Ozone depletion nitrous oxide emissions over the natural background, which would in turn result in an increase in the amount of NO in the stratosphere. Thus human activity could affect the stratospheric ozone layer. In the following year, Crutzen and (independently) Harold Johnston suggested that NO emissions from supersonic passenger aircraft, which would fly in the lower stratosphere, could also deplete the ozone layer. However, more recent analysis in 1995 by David W. Fahey, an atmospheric scientist at the National Oceanic and Atmospheric Administration, found that the drop in ozone would be from 1–2 percent if a fleet of 500 supersonic passenger
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