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Titel |
Transport of North African dust from the Bodélé depression to the Amazon Basin: a case study |
VerfasserIn |
Y. Ben-Ami, I. Koren, Y. Rudich, P. Artaxo, S. T. Martin, M. O. Andreae |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7316
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 10, no. 16 ; Nr. 10, no. 16 (2010-08-16), S.7533-7544 |
Datensatznummer |
250008703
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Publikation (Nr.) |
copernicus.org/acp-10-7533-2010.pdf |
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Zusammenfassung |
Through long-range transport of dust, the North-African desert supplies
essential minerals to the Amazon rain forest. Since North African dust
reaches South America mostly during the Northern Hemisphere winter, the dust
sources active during winter are the main contributors to the forest. Given
that the Bodélé depression area in southwestern Chad is the main
winter dust source, a close link is expected between the Bodélé
emission patterns and volumes and the mineral supply flux to the Amazon.
Until now, the particular link between the Bodélé and the Amazon
forest was based on sparse satellite measurements and modeling studies. In
this study, we combine a detailed analysis of space-borne and ground data
with reanalysis model data and surface measurements taken in the central
Amazon during the Amazonian Aerosol Characterization Experiment (AMAZE-08)
in order to explore the validity and the nature of the proposed link between
the Bodélé depression and the Amazon forest.
This case study follows the dust events of 11–16 and 18–27 February 2008,
from the emission in the Bodélé over West Africa (most likely with
contribution from other dust sources in the region) the crossing of the
Atlantic Ocean, to the observed effects above the Amazon canopy about 10 days
after the emission. The dust was lifted by surface winds stronger
than 14 m s−1, usually starting early in the morning. The lofted dust,
mixed with biomass burning aerosols over Nigeria, was transported over the
Atlantic Ocean, and arrived over the South American continent. The top of
the aerosol layer reached above 3 km, and the bottom merged with the
boundary layer. The arrival of the dusty air parcel over the Amazon forest
increased the average concentration of aerosol crustal elements by an order
of magnitude. |
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