A proposed paradigm for solar cycle dynamics mediated via turbulent pumping of magnetic flux in Babcock-Leighton type solar dynamos

Abstract

At present, Babcock-Leighton flux transport solar dynamo models appear as the most promising model for explaining diverse observational aspects of the sunspot cycle. The success of these flux transport dynamo models is largely dependent upon a single-cell meridional circulation with a deep equatorward component at the base of the Sun's convection zone. However, recent observations suggest that the meridional flow may in fact be very shallow (confined to the top 10 % of the Sun) and more complex than previously thought. Taken together these observations raise serious concerns on the validity of the flux transport paradigm. By accounting for the turbulent pumping of magnetic flux as evidenced in magnetohydrodynamic simulations of solar convection, we demonstrate that flux transport dynamo models can generate solar-like magnetic cycles even if the meridional flow is shallow. Solar-like periodic reversals is recovered even when meridional circulation is altogether absent, however, in this case the solar surface magnetic field dynamics does not extend all the way to the polar regions. Very importantly, our results demonstrate that the Parker-Yoshimura sign rule for dynamo wave propagation can be circumvented in Babcock-Leighton dynamo models by the latitudinal component of turbulent pumping -- which can generate equatorward propagating sunspot belts in the absence of a deep, equatorward meridional flow. We also show that variations in turbulent pumping coefficients can modulate the solar cycle amplitude and periodicity. Our results suggest the viability of an alternate magnetic flux transport paradigm -- mediated via turbulent pumping -- for sustaining solar-stellar dynamo action.

11 Pages; 8 Figures; Accepted for publication in Astrophysical Journal

References in corpus (12)

• The case for a distributed solar dynamo shaped by near-surface shear
• Exploring the Physical Basis of Solar Cycle Predictions: Flux Transport Dynamics and Persistence of Memory in Advection versus Diffusion Dominated Solar Convection Zones
• Solar Cycle Propagation, Memory, and Prediction: Insights from a Century of Magnetic Proxies
• The unusual minimum of sunspot cycle 23 a consequence of Sun's meridional plasma flow variations
• Turbulent magnetic pumping in a Babcock-Leighton solar dynamo model
• A Double-Ring Algorithm for Modeling Solar Active Regions: Unifying Kinematic Dynamo Models and Surface Flux-Transport Simulations
• Helioseismic data inclusion in solar dynamo models
• Solar dynamo models with alpha-effect and turbulent pumping from local 3D convection calculations
• Meridional flow profile measurements with SOHO/MDI
• How does the shape and thickness of the tachocline affect the distribution of the toroidal magnetic fields in the solar dynamo?
• Meridional circulation dynamics from 3D MHD global simulations of solar convection
• Stellar dynamos with $\vec{\Omega }\times \vec{J}$ effect

Cited by in corpus (17)

• Solar Cycle Variability Induced by Tilt Angle Scatter in a Babcock--Leighton Solar Dynamo Model
• Evolution of solar and stellar dynamo theory
• Physical Models for Solar Cycle Predictions
• Mean field models of flux transport dynamo and meridional circulation in the Sun and stars
• A 3D kinematic Babcock Leighton solar dynamo model sustained by dynamic magnetic buoyancy and flux transport processes
• An update of Leighton's solar dynamo model
• Impact of Anomalous Active Regions on the Large-scale Magnetic Field of the Sun
• Modeling Solar Wind Variations over an 11-yr Cycle with Alfvén Wave Dissipation: a Parameter Study
• Deconstructing the Properties of Solar Super Active Region 13664 in the Context of the Historic Geomagnetic Storm of 2024 May 10-11
• Modeling effects of starspots on stellar magnetic cycles
• Algebraic Quantification of the Contribution of Active Regions to the Sun's Dipole Moment: Applications to Century-scale Polar Field Estimates and Solar Cycle Forecasting
• A Potential New Mechanism for the Butterfly Diagram of the Solar Cycle: Latitude-dependent Radial Flux Transport
• Minimal Roles of Solar Subsurface Meridional Flow in the distributed-shear Babcock-Leighton Dynamo
• Variation of small scale magnetic fields over a century using Ca-K images as proxy
• Coronal magnetic field evolution over the cycle 24
• Extreme Fluctuations in the Sun's Activity over the Modern Maximum: Understanding the Enigmatic Solar Cycles 19-20
• Can meridional flow variations explain the observed rising/declining phase asymmetry in the solar cycle?