Long-Term Changes in Summertime Nitrate Chemistry in the Top Boundary Layer of North China
Reducing fine particulate nitrate (pNO<sub>3</sub><sup>-</sup>) is critical for further mitigating PM<sub>2.5</sub> pollution in China. However, previous NO<sub><i>x</i></sub> emission reductions have failed to achieve the expected pNO<sub>3</sub><sup>-</sup> decreases. The present study reports that pNO<sub>3</sub><sup>-</sup> concentration in summer increased by 55.8% and 5.6% at North China Peak (1534 m a.s.l.) from 2007 to 2014 and 2014 to 2021, respectively. pNO<sub>3</sub><sup>-</sup> formation enhancement was caused mainly by decreased aerosol acidity due to notable SO<sub>4</sub><sup>2-</sup> reduction. pNO<sub>3</sub><sup>-</sup> formation changed from a process limited by NH<sub>4</sub><sup>+</sup> to one colimited by NO<sub>2</sub> and NH<sub>4</sub><sup>+</sup>, suggesting an increased effect of NO<sub><i>x</i></sub> reduction on decreasing pNO<sub>3</sub><sup>-</sup> production. Vertical transport represents a significant source of pNO<sub>3</sub><sup>-</sup> near the surface, illustrating a percentage as high as 98% recorded during daytime hours and a proportion of 34% in the dark over North China in the simulation scenario during summer 2020. The scheme to reduce NO<sub><i>x</i></sub> emissions by 10% from 2020 to 2025 is predicted to slowly decrease aloft pNO<sub>3</sub><sup>-</sup> over North China, which may facilitate further reductions in pNO<sub>3</sub><sup>-</sup> concentrations near the surface via vertical transport. The inflection of nitrate chemistry in the top boundary layer suggests an opportunity to accelerate PM<sub>2.5</sub> reduction under projected further emission reductions.
Authors
- Hartmut Herrmann (ORCID: https://orcid.org/0000-0001-7044-2101)
- Wei Tang (ORCID: https://orcid.org/0000-0002-7529-3608)
- Fahe Chai (ORCID: https://orcid.org/0000-0002-8796-232X)
- Jian Gao (ORCID: https://orcid.org/0000-0001-8605-8454)
- Yujiao Zhu (ORCID: https://orcid.org/0000-0002-0007-7468)
- Yang Li (ORCID: https://orcid.org/0000-0003-0021-0166)
- Guigang Tang
- Can Dong (ORCID: https://orcid.org/0000-0003-0911-2378)
- Likun Xue (ORCID: https://orcid.org/0000-0001-7329-2110)
- Jingnan Hu (ORCID: https://orcid.org/0000-0003-0078-6181)
- Rui Gao (ORCID: https://orcid.org/0000-0002-8476-0925)
- Abdelwahid Mellouki (ORCID: https://orcid.org/0000-0002-6594-5262)
- Aijun Ding (ORCID: https://orcid.org/0000-0003-4481-5386)
- Jiaqi Wang (ORCID: https://orcid.org/0000-0001-9445-5652)
- Yujie Zhang (ORCID: https://orcid.org/0000-0003-4833-2031)
- Tao Wang (ORCID: https://orcid.org/0000-0002-4765-9377)
- Haisheng Li
- Jianmin Chen (ORCID: https://orcid.org/0000-0001-5859-3070)
- Liang Wen (ORCID: https://orcid.org/0000-0003-3086-7337)
- Yong Zhao (ORCID: https://orcid.org/0000-0002-2841-047X)
- Xinfeng Wang (ORCID: https://orcid.org/0000-0003-0911-7312)
- Xiaohui Du (ORCID: https://orcid.org/0000-0001-5444-9434)
- Zhaoxin Guo (ORCID: https://orcid.org/0000-0002-1655-3457)
Institutions
- Centre National de la Recherche Scientifique (FR)
- Hong Kong Polytechnic University (HK)
- Shandong University (CN)
- Fudan University (CN)
- China National Environmental Monitoring Center (CN)
- Leibniz Institute for Tropospheric Research (DE)
- Sustainable Innovation (Sweden) (SE)
- The Polytechnic University of Japan (JP)
- Université Mohammed VI Polytechnique (MA)
- Institut de Combustion Aérothermique Réactivité et Environnement (FR)
- Chinese Research Academy of Environmental Sciences (CN)
- Nanjing University (CN)
Publication Details
- Journal
- Environmental Science & Technology
- Published
- 2025-05-28
- DOI
- https://doi.org/10.1021/acs.est.5c03079
- Citations
- 2
- Primary Topic
- Atmospheric chemistry and aerosols
- Type
- article
- Field-Weighted Citation Impact
- 2.60
Funders
- National Natural Science Foundation of China
- National Key Research and Development Program of China