Dust storms are associated with large amounts of particulate matter (PM) that can have adverse effects on health and the environment. The contribution of natural dust to atmospheric PM levels represents a scientific challenge, especially in areas with close proximity to dust sources. To improve our knowledge in this area, we collected 300 PM filter-samples across five oasis cities on the southern edge of the Taklimakan Desert in 2016, and applied the Modern-Era Retrospective Analysis for Research and Applications version 2 (MERRA-2) data to quantify the contribution of natural dust to PM on sand dust and non-sand dust days. Research has shown that the particle size distribution of mineral dust in Taklimakan dust aerosols was relatively uniform. On sand dust days, CaSO4 and Na2SO4 were directly emitted from the surface, leading to higher sulfate concentrations in PM. While the increase in the proportions of organic carbon - OC1 and OC2 was attributed to the mixed anthropogenic emissions. On non-sand dust days, SO42− concentration was significantly affected by emissions from anthropogenic sources. The automotive composite emissions and coal combustion were the main sources of elemental carbon - EC1. Based on the results of MERRA-2 reanalysis data, natural dust constituted 53 % and 70 % of the total PM2.5 and PM10, respectively. In this study, we have quantified the contribution of natural dust under different weather conditions and identifying potential sources of PM in oasis cities. This study provides support for the assessment of natural dust and PM prevention in oasis cities.

中文翻译：

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基于MERRA-2和多站点地面观测的塔克拉玛干沙漠南缘绿洲城市人为和自然成分对颗粒物的影响


沙尘暴与大量颗粒物 （PM） 有关，这些颗粒物 （PM） 可能对健康和环境产生不利影响。自然尘埃对大气 PM 水平的贡献是一项科学挑战，尤其是在靠近尘埃源的地区。为了提高我们在这一领域的知识，我们于 2016 年在塔克拉玛干沙漠南部边缘的五个绿洲城市收集了 300 个 PM 过滤样本，并应用了研究和应用现代回顾性分析第 2 版 （MERRA-2） 数据来量化自然尘埃对沙尘和非沙尘日颗粒物的贡献。研究表明，塔克拉玛干尘埃气溶胶中矿物尘埃的粒径分布相对均匀。在沙尘日，CaSO4 和 Na2SO4 直接从表面排放，导致 PM 中的硫酸盐浓度更高。而有机碳 - OC1 和 OC2 比例的增加归因于混合人为排放。在非沙尘日，SO42− 浓度受到人为来源排放的显着影响。汽车复合材料排放和煤炭燃烧是元素碳 - EC1 的主要来源。根据 MERRA-2 再分析数据的结果，天然尘埃分别占 PM2.5 和 PM10 总量的 53% 和 70%。在这项研究中，我们量化了不同天气条件下自然尘埃的贡献，并确定了绿洲城市中 PM 的潜在来源。本研究为绿洲城市自然尘埃和 PM 预防的评估提供了支持。