Temporal variability of mineral dust concentrations over West Africa: analyses of a pluriannual monitoring from the AMMA Sahelian Dust Transect

摘要: Abstract. The Sahelian belt is known to be a region where atmospheric levels of suspended mineral dust are among the highest observed on Earth. In framework AMMA (African Monsoon Multidisciplinary Analysis) International Program, transect 3 ground based stations, "Sahelian Dust Transect" (SDT), has been deployed in order obtain quantitative information content and its variability over Sahel. three namely Banizoumbou (Niger), Cinzana (Mali) M'Bour (Senegal) aligned around 14° N along east-westward main pathway Saharan towards Atlantic Ocean. We discuss data collected between January 2006 December 2008 investigate characteristics concentration West Africa their connection with dominant meteorological situations. succession dry season during which Sahel under influence Harmattan wind wet induced by entrance monsoon flow clearly identified from basic parameters (air temperature moisture, direction). Atmospheric concentrations at stations exhibit similar seasonal cycle, monthly maximum minimum occurring rainy season, indicating that general pattern regional scale. This cycle not phased surface velocity locally measured, suggesting it mainly controlled transport. Local emissions strong winds responsible for occurrence extremely high daily beginning season. A decrease when moving Niger Senegal.