Bremen 2017 – wissenschaftliches Programm
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EP: Fachverband Extraterrestrische Physik
EP 5: Postersitzung I
EP 5.1: Poster
Dienstag, 14. März 2017, 16:30–18:00, GW2 2.OG
On the optimum use of the Mg II Index as a proxy for UV solar spectral irradiance variations — •Neda Darvishsefat1,2, Mark Weber1, and John P. Burrows1 — 1IUP Institute of Environmental Physics, University of Bremen — 2AWI Alfred Wegner Institute, Bremerhaven
The Mg II index is a useful proxy to model solar spectral irradiances (SSI) in the UV spectral region. In order to confirm how suitable the use of this proxy is, the correlation of the Mg II index composite with available SSI satellite data from SORCE SOLSTICE (2003-present), UARS SOLSTICE (1991-2001) and UARS SUSIM (1991-2005) has been analyzed. The observation periods of each of these instruments cover solar minima and maxima of the 11-year solar cycle. The spectral range investigated is from 115 to 300 nm in the UV. The SSI sensitivity with respect to changes in the Mg II index has been obtained and its stability over the 11-year solar cycle is discussed. The results show for all three instruments in most parts, stability of the sensitivity within its uncertainty range through the observation time, particularly for the lower wavelengths in the UV region. For higher wavelengths above about 250 nm additional parameters like sunspots have to be considered in the linear regression in order to achieve better results.