The three-dimensional structure of relativistic galactic cosmic ray anisotropies associated with solar rotation
Abstract
Temporal power spectral analysis of data from a network of neutron monitors is used to determine the three-dimensional anisotropy vector associated with quasi-periodic 27 day solar rotational recurrences in the flux of relativistic (∼10 GV) cosmic rays near Earth. From the diurnal anisotropy, we show that the recurrent flux in the ecliptic plane is perpendicular to the average interplanetary magnetic field direction. The observed north-south intensity difference indicates that there is a similar recurrent flux in the direction perpendicular to the ecliptic. The observations are accounted for by a simple theoretical model in which the observed fluxes are attributed to particle gradient drifts arising from a symmetric cosmic-ray gradient about the average interplanetary magnetic field direction of ∼7% per AU.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 1980
- DOI:
- 10.1086/157827
- Bibcode:
- 1980ApJ...236.1012O
- Keywords:
-
- Cosmic Rays;
- Interplanetary Medium;
- Solar Rotation;
- Solar Terrestrial Interactions;
- Anisotropy;
- Interplanetary Magnetic Fields;
- Power Spectra;
- Spectrum Analysis;
- Twenty-Seven Day Variation;
- Space Radiation