Sahel dust zone and synoptic background



[1] Present weather reports from synoptic station data from 1983 to 2008 are analyzed to establish the climatological existence of a zone of frequent dust events and high dust concentration over the Sahel. This zone, to be referred to as the “Sahel dust zone” (SDZ), is situated between 10°N and 16°N, and is most prevalent during the period between December and April, stretching almost over the entire North African continent from west to east. SDZ corresponds well to the convergence zone located to the north of the African monsoon trough, and the dust is primarily transported from the Sahara. Using the ERA-Interim Reanalysis data, we examine the synoptic patterns in February and March, which generate dust emission from the Sahara and subsequently transport the dust to the Sahel. Three synoptic patterns are found to be mainly responsible for the formation of SDZ.