Related papers: Near-surface shear layer dynamics
Mercury, due to its close location to the Sun, is surrounded by an environment whose conditions may be considered as "extreme" in the entire Solar System. Both solar wind and radiation are stronger with respect to other Solar System bodies,…
We extend earlier models of turbulent dynamos with an upper, nearly force-free exterior to spherical geometry, and study how flux emerges from lower layers to the upper ones without being driven by magnetic buoyancy. We also study how this…
One of the puzzling features of solar magnetism is formation of long-living compact magnetic structures; such as sunspots and pores, in the highly turbulent upper layer of the solar convective zone. We use realistic radiative 3D MHD…
Observations with the 1-m Swedish Solar Telescope of the flows seen in penumbral filaments are presented. Time sequences of bright filaments show overturning motions strikingly similar to those seen along the walls of small isolated…
Using three-dimensional convection simulations it is shown that a sinusoidal variation of horizontal shear leads to a kinematic \alpha effect with a similar sinusoidal variation. The effect exists even for weak stratification and arises…
In-situ measurements by several spacecraft have revealed that the solar wind is frequently perturbed by transient structures (magnetic folds, jets, waves, flux-ropes) that propagate rapidly away from the Sun over large distances. Parker…
Spectral analysis of the spatial structure of solar subphotospheric convection is carried out for subsurface flow maps constructed using the time--distance helioseismological technique. The source data are obtained from the Helioseismic and…
Stellar dynamos are driven by complex couplings between rotation and turbulent convection, which drive global-scale flows and build and rebuild stellar magnetic fields. When stars like our sun are young, they rotate much more rapidly than…
Internal gravity waves excited by overshoot at the bottom of the convection zone can be influenced by rotation and by the strong toroidal magnetic field that is likely to be present in the solar tachocline. Using a simple Cartesian model,…
After the sunset, under calm and clear sky conditions, aerosol laden surface air-layer, cools radiatively to the upper atmosphere. Predominant effect of the radiative cooling on the vertical temperature profile extends to several hundred…
We present the initial results of an observational study into the variation of the dominant length-scale of quiet solar emission: supergranulation. This length-scale reflects the radiative energy in the plasma of the upper solar…
Besides a dense coverage of their high latitudes by starspots, rapidly rotating cool stars also display low-latitude spots in Doppler images, although generally with a lower coverage. In contrast, flux emergence models of fast-rotating…
Vortex-type motions have been measured by tracking bright points in high-resolution observations of the solar photosphere. These small-scale motions are thought to be determinant in the evolution of magnetic footpoints and their interaction…
In this paper, we study the properties of solar granulation in a facular region from the photosphere up to the lower chromosphere. Our aim is to investigate the dependence of granular structure on magnetic field strength. We use…
Stars are not smooth. Their photosphere is covered by a granulation pattern associated with the heat transport by convection. The convection-related surface structures have different size, depth, and temporal variations with respect to the…
The atmosphere of the Sun is highly structured and dynamic in nature. From the photosphere and chromosphere into the transition region and the corona plasma-$\beta$ changes from above to below one, i.e. while in the lower atmosphere the…
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…
We present results from numerical modeling of emerging flux regions on the solar surface. The modeling was carried out by means of 3D radiative MHD simulations of the rise of buoyant magnetic flux tubes through the convection zone and into…
Context. Solar eruptions and high flare activity often accompany the rapid rotation of sunspots. The study of sunspot rotation and the mechanisms driving this motion are therefore key to our understanding of how the solar atmosphere attains…
The solar convection manifests as granulation and intergranulation at the solar surface. In the photosphere, convective motions induce differential Doppler shifts to spectral lines. The observed convective blueshift varies across the solar…