Single-scattering albedo and hemispherical emissivity as a function of grain size and wave number or wavelength. (top) Single-scattering albedo ω₀(w_n, a) of a grain with size a (bottom) hemispherical emissivity ε_h(w_n, a) of regolith covered with these grains made of pure crystalline water ice Ih90. Calculations with the Mie theory (dotted line) or after diffraction corrections such as delta-Eddington (dash-dotted line) or equivalent slab approximation (solid line) are displayed. (Left) 10–700 cm⁻¹ range and (right) 5–14.3 µm range (or 700–2000 cm⁻¹).