Mean-field dynamo theory has important applications in solar physics and galactic
magnetism. We discuss some of the many turbulence effects relevant to the generation of …

Reconnection and turbulence are two of the most commonly observed dynamical processes
in plasmas, but their relationship is still not fully understood. Using 2.5 D kinetic particle-in …

Turbulence and the associated turbulent transport of scalar and vector fields is a classical
physics problem that has dazzled scientists for over a century, yet many fundamental …

In the presence of strong density stratification, hydromagnetic turbulence attains qualitatively
new properties: the formation of magnetic flux concentrations. We review here the theoretical …

We investigate the dynamics of solar activity using a nonlinear one-dimensional dynamo
model and a phenomenological equation for the evolution of Wolf numbers. This system of …

We apply a nonlinear mean-field dynamo model which includes a budget equation for the
dynamics of Wolf numbers to predict solar activity. This dynamo model takes into account the …

Finding the formation mechanisms for bipolar configurations of a strong local magnetic field
under control of the relatively weak global magnetic field of the Sun is a key problem of the …

Context. Analytic solutions of the mean-field induction equation predict a nonoscillatory
dynamo for homogeneous helical turbulence or constant α effect in unbounded or periodic …

In this chapter, we discuss a mean field solar dynamo model with algebraic and dynamic
nonlinearities, various mechanisms of sunspot formation, and prediction of solar activity. The …

Context. The formation of sunspots requires the concentration of magnetic flux near the
surface. The negative effective magnetic pressure instability (NEMPI) might be a possible …