Evolution of the Ideas About the Heliosphere and Cosmic Ray Modulation in Interplanetary Space

Abstract

The history of the evolution of ideas, models, and theories concerning modulation of galactic cosmic rays in the interplanetary space is described in brief, including the effects of the Sun's dipolar field, the steady-state diffusion, the corpuscular streams with induced electric fields, the dynamic solar wind, the magnetic inhomogeneity spectrum, the particle energy variations, the isotropic and anisotropic diffusion, the nonlinear and drift effects, the role of shock waves, the hysteresis and estimation of heliospheric dimensions, the neutral current sheet, and the terminal shock wave. The studies of the long-term modulation of galactic cosmic rays are shown to have played an important role in the formation of the present-day concepts concerning the heliosphere, in particular its outer zone.