Related papers: Calculation of Solar P-mode Oscillation Frequency …
The principal aim of observational helioseismology is to determine mode parameters of the solar oscillations as accurately as possible. Yet estimates of the mode parameters are subject to many sources of noise, including inevitable gaps in…
We study the variation of the frequency splitting coefficients describing the solar asphericity in both GONG and MDI data, and use these data to investigate temporal sound-speed variations as a function of both depth and latitude during the…
At high frequencies beyond the acoustic cut-off, a peak-like structure is visible in the solar power spectrum. Known as the pseudo-modes, their frequencies have been shown to vary in anti-phase with solar magnetic activity. In this work, we…
High quality observations of the low-degree acoustic modes (p-modes) exist for almost two complete solar cycles using the solar spectrophotometer Mark-I, located at the Observatorio del Teide (Tenerife, Spain) and operating now as part of…
The solar-cyle variation of acoustic mode frequencies has a frequency dependence related to the inverse mode inertia. The discrepancy between model predictions and measured oscillation frequencies for solar and solar-type stellar acoustic…
We investigate spatio-temporal evolution of high-degree acoustic mode frequencies of the Sun and the surface magnetic activity, over the course of multiple solar cycles, to improve our understanding of the connection between the solar…
Perturbation theory is used to calculate the frequency shift of acoustic modes of an homogeneous turbulent fluid and the frequency shifts of solar modes due to turbulent convection. For sound waves in a random flow, the fractional frequency…
Acoustic power and oscillation amplitudes of radial oscillations computed for a solar model are compared with solar seismic observations. The oscillations are assumed stochastically excited by turbulence. The numerical computations are…
Using the recently obtained GONG frequencies, we investigate the properties of the solar interior by constructing solar models with various input physics like opacities, equation of state, nuclear reaction rates etc. The differential…
We present a correlation analysis of GONG p-mode frequencies with nine solar activity indices for the period 1995 August to 1997 August. This study includes spherical harmonic degree in the range 2 to 150 and the frequency range of…
We calculate non-axisymmetric oscillations of uniformly rotating polytropes magnetized with a purely toroidal magnetic field, taking account of the effects of the deformation due to the magnetic field. As for rotation, we consider only the…
Recent studies have established that peaks in solar oscillation power spectra are not Lorentzian in shape, but have a distinct asymmetry. Fitting a symmetric Lorentzian profile to the peaks therefore produces a shift in frequency of the…
We analyze intermediate degree p- and f-mode eigenfrequencies measured by GONG and MDI/SOHO for a complete solar cycle to study their correlation with solar activity. We demonstrate that the frequencies do vary linearly with the activity,…
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…
Using intermediate degree p mode frequency data sets for solar cycle 22, we find that the frequency shifts and magnetic indices show a `hysteresis' phenomenon. It is observed that the magnetic indices follow different paths for the…
Solar-like oscillations are excited stochastically by convection. They occur in stars with an outer convection zone, which includes the Sun and other stars on the lower main sequence, as well as cool subgiants and red giants. This chapter…
Using even-order frequency splitting coefficients of global p-modes it is possible to infer the magnetic field in the solar interior as a function of radial distance and latitude. Results obtained using GONG and MDI data are discussed.…
Waves are thought to play a significant role in the heating of the solar atmosphere and the acceleration of the wind. Among the many types of waves observed in the Sun, the so-called p-modes with a 3 mHz frequency peak dominate the lower…
This article presents a power-spectrum analysis of 39,024 measurements of the solar diameter made at the Mount Wilson Observatory from 1968.670 to 1997.965. This power spectrum contains a number of very strong peaks. We find that eight of…
A new fitting methodology is presented which is equally well suited for the estimation of low-, medium-, and high-degree mode parameters from $m$-averaged solar oscillation power spectra of widely differing spectral resolution. This method,…