Use of the Wolf number to estimate solar modulation
Abstract
An approximate relation between the solar modulation of galactic cosmic rays, in the heliocentric potential model, and the mean annual Zurich sunspot number (Wolf number) was obtained. The heliocentric potential (in MV) is shown to be approximately 4.34 times the Wolf number with a standard deviation of about 160 MV. This ratio allows an estimate of solar activity during periods where neutron monitor data are missing. The mean level of solar activity over the last 10 solar cycles, is based on the mean annual sunspot number, about 200 MV.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- December 1977
- Bibcode:
- 1977STIN...7910988O
- Keywords:
-
- Estimating;
- Modulation;
- Solar Activity;
- Sunspot Cycle;
- Cosmic Rays;
- Radiant Flux Density;
- Solar Wind;
- Solar Physics