Fig. 2

SEM images of Asian dust particles acquired at an acceleration voltage of 15 kV and a working distance of 9 mm using a TESCAN MIRA 3XMH field emission SEM. EDS spectra were acquired at 15 kV using an Oxford X-MAX detector. EDS spectra in the energy range of 0.6–5 keV are added on the images. Scale bar = 2 μm. a Dust particles collected on cellulose filter using a TSP sampler. b–l Coarse mineral grains coated with the coatings of micron and submicron clay minerals. Coarse minerals are quartz in (b), Na-rich plagioclase (albite) in (c), plagioclase in (d), K-feldspar in (e), illite/muscovite plate in (f), biotite plate (g). chlorite in (h), amphibole in (i), calcite in (j), dolomite in (k), and iron oxide in (l). m Aggregate of kaolinite. n and o Aggregate of ISCMs (illite–smectite series clay minerals). p Amorphous silica (diatom frustule). q Very coarse dust particle. Arrows in (c) indicate calcite nanofibers. Arrow in (o) indicates gypsum blade. Dust particles in (a) were collected in Korea, 16 Mar 2009. Dust particles in (b)–(p) were collected in Korea, 23 Feb 2015. Dust particle in (q) was collected in Korea, 31 Mar 2012