Estimating effective dust particle size from satellite observations

Abstract

Particle size is a fundamental variable in the dust aerosol cycle. A dust layer effective particle size is strongly related to its’ radiative forcing and the extent of its impact on an area of interest. However, in-situ measurements of dust particle size are costly, spatially sparse and time-consuming. This paper presents a simple empirically derived model to estimate effective dust diameter using infrared band brightness temperature difference of the 8.7 and 12.0 µm wavelength bands retrieved from the SEVIRI (Spinning Enhanced Visible and InfaRed Imager) radiometer onboard Meteosat satellites. Three case studies were used to test the model. The results showed consistency between the model and in-situ aircraft fly through sampling of dust particle size. The use of the model is demonstrated by presenting an analysis of a severe dust storm over Western Asia. This model is expected to contribute to addressing the discrepancies between the current particle size retrieval techniques and aircraft measurements. There are many potential applications for this model including providing an independent reference data for atmospheric dust models, forecasting the impact of dust storms on horizontal visibility as well as the solar energy system performance over regions prone to dust storms.