Meridional Circulation in Solar and Stellar Convection Zones

Abstract

We present a series of 3-D nonlinear simulations of solar-like convection, carried out using the Anelastic Spherical Harmonic (ASH) code, that are designed to isolate those processes that drive and shape meridional circulations within stellar convection zones. These simulations have been constructed so as to span the transition between solar-like differential rotation (fast equator/slow poles) and ``anti-solar' differential rotation (slow equator/fast poles). Solar-like states of differential rotation, arising when convection is rotationally constrained, are characterized by a very different convective Reynolds stress than anti-solar regimes, wherein convection only weakly senses the Coriolis force. We find that the angular momentum transport by convective Reynolds stress plays a central role in establishing the meridional flow profiles in these simulations. We find that the transition from single-celled to multi-celled meridional circulation profiles in strong and weak regimes of rotational constraint is linked to a change in the convective Reynolds stress, a clear demonstration of gyroscopic pumping. Latitudinal thermal variations differ between these different regimes, with those in the solar-like regime conspiring to suppress a single cell of meridional circulation, whereas the cool poles and warm equator established in the anti-solar states tend to promote single-celled circulations. Though the convective angular momentum transport becomes radially inward at mid-latitudes in anti-solar regimes, it is the meridional circulation that is primarily responsible for establishing a rapidly-rotating pole. We conclude with a discussion of how these results relate to the Sun, and suggest that the Sun may lie near the transition between rapidly-rotating and slowly-rotating regimes.

23 pages, 14 Figures, Submitted to the Astrophysical Journal

References in corpus (16)

• Global-Scale Turbulent Convection and Magnetic Dynamo Action in the Solar Envelope
• Structure and Evolution of Giant Cells in Global Models of Solar Convection
• Solar differential rotation and meridional flow: The role of a subadiabatic tachocline for the Taylor-Proudman balance
• 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
• A simulation of convective dynamo in the solar convective envelope: maintenance of the solar-like differential rotation and emerging flux
• Rapidly Rotating Suns and Active Nests of Convection
• On the role of meridional flows in flux transport dynamo models
• Importance of Meridional Circulation in Flux Transport Dynamo: The Possibility of a Maunder-like Grand Minimum
• Magnetically controlled stellar differential rotation near the transition from solar to anti-solar profiles
• High-resolution calculation of the solar global convection with the reduced speed of sound technique: II. Near surface shear layer with the rotation
• Reynolds stress and heat flux in spherical shell convection
• 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
• Measurements of the Sun's High Latitude Meridional Circulation
• Meridional flow profile measurements with SOHO/MDI

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