Solar Spectral Variability as Measured by the SORCE SIM Instrument.

Jerald Harder [harder@lasp.colorado.edu], Juan Fontenla, Sean Davis, Gary Rottman, and Thomas Woods, LASP, University of Colorado, Boulder

The Spectral Irradiance Monitor (SIM) is a prism spectrometer that measures the solar spectrum four times a day in the 200-2700 nm region with a wavelength dependent resolution of 1 33 nm. SIM has been operational for over 18 months and is now providing the first continuous record of solar variability throughout the visible and near infrared spectral regions. The 200-300 nm ultraviolet channel provides high quality spectra that is comparable to other instruments such as SORCE SOLSTICE and the NOAA 16 SBUV. The SIM measurement record of solar irradiance variability in the ultraviolet, visible and infrared is consistent with other indicators of solar activity such as Mg II index, time series of solar images, and comparisons with the spectral irradiance synthesis model of Fontenla, White, Fox, Avrett, and Kurucz (ApJ, 1999, 518, 480). This analysis will be discussed in this presentation.