Articles | Volume 26, issue 1
https://doi.org/10.5194/acp-26-623-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-26-623-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Divergent drivers of aerosol acidity: evidence for shifting regulatory regimes in a coastal region
Jinghao Zhai
Shenzhen Key Laboratory of Precision Measurement and Early Warning Technology for Urban Environmental Health Risks, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
Guangdong Provincial Observation and Research Station for Coastal Atmosphere and Climate of the Greater Bay Area, Shenzhen 518055, China
Department of Geophysical Sciences, University of Chicago, Chicago 60637, IL, USA
Yujie Zhang
Shenzhen Key Laboratory of Precision Measurement and Early Warning Technology for Urban Environmental Health Risks, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
Baohua Cai
Shenzhen Key Laboratory of Precision Measurement and Early Warning Technology for Urban Environmental Health Risks, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
Yaling Zeng
Shenzhen Key Laboratory of Precision Measurement and Early Warning Technology for Urban Environmental Health Risks, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
Guangdong Provincial Observation and Research Station for Coastal Atmosphere and Climate of the Greater Bay Area, Shenzhen 518055, China
Jingyi Zhang
Shenzhen Key Laboratory of Precision Measurement and Early Warning Technology for Urban Environmental Health Risks, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
Jianhuai Ye
Shenzhen Key Laboratory of Precision Measurement and Early Warning Technology for Urban Environmental Health Risks, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
Guangdong Provincial Observation and Research Station for Coastal Atmosphere and Climate of the Greater Bay Area, Shenzhen 518055, China
Chen Wang
Shenzhen Key Laboratory of Precision Measurement and Early Warning Technology for Urban Environmental Health Risks, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
Guangdong Provincial Observation and Research Station for Coastal Atmosphere and Climate of the Greater Bay Area, Shenzhen 518055, China
Tzung-May Fu
Shenzhen Key Laboratory of Precision Measurement and Early Warning Technology for Urban Environmental Health Risks, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
Guangdong Provincial Observation and Research Station for Coastal Atmosphere and Climate of the Greater Bay Area, Shenzhen 518055, China
Shenzhen Key Laboratory of Precision Measurement and Early Warning Technology for Urban Environmental Health Risks, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
Guangdong Provincial Observation and Research Station for Coastal Atmosphere and Climate of the Greater Bay Area, Shenzhen 518055, China
Huizhong Shen
Shenzhen Key Laboratory of Precision Measurement and Early Warning Technology for Urban Environmental Health Risks, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
Guangdong Provincial Observation and Research Station for Coastal Atmosphere and Climate of the Greater Bay Area, Shenzhen 518055, China
Shenzhen Key Laboratory of Precision Measurement and Early Warning Technology for Urban Environmental Health Risks, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
Guangdong Provincial Observation and Research Station for Coastal Atmosphere and Climate of the Greater Bay Area, Shenzhen 518055, China
Related authors
Baohua Cai, Yuanlong Huang, Wenqing Jiang, Yanchen Li, Yali Li, Jinghao Zhai, Yaling Zeng, Jianhuai Ye, Huizhong Shen, Chen Wang, Lei Zhu, Tzung-May Fu, Qi Zhang, and Xin Yang
EGUsphere, https://doi.org/10.5194/egusphere-2025-5323, https://doi.org/10.5194/egusphere-2025-5323, 2025
Short summary
Short summary
This study reveals a novel Ultraviolet A-driven, metal-free mechanism for aqueous-phase tetravalent sulfur (S(IV)) oxidation that leads to organosulfates formation, addressing a critical knowledge gap in atmospheric sulfur and organic aerosol chemistry and highlighting a previously overlooked photochemical pathway with broad environmental implications.
Jinghao Zhai, Yin Zhang, Pengfei Liu, Yujie Zhang, Antai Zhang, Yaling Zeng, Baohua Cai, Jingyi Zhang, Chunbo Xing, Honglong Yang, Xiaofei Wang, Jianhuai Ye, Chen Wang, Tzung-May Fu, Lei Zhu, Huizhong Shen, Shu Tao, and Xin Yang
Atmos. Chem. Phys., 25, 7959–7972, https://doi.org/10.5194/acp-25-7959-2025, https://doi.org/10.5194/acp-25-7959-2025, 2025
Short summary
Short summary
Our study shows that the optical properties of brown carbon depend on its source. Brown carbon from ozone pollution had the weakest light absorption but the strongest wavelength dependence, while biomass burning brown carbon showed the strongest absorption and the weakest wavelength dependence. Nitrogen-containing organic carbon compounds were identified as key light absorbers. These results improve understanding of brown carbon sources and help refine climate models.
