Reflectance simulations (first column) and polarized observations and simulations (second column) from our Earthshine catalog. We examine different diagnostic metrics: the spectral slope in the visible range (first row), the B–R broadband difference (second row), and the continuum reflectance or polarization at single wavelengths (λ = 500 nm and 700 nm; third and fourth rows, respectively), to assess whether we can reliably distinguish between Pacific (ocean-dominated) and Atlantic (mixed land-ocean) viewing geometries. The simulated values at single wavelengths in both reflected and polarized light are derived from the reference phase curves presented in Roccetti et al. (2025a), with the shaded regions indicating the 1σ cloud variability spread.