Contributions of Particle Absorption to Mass Extinction Coefficients (0.55-14Micrometer) of Soil-Derived Atmospheric Dusts

摘要

Mass extinction coefficients of soil-derived atmospheric dust often are determined largely by the absorption (rather than scattering) by individual particles, especially at longer infrared wavelengths. Under many conditions, reasonable estimates of mass extinction coefficients of dusts can be made from absorption coefficients without detailed knowledge of particle optical constants to perform, for example, Mie calculations. This report discusses absorption coefficients of dusts in the visible and IR wavelengths and the physical mechanisms of dust aerosol generation determining that portion of extinction attributable to absorption in a given dust cloud. Some soils, especially clays, can produce dust clouds that are almost pure absorbers at longer IR wavelengths. Soils, Dusts, Aerosols, Optical extinction, Infrared absorption, Extinction coefficients, Fort benning, Atmospheric dusts, Dust minerals. (mjm)