88th Annual Meeting (20-24 January 2008)

Monday, 21 January 2008: 10:45 AM
North African dust production: past, present and future (Invited)
217-218 (Ernest N. Morial Convention Center)
Richard Washington, University of Oxford, Oxford, United Kingdom
Dust production mechanisms in North Africa are evaluated for two key sources regions, the Bodele Depression in Chad, the primary winter source and the summer source in Mali and Mauritania. Controls on these mechanisms in both the present and the past are evaluated and, in the case of the Bodele, a conceptual model of the long term dust cycle is presented. The winter source is spatially anchored by the co-location of the Bodele Low Level Jet and the erodible sediments of palaeo lake Chad, both of which were quantified by the BoDEx 2005 field experiment. This source is unambiguously represented in a variety of satellite derived estimates of dust loadings. In contrast, the summer source is spatially variable, difficult to trace to specific erosivity mechanisms and is variably represented by the satellite products. The future of the Bodele is assessed from an assortment of IPCC AR4 simulations.

Supplementary URL: