1999 EARTH SCIENCE VIDEOTAPES |
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Tape Title | Record ID | Date Produced | TRT: |
Synopsis |
| LA NINA CONDITIONS PERSIST: 18 MONTHS AND COUNTING | G99-110 | 12/21/99 | 00:12:07 | New satellite images and ocean buoy measurements show that the colder than normal ocean temperatures associated with La Nina have intensified. The current La Nina spans most of the equatorial Pacific with the coolest surface temperatures about 4F colder than the climatological average. Researchers are just beginning to understand how La Nina can influence world weather patterns.
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TAPE CONTENTS: |
| ITEM (1): LA NINA CONDITIONS AS SEEN BY TOPEX - This data sequence traces the evolution and demise of warm El Nino condition in 1997 and early 1998. The cooler waters associated with La Nina began to emerge in the spring of 1998, peaked in the winter of 1998 and became much less organized in the spring of 1999. During the past four months, the cool La Nina waters have resurfaced and intensified. Sea height data is from NASA's TOPEX/Poseidon radar altimeter. Blue colors indicate lower than normal sea heights (and temperatures). Red indicates higher than normal sea heights (and temperatures). Courtesy: NASA
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| ITEM (2): SEA SURFACE TEMPERATURES
- - This data sequence traces the evolution and demise of warm El Nino condition in 1997 and early 1998. The cooler waters associated with La Nina began to emerge in the spring of 1998, peaked in the winter of 1998 and became much less organized in the spring of 1999. During the past four months, the cool La Nina waters have resurfaced and intensified. Sea temperature data is from NOAA's Advanced Very High Resolution Radiometer (AVHRR). Blue colors indicate lower than normal sea temperatures and red indicates warmer than normal sea temperatures. Courtesy: NASA / NOAA
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| ITEM (3): A 3-D LA NINA - Scientists combine sea height data from NASA's TOPEX/Poseidon with sea surface temperature data from NOAA's AVHRR to better understand the correlation between sea height and temperature. The cool waters of La Nina (shown in blue) can be seen as a depressed region along the equatorial Pacific. La Nina replaced warm El Nino waters in June of 1998 and have persisted through 1999. Courtesy: NASA / NOAA
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| ITEM (4): 3-D LA NINA - ADD THE WINDS - Scientists add wind data (black arrows) to the sea surface temperatures and sea surface height to understand the complex interaction between the ocean and atmosphere. The arrows indicate stronger than normal wind patterns. Note that winds tend to converge on the equatorial Pacific during El Nino while diverging from the equator during La Nina. Courtesy: NASA
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| ITEM (5): THE WINDS OF LA NINA
- Stronger than normal low-level equatorial winds have helped bring the cooler than normal waters to the ocean surface. Courtesy: NASA
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| ITEM (6): LA NINA RESURFACES - SATELLITE / BUOY COMPOSITE - By combining data from satellites and ocean buoys, scientists can better understand what is happening beneath the surface of the ocean. This data sequence traces the evolution and demise of El Nino in 1997 and early 1998. La Nina conditions began to emerge in the spring of 1998 and have intensified during the winters of 1998 and 1999. Red indicates warmer than normal temperatures, and blue indicates cooler than normal temperatures. Sea height data from NASA TOPEX/Poseidon. Subsurface temperature data from NOAA's TOGA TAO. Sea surface temperature data from NOAA's AVHRR.
Courtesy: NASA / NOAA
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| ITEM (7): THE HURRICANE CONNECTION - Animation compares the effects of La Nina and El Nino on the formation of Atlantic Hurricanes. El Nino tends to suppress the formation of hurricanes by steering the subtropical jet stream into the hurricanes' path. During La Nina, the jet stream moves north, and tends to allow the hurricanes to more easily move up the U.S. coast. Courtesy: NASA
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| ITEM (8): WORLDWIDE CLIMATE CHANGES - Animation illustrates how El Nino and La Nina drive global climate changes. As warm water in the tropical pacific shifts its location one-third of the way around the globe, this major heat source to the atmosphere changes the position of atmospheric high and low pressure centers. This causes changes in the position of the jet streams hitting North America and associated temperature and rainfall patterns. The jet stream location is critical for steering storms into the continental U.S. During El Nino, the subtropical jet is displaced southward and storms are steered by the subtropical jet into southern California. During La Nina, the subtropical and polar jet streams combine to steer storms toward the northwest United States. Courtesy: NASA
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| ITEM (9): INTERVIEW EXCERPTS WITH DAVID ADAMEC, RESEARCH OCEANOGRAPHER, NASA GODDARD SPACE FLIGHT CENTER
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