The solar ultraviolet spectrum from 1200 angstrom to 1560 angstrom: a radiometric comparison between SUMER/SOHO and SOLSTICE/UARS

After short descriptions of the SUMER (Solar Ultraviolet Measurements of Em itted Radiation) spectrometer onboard SOHO (tho Solar and Heliospheric Obse rvatory) and the SOLSTICE (Solar-Stellar Irradiance Comparison Experiment) spectrometer on UARS (the Upper Atmosphere Research Satellite), a radiometr ic comparison is carried out of solar irradiance spectra measured by SOLSTI CE and spectra derived from SUMER radiance observations of quiet-Sun region s in the wavelength range from 1200 Angstrom to 1560 Angstrom. The emission lines N V (lambda 1238) and C IV (lambda 1548) are considered in detail. F or these lines, irradiance data are also available from full-Sun raster sca ns of SU,MER and deviations of less than 15% are found between SOLSTICE and SUMER results - well within the combined uncertainty margins.