Modelling stellar activity cycles using deep-seated dynamos and surface flux transport

Isik Emre, e.isik@iku.edu.tr, Istanbul Kultur University, Turkey

Abstract
We investigate the relations between tachocline-based dynamos and surface flux transport mechanisms in stars with outer convection zones. Using the combined models of flux generation and transport (Isik et al. 2011 A&A 528, A135), we demonstrate the importance of the buoyant rise of magnetic flux, which physically determines the emergence latitudes and tilt angles of bipolar regions. The combined effects of dynamo strength, flux rise, and surface transport lead to regular and irregular cycles of total (unsigned) surface magnetic flux. We also give an interpretation of our numerical simulations with respect to observational results, such as multiple periodicities in active stars and active longitudes.