1999 EARTH SCIENCE VIDEOTAPES |
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Tape Title | Record ID | Date Produced | TRT: |
Synopsis |
| LA NINA RESURFACES AND INTENSIFIESSCIENTISTS EXAMINE IMPACT ON ATLANTIC HURRICANES | G99-072 | 9/10/99 | 00:17:12 | New satellite images show that the colder than normal ocean temperatures associated with La Nina have again strengthened and now extend nearly the entire length of the equatorial Pacific - a length of nearly 6000 miles. Researchers are beginning to understand just how La Nina conditions can influence the formation of hurricanes. |
TAPE CONTENTS: |
| ITEM (1): LA NINA RESURFACES - SATELLITE / BUOY COMPOSITE - This data sequence shows 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 two months the cool La Nina waters have resurfaced. Red indicates warmer than normal temperatures, and blue indicates cooler than normal temperatures. Sea height data from NASA/CNES TOPEX/Poseidon radar altimeter. Subsurface temperature data from NOAA TOGA TAO. Sea surface temperature data from NOAA NCEP SST analysis through 8/28/99.
Courtesy NASA
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| ITEM (2): LA NINA RESURFACES - SATELLITE SEA TEMPERATURES - This data sequence traces the evolution and demise of warm El Nino condition in 1997 and early 1998. In June 1998, Scientists were surprised by the rapid transition to cool La Nina conditions when water temperatures near the Galapagos Islands dropped over 10 degrees (f) in just a week. La Nina then became much less organized in the spring of 1999. During the past two months the cool La Nina waters have resurfaced. Sea surface temperature data from NOAA NCEP SST analysis through 9/4/99. Courtesy NASA
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| ITEM (3): 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 (4): 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 Atlantic hurricanes. During El Nino, the subtropical jet is displaced southward toward hurricane generation areas in the Atlantic. The quick moving air aloft tends to blow the top of the developing clouds in a hurricane which inhibits full growth of the system and decreases the number of hurricanes making North American landfall. During La Nina, the subtropical jet is displaced northward away from hurricane generation areas and hurricanes are not inhibited by the shearing effect of the quick moving air aloft, and are more free than normal to develop and make North American landfall.
Courtesy NASA
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| ITEM (5): HURRICANES OF 1999 - Images of Hurricanes of 1999. Hurricane Dennis as seen from SeaWiFS and GOES.
Courtesy NASA/NOAA
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| ITEM (6): HURRICANE MITCH - (TRMM) - The 1998 hurricane season was unusually severe. This "CAT scan" image of Hurricane Mitch was captured by NASA's Tropical Rainfall Measuring Mission (TRMM) spacecraft. The spaceborne rain radar allows scientists to create 3-D views of precipitation and the height of the rain column inside hurricanes. Red colors indicate rain rates in excess of 2 inches per hour. Data for this sequence were collected on 10/27/98.
Courtesy NASA/NASDA
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| ITEM (7): HURRICANE MITCH - (GOES) - - This time-lapse sequence of Hurricane Mitch was captured by the Geostationary Operational Environmental Satellite (GOES). Courtesy NASA/NOAA
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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): SEASONAL EFFECTS OF LA NINA - Graphic shows seasonal changes in temperature and precipitation in the United States as seen in previous El Nino events. Courtesy NASA
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| ITEM (10): B-ROLL: SCIENTISTS DECIPHER LA NINA PUZZLE
Courtesy NASA
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| ITEM (11): REBOUND FROM EL NINO - - El Nino also has a dramatic impact on the global biosphere. Satellite instruments that measure color in the oceans monitor chlorophyll concentrations. These measurements help scientists monitor changes in phytoplankton, the lowest level of the marine food chain. During El Nino, an upwelling of nutrients in colder water is suppressed with often disastrous implications for marine ecosystems. NASA's SeaWiFS instrument enabled scientists to witness the ocean transition from El Nino (first image) to La Nina (second image) conditions in the equatorial Pacific. The cooler, upwelled nutrient-rich waters associated with the demise of El Nino and the transition to La Nina initiated a huge plankton bloom along the equator. Courtesy NASA
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| ITEM (12): EXPLOSION IN THE GALAPAGOS - On regional scales, the SeaWiFS instrument documented the rapid demise of El Nino in the waters around the Galapagos Islands. The images show a explosion in plankton growth as the warm El Nino waters blamed for choking off essential ocean nutrients are replaced by deep, cold, upwelled waters. The false color images, which document plankton concentrations over a period from May 9 - 24 1998, show that life in the region to the west archipelago has returned in remarkable abundance. High concentrations are shown in red. Areas occluded by clouds are shown in white.Courtesy NASA
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| ITEM (13): INTERVIEW EXCERPTS WITH DAVID ADAMEC, RESEARCH OCEANOGRAPHER, NASA GODDARD SPACE FLIGHT CENTER
Courtesy NASA
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