Retrieval of microphysical properties of dust aerosols from extinction, backscattering and depolarization lidar measurements using various particle scattering models

Abstract. Mineral dust is a key atmospheric aerosol agent that impacts the radiation budget and plays a significant role in cloud formation. However, studies on retrieving height-resolved microphysical properties of dust aerosols, which are crucial for understanding dust evolution and transport processes, from lidar measurements are still insufficient. Here, we retrieve dust aerosol microphysical properties, including the volume size distribution, volume concentration, effective radius (r_eff), refractive index and single-scattering albedo, from spectral extinction, backscattering and depolarization lidar measurements. We evaluate the performance of three particle scattering models – Sphere, Spheroid and Irregular–Hexahedral (IH) models in terms of mimicking dust optical properties and deriving retrieval results. We also explore the influence of inverting different measurement sets, namely the conventional 3β (backscattering coefficients at 355, 532 and 1064 nm) + 2α (extinction coefficients at 355 and 532 nm) and the expanded 3β + 2α + 3δ (depolarization ratio at 355, 532 and 1064 nm) measurements, on the retrieval. Both simulations and inversions of real lidar measurements show that it is necessary to use non-spherical models and incorporate 3δ measurements to improve the retrieval accuracy. An increase of discrepancy in depolarization ratio produced by the IH and Spheroid models is observed for r_eff > 0.5 μm, resulting in larger retrieval difference between the two non-spherical models after the inclusion of 3δ. The study demonstrates the prospect of retrieving height-resolved dust microphysical properties from lidar measurements, as well as potential limitations of the prevailing scattering models in simulating particle backscattering properties.