Shao Shi, Jinghao Zhai, Xin Yang, Yechun Ruan, Yuanlong Huang, Xujian Chen, Antai Zhang, Jianhuai Ye, Guomao Zheng, Baohua Cai, Yaling Zeng, Yixiang Wang, Chunbo Xing, Yujie Zhang, Tzung-May Fu, Lei Zhu, Huizhong Shen, and Chen Wang
Atmos. Chem. Phys., 24, 7001–7012, https://doi.org/10.5194/acp-24-7001-2024, https://doi.org/10.5194/acp-24-7001-2024, 2024
Short summary
Short summary
The determination of ions in the mass spectra of individual particles remains uncertain. We have developed a standard-free mass calibration algorithm applicable to more than 98 % of ambient particles. With our algorithm, ions with ~ 0.05 Th mass difference could be determined. Therefore, many more atmospheric species could be determined and involved in the source apportionment of aerosols, the study of chemical reaction mechanisms, and the analysis of single-particle mixing states.
Qianqian Gao, Shengqiang Zhu, Kaili Zhou, Jinghao Zhai, Shaodong Chen, Qihuang Wang, Shurong Wang, Jin Han, Xiaohui Lu, Hong Chen, Liwu Zhang, Lin Wang, Zimeng Wang, Xin Yang, Qi Ying, Hongliang Zhang, Jianmin Chen, and Xiaofei Wang
Atmos. Chem. Phys., 23, 13049–13060, https://doi.org/10.5194/acp-23-13049-2023, https://doi.org/10.5194/acp-23-13049-2023, 2023
Short summary
Short summary
Dust is a major source of atmospheric aerosols. Its chemical composition is often assumed to be similar to the parent soil. However, this assumption has not been rigorously verified. Dust aerosols are mainly generated by wind erosion, which may have some chemical selectivity. Mn, Cd and Pb were found to be highly enriched in fine-dust (PM2.5) aerosols. In addition, estimation of heavy metal emissions from dust generation by air quality models may have errors without using proper dust profiles.
Huirong Yang, Kai Wu, Huizhong Shen, Greet Janssens-Maenhout, Monica Crippa, Diego Guizzardi, and Minqiang Zhou
Atmos. Chem. Phys., 25, 18111–18127, https://doi.org/10.5194/acp-25-18111-2025, https://doi.org/10.5194/acp-25-18111-2025, 2025
Short summary
Short summary
We compare six major anthropogenic CO2 emission inventories in China during the period 2000–2023 to assess emission trends and uncertainties. National emissions show a clear three‑phase pattern, with uncertainties below 5 % (1σ) at the national scale but much higher at the provincial level (10–50 %, 1σ). High-emission regions often have the largest uncertainties. Our findings support more accurate emission estimates and the verification emission reduction policies.
Yuguang Zhu, Zhilin Guo, Sichen Wan, Kewei Chen, Yushan Wang, Zhenzhong Zeng, Huizhong Shen, Jianhuai Ye, and Chunmiao Zheng
EGUsphere, https://doi.org/10.5194/egusphere-2025-5534, https://doi.org/10.5194/egusphere-2025-5534, 2025
Short summary
Short summary
Groundwater is rapidly being depleted in many regions, threatening water security and food production. We studied a major groundwater depression in northern China to test whether recharging aquifers with diverted river water can help recovery. Using long-term computer simulations, we found that recharge raises water levels and dilutes nitrate pollution, offering an effective way to restore overused aquifers.
