Sources and atmospheric dynamics of organic aerosol in New Delhi, India: insights from receptor modeling
Sources and atmospheric dynamics of organic aerosol in New Delhi, India: insights from receptor modeling
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DOI：
10.5194/acp-20-735-2020
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发表时间：
2020-01-22
影响因子：
6.3
通讯作者：
Hildebrandt Ruiz, Lea
中科院分区：
文献类型：
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作者：
Bhandari, Sahil;Gani, Shahzad;Hildebrandt Ruiz, Lea
印度德里是世界上人口第二多的城市，经常经历地球上任何大城市中最高的颗粒物浓度，对公共卫生构成严峻挑战（世界卫生组织，2018年）。然而，目前对德里PM污染的来源和动态的了解是有限的。在德里气溶胶超级站点（DAS）的测量提供了德里环境亚微米气溶胶的长期化学特征，并对气溶胶成分进行了近乎连续的在线测量。本文报告了基于正矩阵分解（PMF）的源分配，该分配在2017年1月至2018年3月期间对15个月的高度时间分辨的特定亚微米非耐火PM1 （NR-PM1）进行了研究。我们使用2017年和2018年两个冬季和春季的数据报告了2017年四个季节的季节变化和年际变化。我们表明，一个改进的基于示踪剂的有机成分分析提供了一个实时源分配方法在德里的有机物的机会。使用扩展气溶胶无机物模型（E-AIM）的气溶胶相平衡建模预测平衡气相浓度，并允许评估通风系数（VC）和温度在控制初级和次级有机气溶胶中的重要性。我们还发现，一次气溶胶在严重空气污染事件中占主导地位，而二次气溶胶在季节平均值中占主导地位。
Delhi, India, is the second most populated city in the world and routinely experiences some of the highest particulate matter concentrations of any megacity on the planet, posing acute challenges to public health (World Health Organization, 2018). However, the current understanding of the sources and dynamics of PM pollution in Delhi is limited. Measurements at the Delhi Aerosol Supersite (DAS) provide long-term chemical characterization of ambient submicron aerosol in Delhi, with near-continuous online measurements of aerosol composition. Here we report on source apportionment based on positive matrix factorization (PMF), conducted on 15 months of highly time-resolved speciated submicron non-refractory PM1 (NR-PM1) between January 2017 and March 2018. We report on seasonal variability across four seasons of 2017 and interannual variability using data from the two winters and springs of 2017 and 2018. We show that a modified tracer-based organic component analysis provides an opportunity for a real-time source apportionment approach for organics in Delhi. Phase equilibrium modeling of aerosols using the extended aerosol inorganics model (E-AIM) predicts equilibrium gasphase concentrations and allows evaluation of the importance of the ventilation coefficient (VC) and temperature in controlling primary and secondary organic aerosol. We also find that primary aerosol dominates severe air pollution episodes, and secondary aerosol dominates seasonal averages.