Effects of turbulent pumping on stellar activity cycles

Abstract

Stellar magnetic activity of solar like stars is thought to be due to an internal dynamo. While the Sun has been the subject of intense research for refining dynamo models, observations of magnetic cyclic activity in solar type stars have become more and more available, opening a new path to understand the underlying physics behind stellar cycles. For instance, it is key to understand how stellar rotation rate influences magnetic cycle period $\Pcyc$. Recent numerical simulations of advection-dominated Babcock Leighton models have demonstrated that it is difficult to explain this observed trend given a) the strong influence of the cycle period to the meridional circulation amplitude and b) the fact that 3D models indicate that meridional flows become weaker as the rotation rate increases. In this paper, we introduce the turbulent pumping mechanism as another advective process capable also of transporting the magnetic fields. We found that this model is now able to reproduce the observations under the assumption that this effect increases as ${\Omega }^2$. The turbulent pumping becomes indeed another major player able to circumvent the meridional circulation. However, for high rotation rates ($\Omega \simeq 5{\Omega }_{\odot }$), its effects dominate those of the meridional circulation, entering a new class of regime dominated by the advection of turbulent pumping and thus leading to a cyclic activity qualitatively different from that of the sun.

Published in Astronomische Nachrichten; 11 pages, 8 figures

References in corpus (17)

• Simulations of dynamo action in fully convective stars
• Toroidal versus poloidal magnetic fields in Sun-like stars: a rotation threshold
• Persistent Magnetic Wreaths in a Rapidly Rotating Sun
• Structure and Evolution of Giant Cells in Global Models of Solar Convection
• Magnetic Cycles in a Convective Dynamo Simulation of a Young Solar-type Star
• Flux-transport dynamos with Lorentz force feedback on differential rotation and meridional flow: Saturation mechanism and torsional oscillations
• Exploring the Physical Basis of Solar Cycle Predictions: Flux Transport Dynamics and Persistence of Memory in Advection versus Diffusion Dominated Solar Convection Zones
• Rapidly Rotating Suns and Active Nests of Convection
• On the role of meridional flows in flux transport dynamo models
• Alpha effect and turbulent diffusion from convection
• Coupling the solar dynamo and the corona: wind properties, mass and momentum losses during an activity cycle
• Turbulent magnetic pumping in a Babcock-Leighton solar dynamo model
• Simulations of turbulent convection in rotating young solar-like stars: Differential rotation and meridional circulation
• On the penetration of meridional circulation below the solar convection zone
• Magnetoconvection and dynamo coefficients III: alpha-effect and magnetic pumping in the rapid rotation regime
• Polar Field Puzzle: Solutions from Flux-Transport Dynamo and Surface Transport Models
• Mean-field solar dynamo models with strong meridional flow at the bottom of the convection zone

Cited by in corpus (11)

• Modeling Solar Cycles 15 to 21 Using a Flux Transport Dynamo
• The Solar-Stellar Connection
• Turbulent Pumping of Magnetic Flux Reduces Solar Cycle Memory and thus Impacts Predictability of the Sun's Activity
• Surface flux evolution constraints for flux transport dynamos
• Quenching and anisotropy of hydromagnetic turbulent transport
• Exploring cycle period and parity of stellar magnetic activity with dynamo modeling
• Dynamo modelling for cycle variability and occurrence of grand minima in Sun-like stars: Rotation rate dependence
• Does the mean-field alpha effect have any impact on the memory of the solar cycle?
• Impact of anti-solar differential rotation in mean-field solar-type dynamos -- Exploring possible magnetic cycles in slowly rotating stars
• Modeling effects of starspots on stellar magnetic cycles
• Forecasting the solar cycle using variational data assimilation: validation on cycles 22 to 25