Topic 3a - Atmospheric composition
In this video Professor John Burrows from the University of Bremen will be discussing observing atmospheric composition and the impacts of human activity on the Ozone layer from space.
Instruments such as GOME-2 on the polar-orbiting Metop satellites, use reflected sunlight to measure different gases in the atmosphere. Different elements absorb light at slightly different wavelengths, giving signature absorption lines on the reflected spectrum. This can help track pollution and gases released by volcanic activity, and can be used for planning, policymaking and hazard warnings. Ozone at low levels is considered a pollutant, but the stratospheric ozone layer is important for global health because it helps to filter ultraviolet light from the Sun.
The ozone layer was found to have thinned and developed a hole during the 1980s. The ozone was breaking down in sunlight because of chemicals called Chlorofluorocarbons (CFCs) which had been released into the atmosphere by industrial processes, refrigerators, and pressurized spray cans. CFCs were banned under the Montreal Protocol agreed in 1987 and implemented in 1989. Since then the ozone layer has been observed carefully for signs of recovery, although the thickening of the ozone layer was not instant because some CFCs persisted in the atmosphere long after people stopped using them.
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- Professor John Burrows
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Don’t forget you can download the video, transcript and take any quizzes available with the links on the right.
