Cosmic Ray Spectra in the Planet Atmospheres

M. Buchvarova¹, P. Velinov²

¹Space Research Institute, BAS, 6 Moskovska Str., Sofia 1000, Bulgaria
²Solar-Terrestrial Influences Laboratory, Acad. G. Bonchev, bl.3, Sofia 1113, Bulgaria

The primary cosmic rays influence strongly on the ionization state of the whole atmosphere. We propose a model which generalizes the differential D(E) and integral D(> E) spectra of galactic (GCR) and anomalous cosmic rays (ACR) during the 11-year solar cycle. The model takes into account the cosmic ray (CR) modulation by the solar wind. The modulated differential spectra of galactic cosmic rays are compared with a simple numerical solution of the one-dimensional cosmic ray transport equation and the force field approximation to the transport equation. The model results are compared with IMAX92, CAPRICE94, AMS98 and BESS measurements. The calculated integral spectra are on the basis on mean gradients: for GCR - 3 AU (Fuji Z. et al., 1997; Heber B et al., 1995), 7 AU for anomalous protons (McKibben et al., 1979; Christian et al., 1999), and 8.5 AU for anomalous helium (McKibben et al., 1985). The obtained integral spectra are compared with experimental data and the model CREME [CREME96, 2002] for the Earth. The model calculations are compared with Voyager and Pioneer measurements in the outer heliosphere. The proposed analytical model gives practical possibility for investigation of experimental data from measurements of galactic cosmic rays and their anomalous component. The obtained parameters are used for determination of the profiles of the ionization in the ionosphere of Saturn.