Anomalous Active Region Dynamics and Influence on Activity Cycles

Abstract:

We present a study of the influence of anomalous active regions on solar variability, in particular on the suppression of solar activity cycles in grand minima. The study involves the application of a Solar Flux Transport (SFT) model [Schrijver 2001] which has, in this work, been modified to allow for the emergence and evolution of anomalously oriented (anti-Hale and/or anti-Joy) active regions. Such anomalous active regions have been shown preliminarily to ‘shut down’ dynamo action in dynamo modeling efforts, potentially explaining the appearance of Grand Minima in the Sun’s cycle behavior [Nagy et al. 2017].

Following on from these efforts, we test the behavior of anomalous active regions with the computationally lightweight SFT model, which tracks the emergence, evolution, and decay of photospheric magnetic flux concentrations without complex feedback to interior dynamo models. Previous work [Farrish et al. 2019, Farrish et al. 2020 (in prep.)] that the SFT model can be extended to represent the behavior of other cool stars. We aim to study the behavior and influence of anomalous active regions on magnetic activity cycles for the Sun and other stars, with an eye toward the impact of magnetic cycle variability on associated exoplanets.