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The variability of the volume concentration and mean radius of particles of the fine and coarse fractions of surface aerosol in summer has been studied from the results of solution of the inverse problem for spectral measurements of the aerosol extinction coefficient. It has been shown that the main contribution (80%) to the total volume of near-surface aerosol is made by particles of the coarse fraction. The mean radius of fine particles varies from 0.08 to 0.25 μm. The variation range of the mean radius of coarse aerosol is 1.06–3 μm. The influence of atmosphere smokiness on variations in microstructure parameters is considered. The variability of retrieved microstructure parameters of near-surface aerosol is compared with similar results obtained from solar photometry data.

Aerosol profiles at 607 nm over ranges from 2 to 20 km were obtained using Raman lidar in Nanjing, China. The measured aerosol extinction coefficient was largely stable at about 1.5–2.5 × 10–4 m–1 after noise and Rayleigh corrections were applied. The noise effect in Raman lidar aerosol measurements is analyzed, and a formula relating aerosol extinction coefficient error and noise is presented in detail. Simulation and experimental results are in good agreement, indicating that the noise-related calculation for the Raman lidar aerosol measurement error is reasonable.

This paper considers the relationship between the accuracy of aerosol extinction inversion and the boundary value, and derives a theoretical high-accuracy aerosol extinction coefficient inversion. Aerosol extinction coefficient profiles depend on the boundary value. The relationship function of the differential extinction coefficient and differential boundary value is expressed by a maximum value. The smaller the differential boundary value, the smaller the differential extinction coefficient. The clean atmosphere layer is easily found from the lidar range-corrected signal, and the extinction coefficient of the clean atmosphere layer can be obtained using the slope method. By relating the extinction coefficient of the clean atmosphere layer to the extinction coefficient profiles at different boundary values, an accurate aerosol extinction coefficient profile can be obtained.

The surface area and volume densities (S and V) of the particles of stratospheric background aerosol in the 15–20 km and 20–25 km layers for 2002–2005 were obtained from measurements of the aerosol extinction coefficient with the SAGE III instrument by using the linear-regression method of solving the inverse problem. The measurements were taken within the latitudinal belts 43°–80°N and 34°–58°S. The spatial and temporal dependences of S and V demonstrate homogeneous distribution fields in summer, whereas noticeable inhomogeneities are observed in winter and early spring. In all years of the measurements, an increase in the integral characteristics of stratospheric background aerosol was observed during the fall-to-winter transition period. Longitudinal variations in S and V can be both slight and significant (50–70%). Analysis of the interannual variability of the mean areas and volumes of aerosol particles shows that their minima (as a rule) were observed in 2002 and their maxima were observed in 2005. In most of the cases, no monotonic annual variations in the aerosol characteristics are noted. The dependence of the aerosol parameters on the phase of the quasi-biennial oscillations of zonal wind in the stratosphere is observed. The data obtained for 2002–2005 are, on the whole, in good agreement with the climatological data obtained for 1996–1999.