Related papers: Sub-Wavelength Resolution Imaging of the Solar Dee…
Solar radio bursts are strongly affected by radio-wave scattering on density inhomogeneities, changing their observed time characteristics, sizes, and positions. The same turbulence causes angular broadening and scintillation of galactic…
Local helioseismology has opened new frontiers in our quest for understanding of the internal dynamics and dynamo on the Sun. Local helioseismology reconstructs subsurface structures and flows by extracting coherent signals of acoustic…
Context. The frequencies, lifetimes, and eigenfunctions of solar acoustic waves are affected by turbulent convection, which is random in space and in time. Since the correlation time of solar granulation and the periods of acoustic waves…
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…
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…
A new time--distance far-side imaging technique was recently developed by utilizing multiple multi-skip acoustic waves. The measurement procedure is applied to 11 years of Doppler observations from the Solar Dynamics Observatory /…
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…
We find evidence for the first observation of the parametric decay instability (PDI) in the lower solar atmosphere. Specifically, we find that the power spectrum of density fluctuations near the solar transition region resembles the power…
Supergranules are divergent 30-Mm sized cellular flows observed everywhere at the solar photosphere. Their place in the hierarchy of convective structures and their origin remain poorly understood (Rincon et al., 2018). Estimating…
Correct interpretation of acoustic travel times measured by time-distance helioseismology is essential to get an accurate understanding of the solar properties that are inferred from them. It has long been observed that sunspots suppress…
We present the results of numerical simulations of shock wave-driven jets in the solar atmosphere. The dependence of observable quantities like maximum velocity and deceleration on parameters such as the period and amplitude of initial…
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…
We present a high-resolution, highly stratified numerical simulation of rotating thermal convection in a spherical shell. Our aim is to study in detail the processes that can maintain a near surface shear layer (NSSL) as inferred from…
We present a seismological method to probe the solar atmosphere above sunspot umbrae with three-minute oscillations. Our technique allows us to estimate both the vertical distance between atmospheric layers and the wave-propagation speed…
Context: Helioseismic inversions rely largely on sensitivity kernels, 3-D spatial functions describing how do the changes in the solar interior translate into the changes of helioseismic observables. These sensitivity kernels come in most…
This paper presents a preliminary analysis of the turbulence spectrum of the solar wind in the near-Sun region R < 50 Rs, obtained from interplanetary scintillation measurements with the Ooty Radio Telescope at 327 MHz. The results clearly…
Results of numerical 3D simulations of propagation of acoustic waves inside the Sun are presented. A linear 3D code which utilizes realistic OPAL equation of state was developed by authors. Modified convectively stable standard solar model…
We present results on the structure of the near-surface layers of the Sun obtained by inverting frequencies of high-degree solar modes from "ring diagrams". We have results for eight epochs between June 1996 and October 2003. The…
High-precision pulsar timing requires accurate corrections for dispersive delays of radio waves, parametrized by the dispersion measure (DM), particularly if these delays are variable in time. In a previous paper we studied the Solar-wind…
The latitudinal sound-speed structure of the Sun's convection zone gives insight into the physical processes occurring there, specifically the cellular convection and possibly the presence of magnetic fields. Using helioseismic data from…