Optical constants of ice from the ultraviolet to the microwave: A revised compilation

A compilation of the spectral absorption coefficient of ice Ih is presented for temperatures near the melting point, superseding the compilation of Warren (1984). Significant changes are made to nearly all spectral regions. The blue and near‐ultraviolet absorption is much weaker than the prior estimates, which were already very small. The near‐infrared absorption coefficient differs by as much as a factor of 2 from the prior compilation at some wavelengths. The midinfrared absorption coefficient is rather uncertain in the weakly absorbing regions near 9 and 20 μ m. New far‐infrared measurements at low temperatures are extrapolated to higher temperatures, which shifts the peak positions. New microwave measurements find absorption much weaker than previously reported, by factors of 2–5. The real part of the index of refraction is computed using Kramers‐Kronig analysis; it differs from the prior compilation only in the far infrared. Tables of the revised optical constants are available on a website.