2004 EARTH SCIENCE VIDEOTAPES |
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Tape Title | Record ID | Date Produced | TRT: |
Synopsis |
| "HOT TOWERS" ABOVE A STORM'S EYE PROVIDES CLUES TO FORECASTING HURRICANES | G04-003 | 1/12/04 | 00:05:09 | They are called hurricanes in the Atlantic, typhoons in the West Pacific, and tropical cyclones worldwide, but wherever these storms roam, the forces that determine their severity are now a little less mysterious. NASA scientists have found that "hot tower" clouds are associated with tropical cyclone intensification. Future work might use this association to improve forecasts of a cyclone's destructive potential.
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TAPE CONTENTS: |
| ITEM (1): GOES Animation of Hurricane Bonnie (G98-064) - A particularly tall "hot tower" rose above Hurricane Bonnie in August 1998, as Bonnie intensified a few days before striking North Carolina. New research indicates a tropical cyclone with a hot tower in its eyewall is twice as likely to intensify in the next six hours than a cyclone that lacked a tower. National Weather Services Geostationary Operational Environmental Satellite (GOES)-10 acquired these satellite images of Bonnie August 25-26, 1998. The video was enhanced and rendered at the NASA Goddard Space Flight Center, Laboratory for Atmospheres.
Courtesy: NASA/NOAA
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| ITEM (2): Hot Tower Inside Hurricane Bonnie - Scientists define a hot tower as a rain cloud that reaches at least to the top of the troposphere, which the lowest layer of the atmosphere and which extends about 9 miles high in the Tropics. A hot tower rose above hurricane Bonnie in August 1998, as seen in this 3-D satellite image of the hurricane. The image shows a (cumulonimbus) storm cloud, towering like a sky scraper, 59,000 feet (18 kilometers) into the sky from the eyewall. Red color indicates rain rates in excess of 2 inches per hour. The image was acquired by the Tropical Rainfall Measuring Mission (TRMM).
Courtesy: NASA/NASDA
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| ITEM (3): Hurricane Heat Engine (G03-051) - A Hurricane acts essentially like a "heat engine," drawing up energy from the tropical ocean to power intense winds, thunderstorms, and immense ocean surges. Water vapor from the warm ocean surface evaporates for hundreds of miles around the hurricane and moves toward the hurricane's eye due to the wind pattern created by the hurricane. As the water vapor cools and rises, it condenses from a gas back to a liquid state and it releases latent heat. The released heat warms the surrounding air, causes it to rise, and that in turn causes more water to condense into rain. Because of this strong rising motion, the 74 to 160 mph winds that spiral in towards the eye never actually reach the eye. Instead, they rise up to form towering rain clouds in a ring around the relatively peaceful eye. This ring of clouds is called the "eyewall" because, from an aircraft, it looks like a wall surrounding the eye. Scientists are currently studying if the strength of the rainfall in just the eyewall can give us a clue to how strong the whole hurricane will become hours or days later.
Courtesy: NASA
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| ITEM (4): Model Hurricane (G03-051) - By synthesizing data from multiple instruments and satellites, scientists get a full picture of the many ingredients of a hurricane. Satellites that monitor Earth day-to-day give pictures of both normal and unusual terrestrial, oceanic, and atmospheric activity. Scientists then build physical and computer models of the interactions and activity, which they can study to find patterns and ultimately make predictions. Scientists can use these models to make better predictions of severe weather patterns.
Courtesy: NASA
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| ITEM (5): TRMM Animation - The TRMM satellite, a joint U.S. and Japanese mission, is the first satellite dedicated to studying tropical rainfall. Tropical rainfall, that which falls within 35 degrees north or south of the equator, comprises more than two-thirds of global total rainfall.
Courtesy: NASA
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