-05-27 Jaime de la Cruz Rodríguez , Dan Kiselman , Mats Carlsson

Recently, Karoff and Kjeldsen (2008) presented evidence of strong correlation between the energy in the high-frequency part (5.3<\nu<8.3 mHz) of the acoustic spectrum of the Sun and the solar X-ray flux. They have used disk-integrated…

Solar and Stellar Astrophysics · Physics 2015-05-18 Brajesh Kumar , Savita Mathur , R. A. Garcia , P. Venkatakrishnan

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

Context. Solar filament eruptions usually appear to occur in association with the sudden explosive release of magnetic energy accumulated in long-lived arched magnetic structures. It is the released energy that occasionally drives…

Solar and Stellar Astrophysics · Physics 2024-07-01 Denis P. Cabezas , Kiyoshi Ichimoto , Ayumi Asai , Satoru UeNo , Satoshi Morita , Ken-ichi Otsuji , Kazunari Shibata

Spectra of the cellular photospheric flows are determined from full-disk Doppler velocity observations acquired by the Helioseismic and Magnetic Imager (HMI) instrument on the Solar Dynamics Observatory (SDO) spacecraft. Three different…

Solar and Stellar Astrophysics · Physics 2015-10-01 David H. Hathaway , Thibaud Teil , Aimee A. Norton , Irina Kitiashvili

New data was obtained for a frequency band that had not been so well-studied for sea surface probing applications before. During the described 2-weeks sea experiment 1-3 kHz tonal pulses were emitted from a platform, located on the northern…

Atmospheric and Oceanic Physics · Physics 2022-05-31 Alexey V. Ermoshkin , Dmitry A. Kosteev , Alexander A. Ponomarenko , Dmitry D. Razumov , Mikhail B. Salin

We present evidence supporting wave reflection in the lower solar chromosphere based on helioseismic analysis of multi-height Doppler data. This evidence is derived through a wave propagation model that incorporates both upward- and…

Solar and Stellar Astrophysics · Physics 2024-03-29 Varun Chaturmutha , Bernhard Fleck , Stuart Jefferies

Spectral-line displacements away from the wavelengths naively expected from the Doppler shift caused by stellar radial motion may originate as convective shifts (correlated velocity and brightness patterns in the photosphere), as…

Astrophysics · Physics 2007-05-23 D. Dravins , L. Lindegren , H. -G. Ludwig , S. Madsen

Advances in hydrodynamical simulations have provided new insights into the effects of convection on the frequencies of solar oscillations. As more accurate observations become available, this may lead to an improved understanding of the…

Differences between observed and theoretical eigenfrequencies of the Sun have characteristics which identify them as arising predominantly from properties of the oscillations in the vicinity of the solar surface: in the super-adiabatic,…

Pulsar dynamic spectra exhibit high visibility fringes arising from interference between scattered radio waves. These fringes may be random or highly ordered patterns, depending on the nature of the scattering or refraction. Here we…

Astrophysics · Physics 2009-11-10 Mark Walker , Dan Stinebring

This work aims to understand the behavior of non-linear waves in the vicinity of a coronal null point. In previous works we have showed that high frequency waves are generated in such magnetic configuration. This paper studies those waves…

Solar and Stellar Astrophysics · Physics 2017-06-07 I. C. Santamaria , E. Khomenko , M. Collados , A. de Vicente

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

The solar wind in the inner heliosphere has been observed by Parker Solar Probe (PSP) to exhibit abundant wave activities. The cyclotron wave modes in the sense of ions or electrons are among the most crucial wave components. However, their…

Solar and Stellar Astrophysics · Physics 2022-07-27 Jiansen He , Ying Wang , Xingyu Zhu , Die Duan , Daniel Verscharen , Guoqing Zhao

I review the literature on observational aspects of waves in the solar chromosphere in the first part of this contribution. High-frequency waves are invoked to build elaborate cool-star chromosphere heating theories but have not been…

Solar and Stellar Astrophysics · Physics 2015-03-17 R. J. Rutten

Here we present a detailed analysis of solar acoustic mode frequencies and their rotational splittings for modes with degree up to 900. They were obtained by applying spherical harmonic decomposition to full-disk solar images observed by…

Astrophysics · Physics 2008-08-22 M. C. Rabello-Soares , S. G. Korzennik , J. Schou

We search for signatures of high-frequency oscillations in the upper solar photosphere and low chromosphere in the context of acoustic heating of outer stellar atmospheres. We use ultraviolet image sequences of a quiet center-disk area from…

Astrophysics · Physics 2009-06-23 A. G. de Wijn , R. J. Rutten , T. D. Tarbell

Absorbtion of Alfven waves is considered to be the main mechanism of heating in the solar corona. It is concluded that the sharp increase of the plasma temperature by two orders of magnitude is related to a self-induced opacity with respect…

Astrophysics · Physics 2008-11-26 T. M. Mishonov , M. V. Stoev , Y. G. Maneva

Height series of Doppler observation at the solar limb (covering 3800 - 8700 km distance above the photosphere) in $H_{\alpha}$ spectral line obtained by big coronagraph of Abastumani Astrophysical Observatory \citep{khu} show the periodic…

Astrophysics · Physics 2007-05-23 V. Kukhianidze , T. V. Zaqarashvili , E. Khutsishvili

The fast solar wind is a collisionless plasma permeated by plasma waves on many different scales. A plasma wave represents the natural interplay between the periodic changes of the electromagnetic field and the associated coherent motions…

Space Physics · Physics 2011-07-29 Daniel Verscharen , Eckart Marsch