Retrieving the solar EUV spectral irradiance from the observation of 6 lines

We use recent solar extreme ultraviolet (EUV) irradiance data from the Solar EUV Experiment aboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics satellite to investigate the possibility to retrieve the whole solar EUV irradiance from a minimum number of measurements. Computing a differential emission measure for the whole Sun from the irradiances of 5 lines and using a sixth line to model optically thick emission, we are able to reproduce with a good agreement the variability of the whole solar EUV irradiance.