Volumetric heating rate, ⟨Q⟩_vol, as a function of the incident wave period, P = 2π/ω, for the same physical conditions as in Fig. 3 with ξ_i = 0.1 (black line) and ξ_i = 0.5 (red line). In panel a) we considered I₁ = −I₂ so that only odd resonances are present, while in panel b) we used I₁ = I₂ to excite even resonances only. In both cases we consider 10 km s^-1 as the velocity amplitude of the incident waves; the horizontal axis range is different in the two panels.