Analysis of the Components of a Different Physical Nature in the Interannual Variability of the Total Solar Irradiance Flux

Abstract

By its physical nature, the interannual variability of the solar radiation arriving at the Earth is a duplex with varying ratios of the amplitudes of the components depending on the time resolution. The analysis shows that the amplitude of the long-term variability of the radiation intensity is approximately 95% determined by the variations related to changes in the solar activity. At an annual resolution, the component determined by the solar activity is predominant in amplitude (approximately 80%). At a monthly resolution, the leading component of the duplex is the variation caused by the celestial-mechanical processes (approximately 55%). Thus, the interannual variations determined by the celestial-mechanical processes dominate in the interannual variability of incoming solar radiation within seasonal changes. The results point toward the necessity for a differentiated approach to the use of the values of the interannual solar radiation variability of different physical nature in the climatic models since their weight ratios depend on the time resolution.