Ice Crystal Parameterizations in Arctic Cirrus – Towards a Better Representation in Global Climate Models and Aircraft Icing Potential Studies

Cirrus clouds are one of the largest uncertainties in the radiative budget, crucial to understanding trends in climate. While parameterizations exist for cirrus in the tropical- and mid-latitudes, high-latitude (arctic) cirrus are poorly represented in global climate models (GCMs). In addition, ice and mixed-phase clouds present a hazard in aircraft icing formed by nonclassical formation mechanisms; i.e. freezing precipitation that forms without a melting layer. In-flight icing is a significant threat to aviation operations, resulting in loss of lift and reduced airspeed.

The goal of this research is to analyze microphysics data for arctic cirrus. Parameterizations of the size distributions (SDs), temperature, and ice water content (IWC) in ice and mixed-phase clouds will lead to a better understanding of their radiative properties and their role in the Earth's radiation budget as depicted by the GCMs. This study may help improve airplane icing prediction through better understanding of the ice microphysical properties.