Solar Hemispheric Helicity Rules: A New Explanation

Abstract

Large-scale solar surface magnetic fields are believed to emerge from the deep solar interior due to magnetic buoyancy and are observed as sunspots, embedded in active regions. The geometry and bi-polar nature of the pairwise emergence of sunspots has motivated the consideration of the rising and emerging strong toroidal magnetic flux concentrations in the interior as cylindrical flux tubes. Since magnetic flux is not expected to exist as isolated flux tubes in the deep solar interior, we have investigated the dynamics of more realistic magnetic flux concentrations embedded in a larger-scale diffused field. We find that the presence of a weak large-scale background field, through which the flux tube rises, can significantly alter the dynamics and lead to interesting insights about solar observations of current/magnetic helicity. We further carry out a Monte Carlo study to explore these dynamics quantitatively for a direct comparison with Solar Hemispheric Helicity rules.