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.

arXiv comment11 Pages; 8 Figures; Accepted for publication in Astrophysical Journal

References in corpus (25)

• The case for a distributed solar dynamo shaped by near-surface shear
• Detection of Equatorward Meridional Flow and Evidence of Double-Cell Meridional Circulation inside the Sun
• Sunspot group tilt angles and the strength of the solar cycle
• Full--Sphere Simulations of a Circulation--Dominated Solar Dynamo: Exploring the Parity Issue
• 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
• Grand Minima and Equatorward Propagation in a Cycling Stellar Convective Dynamo
• Towards A Mean-Field Formulation Of The Babcock-Leighton Type Solar Dynamo. I. Alpha Coefficient Versus Durney's Double Ring Approach
• Is a deep one-cell meridional circulation essential for the flux transport Solar Dynamo?
• Magnetoconvection and dynamo coefficients: II. Field-direction dependent pumping of magnetic field
• A Solar Dynamo Model Driven by Mean-Field Alpha and Babcock-Leighton Sources: Fluctuations, Grand-Minima-Maxima and Hemispheric Asymmetry in Sunspot Cycles
• The origin of grand minima in the sunspot cycle
• Turbulent magnetic pumping in a Babcock-Leighton solar dynamo model
• Modeling Solar Cycles 15 to 21 Using a Flux Transport Dynamo
• Supergranules as Probes of the Sun's Meridional Circulation
• A Double-Ring Algorithm for Modeling Solar Active Regions: Unifying Kinematic Dynamo Models and Surface Flux-Transport Simulations
• A Stochastically Forced Time Delay Solar Dynamo Model: Self-Consistent Recovery from a Maunder-like Grand Minimum Necessitates a Mean-Field Alpha Effect
• 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
• Pumping velocity in homogeneous helical turbulence with shear
• 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

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• Progress in Solar Cycle Predictions: Sunspot Cycles 24-25 in Perspective
• 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
• The Origin of Parity Changes in the Solar Cycle
• An update of Leighton's solar dynamo model
• A 3D kinematic Babcock Leighton solar dynamo model sustained by dynamic magnetic buoyancy and flux transport processes
• Stellar mid-life crisis: subcritical magnetic dynamos of solar-like stars and the breakdown of gyrochronology
• 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
• Does the mean-field alpha effect have any impact on the memory of the solar cycle?
• Is hemispheric asymmetry in the sunspot cycle solely governed by polar flux imbalance in the previous cycle?
• Incorporating Surface Convection into a 3D Babcock-Leighton Solar Dynamo Model
• Nonkinematic solar dynamo models with double-cell meridional circulation
• Deconstructing the Properties of Solar Super Active Region 13664 in the Context of the Historic Geomagnetic Storm of 2024 May 10-11
• 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
• Modeling effects of starspots on stellar magnetic cycles
• 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
• Coronal magnetic field evolution over the cycle 24
• Variation of small scale magnetic fields over a century using Ca-K images as proxy
• 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?