Long-term cosmic ray modulation in the period 1966--1972 and interplanetary magnetic fields

Journal Article · Thu Jul 01 04:00:00 EDT 1976 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA081i019p03198· OSTI ID:7266982

Winkler, C N; Bedijn, P J

The changes in the energy spectra of cosmic ray electrons, protons, and ..cap alpha.. particles above roughly 50 MeV/nucleon, as observed during the period 1966--1972, have all been theoretically reproduced by numerical solutions of the steady state transport equation for cosmic rays in the solar system. These solutions have been obtained by smoothly varying the rigidity and radial dependence in a nonseparable model of the interplanetary diffusion coefficient, which is characterized by four parameters. The diffusion coefficient which is implied by these numerical solutions is then compared with the observed power spectra of interplanetary magnetic field fluctuations, validity of the quasi-linear adiabatic theory being assumed. It appears that the changes occurring in the two observables, i.e., diffusion coefficient and magnetic power spectra, agree qualitatively surprisingly well. Uncertainties and simplifying assumptions implied in the theory and data do not permit comparison of the two observables in absolute magnitude with good accuracy, but it is shown that they are not in conflict. It is concluded that the nonseparable model used for the diffusion coefficient matches, within the limitations of theoretical and observational accuracy, the available data of cosmic ray modulation as well as of interplanetary magnetic field fluctuations. (AIP)

• Research Organization: Cosmic Ray Working Group, Huygens Laboratorium, Leiden, Netherlands
• OSTI ID: 7266982
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 81:19; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640101* -- Astrophysics & Cosmology-- Cosmic Radiation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COSMIC RADIATION
COSMIC RAY PROPAGATION
DIFFUSION
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
INTERPLANETARY MAGNETIC FIELDS
INTERPLANETARY SPACE
IONIZING RADIATIONS
LEPTONS
MAGNETIC FIELDS
NUCLEI
PRIMARY COSMIC RADIATION
RADIATIONS
SPACE
VARIATIONS