Cosmic Rays, the Sun and Geomagnetism: The Works of Scott E. Forbush

Published by the American Geophysical Union as part of the Special Publications Series.
This monograph is a tribute to the character and achievements of Scott Ellsworth Forbush (1904-1984) who, almost single-handedly with only technical assistance, laid the observational foundations for an important part of the subject of solar-interplanetary-terrestrial physics. The heart of his research was the meticulous and statistically sophisticated analysis of the temporal variations of cosmic-ray intensity as measured by ground-based detectors at various latitudes and altitudes.

Forbush either discovered or put on a firm basis for the first time the following fundamental cosmic-ray effects: The quasi-persistent 27-day variation of intensity.The diurnal variation of intensity. The sporadic emission of very energetic (up to ?GeV) protons by solar flares. Worldwide impulsive decreases (Forbush decreases) in intensity followed by gradual recovery. The 11-year cycle of intensity and its anticorrelation with the solar activity cycle as measured by sunspot numbers. The 22-year cycle in the amplitude of the diurnal variations.