Solar cosmic rays have energies of ~10⁷ to 10¹⁰ eV and are ejected primarily in solar flares and coronal mass ejections (CME). They have a composition similar to that of the Sun, and are produced in the corona by shock acceleration, or when part of the solar magnetic field reconfigures itself.

An increase in solar cosmic rays usually heralds a decrease in galactic cosmic rays (called the Forbush decrease), as the solar wind and its associated magnetic field, augmented by the solar flare or CME, sweeps some of the incoming galactic cosmic rays away from the Earth.