HR: 1330h
AN: A22A-1039    [PDF]
TI: Dust transport and deposition observed from the Terra-MODIS space observations
AU: * Kaufman, Y J
EM: kaufman@climate.gsfc.nasa.gov
AF: NASA, NASA Goddard Space Flight Center, code 913, Greenbelt, MD 20771 United States
AU: Koren, I
AF: National Research Council, NASA Goddard Space Flight Center, code 913, Greenbelt, MD 20771 United States
AU: Tanre, D
AF: Laboratoire d'Optique Atmospherique, CNRS,, Universit‚, de Scie. et Techniq. de Lille,, Villeneuve d'Ascq, VA 59655 France
AU: Fan, S
AF: NOAA GFDL,, Princeton University,, Princeton, NJ United States
AU: Remer, L
AF: NASA, NASA Goddard Space Flight Center, code 913, Greenbelt, MD 20771 United States
AU: Ginoux, P
AF: NOAA GFDL,, Princeton University,, Princeton, NJ United States
AB: Meteorological observations, in situ data and satellite images of dust episodes were used already in the 1970s to estimate that 100 tg of dust are transported from Africa over the Atlantic Ocean every year between June and August and deposited in the Atlantic Ocean and the Americas. Desert dust is a main source of nutrients to oceanic biota and the Amazon forest, but deteriorates air quality and caries pathogens as shown for Florida. Dust affects the Earth radiation budget, thus participating in climate change and feedback mechanisms. There is an urgent need for new tools for quantitative evaluation of the dust distribution, transport and deposition. The Terra spacecraft launched at the dawn of the last millennium provides first systematic well calibrated multispectral measurements from the MODIS instrument, for daily global analysis of aerosol. MODIS data are used here to distinguish dust from smoke and maritime aerosols and evaluate the African dust column concentration, transport and deposition. We found that 230ñ80 tg of dust are transported annually from Africa to the Atlantic Ocean, 30 tg return to Africa and Europe, 70 tg reach the Caribbean, 45 tg fertilize the Amazon Basin, 4 times as previous estimates thus explaining a paradox regarding the source of nutrition to the Amazon forest, and 120ñ40 tg are deposited in the Atlantic Ocean. The results are compared favorably with dust transport models for particle radius * 12 æm. This study is a first example of quantitative use of MODIS aerosol for a geophysical study.
DE: 0305 Aerosols and particles (0345, 4801)
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting