Advanced Bulk Optical Models Linking the Backscattering and Microphysical Properties of Mineral Dust Aerosol

Sensitivities of the backscattering properties to the microphysical properties (in particular, size and shape) of mineral dust aerosols are examined based on TAMUdust2020, a comprehensive single-scattering property database of irregular aerosol particles. We develop the bulk mineral dust particle models based on size-resolved particle ensembles with randomly distorted shapes and spectrally resolved complex refractive indices, which are constrained by using in situ observations reported in the literature. The light detection and ranging (lidar) ratio is more sensitive to particle shape than particle size, while the depolarization ratio depends strongly on particle size. The simulated bulk backscattering properties (i.e., the lidar ratio and the depolarization ratio) of typical mineral dust particles with effective radii of 0.5-3 mu m are reasonably consistent with lidar observations made during several field campaigns. The present dust bulk optical property models are applicable to lidar-based remote sensing of dust aerosol properties.

Automated summary

The study found that the lidar ratio is more sensitive to particle shape than size, while the depolarization ratio strongly depends on particle size. The simulated results are consistent with lidar observations, indicating that the current dust bulk optical property models are applicable for remote sensing of dust aerosol properties.