2001 EARTH SCIENCE VIDEOTAPES |
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Tape Title | Record ID | Date Produced | TRT: |
Synopsis |
| ARCTIC OZONE TRIGGER
| G01-069 | 9/17/01 | 00:03:09 | Similar to weather changes on Earth, temperature changes in the upper atmosphere, or stratosphere, also vary leading to changes in ozone depletion. Using 22 years of satellite-derived data, NASA researchers found bands of atmospheric energy, or "long waves" that circle the Earth, regulating the temperatures in the upper atmosphere of the Arctic, thus playing a role in controlling ozone losses. These findings will help scientists predict stratospheric ozone loss in the future.
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TAPE CONTENTS: |
| ITEM (1): Arctic Ozone 'Hole'
-Bands of energy thousands of miles in length flow eastward in the upper atmosphere, affecting the atmospheric circulation in the Arctic by either strengthening it resulting in warmer temperatures, or by weakening it for cooling temperatures. Warmer temperatures allow ozone to exist while colder temperatures cause a chemical reaction eventually depleting the ozone layer. An unconfirmed theory is that greenhouse gases may be responsible for decreasing the number of long waves that enter the stratosphere, which thins the ozone layer.
While not the 'hole' that exists over the Antarctic, the depleted region of ozone in the Arctic reached its lowest point in 1999 to an altitude of nearly 60,000 feet. This view of the Arctic ozone was created with data obtained by the Total Ozone Mapping Spectrometer (TOMS) instrument aboard NASA's Earth Probe spacecraft.
Courtesy: NASA
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| ITEM (2): Arctic Vortex - During winter, stratospheric winds (uppermost atmosphere) tend to form a vortex around the North Pole. These polar clouds lead to chemical reactions that affect the chemical form of chlorine in the stratosphere. In certain chemical forms, chlorine can deplete the ozone layer.
Courtesy: NASA
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| ITEM (3): Ozone-Watching - The ozone measurements were collected by the Total Ozone Mapping Spectrometer (TOMS) aboard NASA's Earth Probe (TOMS-EP) satellite. NASA's TOMS instruments have been measuring Antarctic ozone levels since November 1978.
Courtesy: NASA
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