Back-reactions of dynamo-generated magnetic fields: Torsional oscillations and variations in meridional circulation

TL;DR

This paper investigates how the solar dynamo's magnetic fields cause torsional oscillations and variations in meridional circulation, explaining their origins and observational evidence through theoretical modeling.

Contribution

It presents a theoretical model explaining the initiation of torsional oscillations before sunspot cycles and discusses the variations in meridional circulation due to dynamo-generated magnetic fields.

Findings

Theoretical model explains early onset of torsional oscillations.

Observational evidence supports the existence of circulation variations.

Magnetic Lorentz force influences solar internal motions.

Abstract

The periodically varying Lorentz force of the periodic solar magnetic field generated by the solar dynamo can induce two kinds of motions: torsional oscillations and periodic variations in the meridional circulation. Observational evidence now exists for both these kinds of motions. We discuss our ongoing effort in theoretically studying the variations of the meridional circulation. Then we present our theoretical model of torsional oscillations, which addresses the question why these oscillations start before sunspot cycles at latitudes higher than where sunspots are seen.