1998 EARTH SCIENCE VIDEOTAPES |
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Tape Title | Record ID | Date Produced | TRT: |
Synposis |
| INCREASING GREENHOUSE GASES MAY BE WORSENING ARCTIC OZONE | G98-022 | 4/8/99 | 00:04:45 | In late 1997, larger levels of ozone depletion were observed over the Arctic than in any previous year on record. Now, using climate models, a team of scientists reports why this may be related to greenhouse gases, according to a paper published in the April 9 issue of Nature.
The study suggests the increase in greenhouse gas emissions is one possible cause of the observed trends in Arctic ozone losses and that this may delay recovery of the ozone layer. The research team, consisting of researchers from NASA's Goddard Institute for Space Studies (GISS) and Columbia University, New York, investigated the response of ozone to projected future emissions of greenhouse gases and ozone-depleting halogens over time, using the GISS climate model. This is the first time ever that the interaction between ozone chemistry and the gradual buildup of greenhouse gases has been studied in a climate model.
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TAPE CONTENTS: |
| ITEM (1): 1997 ARCTIC OZONE DEPLETION - Animation developed from data collected by satellite-based instruments operated by NASA and depict unusually low levels of ozone in the Arctic 1997. A new study indicates the increase in greenhouse gas emissions is one possible cause of the observed trends in Arctic ozone losses. Higher levels are shown in red. Lower levels in purple. The black regions indicate areas where no data were recorded due to lack of sunlight during the Arctic winters.
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| ITEM (2): OZONE PROTECTS THE EARTH - Animation illustrating how ozone protects the Earth by absorbing harmful ultraviolet radiation. The ozone molecule is split into one free oxygen atom and one molecule of ordinary oxygen. The free oxygen eventually may collide with an oxygen molecule to again form ozone molecules. |
| ITEM (3): OZONE AND CFCs - Animation illustrating the destructive effects of Chlorofluorocarbons. Chlorofluorocarbons (CFCs) can break up the protective ozone molecules located in the stratosphere. Ultraviolet radiation strikes a CFC molecule and causes a chorine atom to break away. The chlorine atom collides with an ozone molecule and steals an oxygen atom, thus destroying the ozone molecule. One chlorine atom can destroy many thousands of ozone molecules in its lifetime.
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| ITEM (4): STRATOSPHERE - Buildup of greenhouse gases leads to global warming at Earth's surface, but it also cools the stratosphere, which increases the amount of ozone depletion in the polar regions. Research shows that even very small amounts of stratospheric cooling can greatly increase ozone depletion. Colder stratospheric temperatures associated with global warming may enhance the depletion of Arctic ozone.
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| ITEM (5): TOMS SATELLITE - The observations were taken by Total Ozone Mapping Spectrometer (TOMS) interments onboard NASAÕs Earth Probe (TOMS-EP) satellite
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| ITEM (6): B-ROLL - SCIENTISTS STUDY OZONE - Dr. Paul Newman works with ozone data.
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