Two-component concept for ground level enhancements of solar cosmic rays: Solar and interplanetary aspects
We discuss solar and interplanetary aspects concerning the observations and interpretation of two relativistic components of solar cosmic rays (SCRs), namely, impulsive (prompt) and slow (delayed) components (PC and DC, respectively). The prompt component is characterized by the strong anisotropy and exponential energy spectrum. The delayed component is essentially isotropic and has a power-law energy spectrum. Our analysis of observational data and theoretical arguments rules out the interplanetary propagation as the origin for these two components. Most likely, they are formed in the SCR generation on the Sun within the framework of two-source model with multiple acceleration processes in the solar atmosphere.