Studying Solar Irradiance Variability With Wavelet Technique

The detection of variations in solar irradiance by satellitebased experiments during the last 17 years stimulated modelling e orts to help to identify their causes and to provide estimates for irradiance data when no satellite observations exist. Because of the lack of quantitative physical models of solar irradiance, the current empirical models have been developed with linear regression analysis, which can give only overall information about the physical origin of irradiance changes. In this paper we use wavelet and cross-correlation techniques to analyze the changes observed in total solar irradiance and its surrogates, including the Mg h & k core-to-wing ratio and the full disk integrated magnetic ux.