The solar ultraviolet spectrum from 1200 Å to 1560 Å: a radiometric comparison between SUMER/SOHO and SOLSTICE/UARS
Wilhelm, K.; Curdt, W.; Schühle, U.; Lemaire, P.; Woods, T. N.; Rottman, G. J.
Germany, United States, France
Abstract
After short descriptions of the SUMER (Solar Ultraviolet Measurements of Emitted Radiation) spectrometer onboard SOHO (the Solar and Heliospheric Observatory) and the SOLSTICE (Solar-Stellar Irradiance Comparison Experiment) spectrometer on UARS (the Upper Atmosphere Research Satellite), a radiometric comparison is carried out of solar irradiance spectra measured by SOLSTICE and spectra derived from SUMER radiance observations of quiet-Sun regions in the wavelength range from 1200 Å to 1560 Å. The emission lines N v (lambda 1238) and C iv (lambda 1548) are considered in detail. For these lines, irradiance data are also available from full-Sun raster scans of SUMER and deviations of less than 15% are found between SOLSTICE and SUMER results - well within the combined uncertainty margins.