One obvious feature of the solar cycle is its variation from one cycle to another. In this article,
we review the dynamo models for the long-term variations of the solar cycle. By long-term …

This paper reviews recent advances and current debates in modeling the solar cycle as a
hydromagnetic dynamo process. Emphasis is placed on (relatively) simple dynamo models …

Solar meridional circulation is an axisymmetric flow system, extending from the equator to
the poles (∼ 20 m/s at the surface,≈ 1% of the mean solar rotation rate), plunging inwards …

The observational absence of giant convection cells near the Sun's outer surface is a long-
standing conundrum for solar modelers. We herein propose an explanation. Rotation …

We analyze the simulation result shown in Hotta & Kusano (2021) in which the solar-like
differential rotation is reproduced. The Sun is rotating differentially with the fast equator and …

The Sun's axisymmetric large-scale flows, differential rotation and meridional circulation, are
thought to be maintained by the influence of rotation on the thermal-convective motions in …

Recent advances in mean-field theory are reviewed and applications to the Sun, late-type
stars, accretion disks, galaxies and the early Universe are discussed. We focus particularly …

Thermal convection is the dominant mechanism of energy transport in the outer envelope of
the Sun (one-third by radius). It drives global fluid circulations and magnetic fields observed …

Convection plays a central role in the dynamics of any stellar interior, and yet its operation
remains largely hidden from direct observation. As a result, much of our understanding …

Supergranulation is a fluid-dynamical phenomenon taking place in the solar photosphere,
primarily detected in the form of a vigorous cellular flow pattern with a typical horizontal …