Baohua Cai, Yuanlong Huang, Wenqing Jiang, Yanchen Li, Yali Li, Jinghao Zhai, Yaling Zeng, Jianhuai Ye, Huizhong Shen, Chen Wang, Lei Zhu, Tzung-May Fu, Qi Zhang, and Xin Yang
EGUsphere, https://doi.org/10.5194/egusphere-2025-5323, https://doi.org/10.5194/egusphere-2025-5323, 2025
Short summary
Short summary
This study reveals a novel Ultraviolet A-driven, metal-free mechanism for aqueous-phase tetravalent sulfur (S(IV)) oxidation that leads to organosulfates formation, addressing a critical knowledge gap in atmospheric sulfur and organic aerosol chemistry and highlighting a previously overlooked photochemical pathway with broad environmental implications.
Aoxing Zhang, Tzung-May Fu, Yuhang Wang, Enyu Xiong, Wenlu Wu, Yumin Li, Lei Zhu, Wei Tao, Kelley C. Wells, Dylan B. Millet, Zhe Wang, Bin Yuan, Min Shao, Christophe Lerot, Thomas Danckaert, Ruixiong Zhang, and Kelvin H. Bates
EGUsphere, https://doi.org/10.5194/egusphere-2025-5083, https://doi.org/10.5194/egusphere-2025-5083, 2025
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
Short summary
Glyoxal, a product of volatile organic compound oxidation, influences atmospheric oxidation and aerosol formation but is underestimated in models. By improving emissions, chemistry, and marine sources in GEOS-Chem, we better reproduce observed glyoxal over land and ocean, which strengthens global oxidation capacity and aerosol formation. The results highlight glyoxal's role as a proxy of atmospheric oxidation, and emphasize the needs of accurately representing glyoxal chemistry.
Dukun Chen, Weifeng Su, Shaojie Jiang, Honglong Yang, Chunsheng Zhang, Shutong Jiang, Dongyang Chang, Yuxin Liang, Hao Wang, Xin Yang, Tzung-May Fu, Zhenzhong Zeng, Lei Zhu, Huizhong Shen, Chen Wang, and Jianhuai Ye
EGUsphere, https://doi.org/10.5194/egusphere-2025-4752, https://doi.org/10.5194/egusphere-2025-4752, 2025
Short summary
Short summary
This research turns unmanned aerial vehicles (UAVs) into sensitive weather stations by measuring how wind pushes and tilts them in flight. This method accurately gauges wind speed and direction without extra sensors, providing a low-cost way to map complex wind patterns. The findings are vital for improving air quality forecasts, tracking pollution, and ensuring safe drone operations, supporting smarter environmental management.
Guangyuan Yu, Yan Zhang, Qian Wang, Zimin Han, Shenglan Jiang, Fan Yang, Xin Yang, and Cheng Huang
Atmos. Chem. Phys., 25, 9497–9518, https://doi.org/10.5194/acp-25-9497-2025, https://doi.org/10.5194/acp-25-9497-2025, 2025
Short summary
Short summary
China has carried out staged low-sulfur fuel policies since 2017. This study simulated the changing spatiotemporal patterns of the impacts of ship emissions on PM2.5 from 2017 to 2021 based on the updated emission inventories and mapping of chemical species in the CMAQ (Community Multiscale Air Quality). Fuel policies caused evident relative changes in inorganic and organic components of the shipping-related PM2.5 over China’s port cities. The driving factors of the interannual, seasonal, and diurnal patterns were discussed.
Sijia Lou, Manish Shrivastava, Alexandre Albinet, Sophie Tomaz, Deepchandra Srivastava, Olivier Favez, Huizhong Shen, and Aijun Ding
Atmos. Chem. Phys., 25, 8163–8183, https://doi.org/10.5194/acp-25-8163-2025, https://doi.org/10.5194/acp-25-8163-2025, 2025
Short summary
Short summary
Polycyclic aromatic hydrocarbons (PAHs), emitted from incomplete combustion, pose serious health risks due to their carcinogenic properties. This research demonstrates that viscous organic aerosol coatings significantly hinder PAH oxidation, with spatial distributions sensitive to the degradation modeling approach. Our findings emphasize the need for accurate modeling of PAH oxidation processes in risk assessments, considering both fresh and oxidized PAHs in evaluating human health risks.
