Spectral irradiance refers to the amount of energy that different colors of light contain. It indicates the intensity of light present in each color of the spectrum. Full definition
Recently (Krivova et al. 2009b) the theoretical SATIRE (Spectral And Total Irradiance REconstruction)(Krivova et al. 2003; Krivova & Solanki 2008) model and SUSIM (Solar Ultraviolet Spectral Irradiance Monitor) measurements were used to reconstruct the solar UV irradiance back to 1974. (aanda.org)
Harder, J. W., Fontenla, J. M., Pilewskie, P., Richard, E. C. & Woods, T. N. Trends in solar spectral irradiance variability in the visible and infrared. (nature.com)
New reconstructions of spectral irradiance are developed since 1600 with absolute scales traceable to space - based observations. (junksciencearchive.com)