Beschreibung: The EarthCARE satellite mission plans to perform a continuous closure experiment to assess the quality of retrieved cloud and aerosol properties. It will do so by comparing top-of-atmosphere (TOA) broadband (BB) fluxes to simulated values produced by 3D radiative transfer models that act on the 2D retrieved cross-section and a 3D atmosphere around it produced by a scene construction algorithm (SCA). This study proposes and tests a method for estimating errors in simulated TOA BB fluxes due to the SCA. Two methods for estimating SCA-related errors for TOA fluxes are presented. The primary one relies on computation of errors for reconstructed narrowband imager nadir radiances. A-train satellite data were used to show that for constructed domains measuring (11 km) 2 , approximately the size of EarthCARE assessment domains, with total cloud fractions 〉 0.2, errors for reflected BB shortwave fluxes due to the SCA are smaller than ±4.2 W m − 2 and ±11.5 W m − 2 for 66% and 90% of the domains, respectively. Corresponding values for outgoing longwave fluxes are ±1.2 W m − 2 and ±3.0 W m − 2 . Largest and smallest errors are associated with fields of broken convective cloud and overcast stratiform cloud, respectively. The SCA was applied to simulated measurements for a (153 km) 2 field of deep convective clouds produced by a cloud system-resolving model. Actual and estimated TOA BB shortwave flux errors due to the SCA agree well and are smaller than ±22 W m − 2 and ±40 W m − 2 for 66% and 90% of the (11 km) 2 sampled sub-domains. Assuming that errors due to the SCA are purely bias errors, they were subtracted from fluxes estimated for the constructed domains. This resulted in TOA BB shortwave flux errors smaller than ±7 W m − 2 and ±25 W m − 2 for 66% and 90% of the sampled sub-domains. This suggests that estimated errors due to the SCA should be removed directly from simulated TOA BB fluxes before executing the closure assessment.