Surface flux transport modeling for solar cycles 15--21: effects of cycle-dependent tilt angles of sunspot groups

TL;DR

This study models the Sun's surface magnetic field and open flux over multiple solar cycles, incorporating cycle-dependent sunspot group tilt angles, and finds correlations between polar fields at cycle minimum and subsequent cycle strength.

Contribution

Introduces a surface flux transport model that accounts for cycle-dependent tilt angles, improving understanding of solar magnetic field evolution and cycle prediction.

Findings

Model reproduces observed open flux evolution

Polar field and dipole moment correlate with next cycle strength

Cycle-dependent tilt angles significantly impact magnetic field modeling

Abstract

We model the surface magnetic field and open flux of the Sun from 1913 to 1986 using a surface flux transport model, which includes the observed cycle-to-cycle variation of sunspot group tilts. The model reproduces the empirically derived time evolution of the solar open magnetic flux, and the reversal times of the polar fields. We find that both the polar field and the axial dipole moment resulting from this model around cycle minimum correlate with the strength of the following cycle.