Ice Particle Properties Inferred from Aggregation Modelling

We generated a large number (105'000) of aggregates composed of various monomer types and sizes using an aggregation model. Combined with hydrodynamic theory, we derived ice particle properties such as mass, projected area, and terminal velocity as a function of monomer number and size. This particle ensemble allows us to study the relation of particle properties with a high level of detail which is often not provided by in-situ measurements. The ice particle properties change rather smoothly with monomer number. We find very little differences in all particle properties between monomers and aggregates at sizes below 1 mm which is in contrast to many microphysics schemes. The impact of the monomer type on the particle properties decreases with increasing monomer number. Whether e.g., the terminal velocity of an aggregate is larger or smaller than an equal-size monomer, depends mostly on the monomer type. We fitted commonly used power laws as well as Atlas-type relations, which represent the saturation of ...