Sydney Chapman

Sydney Chapman was a British mathematician and geophysicist, born in 1888 in Eccles, Greater Manchester, England, and died in 1970 in Boulder, Colorado. His work addressed the kinetic theory of gases, solar-terrestrial physics and Earth's ozone layer, and in 1930 he developed the photochemical mechanism, now called the Chapman cycle, explaining how the ozone layer forms and is maintained. With Vincenzo Ferraro he predicted the existence of Earth's magnetosphere in the early 1930s, and the Chapman function used in atmospheric physics is also named for him.