2008 EARTH SCIENCE VIDEOTAPES |
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Tape Title | Record ID | Date Produced | TRT: |
Synopsis |
| NASA OBSERVES THE 2007-2008 LA NINA (720p/59.94) | G08-HD030 | 2/15/08 | 10:21 | Cool, wet conditions in the Northwest, frigid weather on the Plains, and record dry conditions in the Southeast, all signs that La Nina is in full swing. With winter gearing up, a moderate La Nina is hitting its peak. And we are just beginning to see the full effects of this oceanographic phenomenon, as La Nina episodes are typically strongest in January.
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TAPE CONTENTS: |
| ITEM (1): Global View of 2007-2008 La Nina - A La Nina event is characterized by the appearance of cooler than normal sea surface temperatures along the equator in the Pacific Ocean, specifically in the eastern to central Pacific. The La Nina we are experiencing now has a significant presence in the eastern part of the ocean, which will mean a stronger impact on the U.S. since the event is geographically closer to us. This visualization shows the cooler sea surface temperature of this La Nina event.
Courtesy: NASA
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| ITEM (2): La Nina's Cloud Cover - One effect of La Nina is that the colder ocean temperatures inhibit cloud growth overhead. These two images show the area over the equatorial Pacific Ocean on Nov. 7, 2007, during this La Nina event. The lack of rain-producing clouds sparks changes across the globe, keeping nearby landmasses very dry, while areas on the other side of the Pacific tend to be wetter than usual.
Courtesy: NASA
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| ITEM (3): The Evolution of the 2007-2008 La Nina - This time-series animation of the Pacific Ocean showing the rise of the current La Nina was produced using sea-surface height measurements taken by the joint U.S./French Jason altimetric satellite from mid 2007 to November 2007. In the animation, places where the Pacific sea surface height is higher (warmer) than normal are yellow and red, and places where the sea surface is lower (cooler) than normal are blue and purple. Green shows where conditions are near normal. Sea-surface height is an indicator of the heat content of the upper ocean.
Courtesy: NASA
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| ITEM (4): Indecisive El Nino - This animation shows El Nino's and La Nina's multiple personalities. The sequence begins with normal jet streams, normal sea surface temperatures, and normal wind patterns. The first change illustrates what occurs when a very strong El Nino strikes surface waters in the central equatorial Pacific Ocean. The second change in the animation illustrates typical La Nina conditions. The third change in the animation illustrates the following, weaker El Ni–o.
Courtesy: NASA
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| ITEM (5): Cold Water Upwelling - Changes in sea surface temperature that become El Nino and La Nina events occur because of changes in the strength of the trade winds. Blowing over equatorial seas, trade winds push warm surface water westward, causing colder water to upwell in its place along the coast of South America. During La Nina events, the trade winds get stronger, more water is pushed westward, and more cold water wells up from the deeper ocean. This upwelling also brings up nutrients from deep in the ocean.
Courtesy: NASA
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| ITEM (6): Comparing El Nino and La Nina - El Nino is the opposite of La Nina. During an El Nino episode the sea surface temperature and height rise, while during a La Nina event sea surface temperature and height drop. This visualization shows sea surface temperature and height anomalies in the Pacific Ocean between December 1997 and December 1998, during the last major El Nino and La Nina episodes.
Courtesy: NASA
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| ITEM (7): NASA's Earth Observing Fleet - NASA's Earth-observing fleet of satellites constitutes a major milestone in the history of Earth science, facilitating the kinds of wide scale and synergistic research endeavors that until the last decade have been impossible to even consider. NASA monitors La Nina events with several of its key Earth-observing satellites. NASA's Aqua satellite maps the Earth's water system to help scientists gain a fuller understanding of the Earth's climate and interactions between Earth's systems.
Courtesy: NASA
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Earth Science Gallery