Dust transport and deposition

Abstract

Dust particles, once airborne, can be carried by winds to various distances from the source region and deposited back onto the surface somewhere downstream. Dust transport and deposition are thus key links in the dust cycle. The understanding of these processes has applications in a wide range of research fields. From the perspective of geological studies, dust transport and deposition are important mechanisms for the delivery of sediments and minerals from continent to ocean and for the evolution of surface topography. For example, the formation of the loess plateau in China is believed to be a result of the deposition of dust and silt particles originating from the upstream desert areas. In the atmosphere, the presence of dust particles influences processes such as cloud formation and radiation transfer. High concentration of fine particulates in air is of concern to human health, and PM10 and PM2.5 have been used as key indicators of air quality. Dust particles from certain regions may carry harmful substances, and the fates of such particles are naturally of environmental concern. In this chapter, we focus on the physics of dust transport and deposition and study how these processes can be quantified.