The contribution of this country's scientists to research on the ionosphere and solar-terrestrial relationships

This paper analyzes the achievements of our country's scientists in heliogeophysical studies in the period after the first International Geophysical Year (1957-58), the experience of which was taken into account in organizing and carrying out an array of projects in solar-terrestrial physics. The use of the first geophysical rockets and later of scientific satellites in the study of the ionosphere showed that fundamental improvements were needed in the theory of the formation of the ionosphere. It was necessary to construct de novo empirical and theoretical models of the spectra and fluxes of short-wavelength solar radiation from the x-ray to the UV range. To do this, a model of the sun's upper atmosphere was created in which the main role belongs to the transitional region between the chromosphere and the corona. (C) 2005 Optical Society of America.