We extend the analysis of to calculate effective viscosities for the surface convective zones of three main sequence stars of 0.775 M _ { \odot } , 0.85 M _ { \odot } and the present day Sun .
In addition we also pay careful attention to all normalization factors and assumptions in order to derive actual numerical prescriptions for the effective viscosity as a function of the period and direction of the external shear .
Our results are applicable for periods that are too long to correspond to eddies that fall within the inertial subrange of Kolmogorov scaling , but no larger than the convective turnover time , when the assumptions of the calculation break down .

We find a significantly anisotropic viscosity , scaling linearly with the period of the external perturbation and magnitudes of the different components between three and ten times smaller than the prescription .