Solar Activity Asymmetries and Their Possible Effect on the High Energy Cosmic Ray Perpendicular Gradient
Abstract
The northern solar hemisphere was considerably more active than the southern during the latter portion of sunspot cycle 19 and the first part of cycle 20 in all parameters investigated: solar flare reports, type II radio bursts, sunspot numbers and sunspot areas. Since 1874, sunspot area measurements suggest only one other lengthy time period (1883-1900) when one hemisphere of the sun was persistently more active than the other. For the remaining time periods, the sunspot areas appear to have been approximately equal for each hemisphere. From this we suggest the possibility that the perpendicular cosmic ray gradient inferred between 1959 and 1970 may not be representative of normal conditions primarily because solar activity was not evenly distributed between the two hemispheres, and consequently the cosmic ray propagation characteristics may have been symmetric between the northern and southern portions of the heliosphere. Keywords: Solar activity; Solar asymmetries; Cosmic radiation; Sunspot areas; Cosmic ray gradients; Reprints.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 12, 1989
- Accession Number
- ADA212496
Entities
People
- C.c. Abston
- D. B. Swinson
- D. F. Smart
- J. A. Mckinnon
- J. E. Humble
- M. A. Shea
Organizations
- Air Force Systems Command