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Related papers: Rapid Fluctuations in the Lower Solar Atmosphere

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The frequencies of the solar acoustic oscillations vary over the activity cycle. The variations in other activity proxies are found to be well correlated with the variations in the acoustic frequencies. However, each proxy has a slightly…

Solar and Stellar Astrophysics · Physics 2016-12-07 A. R. G. Santos , M. S. Cunha , P. P. Avelino , W. J. Chaplin , T. L. Campante

We present an investigation of line-of-sight (LOS) velocity oscillations in solar faculae and sunspots. To study the phase relations between chromosphere and photosphere oscillations of the LOS velocity, we measured the time lag of the…

Solar and Stellar Astrophysics · Physics 2014-11-25 Nikolai Kobanov , Dmitri Kolobov , Arseniy Kustov , Sergey Chupin , Andrey Chelpanov

The interplanetary magnetic fluctuation spectrum obeys a Kolmogorovian power law at scales above the proton inertial length and gyroradius which is well regarded as an inertial range. Below these scales a power law index around $-2.5$ is…

Solar and Stellar Astrophysics · Physics 2015-05-19 R. Meyrand , S. Galtier

Radial velocity fluctuations on the plane of the sky are a powerful tool for studying the turbulent dynamics of emission line regions. We conduct a systematic statistical analysis of the H alpha velocity field for a diverse sample of 9 H II…

Astrophysics of Galaxies · Physics 2023-06-14 J. García-Vázquez , William J. Henney , H. O. Castañeda

Using long-duration observations in the He II 304 Angstrom passband of the Solar and Heliospheric Observatory (SOHO) Extreme-ultraviolet Imaging Telescope (EIT) we investigate the spatial and temporal appearance of impulsive intensity…

Astrophysics · Physics 2009-01-19 Scott W. McIntosh

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

The nature of solar wind turbulence in the dissipation range at scales much smaller than the large MHD scales remains under debate. Here a two-dimensional model based on the hybrid code abbreviated as A.I.K.E.F. is presented, which treats…

Space Physics · Physics 2012-02-20 Daniel Verscharen , Eckart Marsch , Uwe Motschmann , Joachim Müller

In the solar convection zone acoustic waves are scattered by turbulent sound speed fluctuations. In this paper the scattering of waves by convective cells is treated using Rytov's technique. Particular care is taken to include diffraction…

Astrophysics · Physics 2009-10-31 M. Brüggen

The EIT waves [named after the Extreme-ultraviolet Imaging Telescope (EIT) onboard the Solar and Heliospheric Observatory (SOHO)] are in the literature usually described as fast magneto-acoustic (FMA) modes. However, observations show that…

Solar and Stellar Astrophysics · Physics 2015-05-28 J. Vranjes

The solar photosphere provides us with a laboratory for understanding turbulence in a layer where the fundamental processes of transport vary rapidly and a strongly superadiabatic region lies very closely to a subadiabatic layer. Our tools…

Solar radio bursts exhibit complex fine structures that reveal intricate coronal plasma dynamics. Here, we report detection of spike-like repeating burst pairs, characterized by two short-lived (0.1-2 s), narrowband components separated by…

Solar and Stellar Astrophysics · Physics 2026-05-28 Suli Ma , Eduard P. Kontar , Daniel L. Clarkson , Huadong Chen , Yihua Yan

This work reports a novel plasma wave observation in the near-Sun solar wind: frequency-dispersed ion acoustic waves. Similar waves were previously reported in association with interplanetary shocks or planetary bow shocks, but the waves…

Solar and Stellar Astrophysics · Physics 2024-04-24 David M. Malaspina , Robert E. Ergun , Iver H. Cairns , Benjamin Short , Jaye L. Verniero , Cynthia Cattell , Roberto Livi

We analyze and interpret SOHO/MDI data on oscillation frequency changes between 1996 and 2004 focusing on differences between activity minimum and maximum of solar cycle 23. We study only the behavior of the centroid frequencies, which…

Astrophysics · Physics 2009-11-10 W. A. Dziembowski , P. R. Goode

Observational detection of quasi-periodic drifting fine structures in a type III radio burst associated with a solar flare SOL2015-04-16T11:22, with Low Frequency Array, is presented. Although similar modulations of the type III emission…

Solar and Stellar Astrophysics · Physics 2018-07-11 Dmitrii Y. Kolotkov , Valery M. Nakariakov , Eduard P. Kontar

In this work, we studied oscillation parameters in faculae above magnetic knots and in the adjacent to them areas. Using SDO data we analysed oscillations in magnetic strength, Doppler velocity, and intensity signals for the lower…

Solar and Stellar Astrophysics · Physics 2016-08-17 Andrei A. Chelpanov , Nikolai I. Kobanov , Dmitry Y. Kolobov

The power from wind and solar exhibits a nonlinear flickering variability, which typically occurs at time scales of a few seconds. We show that high-frequency monitoring of such renewable powers enables us to detect a transition, controlled…

Physics and Society · Physics 2016-10-17 M. Anvari , G. Lohmann , M. Reza Rahimi Tabar , M. Wächter , P. Milan , D. Heinemann , Joachim Peinke , E. Lorenz

The temporal variations of the rotation rate in the solar interior are studied using frequency splittings from Global Oscillations Network Group (GONG) data obtained during the period 1995-99. We find alternating latitudinal bands of faster…

Astrophysics · Physics 2009-10-31 H. M. Antia , Sarbani Basu

We report and discuss phase-shift and phase travel time of low-frequency ({\nu} < 5.0 mHz) acoustic waves estimated within the photosphere and photosphere-chromosphere interface regions, utilizing multi-height velocities in the quiet Sun.…

Solar and Stellar Astrophysics · Physics 2024-07-01 Hirdesh Kumar , Brajesh Kumar , Shibu K. Mathew , A. Raja Bayanna , S. P. Rajaguru

Solar radio type III bursts are believed to be the most sensitive signature of near-relativistic electron beam propagation in the corona. A solar radio type IIIb-III pair burst with fine frequency structures, observed by the Low Frequency…

Solar and Stellar Astrophysics · Physics 2018-04-11 Xingyao Chen , Eduard P. Kontar , Sijie Yu , Yihua Yan , Jing Huang , Baolin Tan

Below the acoustic cut-off frequency, oscillations are trapped within the solar interior and become resonant. However, signatures of oscillations persist above the acoustic cut-off frequency, and these travelling waves are known as…

Solar and Stellar Astrophysics · Physics 2022-03-30 K. Kosak , R. Kiefer , A. M. Broomhall
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