Intercontinental Transport and Climatic Impact of Saharan and Sahelian Dust

Abstract

The Sahara and Sahel regions of Africa are important sources of dust particles into the atmosphere. Dust particles from these regions are transported over the Atlantic Ocean to the Eastern American Coasts. This transportation shows temporal and spatial variability and often reaches its peak during the boreal summer (June-July-August). The regional climate model (RegCM 4.0), containing a module of dust emission, transport, and deposition processes, is used in this study. Saharan and Sahelian dusts emissions, transports, and climatic impact on precipitations during the spring (March-April-May) and summer (June-July- August) were studied using this model. The results showed that the simulation were coherent with observationsmade by the MISR satellite and the AERONET ground stations, within the domain of Africa (Banizoumba, Cinzana, and M’Bour) and Ragged-point (Barbados Islands). The transport of dust particles was predominantly from North-East to South-West over the studied period (2005–2010). The seasonality of dust plumes’ trajectories was influenced by the altitudes reached by dusts in the troposphere. The impact of dusts on climate consisted of a cooling effect both during the boreal summer and spring over West Africa (except Southern-Guinea and Northern-Liberia), Central Africa, South-America, and Caribbean where increased precipitations were observed.