Dynamics of solar large-scale flows

TL;DR

This paper reviews the current understanding of the Sun's large-scale flows, including differential rotation and meridional circulation, highlighting observational and simulation advances and discussing unresolved issues and future research directions.

Contribution

It provides a comprehensive overview of solar large-scale flows, integrating recent observational data and simulation results, and discusses the role of inertial modes and future research needs.

Findings

Helioseismology constrains flow topology in the solar interior.

Simulations can self-consistently generate large-scale flows.

Inertial modes of oscillation are recently discovered phenomena.

Abstract

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 the solar convection zone. These large-scale flows are crucial for maintaining the Sun's global magnetic field. Over the last several decades, our understanding of large-scale motions in the Sun has significantly improved, both through observational and theoretical efforts. Helioseismology has constrained the flow topology in the solar interior, and the growth of supercomputers has enabled simulations that can self-consistently generate large scale flows in rotating spherical convective shells. In this chapter, we review our current understanding of solar convection and the large-scale flows present in the Sun, including those associated with the recently discovered inertial modes of oscillation. We discuss some issues still outstanding, and provide an outline of future efforts needed to address these.