Related papers: The cross helicity at the solar surface by simulat…
We provide a consistent theory of the tachocline confinement (or anisotropic momentum transport) within an hydrodynamical turbulence model. The goal is to explain helioseismological data, which show that the solar tachocline thickness is at…
Measuring the magnetic helicity distribution in the solar corona can help in understanding the trigger of solar eruptive events because magnetic helicity is believed to play a key role in solar activity due to its conservation property. A…
The purpose of this work is to investigate the spectral properties of the developed isotropic (non-Alfven) MHD turbulence stationary excited by an external force, which injects the cross helicity into the flow simultaneously with the…
Sunspots are the most spectacular manifestation of solar magnetism, yet, 99% of the solar surface remains 'quiet' at any time of the solar cycle. The quiet sun is not void of magnetic fields, though; they are organized at smaller spatial…
Magnetic helicity fluxes in turbulently driven alpha^2 dynamos are studied to demonstrate their ability to alleviate catastrophic quenching. A one-dimensional mean-field formalism is used to achieve magnetic Reynolds numbers of the order of…
Deciphering and understanding the small-scale magnetic activity of the quiet solar photosphere should help to solve many of the key problems of solar and stellar physics, such as the magnetic coupling to the outer atmosphere and the coronal…
Adiabatic oscillation frequencies of stellar models, computed with the standard mixing-length formulation for convection, increasingly deviate with radial order from observations in solar-like stars. Standard solar models overestimate…
We present a comprehensive statistical study of the radial evolution of solar wind turbulence near Mercury's orbit using long-term magnetic field measurements from the MESSENGER mission. Owing to Mercury's highly elliptical orbit and the…
We investigate to what extent the current helicity distribution observed in solar active regions is compatible with solar dynamo models. We use an advanced 2D mean-field dynamo model with dynamo action largely concentrated near the bottom…
A gauge invariant and hence physically meaningful definition of magnetic helicity density for random fields is proposed, using the Gauss linking formula, as the density of correlated field line linkages. This definition is applied to the…
Changes in the solar surface area covered by small-scale magnetic elements are thought to cause long-term changes in the solar spectral irradiance, which are important for determining the impact on Earth's climate. To study the effect of…
We present the results of a statistical analysis of the Doppler shifts and the asymmetry parameters of V profiles of the Fe I 630.25 nm line produced by 2D MHD simulations of solar granulation. The realism of the simulations tested using…
We obtain lower limits on the amplitude of convective velocities in the deep solar convection zone based only on the observed properties of the differential rotation and meridional circulation together with simple and robust dynamical…
The connection between helically isotropic MHD turbulence and mean-field dynamo theory is reviewed. The nonlinearity in the mean-field theory is not yet well established, but detailed comparison with simulations begin to help select viable…
The effects of turbulence on the mixing of gases and dust in the outer Solar nebula are examined using 3-D MHD calculations in the shearing-box approximation with vertical stratification. The turbulence is driven by the magneto-rotational…
The form of the solar meridional circulation is a very important ingredient for mean field flux transport dynamo models. Yet a shroud of mystery still surrounds this large-scale flow, given that its measurement using current helioseismic…
Traditionally, fast solar wind is considered to originate in solar source regions that are continuously open to the heliosphere and slow wind originates in regions that are intermittently open to it. In fast wind, the gradient of the solar…
We show that the MHD theory that explains the solar tachocline by an effect of the magnetic field can work with the decay modes of a fossil field in the solar interior if the meridional flow of the convection zone penetrates slightly the…
All cool main sequence stars including our Sun are thought to have magnetic fields. Observations of the Sun revealed that even in quiet regions small-scale turbulent magnetic fields are present. Simulations further showed that such magnetic…
Electromotive force is an essential quantity in dynamo theory. During a coronal mass ejection (CME), magnetic helicity gets decoupled from the Sun and advected into the heliosphere with the solar wind. Eventually, a heliospheric magnetic…