2001 EARTH SCIENCE VIDEOTAPES |
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Tape Title | Record ID | Date Produced | TRT: |
Synopsis |
| MICROBES RIDE THE DUST | G01-047 | 06/14/01 | 00:14:05 | NASA-funded researchers have discovered that bacteria and fungi are being transported in plumes of North African dust that cross the Atlantic Ocean and arrive in the Americas and the Caribbean. Dust storms and the rising warm air can lift dust 10,000 feet or so above the African deserts and then out across the Atlantic, many times reaching as far as the Caribbean where they often require the local weather services to issue air pollution alerts. Recent studies have linked disease born illnesses and the decline of the coral reefs in the Caribbean to the increasing frequency and intensity of Saharan dust events.
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TAPE CONTENTS: |
| ITEM (1): Dust Particle Landscape - Microbes transported by dust storms in North Africa have been hitching rides across the Atlantic--living in the highly irregular nooks and crannies found in the surfaces of dust particles. These images were taken by an electron microscope magnified 12,000 & 8,000 times. Notice the moon-like craters which protect the microbes from exposure to ultraviolet radiation from the Sun. Scientists also think that upper altitudes of the dust clouds deflect harmful UV rays, shielding microbes at lower altitudes as they are transported across the Atlantic Ocean. Additionally, when dust clouds move over open water in lower latitudes, the moderate temperatures and high humidity are known to enhance microbial survival.
a) Dust Image Magnified 12,000 Times
b) Dust Image Magnified 8,000 Times
Courtesy: USGS
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| ITEM (2): MICROBES RIDE THE DUST ANIMATION - The dust comes every year during northern Africa's dry season, when storm activity in the Sahara Desert and Sahel generate clouds of dust. The dust originating from fine particles in the arid topsoil is transported into the atmosphere by winds and may be carried in excess of 10,000 feet high into the atmosphere by easterly trade winds. Typically, it takes 5 to 7 days for the dust clouds to cross the Atlantic Ocean and reach the Caribbean and Americas. This animation illustrates microbes hitching rides across the Atlantic in the highly irregular nooks and crannies found in the surfaces of dust particles and how they are transported across the Atlantic Ocean.
Courtesy: NASA
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| ITEM (3): TOMS Data Visualizations - During the peak of the 2000 dust season, scientists collected samples of airborne pollutants and dust daily on the island of St. John in the Virgin Islands. The results show that high levels of microbes were collected on the days that NASA's Total Ozone Mapping Spectrometer (TOMS) satellite instrument observed the African dust sweeping into the region, indicating that the microbes had been transported from Africa. The TOMS data were rendered and combined with a world map to help scientists track the progress of the clouds of dust. The tan and orange colors in these images primarily show high concentrations of dust. Some aerosols from biomass burning can also be seen.
a) TOMS July 2000 Aerosol Index
b) TOMS May - June 14,1983 Aerosol Index (dustiest year on record)
Courtesy: NASA
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| ITEM (4): Dust Images From Around The World - The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) on board the Orb View-2 Satellite, has captured images of dust storms around the globe. According to the recent studies, high dust frequency is not necessarily a result of the decreased rainfall, but rather its cause.
1) Off the northwestern coast of the African Continent, February, 26th 2000 - a dust storm the size of Spain
2) Mediterranean Sea
a)July 18th 2000 from north Africa towards Italy
b) April 18th 2001 northward from Egypt
All three continents bordering the Mediterranean Sea are subject to affects of dust storms.
3) Middle East, May 20th 1999
Courtesy: NASA/ORBIMAGE
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| ITEM (5): Air Sampling B-Roll - Dr. Virginia Garrison, USGS, collects samples of airborne pollutants and dust daily on the island of St. John in the Virgin Islands. The samples are then sent to the USGS laboratory in St. Petersburg, Florida, for microbial analysis. Courtesy: Murphy Entertainment Group
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| ITEM (6): Culturing Air Filters B-Roll - Dr. Christina Kellogg cultures samples from St. John in lab. Courtesy: University of South Florida TV/USGS
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| ITEM (7): Culturing Organisms B-Roll - Fungi and bacteria that survive the trans-Atlantic journey in dust include bacterial or fungal cultures that do not produce disease mixed with species that do produce disease in both humans and plants. A fungus, which has been isolated in African dust, Aspergillus sydowii, has been determined to cause Sea Fan disease in coral reefs throughout the Caribbean. Desert dust exposure has also been identified as a source of terrestrial disease outbreaks including: Aspergillosis in animals, and Coccidioidomycosis. B-roll of Drs. Dale Griffin & Christina Kellogg culturing samples from St. John in lab.
Courtesy: Murphy Entertainment Group
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| ITEM (8): Coral Images - A fungus, which has been isolated in African dust, Aspergillus sydowii, has been determined to cause Sea Fan disease in coral reefs throughout the Caribbean. Recent studies have linked the decline of the coral reefs in the Caribbean to the increasing frequency and intensity of Saharan dust events.
Courtesy: NASA/CPN TV
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| ITEM (9): SOLVING THE MYSTERY - Dr. Garriet Smith looking at fungi specimens through microscope in his lab located at the University of South Carolina, Aiken. Dr. Smith and his team determined that a fungus called Aspergillus sydowii, caused Sea Fan disease in coral reefs throughout the Caribbean.
Courtesy: Murphy Entertainment Group
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| ITEM (10): TOMS Spacecraft Animation - NASAÕs Total Ozone Mapping Spectrometer (TOMS) satellite instrument has been used to identify atmospheric conditions such as dust events and other aerosols. Such satellite images enable scientists to notify localities of approaching African dust clouds so that precautions can be taken for those with respiratory problems.
Courtesy: NASA
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| ITEM (11): Interview Excerpts - Dr. Dale Griffin, Microbiologist,
United States Geological Survey, Center For Coastal Geology And Regional Marine Studies
Courtesy: University of South Florida TV/USGS
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Earth Science Gallery