Joint International Research Laboratory of Atmospheric and Earth System Sciences, School of Atmospheric Sciences, Nanjing University, Nanjing 210023, China.
Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing 100084, China.
Environ Sci Technol. 2022 Jun 21;56(12):7629-7636. doi: 10.1021/acs.est.2c00090. Epub 2022 Jun 8.
A great challenge for haze pollution mitigation with the existing emission control measures in China is ozone (O) increase. The chemical processes leading to weakened haze mitigation are still poorly understood. Our work identifies the enhanced aging chemistries of black carbon (BC) with increasing O as an essential driver to weaken haze mitigation based on field observations during autumn/winter haze periods in 2014 and 2018 in North China Plain. The enhanced atmospheric oxidation capacity induced by increasing O promotes the initial aging of accumulated fresh BC from continuous emission under haze pollution conditions and consequently improves the hygroscopicity of BC-containing particles to provide more particulate surfaces and volumes for aqueous and heterogeneous chemistries. The enhanced BC aging amplifies PM concentrations by ∼20%, which can be broken by concurrent reductions in multipollutant emissions (i.e., BC, nitrogen oxides, and volatile organic compounds), especially from residential and industrial sources. Moreover, enhanced BC aging implies an adverse effect of O increase on climate change. Observationally enhanced BC aging will help to constrain estimations of the interactions among O increase, haze pollution, and climate warming in recent years in China.
在中国现有的排放控制措施下，缓解雾霾污染面临的一个巨大挑战是臭氧（O）的增加。导致雾霾缓解减弱的化学过程仍未得到很好的理解。我们的工作通过 2014 年和 2018 年秋冬季在中国华北平原的实地观测，确定了随着 O 的增加，黑碳（BC）的增强老化化学过程是削弱雾霾缓解的一个重要驱动因素。O 的增加引起的大气氧化能力增强，促进了在雾霾污染条件下连续排放的累积新鲜 BC 的初始老化，从而提高了含 BC 颗粒的吸湿性，为水相和非均相化学提供了更多的颗粒表面和体积。增强的 BC 老化使 PM 浓度增加了约 20%，而多污染物排放（即 BC、氮氧化物和挥发性有机化合物）的同时减少（特别是来自住宅和工业源的排放）可以打破这种情况。此外，增强的 BC 老化意味着 O 增加对气候变化的不利影响。观测到的增强的 BC 老化将有助于约束近年来中国 O 增加、雾霾污染和气候变暖之间相互作用的估计。
