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 …

Solar activity has a cyclic nature with the≈ 11-year Schwabe cycle dominating its variability
on the interannual timescale. However, solar cycles are significantly modulated in length …

Theoretical models for the solar dynamo range from simple low-dimensional “toy models” to
complex 3D-MHD simulations. Here we mainly discuss appproaches that are motivated and …

The most widely accepted model of the solar cycle is the flux transport dynamo model. This
model evolved out of the traditional α Ω dynamo model which was first developed at a time …

The emergence of active regions on the Sun is an integral feature of the solar dynamo
mechanism. However, details about the generation of active-region-scale magnetism 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 …

Rapidly rotating fluids have a rotation profile that depends only on the distance from the
rotation axis, in accordance with the Taylor-Proudman theorem. Although the Sun was …

The changing magnetic fields of the Sun are generated and maintained by a solar dynamo,
the exact nature of which remains an unsolved fundamental problem in solar physics. Our …

An actual problem today is the search for observed evidence of the existence of deep small-
scale magnetic fields of the Sun. In this regard, the authors analyzed the theoretical criterion …

We studied the anomalous magnetic regions observed near the minima of solar cycles 24
and 25. The peculiarity of these areas was the deviation of their configuration from Hale's …