Structure of the core flow in response to the m = 2 libration forcing for Ek = 10⁻⁹, with (left) the radial (u _r ) and horizontal (﹩{({{u}_{\theta }}^{2}+{{u}_{\phi }}^{2})}^{1/2}﹩) as a function of the radial coordinate near the CMB and (right) the radial vorticity ﹩{\xi }_{r}=\hat{{\boldsymbol{r}}}\,\cdot \,{\boldsymbol{\nabla }}\times u﹩ at the (local) maximum of horizontal kinetic energy that is indicated by the vertical lines in the left figures. The top panels correspond to the fluid motions in a neutrally stratified core (N ₀ = 0), and the bottom panels correspond to the motions in a core with a stably stratified outer layer with N ₀ = 100.