Reynolds stresses and differential rotation. II  Meanfield models
Abstract
The zonal momentum fluxes in a turbulent rotating system are formally expressed by sums of 'flux modes' whose latitude dependence is the 21st power of the sine of the angle which the radial vector makes with the rotation axis. The resulting profiles in latitude of the angular velocity and the horizontal Reynolds stress are derived for the surface of the fluid. Very thin convection zones and those with strong density stratifications behave in a very similar way: their surface profiles show nearly the same modal structure as the momentum fluxes. Besides the turbulence parameters, only the thickness of the convective layer is required to determine the amplitudes of the resulting profiles; no damping due to the strong density stratification appears. Even the lowest order models can account for both the observed solar rotation law and the horizontal Reynolds stress. The required vertical flux modes represent an inward transport of angular momentum and the required horizontal flux modes an equatorward transport. They must each be increased if the natural outward decrease of the nonfundamental modes of the zonal momentum flux is included.
 Publication:

Geophysical and Astrophysical Fluid Dynamics
 Pub Date:
 1982
 DOI:
 10.1080/03091928208209003
 Bibcode:
 1982GApFD..21....1R
 Keywords:

 Flux Quantization;
 Momentum Transfer;
 Reynolds Stress;
 Rotating Fluids;
 Turbulent Flow;
 Density Distribution;
 Mathematical Models;
 Propagation Modes;
 Viscosity;
 Fluid Mechanics and Heat Transfer;
 CONVECTION;
 ROTATION;
 TURBULENCE;
 THEORY;
 LARGE SCALE CONVECTION