North-South Asymmetry of the Solar Activity at Different Spatial Scales

TL;DR

This paper investigates the North-South asymmetry in solar activity across different spatial scales, revealing distinct mechanisms for long-term and short-term magnetic structures and their relation to the solar dynamo and sunspot formation.

Contribution

It distinguishes the mechanisms behind long-term and short-term solar magnetic structures and explores their connection to the solar dynamo and sunspot formation processes.

Findings

Long-term structures are generated by the mean-field dynamo.

Short-term structures are produced by separate sunspot formation mechanisms.

The 11-year solar cycle is driven by the mean-field dynamo, while spot formation occurs in subsurface layers.

Abstract

Solar activity seems quite understandable when considered on the scales comparable with a solar cycle, i.e. about 11 years, and on a short time scale of about a year. A solar cycle looks basically (anti)symmetric with respect to the solar equator, while the sunspot distribution is more or less random. We investigated the difference in the spatial distribution of magnetic structures on both time scales in terms of sunspots and the surface large-scale magnetic field and arrived at the conclusion that the structures of each type are created by a specific mechanism. For long-term structures, it is the mean-field dynamo. For the short-term ones, it is the spot production considered as a separate physical mechanism. The relationship between the mean-field dynamo mechanism and the processes of sunspot formation is a complex problem of current interest. The 11-year cycle itself is created by the mean-field dynamo and is most likely determined by processes in the convection zone. However, the transformation of magnetic flux into spots and active regions occurs, apparently, on significantly shorter time scales and probably develops directly in the subsurface layers, i.e., Near-Surface Shear Layer (NSSL) or leptocline.