Latitudinal Dynamics and Sectoral Structure of the Solar Magnetic Field

TL;DR

This paper analyzes the large-scale solar magnetic field's latitudinal and longitudinal dynamics, revealing a stable sectoral structure linked to the tachocline, based on three solar cycles of observational data.

Contribution

It identifies a stable longitudinal magnetic field structure over 30 years and links it to the tachocline's rotation, advancing understanding of solar magnetic topology.

Findings

A stable longitude structure persists over 30 years.

The magnetic field's rotation matches the tachocline's rotation.

Magnetic structuring occurs in the solar tachocline.

Abstract

The study of the global structure of the large-scale magnetic field of the Sun is extremely important for creating a theoretical model of the dynamics of the Sun and predictions of the real situation in the helio- and geomagnetosphere. The purpose of the present study was to calculate the differential rotation period of a large-scale photospheric magnetic field, to study its behavior over time and to find out whether there is a sectoral structure of this field along the longitude. However, the choice of the coordinate system in which to search for it is far from unambiguous. This is closely related to the fact that the rotation of the Sun is differential in latitude and varies with depth and over time. Based on the observational data of the J. Wilcox Solar Observatory for three complete cycles of solar activity 21, 22 and 23, the period of rotation of the magnetic field at various latitudes and its change in time were calculated. A uniquely stable over 30 years longitude structure was found. It was determined that its speed of rotation coincides with the one with which the base of the convective shell rotates, that is, the structuring of the magnetic field of the Sun occurs in tachocline. This result clearly demonstrates the close connection of solar activity processes with the topology of magnetic fields, with their dynamics and depth stratification.