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 …

The dynamic activity of stars such as the Sun influences (exo) planetary space environments
through modulation of stellar radiation, plasma wind, particle and magnetic fluxes. Energetic …

The prediction of the strength of an upcoming solar cycle has been a long-standing
challenge in the field of solar physics. The inherent stochastic nature of the underlying solar …

The polar field reversal is a crucial process in the cyclic evolution of the large-scale
magnetic field of the Sun. Various important characteristics of a solar cycle, such as its …

A striking feature of the solar cycle is that at the beginning, sunspots appear around
midlatitudes, and over time the latitudes of emergences migrate toward the equator. The …

Prediction of the solar cycle is challenging but essential because it drives space weather.
Several predictions with varying amplitudes of the ongoing Cycle 25 have been made. We …

We discuss a solar dynamo model of Tayler–Spruit type whose Ω Ω-effect is conventionally
produced by a solar-like differential rotation but whose α α-effect is assumed to be …

Detailed study of the solar magnetic field is crucial to understand its generation, transport,
and reversals. The timing of the reversals may have implications on space weather and thus …

Abstract The Kodaikanal Observatory has provided long-term synoptic observations of
chromospheric activities in the Ca ii K line (393.34 nm) since 1907. This article investigates …