Аннотация:In this paper results of model calculations and measurements of atmospheric parameter changes after several GLEs (Ground Level Enhancements) of Solar Proton Events (SPE) are presented. We have got on lidar high-latitude measurements that after 16 February 1984 GLE event the increase of R(H) (backscattering ratio) at 17 km altitude reached 40%. The model calculations of CN (condensation nuclei) profile, which can be served as centers of sulfate aerosol and Polar Stratospheric Cloud (PSC) formation, demonstrate good coincidence with above-mentioned experimental data. Besides, after other GLE event (2 May 1998) we measured considerable increase of NO2 (nitrogen dioxide) column of incident solar protons in polar region. All these data support the idea that aerosols created by galactic and solar cosmic rays may be one of the key factors in non-direct solar forcing mechanism influencing climate variability. These aerosols can block input of solar radiation to the Earth taking part in creation of additional cloudiness.