Ozone layer an altitude of 100 kilometers from the planet's surface. The photochemical mechanisms that give rise to the ozone layer were discovered by the British physicist Sydney Chapman in 1930. Ozone in the Earth's stratosphere is created by ultraviolet light striking ordinary oxygen molecules containing two oxygen atoms (O), splitting them into individual oxygen atoms (atomic oxygen); the atomic oxygen then combines with unbroken O to create ozone, O. The ozone molecule is unstable (although, in the stratosphere, long-lived) and when ultraviolet light hits ozone it splits into a molecule of O and an individual atom of oxygen, a continuing process
Dobson ozone spectrophotometer Dobson ozone spectrophotometer The Dobson spectrophotometer, also known as Dobsonmeter, Dobson spectrometer, or just Dobson is one of the earliest instruments used to measure atmospheric ozone. The Dobson spectrometer was invented in 1924 by Gordon Dobson. A history of the development of the instrument is here and an example of one of Dobson's own instruments remains on display in the University of Oxford Department of Physics. Dobson spectrophotometers can be used to measure both total column ozone and profiles of ozone in the atmosphere. Ozone is tri-atomic oxygen, O; ozone molecules absorb harmful UV light in the atmosphere before it