2007 EARTH SCIENCE VIDEOTAPES |
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Tape Title | Record ID | Date Produced | TRT: |
Synopsis |
| NASA SATELLITE IMAGES SHOW MAJOR DECREASE IN 2007 ARCTIC SEA ICE (720p/59.94) | G07-HD063 | 10/01/07 | 06:28 | Arctic summer sea ice has reached its lowest extent on record in 2007, nearly 25% less than the previous low set in 2005. Such a dramatic loss has implications for ecology, climate and industry as Arctic accessibility increases. Data from NASA's Earth-observing satellites show these dramatic changes, including the recently opened Northwest Passage, in better detail than ever before.
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TAPE CONTENTS: |
| ITEM (1): Arctic sea ice minimum, 1979-2007 - At the end of each summer, the sea ice cover reaches its minimum extent and the ice that remains is called the perennial ice cover, which consists mainly of thick multi-year ice floes. The area of the perennial ice has been steadily decreasing since the satellite record began in 1979, at a rate of about 10% per decade. But the 2007 minimum, reached around Sept. 14, is far below the previous record made in 2005 and is about 38% lower than the climatological average. This data visualization shows the annual sea ice minimum from 1979 through 2007.
Courtesy: NASA
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| ITEM (2): Previous record vs. today, 2005 vs. 2007 - The difference in area between the 2005 Arctic sea ice minimum, and this year's ice is nearly the size of California and Texas combined, approximately 460,000 square miles. This represents an ice loss of close to 25% between 2005 and 2007.
Courtesy: NASA/GeoEye
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| ITEM (3): A closer look at Arctic sea ice, AMSR-E - The Advanced Microwave Scanning Radiometer (AMSR-E) is a high-resolution passive microwave Instrument on NASA's Aqua satellite. AMSR-E provides a remarkably clear view of sea ice dynamics in greater detail than has ever been seen before. Researchers use this information to study polar bear habitats, plan expeditions to the ice, and to study the interactions between the ocean and sea ice from season to season. This data visualization shows Arctic sea ice from Jan. 1, 2007 to Sept. 16, 2007.
Courtesy: NASA
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| ITEM (4): Ice albedo feedback - Polar ice reflects light from the sun. As this ice begins to melt, less sunlight gets reflected into space. It is instead absorbed into the oceans and land, raising the overall temperature, and fueling further melting. This results in a positive feedback loop called ice albedo feedback, which causes the loss of the sea ice to be self-compounding. The more it disappears, the more likely it is to continue to disappear.
Courtesy: NASA
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| ITEM (5): Satellite images of the Northwest Passage - In September 2007, the Northwest Passage was ice-free for the first time since satellite records began. The passage is a direct route from Europe to Asia for ships traveling through the Arctic. The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA's Terra satellite captured this image of the ice-free Northwest Passage on Sept. 15, 2007.
Courtesy: NASA
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| ITEM (6): NASA's Earth Observing System - NASA has been observing sea ice from space since the 1970s, beginning with the Electricallly Scanning Microwave Radiometer (ESMR), Scanning Multichannel Microwave Radiometer (SSMR) and Special Sensor Microwave/Imager (SSM/I) sensors on the US Defense Meteorological Space Program (DMSP) satellites, and now with the AMSR-E instrument on NASA's Earth Observing System/Aqua satellite. Data collected by these instruments have been instrumental in shaping public policy and international perspectives on the Arctic.
Courtesy: NASA
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Earth Science Gallery