Related papers: What Seismic Minimum Reveals About Solar Magnetism…
We examine the frequency shifts in low-degree helioseismic modes from the Birmingham Solar-Oscillations Network (BiSON) covering the period from 1985 - 2016, and compare them with a number of global activity proxies well as a…
The exact location of the solar dynamo remains uncertain--whether it operates primarily in the near-surface shear layer, throughout the entire convection zone, or near the tachocline, a region of sharp transition in the solar rotation,…
Variations of the weak magnetic fields of the photosphere with periods of the order of the solar magnetic cycle were investigated. Synoptic maps of the photospheric magnetic field produced by NSO Kitt Peak for the period from 1978 to 2016…
Time-distance helioseismic measurements in surface- and deep-focus geometries for wave-paths that distinguish surface magnetic contributions from those due to deeper perturbations beneath a large sunspot are presented and analysed. Travel…
Helioseismology studies the structure and dynamics of the Sun's interior by observing oscillations on the surface. These studies provide information about the physical processes that control the evolution and magnetic activity of the Sun.…
The Sun exhibits episodic surges of magnetic activity across a range of temporal and spatial scales, the most prominent of which is the 11-ish year modulation of sunspot production. Beside the ~170 (min to max) decadal variation in sunspot…
Previously unobservable mirror asymmetry of the solar magnetic field -- a key ingredient of the dynamo mechanism which is believed to drive the 11-year activity cycle -- has now been measured. This was achieved through systematic monitoring…
We investigate the spatial and temporal variations of the high-degree mode frequencies calculated over localized regions of the Sun during the extended minimum phase between solar cycles 23 and 24. The frequency shifts measured relative to…
The internal dynamics of the Sun generate magnetic and plasma structures in the photosphere and overlying atmosphere across a wide range of spatial scales. Identifying the critical spatial scale is essential for interpreting physical…
Solar magnetic activity is expressed via variations of sunspots and active regions varying on different timescales. The most accepted is an 11-year period supposedly induced by the electromagnetic solar dynamo mechanism. There are also some…
Turbulent magnetic fields fill most of the volume of the solar atmosphere. However, their spatial and temporal variations are still unknown. Since 2007, during the current solar minimum, we are periodically monitoring several wavelength…
On the base of the solar magnetic field measurements obtained in Stanford in 1976--2003 the properties of the cyclic evolution of the large-scale magnetic field are investigated. Some regularities are found in longitudinal and latitudinal…
Normal modes of oscillation of the Sun are useful probes of the solar interior. In this work, we use the even-order splitting coefficients to study the evolution of magnetic fields in the convection zone over solar cycle 23, assuming that…
The Sun's variability is controlled by the progression and interaction of the magnetized systems that form the 22-year magnetic activity cycle (the "Hale Cycle'') as they march from their origin at $\sim$55 degrees latitude to the equator,…
The meridional circulation of the solar magnetic fields in Solar Cycles 21-24 was considered. Data from both ground-based and space observatories were used. Three types of time-latitude distributions of photospheric magnetic fields and…
Temporal variations of the subsurface meridional flow with the solar cycle have been reported by several authors. The measurements are typically averaged over periods of time during which surface magnetic activity existed in the regions…
We present evidence of hitherto undiscovered global-scale oscillations in the near-surface shear layer of the Sun. These oscillations are seen as large scale variations of radial shear in both the zonal and meridional flows relative to…
It is well known that the dominant frequency of oscillations in the solar photosphere is $\approx$3 mHz, which is the result of global resonant modes pertaining to the whole stellar structure. However, analyses of the horizontal motions of…
Magneto-convection simulations on meso-granule and granule scales near the solar surface are used to study small scale dynamo activity, the emergence and disappearance of magnetic flux tubes, and the formation and evolution of micropores.…
We derive formulae connecting the frequency variations in the spectrum of solar oscillations to the dynamical quantities that are expected to change over the solar activity cycle. This is done for both centroids and the asymmetric part of…