A Review of the Optical Properties of Atmospheric Ice Crystals and Downstream Applications: History and Recent Advances (Invited Presentation)

Ice clouds in the atmosphere play an important role in terrestrial climate. The optical properties, namely, the extinction efficiency, single-scattering albedo, and phase matrix, of ice crystals are fundamental to understanding of the radiative forcing of ice clouds and remote sensing of their microphysical and radiative properties. Historically, nonspherical ice crystals are normally assumed to be “equivalent” spheres in atmospheric research, which produce significant errors and misleading results. The evolution from spherical to nonspherical ice crystals in light scattering and radiative transfer research has been extremely slow. We will review the progress in this unique and intricate research area in the past thirty years. The presentation contents will be largely based on a recent monograph published by the authors (Liou and Yang, 2016) and will cover basic light scattering theory, numerical simulations, and applications to remote sensing and radiative forcing assessment. Overall, this presentation is intended to be tutorial for non-experts in the area of light scattering and absorption involving ice clouds.

Reference:

Liou, K. N., and P. Yang, 2016: Light Scattering by Ice Crystals: Fundamentals and Applications, Cambridge University Press, pp 443.