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Using eight years (2006–2014) of passive (MODIS/Aqua and OMI/Aura) and active (CALIOP/CALIPSO) satellite measurements of aerosols, we yield a three-dimensional (3D) distribution of the frequency of occurrence (FoO) of aerosols over China. As an indicator of the vertical heterogeneity of aerosol layers detected by CALIOP, two types of Most Probable Height (MPH), including MPH_FoO and MPH_AOD, are deduced. The FoO of “Total Aerosol” reveals significant geographical dependence. Eastern China showed much stronger aerosol FoD than northwestern China. The FoO vertical structures of aerosol layer are strongly dependent on altitudes. Among the eight typical ROIs analyzed, aerosol layers over the Gobi Desert have the largest occurrence probability located at an altitude as high as 2.83 km, as compared to 1.26 km over Beijing–Tianjin–Hebei. The diurnal variation (nighttime–daytime) in MPH_AOD varies from an altitude as low as 0.07 km over the Sichuan basin to 0.27 km over the Gobi Desert, whereas the magnitude of the diurnal variation in terms of MPH_AOD is six times as large as the MPH_FoO, mostly attributable to the day/night lidar SNR difference. Also, the 3D distribution of dust and smoke aerosols was presented. The multi-sensor synergized 3D observations of dust aerosols, frequently observed in the zonal belt of 38°N–45°N, is markedly different from that of smoke aerosols that are predominantly located in the eastern and southern parts. The 3D FoO distribution of dust indicates a west-to-east passageway of dust originating from the westernmost Taklimakan Desert all the way to North China Plain (NCP). The findings from the multi-sensor synergetic observations greatly improved our understanding on the long-range aerosol dispersion, transport and passageway over China. [ABSTRACT FROM AUTHOR]

Raindrop size distribution (DSD) is a basic feature of precipitation microphysics, and it plays a vital role in improving radar quantitative precipitation estimation and forecast accuracy. In South China, due to the influence of atmospheric circulation and weather systems, precipitation is frequent, and the types of precipitation and their temporal and spatial distributions are complex. It has become essential to study the types of precipitation in this area and their seasonal variation characteristics. Therefore, in this study, the DSDs in the dry and wet seasons of southern China are analyzed using measurements from seven ground-based two-dimensional video disdrometers (2DVDs) over the course of four years (2016–2019). The dynamic and microphysical characteristics of precipitation in the dry and wet seasons are established for South China, combined with the Moderate Resolution Imaging Spectroradiometer (MODIS) and the European Centre for Medium-Range Weather Forecasts (ECMWF) Fifth-generation Reanalysis (ERA5) data. Compared to the dry season results, the concentration of small raindrops (diameters <1 mm) in wet season is similar, while the concentration of midsized raindrops (diameters between 1 and 3 mm) and large raindrops (diameters >3 mm) in the wet season are significantly greater. Furthermore, taking the contributions to precipitation into account, the rainfall in the dry season is dominated by stratiform rain, which accounts for 59.3% of the total rainfall. Considering precipitation in the wet season, convective rain accounts for 77.9% of total the rainfall. The obtained relations of the shape parameter (μ) versus the slope parameter (Λ) (μ-Λ) and the radar reflectivity factor (Z) versus the rainfall rate (R) (Z-R) have obvious differences for different type rainfall in the two seasons. In the wet season, the water vapor is sufficient and the upward convection activity is intense in South China, causing the frequent occurrence of raindrop collisions and coalescence. This is also the reason that the D m and R values in the wet season are greater than those in the dry season, while the wet season log 10 N w is relatively small. This not only deepens the understanding of the seasonal DSD variation in South China, but also provides theoretical support for improving numerical weather prediction models. • The differences in the DSD characteristics between dry and wet seasons in South China are analyzed using 2DVD and remote sensing data. • The study provides the Z-R and μ-Λ relations of different types of precipitation in South China. • Dynamical and thermodynamical interactions are found to impact the RSD differences between dry and wet seasons′ rainfall. [ABSTRACT FROM AUTHOR]