1888-1979

English geophysicist who invented theories and made fundamental discoveries in general geophysics, including the idea that solar radiation is the source of terrestrial magnetic phenomena: auroras, magnetic storms, and radio wave-reflecting atmospheric layers. He theorized that the atmosphere has tidal-like characteristics from gravitational and temperature changes; thus, radio wave layers would fluctuate, causing communication disturbances. He discovered lunar atmospheric tides and conceived an accurate model of earth's atmosphere. Chapman, president of the International Geophysical Year committee, coined the name for that historic year of international geophysical research (1957-1958).