Jinghao Zhai, Yin Zhang, Pengfei Liu, Yujie Zhang, Antai Zhang, Yaling Zeng, Baohua Cai, Jingyi Zhang, Chunbo Xing, Honglong Yang, Xiaofei Wang, Jianhuai Ye, Chen Wang, Tzung-May Fu, Lei Zhu, Huizhong Shen, Shu Tao, and Xin Yang
Atmos. Chem. Phys., 25, 7959–7972, https://doi.org/10.5194/acp-25-7959-2025, https://doi.org/10.5194/acp-25-7959-2025, 2025
Short summary
Short summary
Our study shows that the optical properties of brown carbon depend on its source. Brown carbon from ozone pollution had the weakest light absorption but the strongest wavelength dependence, while biomass burning brown carbon showed the strongest absorption and the weakest wavelength dependence. Nitrogen-containing organic carbon compounds were identified as key light absorbers. These results improve understanding of brown carbon sources and help refine climate models.
Tiangang Yuan, Tzung-May Fu, Aoxing Zhang, David H. Y. Yung, Jin Wu, Sien Li, and Amos P. K. Tai
Atmos. Chem. Phys., 25, 4211–4232, https://doi.org/10.5194/acp-25-4211-2025, https://doi.org/10.5194/acp-25-4211-2025, 2025
Short summary
Short summary
This study utilizes a regional climate–air quality coupled model to first investigate the complex interaction between irrigation, climate and air quality in China. We found that large-scale irrigation practices reduce summertime surface ozone while raising secondary inorganic aerosol concentration via complicated physical and chemical processes. Our results emphasize the importance of making a tradeoff between air pollution controls and sustainable agricultural development.
Li Fang, Jianbing Jin, Arjo Segers, Ke Li, Ji Xia, Wei Han, Baojie Li, Hai Xiang Lin, Lei Zhu, Song Liu, and Hong Liao
Geosci. Model Dev., 17, 8267–8282, https://doi.org/10.5194/gmd-17-8267-2024, https://doi.org/10.5194/gmd-17-8267-2024, 2024
Short summary
Short summary
Model evaluations against ground observations are usually unfair. The former simulates mean status over coarse grids and the latter the surrounding atmosphere. To solve this, we proposed the new land-use-based representative (LUBR) operator that considers intra-grid variance. The LUBR operator is validated to provide insights that align with satellite measurements. The results highlight the importance of considering fine-scale urban–rural differences when comparing models and observation.
Shao Shi, Jinghao Zhai, Xin Yang, Yechun Ruan, Yuanlong Huang, Xujian Chen, Antai Zhang, Jianhuai Ye, Guomao Zheng, Baohua Cai, Yaling Zeng, Yixiang Wang, Chunbo Xing, Yujie Zhang, Tzung-May Fu, Lei Zhu, Huizhong Shen, and Chen Wang
Atmos. Chem. Phys., 24, 7001–7012, https://doi.org/10.5194/acp-24-7001-2024, https://doi.org/10.5194/acp-24-7001-2024, 2024
Short summary
Short summary
The determination of ions in the mass spectra of individual particles remains uncertain. We have developed a standard-free mass calibration algorithm applicable to more than 98 % of ambient particles. With our algorithm, ions with ~ 0.05 Th mass difference could be determined. Therefore, many more atmospheric species could be determined and involved in the source apportionment of aerosols, the study of chemical reaction mechanisms, and the analysis of single-particle mixing states.
Qianqian Gao, Shengqiang Zhu, Kaili Zhou, Jinghao Zhai, Shaodong Chen, Qihuang Wang, Shurong Wang, Jin Han, Xiaohui Lu, Hong Chen, Liwu Zhang, Lin Wang, Zimeng Wang, Xin Yang, Qi Ying, Hongliang Zhang, Jianmin Chen, and Xiaofei Wang
Atmos. Chem. Phys., 23, 13049–13060, https://doi.org/10.5194/acp-23-13049-2023, https://doi.org/10.5194/acp-23-13049-2023, 2023
Short summary
Short summary
Dust is a major source of atmospheric aerosols. Its chemical composition is often assumed to be similar to the parent soil. However, this assumption has not been rigorously verified. Dust aerosols are mainly generated by wind erosion, which may have some chemical selectivity. Mn, Cd and Pb were found to be highly enriched in fine-dust (PM2.5) aerosols. In addition, estimation of heavy metal emissions from dust generation by air quality models may have errors without using proper dust profiles.
