Scientists Dust Off Desert Sands From The French Alps

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 Université 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 Pyrénées 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 more information about the research and images on the Internet, visit:

http://www.gsfc.nasa.gov/topstory/2003/0427sandalps.html

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/