Light scattering and absorption by wind blown dust: Theory, measurement, and recent data

Large quantities of dust with diameters <10 μm are dispersed in earth’s atmosphere by wind-driven processes. This dust is of significant scientific interest owing to its ability to potentially alter climate, reduce local visibility, cause respiratory problems in humans, and affect biogeochemical cycles in the world’s oceans. In this work, we present a review of the theory of light scattering and absorption by small particles, discuss common measurement techniques used to characterize the optical properties of airborne particulates, and summarize recent measurements of the optical properties of airborne dust. For the review of recent measurements we focus on the visible and near IR properties of dust, and present Angstrom exponents, real and imaginary parts of refractive index, and single scatter albedo data obtained and published by other authors for a variety of locations in the Northern Hemisphere dust belt and Australia.