(a) Example of the Reynolds number near the CMB in function of the Ekman number when the core is stably stratified with stratification parameters N ₀ = 100, r _ICB = 0.4, r _C = 0.7, and h = 0.1 and the mantle is forced by the radial components of libration, m = 2 (blue) and −2 (red). The expected value of the Reynolds number at Mercurial conditions, Ek = 2 × 10⁻¹³, assuming a linear relationship between ﹩\mathrm{log}(\mathrm{Re})﹩ and ﹩\mathrm{log}(\mathrm{Ek})﹩, is indicated with a circle. (b) Extrapolated Reynolds numbers of the m = 2 core flow response near Mercury’s CMB for different stratification strengths N ₀. The blue circle represents the Reynolds number estimated from the left panel. The slightly irregular behavior for 10 ≲ N ₀ ≲ 10^2.5 is an artifact of the numerical method not being precise enough to determine the location of maximum horizontal velocity when the peak of the horizontal flow profile is less pronounced.