Estimates of current helicity and tilt of solar active regions and Joy's law

TL;DR

This paper estimates the current helicity and tilt of solar active regions using two models, providing insights into their contributions to observable magnetic properties and confirming the relevance of Joy's law.

Contribution

It introduces two methods—turbulent convective cell modeling and a mean-field dynamo model—to estimate solar magnetic parameters, enhancing understanding of their origins.

Findings

Both models yield estimates consistent with observed tilt and helicity.

Helical properties develop during the rise of convective cells in the Sun.

Magnetic helicity conservation influences the observed magnetic field properties.

Abstract

The tilt angle, current helicity and twist of solar magnetic fields can be observed in solar active regions. We carried out estimates of these parameters by two ways. Firstly, we consider the model of turbulent convective cells (super-granules) which have a loop floating structure towards the surface of the Sun. Their helical properties are attained during the rising process in the rotating stratified convective zone. The other estimate is obtained from a simple mean-field dynamo model that accounts magnetic helicity conservation. The both values are shown to be capable to give important contributions to the observable tilt, helicity and twist.