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We extend a two-component model for the evolution of fluctuations in the solar wind plasma so that it is fully three-dimensional (3D) and also coupled self-consistently to the large-scale magnetohydrodynamic (MHD) equations describing the…

Solar and Stellar Astrophysics · Physics 2016-12-14 Tobias Wiengarten , Sean Oughton , Eugene Engelbrecht , Horst Fichtner , Jens Kleimann , Klaus Scherer

Normal-mode coupling is a helioseismic technique that uses measurements of mode eigenfunctions to infer the interior structure of the Sun. This technique has led to insights into the evolution and structure of toroidal flows in the solar…

Solar and Stellar Astrophysics · Physics 2020-08-21 Prasad Subramanian , Shravan Hanasoge

In a previous paper we studied the effect of latitudinal rotation on solar equatorial Rossby modes in the beta-plane approximation. Since then, a rich spectrum of inertial modes has been observed on the Sun, which is not limited to the…

Solar and Stellar Astrophysics · Physics 2022-08-10 Damien Fournier , Laurent Gizon , Laura Hyest

Since the detection of the asymptotic properties of the dipole gravity modes in the Sun, the quest to find the individual gravity modes has continued. A deeper analysis of the GOLF/SoHO data unveils the presence of a pattern of peaks that…

We present a comprehensive set of observations of the interaction of p-mode oscillations with sunspots using surface-focused seismic holography. Maps of travel-time shifts, relative to quiet-Sun travel times, are shown for incoming and…

Astrophysics · Physics 2009-11-13 D. C. Braun , A. C. Birch

It is generally believed that sunspots are the emergent part of magnetic flux tubes in the solar interior. These tubes are created at the base of the convection zone and rise to the surface due to their magnetic buoyancy. The motion of…

Solar and Stellar Astrophysics · Physics 2015-05-14 Franck Plunian , Graeme Sarson , Rodion Stepanov

The Sun is a variable star whose magnetic activity and total irradiance vary on a timescale of approximately 11 years. The current activity minimum has attracted considerable interest because of its unusual duration and depth. This raises…

Solar and Stellar Astrophysics · Physics 2009-07-21 A. -M. Broomhall , W. J. Chaplin , Y. Elsworth , S. T. Fletcher , R. New

Turbulence in the solar wind is characterized by Alfv\'enic fluctuations that exhibit spherical polarization, a geometric condition resulting in the nearly constant magnitude of the magnetic field. This property persists even during the…

Plasma Physics · Physics 2026-05-07 Anna Tenerani , Marco Velli

We analyze helioseismic waves near the solar equator in the presence of magnetic fields deep within the solar radiative zone. We find that reasonable magnetic fields can significantly alter the shapes of the wave profiles for helioseismic…

Astrophysics · Physics 2008-11-26 C. P. Burgess , N. S. Dzhalilov , T. I. Rashba , V. B. Semikoz , J. W. F. Valle

The Birmingham Solar-Oscillations Network (BiSON) has been collecting data for over 30yrs and so observations span nearly three 11yr solar activity cycles. This allows us to address important questions concerning the solar cycle and its…

Astrophysics · Physics 2008-10-21 A. M. Broomhall , W. J. Chaplin , Y. Elsworth , R. New , G. A. Verner

Intermittent magnetohydrodynamical turbulence is most likely at work in the magnetized solar atmosphere. As a result, an array of scaling and multi-scaling image-processing techniques can be used to measure the expected self-organization of…

Astrophysics · Physics 2007-05-23 Manolis K. Georgoulis

The goal of this research is to investigate how well various turbulence models can describe physical properties of the upper convective boundary layer of the Sun. An accurate modeling of the turbulence motions is necessary for understanding…

Astrophysics · Physics 2009-11-13 L. Jacoutot , A. G. Kosovichev , A. Wray , N. N. Mansour

The region of the second ionization of helium in the Sun is a narrow layer near the surface. Ionization induces a local change of the adiabatic exponent $\Gamma_1$, which produces a characteristic signature in the frequencies of p-modes. By…

Astrophysics · Physics 2007-05-23 M. J. P. F. G. Monteiro , M. J. Thompson

The calculus of apsidal precession frequencies of the planets is developed by means of a perturbation thecnique. A model of concentric rings (ring model), suitable for improving calculations, is introduced. Conclusive remarks concerning a…

Classical Physics · Physics 2020-07-16 L. Barbieri , F. Talamucci

Understanding differential rotation of Sun-like stars is of great importance for insight into the angular momentum transport in these stars. One means of gaining such information is that of asteroseismology. By a forward modeling approach…

Solar and Stellar Astrophysics · Physics 2016-02-22 Mikkel N. Lund , Mark S. Miesch , Jørgen Christensen-Dalsgaard

The amplitudes of solar-like oscillations depend on the excitation and damping, both of which are controlled by convection. Comparing observations with theory should therefore improve our understanding of the underlying physics. However,…

Inertial wave modes in the Sun are of interest owing to their potential to reveal new insight into the solar interior. These predominantly retrograde-propagating modes in the solar subsurface appear to deviate from the thin-shell…

Solar and Stellar Astrophysics · Physics 2023-08-25 Jishnu Bhattacharya , Chris S. Hanson , Shravan M. Hanasoge , Katepalli R. Sreenivasan

According to a recent ray-based asymptotic theory, the high-frequency p-mode spectrum of rapidly rotating stars is a superposition of frequency subsets associated with dynamically independent regions of the ray-dynamics phase space. At high…

Solar and Stellar Astrophysics · Physics 2015-05-20 F. Lignieres , B. Georgeot , J. Ballot

In stratified atmospheres, acoustic waves can only propagate if their frequency is above the cutoff value. Different theories provide different cutoff values. We developed an alternative method to derive the cutoff frequency in several…

Solar and Stellar Astrophysics · Physics 2020-07-29 T. Felipe , C. R. Sangeetha

Departures from standard spherically symmetric solar models, in the form of perturbations such as global and local-scale flows and structural asphericities, result in the splitting of eigenfrequencies in the observed spectrum of solar…

Solar and Stellar Astrophysics · Physics 2020-07-03 Srijan Bharati Das , Tuneer Chakraborty , Shravan M. Hanasoge , Jeroen Tromp
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