Incorporated constraints on mineral abundances and complex refractive indices for mineral dust components simulation

Abstract

The sources, transport, and optical properties of various mineral dust components vary significantly. However, most simulations treat dust as a homogeneous mixture, failing to differentiate between individual components. Here, we conducted a comprehensive and quantitative analysis based on mineral abundances from the Earth Surface Dust Source Investigation (EMIT) hyperspectral payload and complex refractive indices to constrain dust emissions. The results indicated that dust emissions in southwestern Asia amounted to 720.3 Tg yr−1, with silicate minerals (quartz and feldspar) and aluminum hydroxide minerals, which are known for their strong scattering properties, accounting for the majority (82.9%), followed by iron-rich minerals with high absorbing characteristics (7.2%). We found pronounced regional variability in the emission, transport, and deposition of different mineral components. Mineral dust component simulation may be the primary approach for reducing uncertainties in dust impacts. Furthermore, only hematite resulted in a significant warming effect (0.17 W/m²) among all the mineral components. The absorbing effect of dust in the mixed dust model has been found to be presumptively overestimated. This study provides a new methodological reference for accounting for mineral element transport in the biosphere and helps reduce uncertainties in analyzing dust optical properties and radiation effects.

Affiliated Institutions

• Qinghai University CN
• Chinese Academy of Sciences CN
• Shaanxi Normal University CN
• Chinese Academy of Agricultural Sciences CN
• Institute of Atmospheric Physics CN

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