"Modeled solar EUV flux during the Equinox Transition Study: September 17–24, 1984""

A new empirical model of solar extreme ultraviolet (EUV) irradiance variability has been developed based on satellite and rocket EUV observations for all levels of solar activity. Its results for the Equinox Transition Study (ETS) period of September 17–24, 1984, have been calculated, and the tabulated results of photon and energy fluxes for each day of this period are presented. The model average total EUV full‐disk energy flux for the spectral range between 1.9 and 105.0 nm for the ETS period is 2.9 ergs cm−2 s−1, with a general secular increase in the total flux level between September 17 and September 24. This modeled rise corresponds to the increased EUV irradiance variability due to active region evolution and passage across the disk. The modeled EUV values in September 1984 near solar cycle 21 minimum conditions are higher than rocket‐ and satellite‐measured EUV values near solar minimum conditions of cycle 20. However, the results are consistent with recent trends in the literature to revise the solar cycle 20 minimum flux values upward.