Variations of cosmic ray (CR) rigidity spectrum during Forbush effect on 17 January and solar proton event on 20 January, 2005 (the beginning at 06:36 UT, solar coordinates N14W61) have been researched using the method of spectrographic global survey according to ground-based observations of cosmic ray intensity at the world-wide network of stations. In integrally analyzing ground-based and satellite measurements of protons in the energy range from a few MeV to tens GeV, parameters of CR rigidity spectrum representing electromagnetic characteristics of heliosphere over the period of the event under investigation have been determined. The analysis provides an explanation of CR variations within a wide energy range.

Proceedings of the 30th International Cosmic Ray Conference; Rogelio Caballero, Juan Carlos D'Olivo, Gustavo Medina-Tanco, Lukas Nellen, Federico A. Sánchez, José F. Valdés-Galicia (eds.); Universidad Nacional Autónoma de México, Mexico City, Mexico, 2008; Vol. 1 (SH), pages 155-158