Fraction of kinetic energy density, E = ⟨ρ₀u²⟩, of the RZ Rossby modes contained in the CZ as a function of the absolute difference between the eigenfrequency of each mode and that of the nearest CZ inertial mode (see Fig. 8). For clarity, we show only the RZ Rossby modes with ℓ_RZ = m (circles), ℓ_RZ = m + 1 (diamonds), and ℓ_RZ = m + 2 (squares). The colour of the symbols denotes the number of radial nodes (n_RZ) in the region 0.5 R_⊙ ≤ r ≤ 0.71 R_⊙. Only modes with n_RZ ≤ 5 are shown.