Global transport of dust emitted from different regions of the Sahara

Abstract

An improved understanding of how emissions from different regions are transported globally is necessary to establish stronger causal relationships between particulate matter emissions and global scale circulation. This study uses the GEOS-Chem global chemical transport model to identify spatial differences in the transport of Saharan dust emitted from different regions in Northern Africa, during different seasons, and in different particle size modes. This study finds noticeable spatial differences in the transport of dust emitted from each region of the Sahara and during each season. Dust emitted from the northern regions of the Sahara undergoes 25% more latitudinal and 2% more longitudinal transport than dust emitted from the more southern regions. Dust originating from the central regions of the Sahara experiences 28% and 11% more longitudinal transport than dust from western and eastern regions, respectively. Dust emitted from the Sahara during the period from April to June travels 10%, 25%, and 17% percent further latitudinally, longitudinally, and vertically, respectively, than the annual average. As expected coarse mode particles travel shorter distances than fine mode particles. Rather than determining the regions which produce the most dust, we focus on identifying the regions producing the dust that is most extensively transported.