Millimeter wave radar scattering from model ice crystal distributions

Dual-polarization radar observables of cloud ice crystals are simulated at 94 and 220 GHz frequencies. Three crystal shapes are considered: hexagonal columns, hexagonal plates, and stellar crystals. A gamma model size distribution and a three dimensional (3D) canting distribution are used. The radar observables are displayed as a function of radar elevation angle. The linear depolarization ratios LDR_h and LDR_v, the circular depolarization ratio CDR, and the magnitude of the copolarized cross correlation coefficient ρ_hv are found to be useful for differentiating columns from plates and stellar crystals. These radar observables have different trends as a function of elevation angle for the model columns and planar crystals (plates and stellar crystals). Furthermore, at vertical incidence they exhibit significantly different values for the two crystal types