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| ABSTRACT | |
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The atmosphere's ozone is concentrated in the so-called ozone layer. The atmosphere's ozone layer plays a very important role in protecting life on earth from potentially harmful UV rays, and it also helps shape the earth's climate. However, gasses resulting from human activity such as chlorofluorocarbons (CFC’s) are believed to deplete the ozone layer. The discovery of a
hole in the ozone layer which occurs each spring over Antarctica
focused the world's attention on the importance of the ozone layer
and stirred the global community into action. Only satellites can
measure ozone on a global scale, so they are essential for ozone
studies. Satellite ozone data are mainly used for monitoring the
global and vertical distribution of ozone, and are a valuable tool
for policy makers who need to take appropriate measures to protect
the ozone layer. |
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| OBSERVATION AREA | |
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SATELLITE DATA |
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ERBS: SAGE
II |
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| Nadir viewing instruments perform measurements looking almost vertically beneath the satellite to the surface of the earth; as the satellite moves along its orbit, the instrument scans large bands on the earth surface. Such instruments measure the light of the sun (ultraviolet or infrared) that is reflected by the atmosphere and the earth’s surface. As light coming from the sun enters the atmosphere, it is partially absorbed and partially reflected back into space. The reflected part is analysed by the instrument on the satellite and special algorithms allow one to deduce the ozone content of the atmosphere and the vertical distribution of ozone in the stratosphere (ozone profile). |  |
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In the occultation technique, the satellite is positioned so that the earth progressively hides the light coming from the sun or a star as the satellite moves along its orbit. As the instrument sees the sun or star through the earth’s atmosphere, it can measure how the light is absorbed by the atmosphere at different altitudes. This method allows one to retrieve ozone profiles with a higher resolution in the stratosphere and the troposphere, but it has a much lower spatial and temporal coverage. |
| LINKS | |
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On the British National Space Centre website |
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