Lei Shu, Lei Zhu, Juseon Bak, Peter Zoogman, Han Han, Song Liu, Xicheng Li, Shuai Sun, Juan Li, Yuyang Chen, Dongchuan Pu, Xiaoxing Zuo, Weitao Fu, Xin Yang, and Tzung-May Fu
Atmos. Chem. Phys., 23, 3731–3748, https://doi.org/10.5194/acp-23-3731-2023, https://doi.org/10.5194/acp-23-3731-2023, 2023
Short summary
Short summary
We quantify the benefit of multisource observations (GEMS, LEO satellite, and surface) on ozone simulations in Asia. Data assimilation improves the monitoring of exceedance, spatial pattern, and diurnal variation of surface ozone, with the regional mean bias reduced from −2.1 to −0.2 ppbv. Data assimilation also better represents ozone vertical distributions in the middle to upper troposphere at low latitudes. Our results offer a valuable reference for future ozone simulations.
Amir H. Souri, Matthew S. Johnson, Glenn M. Wolfe, James H. Crawford, Alan Fried, Armin Wisthaler, William H. Brune, Donald R. Blake, Andrew J. Weinheimer, Tijl Verhoelst, Steven Compernolle, Gaia Pinardi, Corinne Vigouroux, Bavo Langerock, Sungyeon Choi, Lok Lamsal, Lei Zhu, Shuai Sun, Ronald C. Cohen, Kyung-Eun Min, Changmin Cho, Sajeev Philip, Xiong Liu, and Kelly Chance
Atmos. Chem. Phys., 23, 1963–1986, https://doi.org/10.5194/acp-23-1963-2023, https://doi.org/10.5194/acp-23-1963-2023, 2023
Short summary
Short summary
We have rigorously characterized different sources of error in satellite-based HCHO / NO2 tropospheric columns, a widely used metric for diagnosing near-surface ozone sensitivity. Specifically, the errors were categorized/quantified into (i) an inherent chemistry error, (ii) the decoupled relationship between columns and the near-surface concentration, (iii) the spatial representativeness error of ground satellite pixels, and (iv) the satellite retrieval errors.
Xun Li, Momei Qin, Lin Li, Kangjia Gong, Huizhong Shen, Jingyi Li, and Jianlin Hu
Atmos. Chem. Phys., 22, 14799–14811, https://doi.org/10.5194/acp-22-14799-2022, https://doi.org/10.5194/acp-22-14799-2022, 2022
Short summary
Short summary
Photochemical indicators have been widely used to predict O3–NOx–VOC sensitivity with given thresholds. Here we assessed the effectiveness of four indicators with a case study in the Yangtze River Delta, China. The overall performance was good, while some indicators showed inconsistencies with the O3 isopleths. The methodology used to determine the thresholds may produce uncertainties. These results would improve our understanding of the use of photochemical indicators in policy implications.
Tianlang Zhao, Jingqiu Mao, William R. Simpson, Isabelle De Smedt, Lei Zhu, Thomas F. Hanisco, Glenn M. Wolfe, Jason M. St. Clair, Gonzalo González Abad, Caroline R. Nowlan, Barbara Barletta, Simone Meinardi, Donald R. Blake, Eric C. Apel, and Rebecca S. Hornbrook
Atmos. Chem. Phys., 22, 7163–7178, https://doi.org/10.5194/acp-22-7163-2022, https://doi.org/10.5194/acp-22-7163-2022, 2022
Short summary
Short summary
Monitoring formaldehyde (HCHO) can help us understand Arctic vegetation change. Here, we compare satellite data and model and show that Alaska summertime HCHO is largely dominated by a background from methane oxidation during mild wildfire years and is dominated by wildfire (largely from direct emission of fire) during strong fire years. Consequently, it is challenging to use satellite HCHO to study vegetation change in the Arctic region.
