Flare parameters for the 7 September, 1973 two-ribbon flare

A study is made of the relative importance of the various energy loss mechanisms for the long-decay event of 7 September, 1973, using spectral scans in the 400 Å–1335 Å range. This spectral range contains many of the important electron density and temperature diagnostic line ratios for the solar transition zone. We refine earlier analyses of the flare energy budget using more detailed emission measure curves and density diagnostics. We examine the constant pressure assumptions used in both coronal loop models and in the interpretation of observations in terms of flare energetics. We find that much of the upper transition region emission originates in cooling loops. Radiative losses are found to dominate.