Ratio between the two physical contributions to either mode damping or the modal surface effect (turbulent pressure vs. turbulent dissipation and redistribution of kinetic energy), as a function of mode frequency. Each panel corresponds to a fixed value of the drift tensor anisotropy, Φ_G, and the colour code refers to the turbulent velocity anisotropy factor, Φ_u. In particular, Φ_u = 1 corresponds to the isotropic case, and Φ_u = 0.5 corresponds to the anisotropy measured in 3D large-eddy simulations (e.g., Samadi et al. 2003). The turbulent frequency is set to ω_t = 0.03 rad.s⁻¹. The region filled in red corresponds to the solar damping plateau, and the vertical dashed red line marks the frequency of maximum spectral height in the Sun, ν_max. The horizontal line marks the threshold R = 1: above this line, the turbulent pressure contribution dominates, and below this line the joint effect of turbulent dissipation and pressure-rate-of-strain correlation prevails. The vertical axis is logarithmic.