2001 EARTH SCIENCE VIDEOTAPES |
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Tape Title | Record ID | Date Produced | TRT: |
Synopsis |
| AFRICAN DUST LEADS TO TOXIC ALGAE BLOOMS IN GULF OF MEXICO
| G01-064 | 08/28/01 | 00:05:43 | Saharan dust clouds travel thousands of miles and fertilize the water off the West Florida coast with iron, which kicks off blooms of toxic algae, according to a new study. The research was partially funded by a NASA grant as part of ECOHAB: Florida (Ecology and Oceanography of Harmful Algal Blooms), a multi-disciplinary research project designed to study harmful algae. Toxic algal blooms, sometimes called red tides, have in the past killed huge numbers of fish, shellfish, marine mammals, birds, and can cause skin and respiratory problems in humans.
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TAPE CONTENTS: |
| ITEM (1): A Dust Storm The Size of Spain
- A massive sandstorm blowing off the northwest African desert blanketed hundreds of thousands of square miles of the eastern Atlantic Ocean with a dense cloud of Saharan sand. The storm was captured by NASA's SeaWiFS (Sea-viewing Wide Field-of-View Sensor) instrument onboard the Orbview-2 satellite on February 26, 2000.
Courtesy: NASA/OBIMAGE
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| ITEM (2): SeaWiFS Florida Images - Each year iron from Saharan dust clouds is deposited in the waters off the West Florida coast. Once there, plant-like bacteria use the iron to set the stage for red tides. When iron levels go up, these bacteria, called Trichodesmium, 'fixes' nitrogen in the water, converting it to a form usable by other marine life. The addition of biologically usable nitrogen in the water makes the Gulf of Mexico a more likely environment for toxic algae to bloom. These two images of Florida taken by NASA's Sea-viewing Wide Field-of-view Sensor (SeaWiFS) on board the Orb View-2 Satellite from Feb. 25, 1998 & Oct. 30, 1998, show phytoplankton blooms (green). Sometimes blooms like the ones shown provide the right conditions for red tides to occur.
Courtesy: NASA/OBIMAGE
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| ITEM (3): Saharan Dust Moving Across Atlantic - Research using satellites to monitor dust arrivals and Trichodesmium blooms could lead to forecasting of red tides. These two visualizations use data from NASA's Total Ozone Mapping Spectrometer (TOMS) satellite instrument show storm activity in the Sahara Desert region generating clouds of dust. Easterly trade winds carry the dust across the Atlantic Ocean and into the Gulf of Mexico. 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): Satellite Images of Saharan Dust Moving Across Atlantic - These two images from NASA's Total Ozone Mapping Spectrometer (TOMS) instrument show dust coming off regional land sources in Africa as they follow their path across the Atlantic. The TOMS instrument aboard the Earthprobe TOMS satellite, captured these images of the dust event from June 17, 1999, as it leaves Africa. The second image from July 2, 1999, shows the progression of this event as it approaches North America. Red shows higher concentrations of dust.
Courtesy: NASA
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| ITEM (5): Traveling 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 one to two weeks for the dust clouds to cross the Atlantic Ocean and reach the continental United States..
Courtesy: NASA
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| ITEM (6): Karenia Brevis Image - An image of the single-celled, plant-like organism that causes red tide in Florida is called Karenia brevis (frequently shortened to K. brevis). K. brevis is a type of microalgae known as a dinoflagellate. It has two flagella, or whip-like tails, to help it move through the water. While K. brevis has come to be known as the Florida Gulf Coast red tide organism, it has been implicated in blooms on Florida's east coast, as well as in Louisiana, Texas, Mississippi, Mexico and the Carolinas.
Courtesy: Florida Fish and Wildlife Conservation Commission/Florida Marine Research Institute
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