The effects of fluctuations and noise on the neutron monitor diurnal anisotropy
Abstract
The effects of fluctuations and noise in the interplanetary magnetic field and in the cosmic ray flux on the diffusive streaming direction obtained from the neutron monitor diurnal anisotropy are presented. Cosmic rays are assumed to stream along the instantaneous magnetic field, but the average diurnal flux still differs from the daily average field direction owing to averaging effects and noise. Comparisons with observational data are given, and the results indicate the existence of a daily non-field-aligned anisotropy about one fourth as large as the field-aligned anisotropy. It is suggested that this anisotropy is due to cosmic ray streaming caused by the antisymmetric terms in the diffusion tensor.
- Publication:
-
Journal of Geophysical Research
- Pub Date:
- March 1977
- DOI:
- 10.1029/JA082i007p01066
- Bibcode:
- 1977JGR....82.1066O
- Keywords:
-
- Anisotropy;
- Cosmic Rays;
- Diurnal Variations;
- Electromagnetic Noise;
- Interplanetary Magnetic Fields;
- Particle Flux Density;
- Radiation Counters;
- Autocorrelation;
- Particle Diffusion;
- Random Noise;
- Particles and Fields-Interplanetary Space: Cosmic rays;
- Particles and Fields-Interplanetary Space: Solar wind magnetic fields