CYCLIC VARIATIONS AND SPORADIC FLUCTUATIONS OF SOLAR COSMIC-RAYS

The principal data on cosmic rays of both solar and galactic origin are presented. Cosmobiological situation on the Earth (including solar-biosphere coupling) is defined in terms of the general problem of solar-terrestrial relations. The characteristics and the likely origin of cyclic variations in the occurrence rate and the fluence of solar proton events (SPE), as well as their relevance to the solar activity (SA) are discussed in detail. There is no unambiguous relation between the mean SCR flux, the SPE fluence and occurrence rate on the one hand, and solar activity, on the other, but cyclic variations of these parameters have been revealed (in particular, a quasi-biennial wave in the SPE occurrence rate). The data on the major proton events have been analysed for three solar cycles. It is shown that SCR can strongly affect some meteorological processes in the atmosphere (production of nitric oxides and composition changes in the stratosphere, devastation of the ozone layer at high latitudes, resistance changes in the global circuit of atmospheric electricity, and stimulation of high-altitude cyclons). The mechanisms of these effects are likely to have a trigger nature. The physical processes thal seem necessary to start triggering effects in the Earth environment are discussed.