Xiaotian Xu, Xu Feng, Haipeng Lin, Peng Zhang, Shaojian Huang, Zhengcheng Song, Yiming Peng, Tzung-May Fu, and Yanxu Zhang
Geosci. Model Dev., 15, 3845–3859, https://doi.org/10.5194/gmd-15-3845-2022, https://doi.org/10.5194/gmd-15-3845-2022, 2022
Short summary
Short summary
Mercury is one of the most toxic pollutants in the environment, and wet deposition is a major process for atmospheric mercury to enter, causing ecological and human health risks. High-mercury wet deposition in the southeastern US has been a problem for many years. Here we employed a newly developed high-resolution WRF-GC model with the capability to simulate mercury to study this problem. We conclude that deep convection caused enhanced mercury wet deposition in the southeastern US.
Xuan Wang, Daniel J. Jacob, William Downs, Shuting Zhai, Lei Zhu, Viral Shah, Christopher D. Holmes, Tomás Sherwen, Becky Alexander, Mathew J. Evans, Sebastian D. Eastham, J. Andrew Neuman, Patrick R. Veres, Theodore K. Koenig, Rainer Volkamer, L. Gregory Huey, Thomas J. Bannan, Carl J. Percival, Ben H. Lee, and Joel A. Thornton
Atmos. Chem. Phys., 21, 13973–13996, https://doi.org/10.5194/acp-21-13973-2021, https://doi.org/10.5194/acp-21-13973-2021, 2021
Short summary
Short summary
Halogen radicals have a broad range of implications for tropospheric chemistry, air quality, and climate. We present a new mechanistic description and comprehensive simulation of tropospheric halogens in a global 3-D model and compare the model results with surface and aircraft measurements. We find that halogen chemistry decreases the global tropospheric burden of ozone by 11 %, NOx by 6 %, and OH by 4 %.
Xu Feng, Haipeng Lin, Tzung-May Fu, Melissa P. Sulprizio, Jiawei Zhuang, Daniel J. Jacob, Heng Tian, Yaping Ma, Lijuan Zhang, Xiaolin Wang, Qi Chen, and Zhiwei Han
Geosci. Model Dev., 14, 3741–3768, https://doi.org/10.5194/gmd-14-3741-2021, https://doi.org/10.5194/gmd-14-3741-2021, 2021
Short summary
Short summary
WRF-GC is an online coupling of the WRF meteorological model and GEOS-Chem chemical transport model for regional atmospheric chemistry and air quality modeling. In WRF-GC v2.0, we implemented the aerosol–radiation interactions and aerosol–cloud interactions, as well as the capability to nest multiple domains for high-resolution simulations based on the modular framework of WRF-GC v1.0. This allows the GEOS-Chem users to investigate the meteorology–atmospheric chemistry interactions.
Bingqing Zhang, Huizhong Shen, Pengfei Liu, Hongyu Guo, Yongtao Hu, Yilin Chen, Shaodong Xie, Ziyan Xi, T. Nash Skipper, and Armistead G. Russell
Atmos. Chem. Phys., 21, 8341–8356, https://doi.org/10.5194/acp-21-8341-2021, https://doi.org/10.5194/acp-21-8341-2021, 2021
Short summary
Short summary
Extended ground-level measurements are coupled with model simulations to comprehensively compare the aerosol acidity in China and the United States. Aerosols in China are significantly less acidic than those in the United States, with pH values 1–2 units higher. Higher aerosol mass concentrations and the abundance of ammonia and ammonium in China, compared to the United States, are leading causes of the pH difference between these two countries.
Yilin Chen, Huizhong Shen, Jennifer Kaiser, Yongtao Hu, Shannon L. Capps, Shunliu Zhao, Amir Hakami, Jhih-Shyang Shih, Gertrude K. Pavur, Matthew D. Turner, Daven K. Henze, Jaroslav Resler, Athanasios Nenes, Sergey L. Napelenok, Jesse O. Bash, Kathleen M. Fahey, Gregory R. Carmichael, Tianfeng Chai, Lieven Clarisse, Pierre-François Coheur, Martin Van Damme, and Armistead G. Russell
Atmos. Chem. Phys., 21, 2067–2082, https://doi.org/10.5194/acp-21-2067-2021, https://doi.org/10.5194/acp-21-2067-2021, 2021
Short summary
Short summary
Ammonia (NH3) emissions can exert adverse impacts on air quality and ecosystem well-being. NH3 emission inventories are viewed as highly uncertain. Here we optimize the NH3 emission estimates in the US using an air quality model and NH3 measurements from the IASI satellite instruments. The optimized NH3 emissions are much higher than the National Emissions Inventory estimates in April. The optimized NH3 emissions improved model performance when evaluated against independent observation.
