Solar irradiances of UV and EUV lines during the minimum of the sunspot activity in 1996

Full Sun observations in UV and EUV emission lines were performed by SUMER (Solar Ultraviolet Measurements of Emitted Radiation) on SOHO (Solar and Heliospheric Observatory) in 1996. The radiometric preflight calibration of SUMER is traceable to a primary radiometric source standard - the electron storage ring BESSY. Based on this calibration and on its inflight refinements, the irradiance values at SOHO have been obtained for the lines He I (λ584.33), O V (λ629.74), Ne VIII (λ770.41), S V (λ786.47), O IV (λ787.72), S VI (λλ933.39, 944.52), H I Ly ε (λ937.80), C III (λ977.04), N V (λ1238.81), Si I (λ1256.52), and C IV (λ1548.20), and the continuum near 1549 Å. In this contribution, we compare our measurements with other recent irradiance determinations and discuss, in particular, the observations in the C IV line.