ENVS 1100 Lecture Notes - Lecture 14: Ozone Depletion, Thermosphere, Montreal Protocol
3 May 2018
School
Department
Course
Professor
Atmospheric Science and Ozone
November 13, 2014
Composition of the Atmosphere:
• 78% nitrogen
• 21% oxygen
• 1% Argon gas and other minute concentrations of:
o water vapor
o carbon dioxide
o nitrous oxide
o ozone
o chloroflurocarbons (CFCs)
• Composition of the atmosphere has not been constant through out history
Structure of the Atmosphere:
• Changes in temperature
• Ozone concentrations change between spheres
• Troposphere provides the air we breath and our weather
• Troposphere – Stratosphere – Mesosphere – Thermosphere
• In stratosphere, a large influx of ozone causes temperature to drop and then
increase steadily
Stratospheric Ozone
• Stratospheric ozone depletion is a separate issue from global climate change
• Ozone depletion as a result of the release of CFCs is taking place in
Stratosphere
• Greenhouse gases and the greenhouse effect exist in the Troposphere
• Try to keep this spatial separation in mind and it should help keep two
concepts separate
Radiation
The type of radiation can be defined by its wavelength.
• Shorter wavelengths have higher frequencies and higher energy
• The sun emits energy in short wavelengths (solar radiation)
• Earth emits energy with long wavelengths (less energy)
• VISIBLE LIGHT SPECTRUM: R O Y G B I V
• UV radiation – 290-400nm
o UV-A reaches troposphere
o UV-B mostly reaches stratosphere while some rays reach troposphere
o UV-C predominantly in mesosphere
o UV photons harms the DNA molecules of living organisms
▪ Adjacent bases bond with each other instead of across
▪ This makes a bulge and results in a distorted DNA molecule
that does not function properly
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Document Summary
Composition of the atmosphere: 78% nitrogen, 21% oxygen, 1% argon gas and other minute concentrations of, water vapor, carbon dioxide, nitrous oxide, ozone, chloroflurocarbons (cfcs, composition of the atmosphere has not been constant through out history. Structure of the atmosphere: changes in temperature, ozone concentrations change between spheres, troposphere provides the air we breath and our weather, troposphere stratosphere mesosphere thermosphere. In stratosphere, a large influx of ozone causes temperature to drop and then increase steadily. Stratospheric ozone: stratospheric ozone depletion is a separate issue from global climate change, ozone depletion as a result of the release of cfcs is taking place in. Stratosphere: greenhouse gases and the greenhouse effect exist in the troposphere, try to keep this spatial separation in mind and it should help keep two concepts separate. Uv breaks diatomic oxygen into two oxygen atoms. One of these oxygen atoms bonds to the diatomic oxygen to create an ozone molecule.
