Solar Polar Field Reversals as the Result of the Global Magnetic field Meridional Flows

TL;DR

This study analyzes solar polar magnetic field reversals across cycles 21 to 25, linking them to meridional flows of magnetic fields and proposing formulas to predict reversal timings and cycle maxima.

Contribution

It introduces formulas for calculating magnetic field flow meridional circulation, enabling predictions of polarity reversal timings and cycle maxima based on solar magnetic data.

Findings

Polar reversals occur at sunspot cycle maxima.

Reversal durations are not linked to Wolf numbers.

Magnetic field flows cyclically migrate between poles.

Abstract

Based on data obtained from Wilcox Solar Observatiry the solar polar magnetic fields reversals in cycles 21\,--\,25 were considered. The results indicate that the polarity reversal occurs at the maximum of sunspot activity of each cycle, but the beginning, end, and duration of the reversals did not demonstrate any association with the Wolf numbers, which are characteristics of local magnetic fields. Moreover, during the periods of polarity reversal, the correlation between global magnetic field (GMF) parameters and Wolf numbers decreased and even moved into anti-correlation mode. The polar field reversals are determined by the GMF flows of positive- and negative-polarity magnetic fields, which cyclically migrate from one pole to the opposite pole. The new polarity magnetic fields are delivered to the poles by a certain flow, and then carried away by the same flow to the opposite pole. The increase in the polar magnetic field strength to its maximal values at the solar activity minimum and following decrees to the next cycle maximum coincides with the latitudinal changes in corresponding magnetic field flow. Formulas for calculating the meridional circulation of positive- and negative-polarity magnetic field flows were proposed. They allow predict the time of polarity reversals, and since polarity reversals occur at the maxima of cycles, then also the time of maxima of both the future and past cycles.