87 citations
8 papers
Hidden magnetic fields of young suns
O. Kochukhov, T. Hackman, J. J. Lehtinen +1
Global magnetic fields of active solar-like stars are nowadays routinely detected with spectropolarimetric measurements and are mapped with Zeeman-Doppler imaging (ZDI). However, d…
Electrodynamics of turbulent fluids with fluctuating electric conductivity
G. Rüdiger, M. Küker, P. J. Käpylä
The influence of fluctuating conductivity on the coefficients known from the mean-field electrodynamics is considered. If the conductivity fluctuations are assumed as uncorrelated…
Rotational dependence of turbulent transport coefficients in global convective dynamo simulations of solar-like stars
J. Warnecke, M. J. Käpylä
For moderate and slow rotation, magnetic activity of solar-like stars is observed to strongly depend on rotation. These observations do not yet have a solid explanation in terms of…
Differences in the solar cycle variability of simple and complex active regions during 1996-2018
Shabnam Nikbakhsh, Eija Tanskanen, Maarit Käpylä +1
Aims. Our aim is to examine the solar cycle variability of magnetically simple and complex active region. Methods. We studied simple ( and ) and complex ( and ) acti…
A new signal of the solar magnetic cycle: Opposite shifts of weak magnetic field distributions in the two hemispheres
Tibebu Getachew, Ilpo Virtanen, Kalevi Mursula
We study the asymmetric distribution of weak photospheric magnetic field values in the two hemispheres separately using synoptic maps from SDO/HMI, SOLIS/VSM and WSO during solar c…
Reconstructing solar magnetic fields from historical observations V. Sunspot magnetic field measurements at Mount Wilson Observatory
Alexei A. Pevtsov, Kseniya A. Tlatova, Alexander A. Pevtsov +7
Context. Systematic observations of magnetic field strength and polarity in sunspots began at Mount Wilson Observatory (MWO), USA in early 1917. Except for a few brief interruption…