Flux-Transport Simulations of Solar Polar Magnetic Fields Based on Various Meridional Surface Flow Profiles

Abstract:

Magnetic fields located in the polar regions of the Sun during solar minima appear to be a useful predictor of the amplitude of the subsequent sunspot cycles. These polar fields are the result of flows that move magnetic flux, on a net basis, poleward from active-region latitudes. This process is captured well by two-dimensional global flux-transport schemes, which use empirical prescriptions for differential rotation, meridional flows, and convective dispersal to kinematically advect flux. As a result, these models are useful for investigating the evolution of solar surface flux and their effects on the formation of the polar fields. In the study presented here, we use a surface-flux transport model to gain intuition toward an understanding of the importance of different meridional flow profiles on the formation and evolution of the polar fields. The meridional flow profiles used for this study are based on helioseismic determinations of near-surface flows during recently activity cycles.