Solar Ultraviolet Spectra Irradiance: Results form the SORCE SOLSTICE
William McClintock [mcclintock@lasp.colorado.edu] and Marty Snow, LASP, University of Colorado, Boulder

The SORCE SOLSTICE has been measuring the UV solar irradiance from 115-320 nm with a resolution of 0.1 nm on a daily basis since March 2003. During this time period, the Sun has declined from near solar maximum conditions towards solar minimum. Emission lines formed in the solar chromosphere and transition region observed by SOLSTICE show large (up to 20%) variation with solar rotation and a similar variation over the first 18 months of SORCE observation due to solar cycle. The important Mg II h & k lines are observed by SOLSTICE at moderately high resolution, and the SOLSTICE Mg II index is an important proxy for solar activity. SOLSTICE has also begun making routine measurements of the mesopheric oxygen and ozone density using stellar occultations.