Polar cap magnetic field reversals during solar grand minima: could pores play a role?

TL;DR

This study suggests that pores outside active regions, which carry significant magnetic flux, may influence the Sun's magnetic field reversals during grand minima, a process previously overlooked due to observational limitations.

Contribution

It introduces the idea that pores outside active regions could play a role in solar magnetic reversals during grand minima, highlighting a potential weak magnetic source overlooked by past observations.

Findings

Pores outside active regions carry flux comparable to polar caps.

Pores at 40-100 Mm from active regions have the correct polarity for reversals.

Such pores may operate as a weak magnetic source during grand minima.

Abstract

We study the magnetic flux carried by pores located outside active regions with sunspots and investigate their possible contribution to the reversal of the global magnetic field of the Sun. We find that they contain a total flux of comparable amplitude to the total magnetic flux contained in polar caps. The pores located at distances of 40--100~Mm from the closest active region have systematically the correct sign to contribute to the polar cap reversal. These pores can predominantly be found in bipolar magnetic regions. We propose that during grand minima of solar activity, such a systematic polarity trend, akin to a weak magnetic (Babcock-Leighton-like) source term could still be operating but was missed by the contemporary observers due to the limited resolving power of their telescopes.