Aerosol Time Variations of the Middle Atmosphere over Obninsk from Data of Lidar Measurements

—The results of lidar observations of middle atmosphere aerosol in the 13–65 km altitude range over the city of Obninsk (55.1° N, 36.6° E) for 2014–2021 are presented. Season and yearly variations of aerosol are considered in dependence on the layer altitude. Volcano eruptions mainly influence yearly aerosol variations at the lower 13–18 km layer. The role of photochemical processes increases in the 24–30 km layer—the summer maximum arises in season variations and yearly variations are observed in phase with the level of solar activity. In the altitude range of 45–65 km, the aerosol is of meteoric origin. Season variations reverse—winter maximum and summer minimum. Yearly variations are observed in antiphase to the level of solar activity. The role of variety of factors influencing aerosol formation and conversion at the 45–65 km layer is discussed.