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May 15, 2003
Scientists Dust Off Desert Sands from the French Alps
NASA funded scientists, using an atmospheric computer model, proved
for the first time dust from China's TaklaMakan desert traveled more
than 12,400 miles (20,000 kilometers) over two weeks and landed on the
French Alps. Chinese dust plumes have reached North America and Greenland,
but had not been reported in Europe.
The findings are highlighted in a paper authored by Francis E. Grousset
of the Lamont-Doherty Earth Observatory of Columbia University (LDEOCU),
Palisades, N.Y., and Universite Bordeaux, France; Aloys Bory and Pierre
E. Biscaye, also of LDEOCU; and Paul Ginoux, University of Maryland,
Baltimore County (UMBC) and NASA's Goddard Space Flight Center (GSFC),
Greenbelt, Md. The study appeared in a recent issue of the American Geophysical
Union's Geophysical Research Letters.
This study looked at dust that traveled from February 25 to March 7,
1990. "The dust particles traveled around the world in about two weeks,
and along their journey, crossed China, the North Pacific, North America
and the North Atlantic Ocean," Ginoux said.
Research conducted in 1994 showed, over the 20 years prior, a score
of red dust events coated the snow cover in the French Alps and Pyrenees
mountains. The red dust topping these European mountain ranges was sampled
and stored in bags for comparison with dust from other parts of the world.
Scientists analyze the minerals and compositions of certain distinctive
elements (isotopes) of the dust to identify its origin. Information about
the origins and final locations of dust are important to help determine
any effects from heavy metal, fungal, bacterial and viral distribution
that may be associated with it.
Ginoux and his colleagues used NASA technology and support in their
research. Meteorological information, such as wind speed and direction,
precipitation, air pressure, and temperature, were put into a computer
model. The model recreated how the atmosphere moved as the dust traveled
from China to the Alps. The meteorological information was from GSFC's
Earth Observing System Data Assimilation System.
Several computer models, simulating the movement of dust in the atmosphere,
were used to track its journey in this study. The Global Ozone Chemistry
Aerosol Radiation Transport computer model, largely funded by NASA, uses
the winds, soil moisture, and surface characteristics to simulate dust
generation and transport. The National Oceanic and Atmospheric Administration's
(NOAA) Air Resources Laboratory (ARL), provided models showing the paths
of air masses, as they moved around the world, from the time the dust
was swept into the atmosphere to when it settled on the Alps.
ARL can project where air pollution will move based on meteorological
conditions. NOAA's National Weather Service National Center for Environmental
Prediction re-analyzed global meteorological conditions and plotted the
dust movement to verify the computer models.
This research was funded by France's National Center for Scientific
Research, NASA's Earth Science Enterprise (ESE), and the National Science
Foundation. NASA's ESE is dedicated to understanding the Earth as an
integrated system and applying Earth System Science to improve prediction
of climate, weather and natural hazards using the unique vantage point
of space.
For information about NASA's Earth Science Enterprise on the
Internet, visit:
http://www.earth.nasa.gov/
For the Global Ozone Chemistry Aerosol Radiation Transport
computer model, visit:
http://code916.gsfc.nasa.gov/People/Chin/aot.html
For NOAA's Air Resources Laboratory, visit:
http://www.arl.noaa.gov/ready/
For the National Center for Scientific Research, visit:
http://www.cnrs.fr/
For the National Weather Service's National Center for
Environmental Prediction, visit:
http://wwwt.ncep.noaa.gov/
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Contacts:
Rob Gutro
Goddard Space Flight Center, Greenbelt, Md.
301-286-4044
Rgutro@pop900.gsfc.nasa.gov
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Dust Storm over China's Taklimakan Desert
This image was taken on April 14, 2002, from the MODIS Instrument on NASA's Terra Satellite.
CREDIT: MODIS Land Rapid Response Team, NASA/GSFC
A Dusty Path from China to France
The spiked line shows the dust's 315 hour (13+ days) trip from the Takla-Makan desert in China,
circling the world (counterclockwise) and landing in the French Alps on March 6, 1990.
The black star is where scientists gathered samples.
CREDIT: NOAA ARL
GOCART Model's Dust Path: 2-25-90 to 3-7-90
This time series of dust movement was generated from the GOCART model, and the NOAA NCEP
projection is depicted by the thick black line. It shows movement from China to the French
Alps projected as moving in the air almost 2 miles above sea-level. CREDIT: NOAA / NASA
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