EXTRA-TERRESTRIAL FACTORS’ INFLUENCE ON CLIMATE: POSSIBLE MECHANISMS AND MODELING RESULTS
Mechanisms of extra-terrestrial influences on the Earth climate are summarised along with their contribution to the climate variations of the last several centuries as well as in the 21st century. According to the latest estimates, the contribution of the radiative forcing due to changes of the total solar irradiance into the climate changes during the last decades is relatively small. Some climate models implement also an indirect mechanism of solar activity influence on the Earth climate, which is related to the impact of UV radiation and fluxes of high-energy particles of Solar origin on the O3 atmospheric content; the latter also leads to the development of the specific radiative forcing. A number of suggested additional indirect mechanisms is related to possible impact of galactic rays and fluxes of high-energy solar particles (intensities of both fluxes are modulated by the solar wind) on the number of cloud condensation nuclei in the atmosphere, and, thus, on the characteristics of cloudiness. A role, which the latter mechanisms play in the climate variations, however, needs more detailed experimental and theoretical evidence.