Comparison to Tiscareno et al. (2007) and Tajeddine et al. (2017) estimates of A-ring viscosities. Left frame: symbols denote viscosities measured from damping of density waves (Tiscareno et al. 2007), while dashed lines show ν_D, the Daisaka et al. (2001) formula estimates (Eq. 14) assuming different internal densities of particles, ρ = 250, 450, and 900 kg m⁻³). In these estimates the same linear trend Σ = 337 + 13 × (a − 124) is adopted as in Tiscareno et al. (2007), where Σ is in units of kg m⁻² and a in units of 1000 km. For comparison, the dash-dotted line uses a fixed Σ = 350 kg m⁻² (Tiscareno & Harris 2018). Right frame: simulated total viscosities for the same models and internal densities as in Fig. 19, assuming a fixed surface density Σ = 350 kg m⁻³. The dashed region indicates the Tajeddine et al. (2017) viscosity estimate from angular momentum flux.