The turbulent transfer of angular momentum and the differential rotation of the sun and stars
Abstract
A derivation is made of angular momentum flows arising in a spherical rotating layer by interaction between convection and rotation. The initial convection, not perturbed by the effect of Coriolis forces, was assumed to be weakly anisotropic with a radially pronounced direction of anisotropy. Effective viscosities that compensate for angular momentum flows were also calculated. A solution of this equation was derived for the case of slow rotation to thirdorder terms with respect to the inverse Rossby number. For generating the observed differential rotation of the sun, it is sufficient that the measure of convection anisotropy reaches 0.1. It is shown that differential rotation is generated most effectively at moderate rotation rates when the Rossby number is of order of unity. Within fastrotating convection shells differential rotation is suppressed. It is suggested that this effect is associated with an inverse correlation between rotation rate and magnetic field, as observed for fastrotating magnetic stars.
 Publication:

Astronomicheskii Zhurnal
 Pub Date:
 February 1987
 Bibcode:
 1987AZh....64..135K
 Keywords:

 Angular Momentum;
 Momentum Transfer;
 Solar Rotation;
 Stellar Rotation;
 Surface Layers;
 Turbulence Effects;
 Angular Velocity;
 Coriolis Effect;
 Rossby Regimes;
 Stellar Magnetic Fields;
 Viscous Flow;
 Astrophysics