Solar irradiances of ultraviolet emission lines measured during the minimum of sunspot activity in 1996 and 1997

Full Sun observations in UV and EUV emission lines were performed by SUMER. (Solar Ultraviolet Measurements of Emitted Radiation) on SOHO (Solar and H eliospheric Observatory) in 1996 and 1997. The pre-flight calibration of SU MER is traceable to a primary radiometric source standard. Irradiance value s have been obtained for the lines He I (lambda 584), O V (lambda 629), Ne VIII (lambda 770), S V (lambda 786), O IV (lambda 787), S VI (lambda lambda 933, 944), H I Ly epsilon (lambda 937), C III (lambda 977), N V (lambda 12 38), Si I (lambda 1256), and C IV (lambda 1548). The spatially resolved mea surements allowed good estimates to be made of the active region contributi ons to the irradiance of the quiet Sun. The centre-to-limb radiance variati ons have also been deduced for these lines. (C) 2000 Elsevier Science Ltd. All rights reserved.