Lidar observations of stratospheric background aerosol filling in Western Siberia in 2017-2025
A.I. Elizarov, V.N. Marichev, D.A. Bochkovsky
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: stratosphere, background aerosol, lidar monitoring, statistical analysis, seasonal trend, Western Siberia
Abstract
This article presents the results of an experimental study of the dynamics of background aerosol filling of the stratosphere over Western Siberia in 2017-2025. The time period under study was characterized by the absence of large global-scale volcanic eruptions, which made it possible to identify natural variations in the background aerosol component. The observations were conducted using the lidar complex of Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences (Tomsk) by the elastic scattering method at a wavelength of 532 nm. To improve the reliability of the estimates, comprehensive statistical time series analysis technique was applied, including seasonal decomposition and iterative Z-score outlier removal. This enabled minimizing the impact of short-term local disturbances, including forest fire traces and instrumental anomalies. The analysis shows that, the overall background stratospheric aerosol level is statistically stable over the long term and does not exhibit a significant trend. At the same time, a clear seasonal asymmetry was revealed: the summer period is characterized by a statistically significant upward trend in aerosol loading, while a steady downward trend is observed in spring. The annual dynamics has a pronounced cyclical nature. The aerosol loading is maximal in winter and minimal in summer, which corresponds to a threefold difference in the integral aerosol backscatter coefficient. The results are valuable for the verification of climate models, as well as for the formation of a regional database of the background state of the stratosphere under conditions of minimal volcanic activity.
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