Size and chemistry for soil-emitted dust aerosols in the Taklimakan desert
Description
The datasets include all the original data used in the paper of New understanding on the geochemical constraints on the sources and chemical processing of dust aerosols from the Taklimakan Desertwhich was submitted to the journal of Earth and Planetary Science Letters (EPSL)
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1. Twenty-four surface (0¬–5 cm) sediments, including 12 from the sandy desert and 12 from the gravel deserts, were collected in the Taklimakan Desert. Soil-emitted dust was laboratory-generated from the surface sediments of gravel and sandy deserts of the Taklimakan Desert by simulating natural dust-emission processes (sandblasting). 2. In situ measurements of the number size distribution of the dust aerosols between 0.5 and 20 μm in aerodynamic diameter were made using an APS 3321 particle counter (TSI Incorporated, Shoreview, MN, USA). Size measurement was carried out at five (800, 1000, 1200, 1400, and 1600 rpm) blade rotation rates. The mass was calculated assuming that the particles were spherical and had a density of 2.65 g cm-3. 3. PM10 and PM2.5 (particulate matter with aerodynamic diameters less than 10 and 2.5 μm, respectively) were collected on quartz and Teflon® filters (diameter = 47 mm, Whatman, USA), respectively, using mini-vol samplers (Airmetrics, Eugene, OR, USA) in a cylindrical gas buffer tank. Field blank samples were collected every day. 4. For the gravimetric measurements, the Teflon® filters were equilibrated at 20–23 °C and relative humidity (RH) 35–50% for 24 h to minimize the possible influences of water absorption. The filters were weighed using an ME 5-F electronic microbalance (Sartorius, Gottingen, Germany), which had a sensitivity of 0.001 mg 5. Elements on the equilibrated Teflon® filters were quantified by energy dispersive X-ray fluorescence (ED-XRF) spectrometry (Epsilon 5 ED-XRF, PANalytical B. V., the Netherlands). 6. Dionex DX-600 ion chromatography (Sunnyvale, CA, USA) was used to quantify the sulfate (SO42-), nitrate (NO3-), chloride (Cl-), sodium (Na+), potassium (K+), ammonium (NH4+), calcium (Ca2+), and magnesium (Mg2+) ions in the quartz filter samples. Half of each filter was extracted in 10 mL distilled water by ultrasonic agitation for 30 min. The extract was filtered through 0.45-µm microporous membranes for water-soluble ions. 7. Mass fractions (abundances) were calculated for each measured component after blank subtraction.