Solar cycle modulation of galactic protons and electrons
A solution of the time-dependent, spherically symmetric cosmic ray transport equations, with a defensible diffusion coefficient and a natural model for an 11-year cycle of diffusive scattering disturbances that originate on the sun and travel through interplanetary space, accounted simultaneously for the spectral changes of both galactic protons and electrons, for the time and phase lag of high- versus low-energy protons, and for the integral radial gradients of protons >100 MeV over most of the solar cycle and over large distances in the heliosphere. Each individual disturbance caused a sudden particle intensity decrease as it passed a point in space; revovery of intensity began immediately afterward. The characteristic recovery time at 1 AU was in the range found in neutron monitor and satellite data, except that the recovery time constant wa rigidity-dependent, contrary to these same data. Also, spectral changes over successive solar minima in 1965 and 1977, heretofore linked to drifts can be explained as an adjunct to the hysteresis effect. Overall, the primary galactic cosmic ray flux over the 11-year solar cycle is dominated in the ecliptic plane by turbulent scattering regions emitted by the sun and at best only secondarily affected by gradient and curvature drifts, effects which may be confined near 1 AU. Copyright American Geophysical Union 1987
- Research Organization:
- NASA Goddard Space Flight Center, Greenbelt, Maryland
- OSTI ID:
- 6270830
- Journal Information:
- J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 92:A8; ISSN JGREA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BARYONS
COSMIC ELECTRONS
COSMIC PROTONS
COSMIC RADIATION
COSMIC RAY FLUX
DATA ANALYSIS
ELECTRONS
ELEMENTARY PARTICLES
ENERGY LEVELS
FERMIONS
HADRONS
HYSTERESIS
IONIZING RADIATIONS
LEPTONS
MODULATION
NUCLEONS
PROTONS
RADIATION FLUX
RADIATIONS
SCATTERING
SOLAR CYCLE
TURBULENCE