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| Titel |
Temporal variability of mineral dust concentrations over West Africa: analyses of a pluriannual monitoring from the AMMA Sahelian Dust Transect |
| VerfasserIn |
B. Marticorena, B. Chatenet, J. L. Rajot, S. Traoré, M. Coulibaly, A. Diallo, I. Koné, A. Maman, T. NDiaye, A. Zakou |
| 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. 18 ; Nr. 10, no. 18 (2010-09-21), S.8899-8915 |
| Datensatznummer |
250008786
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| Publikation (Nr.) |
 copernicus.org/acp-10-8899-2010.pdf |
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| Zusammenfassung |
| The Sahelian belt is known to be a region where atmospheric levels of suspended
mineral dust are among the highest observed on Earth. In the framework of the AMMA
(African Monsoon Multidisciplinary Analysis) International Program, a transect of 3 ground
based stations, the "Sahelian Dust Transect" (SDT), has been deployed in order to obtain
quantitative information on the mineral dust content and its variability over the Sahel. The
three stations, namely Banizoumbou (Niger), Cinzana (Mali) and M'Bour (Senegal) are
aligned around 14° N along the east-westward main pathway of the Saharan and Sahelian dust
towards the Atlantic Ocean.
We discuss data collected between January 2006 and December 2008 to investigate
the main characteristics of the mineral dust concentration over West Africa and their
connection with the dominant meteorological situations. The succession of the dry season
during which the Sahel is under the influence of the dry Harmattan wind and the wet season
induced by the entrance of the monsoon flow is clearly identified from the basic
meteorological parameters (air temperature and moisture, wind direction). Atmospheric dust
concentrations at the three stations exhibit a similar seasonal cycle, with a monthly maximum
during the dry season and a minimum occurring during the rainy season, indicating that the
general pattern of dust concentration is similar at regional scale. This seasonal cycle of the
dust concentrations is not phased with the seasonal cycle of surface wind velocity locally
measured, suggesting that it is mainly controlled by Saharan dust transport. Local dust
emissions induced by strong surface winds are responsible for the occurrence of extremely
high daily concentrations observed at the beginning of the rainy season. A decrease in the dust
concentration is observed when moving from Niger to Senegal. |
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