1. Size distribution of PM20 observed to the north of the Tibetan Plateau
- Author
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Chenglong Zhou, Wen Huo, Xinghua Yang, Ali Mamtimin, and Fan Yang
- Subjects
Global and Planetary Change ,geography ,Plateau ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Geography, Planning and Development ,Geology ,010502 geochemistry & geophysics ,Spatial distribution ,Atmospheric sciences ,complex mixtures ,01 natural sciences ,Particle-size distribution ,Environmental science ,Aeolian processes ,Mass concentration (chemistry) ,Shear velocity ,Particle size ,Observation data ,0105 earth and related environmental sciences ,Nature and Landscape Conservation ,Earth-Surface Processes - Abstract
The size distribution of airborne dust particles is an important parameter in the measurement of dust emissions due to wind erosion, and a quantitative and accurate description is necessary. Observations regarding the size distribution of airborne dust particles are currently lacking in Tibetan Plateau (TP). This study aims to obtain a dust particle size distribution and compare the difference in spatial distribution at a field site (FS) and two urban observation sites (Minfeng and Hetian), in the north of the TP, under the condition of the dust-days and clear-days. The observation data was collected from 5 July to 4 August, 2019. The mass concentration of dust (PM20) was measured with a 10-stage quartz crystal microbalance cascade impactor. The results suggested that 91.9% of the particles were less than 1.4 µm on clear-days, and particles of d ≥ 1.4 µm increased to 27.2% with the occurrence of the dust events. More than 80% of the airborne dust particles were less than 1.4 µm for each friction velocity. The proportion of d 0.7 μm was the greatest at 0.5 m on clear-days. During urban observation, with the occurrence of dust events, the concentration of a particle size greater than 2.5 µm increased most significantly in Minfeng, while the concentration of a particle size less than 0.7 µm increased most significantly in Hetian. Moreover, the proportion of particles with d 1.4 µm had the most obvious difference among these three sites.
- Published
- 2021