The scattering properties of atmospheric ice particles measured during MACPEX by the SID3

A good understanding of the light scattering properties of ice particles in clouds is critical for the radiation calculations necessary for robust long term climate estimates. Ice particle properties such as size, shape, and surface roughness are all have a significant effect on the scattering properties of ice particles. A recently developed particle probe, the Small Ice Detector -3 (SID3) measures the two dimensional near forward light scattering properties of ice particles. The SID3 was flown on the NASA WB-57 aircraft during the Mid-latitude Airborne Cirrus Properties Experiment (MACPEX) field campaign. During MACPEX, the SID3 operated successfully on 9 aircraft missions collecting data from a variety of mid-latitude cloud types. The two dimensional near forward scattering patterns recorded by SID3 are useful for determining a number of characteristics of the observed particles including particle size, the shape of pristine ice crystals, as well as surface roughness or particle complexity. In this study we investigate the prevalence of these ice particle characteristics as a function of atmospheric conditions in the MACPEX dataset. To further investigate particle scattering properties, the angular range observed by SID3 is used to calculate partial scattering phase functions for ensembles of particles. These partial phase functions are compared to ray tracing phase functions from the literature to infer properties of the MACPEX particles.