Department of Chemistry , University of California , Irvine , California 92697 , United States.
Office of Research and Development , U.S. EPA , Research Triangle Park , North Carolina 27709 , United States.
Environ Sci Technol. 2018 Aug 21;52(16):9254-9265. doi: 10.1021/acs.est.8b01869. Epub 2018 Jul 30.
Atmospheric models that accurately describe the fate and transport of trace species for the right reasons aid in the development of effective air-quality management strategies that safeguard human health. Controllable emissions facilitate the formation of biogenic secondary organic aerosol (BSOA) to enhance the atmospheric fine particulate matter (PM) burden. Previous modeling with the EPA's Community Multiscale Air Quality (CMAQ) model predicted that anthropogenic primary organic aerosol (POA) emissions had the greatest impact on BSOA. That experiment included formation processes involving semivolatile partitioning but not aerosol liquid water (ALW), a ubiquitous PM constituent. We conduct 17 summertime CMAQ simulations with updated chemistry and evaluate changes in BSOA due to the removal of individual pollutants and source sectors for the contiguous U.S. CMAQ predicts SO from electricity generating units, and mobile source NO emissions have the largest impacts on BSOA. The removal of anthropogenic NO, SO, and POA emissions during the simulation reduces the nationally averaged BSOA by 23, 14, and 8% and PM by 9.2, 14, and 5.3%, respectively. ALW mass concentrations decrease by 10 and 35% in response to the removal of NO and SO emissions. This work contributes chemical insight into ancillary benefits of Federal NO and SO rules that concurrently reduce organic PM mass.
大气模式能够准确描述痕量物质的归宿和迁移，这对于制定有效的空气质量管理策略以保障人类健康非常重要。可控排放有助于生物成因二次有机气溶胶（BSOA）的形成，从而增加大气细颗粒物（PM）的负担。美国环保署（EPA）的综合空气质量模型（CMAQ）此前的建模预测，人为源一次有机气溶胶（POA）排放对 BSOA 的影响最大。该实验包括涉及半挥发性分配的形成过程，但不包括气溶胶液态水（ALW），ALW 是普遍存在的 PM 成分。我们进行了 17 次夏季 CMAQ 模拟，更新了化学内容，并评估了由于去除个别污染物和美国大陆的源部门对 BSOA 造成的变化。CMAQ 预测来自发电单元的 SO，以及移动源 NO 排放对 BSOA 的影响最大。在模拟过程中去除人为源的 NO、SO 和 POA 排放，将全国平均 BSOA 减少了 23%、14%和 8%，将 PM 减少了 9.2%、14%和 5.3%。NO 和 SO 排放去除后，ALW 质量浓度分别下降了 10%和 35%。这项工作为联邦 NO 和 SO 法规同时减少有机 PM 质量的辅助效益提供了化学方面的见解。
