(ˈfɔr bʊʃ) n. the sudden decrease in the intensity of cosmic rays after an increase in solar activity. Also called For′bush effect`.[after Scott E. Forbush (b. 1904), U.S. physicist]
Forbush decrease
Forbush decrease
[′fȯr‚bu̇sh di′krēs] (astrophysics) A sudden decrease in cosmic-ray intensity which occurs a day or two after a solar flare, and at the same time as the commencement of magnetic storms and auroral activity.