Atoms, Molecules, and Light AMO Science Enabling the Future (2002) / Chapter Skim
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4 AMO Science Protecting the Environment
4 AMO Science Protecting the Environment
Pages 21-28
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From page 21... ...
Above the troposphere is the stratosphere, which contains a high concentration of ozone molecules and is sometimes referred to as the ozone layer. These ozone molecules shield Earth's surface from harmful solar ultraviolet radiation, exposure to which has been linked to skin cancer, eye disorders, and changes in plant growth patterns.
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From page 22... ...
Models allow scientists to carry out controlled virtual experiments on computers to determine how a system will behave under various circumstances. The power of a theoretical model lies in the predictions it makes and its ability to identify key relationships between physical and chemical processes.
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From page 23... ...
to help guide policy makers in drawing up recommendations governing the burning of fossil fuel and the manufacture and use of ozoneclestroying chemicals. Although carbon dioxide is an integral part of plant and animal metabolism and therefore occurs naturally in the troposphere, significant increases in carbon dioxide may cause problematic atmospheric and climatic changes on a global scale.
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From page 24... ...
.While the formation of the Antarctic ozone hole is cyclic, over the last 21 years the hole has grown larger and is more depleted in O3 and more persistent (Figure 9~. Using a variety of measuring techniques based on AMO science, atmospheric scientists have discovered a sequence of chemical reactions occurring in the polar stratosphere during winter, when no sunlight is present.These reactions, which produce ma chlorine molecules (C12)
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From page 25... ...
The concentration of atmospheric molecules can be obtained by using twin laser beams, one of which is tuned to a wavelength the molecule in question likes to absorb. Advances in laser technology, electro-optical materials, and high-powerecl, low-cost lasers in the eye-safe 1.5-micron band now permit remote mapping of lower concentrations of atmospheric constituents at increaser]
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From page 26... ...
While accurate measurement of polar ice cap thickness is very cliff~cult, the Greenian(1 ice sheet, second in size only to the Antarctic ice sheet, lies on land above sea level and provides a stable measuring platform (Figure 10~. Laser altimetry exploits the UNITS = cm/Year +60 +40 +10 +2 -2 -10 -20 -40 -60 FIGURE 10 This map shows that the Greenland ice sheet is thinning, primarily along coastal regions, and thickening in some inland areas.
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From page 27... ...
Internal combustion engine exhaust is a major contributor to grouncl-level air pollution and smog. One of the most important factors lifting the design of modern, cleaner-running diesel engines is the amount of nitrogen oodles that these engines emit.
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From page 28... ...
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