Line similarity in the wavelength domain for the SDO-based SOAP-GPU simulation using the PHOENIX input seed spectra (see Sect. 2.2). Left: similarity of line profiles associated with the Doppler component. Line similarity decreases with wavelength, and therefore it seems that the SDO-based SOAP-GPU simulation can model blue lines better than red lines. This is likely due to telluric line contamination at the red part of the HARPS-N solar spectra. Right: similarity of line profiles associated with the depth component. There is no correlation between the Pearson correlation coefficient value and wavelength.