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

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.

11 pages, 9 figures, accepted for publication in Astronomy&Astrophysics

References in corpus (10)

• Global-Scale Turbulent Convection and Magnetic Dynamo Action in the Solar Envelope
• The crucial role of surface magnetic fields for the solar dynamo
• The unusual minimum of sunspot cycle 23 a consequence of Sun's meridional plasma flow variations
• On Polar Magnetic Field Reversal and Surface Flux Transport During Solar Cycle 24
• Effects of the scatter in sunspot group tilt angles on the large-scale magnetic field at the solar surface
• Calibrating 100 Years of Polar Faculae Measurements: Implications for the Evolution of the Heliospheric Magnetic Field
• On the role of meridional flows in flux transport dynamo models
• The cause of the weak solar cycle 24
• Identifying Potential Markers of the Sun's Giant Convective Scale
• Digitization of sunspot drawings by Spörer made in 1861-1894

Cited by in corpus (2)

• Does the mean-field alpha effect have any impact on the memory of the solar cycle?
• The relationship between bipolar magnetic regions and their sunspots