Title: Solar Total and X-ray irradiance variations
Authors: Sattarov, I., Saidalieva, M.A., Ladenkov, O.V.
Affil: Astronomical Institute of Uzbek Academy of Sciences
Astronomicheskaya 33, Tashkent, 700052, Uzbekistan
Email: isattar@astrin.uzsci.net
Abstract: Space observations of the Sun during 22 years have observed total, UV spectral with sufficient precision to characterize 27 day rotations and the 11 year solar cycle. Fluctuations of total irradiance are caused by the darkening of sunspots, while 11-year cycle variation – by brightening of faculae and network. The observations have shown that solar active regions influence both total and spectral irradiance in a similar fashion, although the amplitude of the variations seems to be largest for UV and EUV wavelngths. Comparison of the total solar irradiance and GOES Daily X-ray Background shows that the total irradiance started to rise in prior to X-ray irradiance. In this report we present the most recent results on VIRGO irradiance variations related to X-ray radiation. The total solar irradiance in the top of the current Cycle ¹ 23 is the same as the one in the top of the cycle ¹22, although numbers of sunspots in them are considerable differently. The methods of the solar irradiance reconstruction in the past are discussed.