Lidar studies of the vertical distribution of aerosol in the stratosphere over Tomsk in 2023

The article presents studies of the intra-annual variability of the vertical-temporal structure of the background aerosol and its integral content in the stratosphere based on an analysis of the optical characteristics of the aerosol. The results were obtained at the lidar complex of the station for high-altitude atmospheric sounding of the IAO SB RAS for 2023. The sounding was carried out at night, the sounding altitude range was from 10 to 50 km. The optical characteristic R(H) — aerosol scattering ratio – is presented as a parameter describing the vertical stratification of the aerosol. According to monitoring data, as in previous years, a stable tendency for aerosol accumulation in the lower stratosphere during the cold period of the year with maximum content in January (R$\approx$1.5 at altitudes of 10–30 km) has been established. In March, a decrease begins, and the vertical stratification of aerosol is estimated at an average value of R$\approx$1.2 in the 10-20 km layer, to virtual absence in June-July (R$\le$1). From September, the aerosol content in the lower stratosphere begins to increase to its maximum value in winter. In the upper stratosphere (30-50 km) there is virtually no background aerosol throughout the year. As a comparative analysis and control over the temporal dynamics of the aerosol filling of the stratosphere, the article provides parameter B – the integral aerosol backscatter coefficient for the period from 2017 to the beginning of 2024. In general, over the years, the maximum aerosol filling of the stratosphere occurs in the winter months and is centered relative to January. At the same time, it is unevenly distributed over the years and is marked by sharp and significant fluctuations