Long Term Modulation of Sidereal Time Variation of Cosmic Rays Related to the Interplanetary Magnetic Field
Abstract
A long term modulation of sidereal diurnal variation of cosmic rays related to the interplanetary magnetic field is examined. The amplitude of the variation shows a positive correlation with sunspot numbers for three solar cycles, and the amplitude is large at the maximum solar activity period, while small at the minimum activity period. A ratio of the averaged amplitudes between the active and quiet periods is estimated at 1.9 plus or minus 0.7. A 22-year variation of the radial density gradient of galactic cosmic ray particles is examined, and it is found that the density gradient changes as the polarity of the polar magnetic field of the sun changes.
- Publication:
-
International Cosmic Ray Conference
- Pub Date:
- 1981
- Bibcode:
- 1981ICRC....4..181I
- Keywords:
-
- Cosmic Rays;
- Diurnal Variations;
- Interplanetary Magnetic Fields;
- Sidereal Time;
- Solar Activity Effects;
- Long Term Effects;
- Particle Density (Concentration);
- Radial Distribution;
- Solar Cycles;
- Sunspots;
- Space Radiation;
- COSMIC RAYS;
- DIURNAL VARIATIONS;
- INTERPLANETARY MAGNETIC FIELDS;
- SIDEREAL TIME;
- SOLAR ACTIVITY EFFECTS;
- LONG TERM EFFECTS;
- PARTICLE DENSITY (CONCENTRATION);
- RADIAL DISTRIBUTION;
- SOLAR CYCLES;
- SUNSPOTS