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Related papers: Are Solar Acoustic Modes Correlated ?

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We present the identification of very low frequency g modes in the asymptotic regime and two important parameters that have long been waited for: the core rotation rate, and the asymptotic equidistant period spacing of these g modes. The…

Observations in the solar wind suggest that the compressive component of inertial-range solar-wind turbulence is dominated by slow modes. The low collisionality of the solar wind allows for non-thermal features to survive, which suggests…

Space Physics · Physics 2017-05-19 Daniel Verscharen , Christopher H. K. Chen , Robert T. Wicks

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 model the stochastic excitation of acoustic modes in solar-like pulsators taking into account the action of differential rotation. We derive the theoretical formalism for the stochastic excitation with differential rotation and make use…

Solar and Stellar Astrophysics · Physics 2024-10-31 Gabriel Biscarrat , Leïla Bessila , Stéphane Mathis

Activity-related variations in the solar oscillation properties have been known for 30 years. However, the relative importance of the different contributions to the observed variations is not yet fully understood. Our goal is to estimate…

Solar and Stellar Astrophysics · Physics 2016-10-24 A. R. G. Santos , M. S. Cunha , P. P. Avelino , W. J. Chaplin , T. L. Campante

The activity-related variations in the solar acoustic frequencies have been known for 30 years. However, the importance of the different contributions is still not well established. With this in mind, we developed an empirical model to…

Solar and Stellar Astrophysics · Physics 2017-11-08 A. R. G. Santos , M. S. Cunha , P. P. Avelino , W. J. Chaplin , T. L. Campante

The inherent stochastic and nonlinear nature of the solar dynamo makes the strength of the solar cycles vary in a wide range, making it difficult to predict the strength of an upcoming solar cycle. Recently, our work has shown that by using…

Solar and Stellar Astrophysics · Physics 2024-12-25 Akash Biswas

Wind farms can be regarded as complex systems that are, on the one hand, coupled to the nonlinear, stochastic characteristics of weather and, on the other hand, strongly influenced by supervisory control mechanisms. One crucial problem in…

Applications · Statistics 2021-01-22 Tobias Braun , Matthias Waechter , Joachim Peinke , Thomas Guhr

In this paper, we aim to develop a predictive model for solar radial $p$-mode line profiles in the velocity spectrum. Unlike the approach favoured by prior studies, this model is not described by free parameters and we do not use fitting…

Solar and Stellar Astrophysics · Physics 2020-03-18 J. Philidet , K. Belkacem , R. Samadi , C. Barban , H. -G. Ludwig

The observed solar p-mode velocity power spectra are compared with theoretically calculated power spectra over a range of mode degree and frequency. The shape of the theoretical power spectra depends on the depth of acoustic sources…

Astrophysics · Physics 2009-10-30 Pawan Kumar , Sarbani Basu

Analyses of a 3D simulation of the upper layers of a solar convective envelope provide constraints on the physical quantities which enter the theoretical formulation of a stochastic excitation model of solar p modes, for instance the…

Astrophysics · Physics 2009-11-07 R. Samadi , A. Nordlund , R. F. Stein , M. J. Goupil , I. Roxburgh

The observed frequency shifts of the high-degree solar fundamental mode are explained using a simple geometrical optics approximation. The predicted fractional frequency shift is proportional to the mean squared velocity of the convection…

Astrophysics · Physics 2007-05-23 Andrei Gruzinov

We use reanalysis data to investigate the daily co-variability of wind and solar irradiance in Britain, and its implications for renewable energy supply balancing. The joint distribution of daily-mean wind speeds and irradiances shows that…

Atmospheric and Oceanic Physics · Physics 2015-10-20 Philip E. Bett , Hazel E. Thornton

The characteristic of the solar acoustic spectrum is such that mode lifetimes get shorter and spatial leaks get closer in frequency as the degree of a mode increases for a given order. A direct consequence of this property is that…

Astrophysics · Physics 2009-11-07 S. G. Korzennik , M. C. Rabello-Soares , J. Schou

The acoustic cut-off frequency -the highest frequency for acoustic solar eigenmodes- is an important parameter of the solar atmosphere as it determines the upper boundary of the p-mode resonant cavities. At frequencies beyond this value,…

Solar and Stellar Astrophysics · Physics 2015-05-30 A. Jimenez , R. A. Garcia , P. L. Palle

The dynamics of the solar radiative interior are still poorly constrained by comparison to the convective zone. This disparity is even more marked when we attempt to derive meaningful temporal variations. Many data sets contain a small…

Solar and Stellar Astrophysics · Physics 2015-06-05 Antonio Eff-Darwich , Sylain G. Korzennik

Several attempts have been made to observe whether solar flares excite acoustic modes since Charles Wolff suggested this possibility almost fifty years ago. We look for the impact of flares on the amplitude of solar acoustic modes and other…

Solar and Stellar Astrophysics · Physics 2021-05-25 M. Cristina Rabello Soares , Frédéric Baudin , Vanessa G. Teixeira

The correlation scale and the Taylor scale are evaluated for interplanetary magnetic field fluctuations from two-point, single time correlation function using the Advanced Composition Explorer (ACE), Wind, and Cluster spacecraft data during…

Space Physics · Physics 2020-08-20 G. Zhou , H. -Q. He , W. Wan

The solar rotation profile is well constrained down to about 0.25 R thanks to the study of acoustic modes. Since the radius of the inner turning point of a resonant acoustic mode is inversely proportional to the ratio of its frequency to…

Astrophysics · Physics 2008-04-01 R. A. Garcia , S. Mathur , J. Ballot , A. Eff-Darwich , S. J. Jimenez-Reyes , S. G. Korzennik

We establish that global solar p-mode frequencies can be measured with sufficient precision on time scales as short as nine days to detect activity-related shifts. Using ten years of GONG data, we report that mode-mass and error-weighted…

Astrophysics · Physics 2009-02-10 S. C. Tripathy , F. Hill , K. Jain , J. W. Leibacher