Three-dimensional stability of the solar tachocline

Abstract

The three-dimensional, hydrodynamic stability of the solar tachocline is investigated based on a rotation profile as a function of both latitude and radius. By varying the amplitude of the latitudinal differential rotation, we find linear stability limits at various Reynolds numbers by numerical computations. We repeated the computations with different latitudinal and radial dependences of the angular velocity. The stability limits are all higher than those previously found from two-dimensional approximations and higher than the shear expected in the Sun. It is concluded that any part of the tachocline which is radiative is hydrodynamically stable against small perturbations.