Comparison of the calculated and measured solar irradiance spectrum. The grey shaded area indicates the measurement error of the SIRS for the 2008 WHI (see Woods et al. 2009 for a detailed description). The light blue shaded area indicates one standard deviation of the 145 measurements taken in 2022 by SSIM on board the FY-3E. The averaged solar irradiance spectrum computed from MURaM cubes is represented by the red line; the light red shaded area indicates one standard deviation in the temporal fluctuations.