The radiative effect resulting from the interaction of aerosol with atmospheric radiation is important for our understanding of the climate system. In an extension of Witthuhn et al. [Atmos. Chem. Phys., 21, 14591–14630 (2021)], the surface irradiance and aerosol radiative effect under clear sky conditions are investigated for the region of Germany and the period from 2003 to 2020. This study is based on observations of solar irradiance at 25 stations throughout Germany by the observational network of the German Weather Service, as well as explicit radiative transfer simulations using the Copernicus Atmosphere Monitoring Service (CAMS) reanalysis as input. It is found that aerosol optical depth decreases over Germany, as a consequence of a long-term change in aerosol composition. The aerosol clear sky radiative effect at the surface decreases in magnitude by 2.5Wm−2 10yr−1. A similar trend is observed in the surface irradiance in clear sky conditions, which increases by 3 Wm−2 10yr−1 in its daily mean.

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