(a) Instantaneous snapshots of the radial magnetic field B_r (contours) and radial velocity component v_r (color) for N_ρ = 2, Ra/Ra_cr = 32 at r/r_o = 0.9. The contour levels are [0.1B_r^min, 0.05B_r^min, 0.05B_r^max, 0.1B_r^max]. (b) The same for the stronger stratification, Ra/Ra_cr = 32, N_ρ = 6. (c) Two-dimensional probability density of the joint distribution of b² and v_r near the surface, r/r_o = 0.9. Left, N_ρ = 6; right, N_ρ = 2. $\stackrel{\sim }{\mathit{Ra}}=32$. Colors are spaced logarithmically. (d) Unbiased sample skewness coefficient G₁ (5) as a function of $\stackrel{\sim }{\mathit{Ra}}$. Red, N_ρ = 6, blue, N_ρ = 4, green, N_ρ = 2.