Solar dynamo model with nonlocal alpha-effect

TL;DR

This paper presents a solar dynamo model incorporating nonlocal alpha-effect and diamagnetic effects, which better aligns with observed solar magnetic cycle features and avoids catastrophic quenching.

Contribution

It introduces a novel solar dynamo model that includes nonlocal alpha-effect and diamagnetic effects, improving the understanding of magnetic field concentration and cycle characteristics.

Findings

Magnetic fields concentrate near the convection zone base.

Model reproduces observed magnetic cycle period and symmetry.

Identifies discrepancies with observations for future improvements.

Abstract

The first results of the solar dynamo model that allows for the diamagnetic effect of inhomogeneous turbulence and the nonlocal alpha-effect due to the rise of magnetic loops are discussed. The nonlocal alpha-effect is not subject to the catastrophic quenching related to the conservation of magnetic helicity. Given the diamagnetic pumping, the magnetic fields are concentrated near the base of the convection zone, although the distributed-type model covers the entire thickness of the convection zone. The magnetic cycle period, the equatorial symmetry of the field, its meridional drift, and the polar-to-toroidal field ratio obtained in the model are in agreement with observations. There is also some disagreement with observations pointing the ways of improving the model.