2003 EARTH SCIENCE VIDEOTAPES |
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Tape Title | Record ID | Date Produced | TRT: |
Synopsis |
| A NEW SPIN ON HURRICANES: SATELLITES SENSE RECIPE FOR A NATURAL DISASTER | G03-051 | 09/9/03 | 00:19:46 | After the first of September, the conditions necessary to trigger a tropical disturbance come together and the Atlantic hurricane season peaks. At the turn of the last century, forecasters only had a vague idea of a hurricane's position, from reports from ships at sea and island stations the storm recently passed. Until a hurricane hit, they couldn't even pinpoint its movements. Thirty years ago, satellites enabled scientists to see hurricanes, yet still they lacked the ability to anticipate the storm's course. These days, with the aid of multiple data sets from a fleet of Earth-observing satellites, scientists more readily understand and predict the formation, intensification, and movement of these super-storms. For full details, see:
http://www.gsfc.nasa.gov/topstory/2003/0909hurricane.html
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TAPE CONTENTS: |
| ITEM (1): Take Warm Water, Stir
- What makes a hurricane? First, warm water - at least 82 degrees. Several weeks after the Sun shines brightest on the tropics in late June in the northern hemisphere, the waters reach their warmest. Orange and red indicate the necessary 82-degree or warmer water, sea surface temperatures (SSTs) from the Advanced Microwave Scanning Radiometer-EOS (AMSR/E) aboard the
Aqua satellite in May 2002. Add a disturbance, generally easterly waves off Africa, formed from winds from a clash between the hot Sahara Desert and the cooler Gulf of Guinea. These waves provide the initial energy and spin required for a hurricane to develop, seen Sept. 1-15, 2001, by the Geostationary
Operational Environmental Satellite (operated by NOAA).
Courtesy: NASA
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| ITEM (2): Mix Thoroughly, Bake
- With the right mix of winds and sea surface temperatures, an ordinary cluster of tropical thunderstorms can explode into a tropical storm. Winds converge, forming the familiar circular pattern of clouds. Warm, rising air in the storms draws water vapor up from the ocean. The vapor condenses in clouds and releases heat, warming the eye, evaporating more surface water and feeding the hurricane's heat engine, continuing the cycle.
Data from Hurricane Erin, September 10-15, 2001.
a) wind speed and direction, from Seawinds instrument on QuikScat satellite.
b) cloud structure, from Visible and Infrared Scanner (VIRS) on the Tropical Rainfall Measuring Mission (TRMM) satellite, cooperation with NASDA.
c) rainfall rates (green, in excess of 2 inches per hour), Microwave Imager (TMI) and Precipitation Radar (PR) on TRMM.
d) eye warmth (red), Convection And Moisture EXperiment (CAMEX).
e) Hurricane Erin, GOES, operated by NOAA.
Courtesy: NASA
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| ITEM (3): Hurricane Heat Engine (G99-045) - Hurricanes essentially act as engines, drawing energy up from warm tropical ocean waters to power the intense winds, powerful thunderstorms, and immense ocean surges. Water vapor from the warm ocean surface evaporates, forming towering convective clouds that surround the eyewall and rainband regions of the storm. As the water vapor cools and condenses from a gas back to a liquid state, it releases latent heat. This heat warms the surrounding air, making it lighter and promoting more clouds. Because the hurricane-speed winds surrounding the clear eye are often absent from the center of a hurricane, the heaviest rain clouds surround the center, leaving a relatively fair-weather eye.
Courtesy: NASA
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| ITEM (4): Model Hurricane (G98-029) - 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. This animation of a 3D hurricane model is based on 1995's Hurricane Luis. The model allows scientists to study the complex structures inside hurricanes.
Courtesy: NASA
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| ITEM (5): Future of Forecasting (G02-017) - The Atmospheric Infrared Sounder (AIRS) aboard NASA's Aqua satellite furnishes three- dimensional views of temperature, humidity and clouds in the atmosphere. AIRS observes the temperatures of cloud tops via infrared energy and, with the help of two companion microwave-energy sensors, maps temperature and humidity inside and below clouds. This reveals a storm's inner structure, including its most intense regions. A high-resolution visible wavelength sensor adds information about the clouds' fine structure. With AIRS, these observations come simultaneously from a single satellite, while previously scientists coordinated observations taken hours apart by several satellites.
For more information, see: http://www-airs.jpl.nasa.gov/images_data/image_releases/2002/guam_pongsona.html
Courtesy: NASA
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| ITEM (6): Supertyphoon Pongsona - Here AIRS shows some of the internal temperature structure of Supertyphoon Pongsona just as it hit the island of Guam on December 8, 2002. Each colored surface represents a particular temperature, (red, warmest to yellow coldest). Normally, these so-called isotherms would be much smoother and nearly horizontal. Here, latent heat released causes upward bulges, seen as much as 50,000 feet above sea level, a rarely observed warm air cap above a hurricane only measurable with an instrument like AIRS. As we zoom in on the lower 30,000 feet, we can discern a dip in the center where cooler, drier air descends and forms the eye.
Courtesy: NASA
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| ITEM (7): Hurricane Isidore and AIRS - Data taken before and after U.S. landfall, September 12 and 28, 2002, from AIRS reveal the extent of flooding due to Isidore. The three images taken by the AIRS sounding system on Aqua show high and cold clouds in blue in the upper left image. The upper right image shows heavy rain cells in blue over Alabama and the lower left image shows swirling clouds in white and the water off the Gulf of Mexico in blue. The eye of the hurricane is common to all three images but it appears to have some clouds and does not show a clear view down to the Gulf's surface water. The dark blue and purple colors in the lower right image show the extent of flooding.
Courtesy: NASA
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| ITEM (8): Hurricane Cat Scans - Rainfall Rates (G03-036) - The world's first and only spaceborne rain radar, TRMM, a joint NASA/NASDA mission, allows scientists to create 3-D views of precipitation and height of the rain column inside powerful hurricanes. Red shows highest rain rates, more than 2 inches per hour.
Isidore - September 26, 2002
Floyd makes landfall - September 15, 1999
Floyd - September 13, 1999
Mitch - October 27, 1998
Courtesy: NASA
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| ITEM (9): Cause and Effect: Bonnie's Trail Weakens Danielle (G00-025) - A hurricane gathers energy from warm waters found in tropical latitudes. As Hurricane Bonnie crosses the Atlantic, it leaves a trail of cooler water in its wake. When Hurricane Danielle crosses Bonnie's path, the wind speed of the second storm drops markedly, as available energy to fuel the storm's Engine drops off.
But once Danielle crosses Bonnie's wake, wind speeds increase as water surface temperatures increase around the storm. TRMM temperatures range from mid 70's (blue) to mid 90's F (red).
Courtesy: NASA
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| ITEM (10): Historical Weather Satellites (G00-066) - Between 1958 and 1967, NASA's experiments with rocketry and satellite technology yielded a way to view our planet as never before: from above. Spacecraft like Nimbus and the Television Infrared Observation Satellite (TIROS), in collaboration with NOAA, started looking at weather from the vantage point of space, testing new technologies and possibilities. From these early still, surface images, NASA and its partners have progressed to the time series and internal storm structure pictures that we see today.
Courtesy: NASA
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| ITEM (11): B-Roll - Dr. Jeff Halverson talks about the ingredients of a hurricane. Scientist uses 3-D model of Luis and VR glasses. TRMM scientists analyze data.
Courtesy: NASA
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| ITEM (12): Satellites and Instruments :
a) Aqua
b) CAMEX
c) GOES
d) TRMM
Courtesy: NASA
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