Cited articles
Amdur, M. O., Bayles, J., Ugro, V., and Underhill, D. W.: Comparative irritant potency of sulfate salts, Environ. Res., 16, 1–8, https://doi.org/10.1016/0013-9351(78)90135-4, 1978.
Battaglia, M. A., Douglas, S., and Hennigan, C. J.: Effect of the Urban Heat Island on Aerosol pH, Environ. Sci. Technol., 51, 13095–13103, https://doi.org/10.1021/acs.est.7b02786, 2017.
Battaglia Jr., M. A., Weber, R. J., Nenes, A., and Hennigan, C. J.: Effects of water-soluble organic carbon on aerosol pH, Atmos. Chem. Phys., 19, 14607–14620, https://doi.org/10.5194/acp-19-14607-2019, 2019.
Bian, Y. X., Zhao, C. S., Ma, N., Chen, J., and Xu, W. Y.: A study of aerosol liquid water content based on hygroscopicity measurements at high relative humidity in the North China Plain, Atmos. Chem. Phys., 14, 6417–6426, https://doi.org/10.5194/acp-14-6417-2014, 2014.
Bougiatioti, A., Nikolaou, P., Stavroulas, I., Kouvarakis, G., Weber, R., Nenes, A., Kanakidou, M., and Mihalopoulos, N.: Particle water and pH in the eastern Mediterranean: source variability and implications for nutrient availability, Atmos. Chem. Phys., 16, 4579–4591, https://doi.org/10.5194/acp-16-4579-2016, 2016.
Boyer, H. C., Gorkowski, K., and Sullivan, R. C.: In Situ pH Measurements of Individual Levitated Microdroplets Using Aerosol Optical Tweezers, Anal. Chem., 92, 1089–1096, https://doi.org/10.1021/acs.analchem.9b04152, 2020.
Cai, B. H., Wang, Y. X., Yang, X., Li, Y. C., Zhai, J. H., Zeng, Y. L., Ye, J. H., Zhu, L., Fu, T. M., and Zhang, Q.: Rapid aqueous-phase dark reaction of phenols with nitrosonium ions: Novel mechanism for atmospheric nitrosation and nitration at low pH, Pnas Nexus, 3, https://doi.org/10.1093/pnasnexus/pgae385, 2024.
Chen, Z., Liu, P., Su, H., and Zhang, Y. H.: Displacement of Strong Acids or Bases by Weak Acids or Bases in Aerosols: Thermodynamics and Kinetics, Environ. Sci. Technol., https://doi.org/10.1021/acs.est.2c03719, 2022.
Clegg, S. L., Pitzer, K. S., and Brimblecombe, P.: thermodynamics of multicomponent, miscible, ionic-solutions .2. mixtures including unsymmetrical electrolytes, J. Phys. Chem., 96, 9470–9479, https://doi.org/10.1021/j100202a074, 1992.
Craig, R. L., Peterson, P. K., Nandy, L., Lei, Z., Hossain, M. A., Camarena, S., Dodson, R. A., Cook, R. D., Dutcher, C. S., and Ault, A. P.: Direct Determination of Aerosol pH: Size-Resolved Measurements of Submicrometer and Supermicrometer Aqueous Particles, Anal. Chem., 90, 11232–11239, https://doi.org/10.1021/acs.analchem.8b00586, 2018.
Cui, X. Y., Tang, M. J., Wang, M. J., and Zhu, T.: Water as a probe for pH measurement in individual particles using micro-Raman spectroscopy, Anal. Chim. Acta, 1186, https://doi.org/10.1016/j.aca.2021.339089, 2021.
Ding, J., Zhao, P., Su, J., Dong, Q., Du, X., and Zhang, Y.: Aerosol pH and its driving factors in Beijing, Atmos. Chem. Phys., 19, 7939–7954, https://doi.org/10.5194/acp-19-7939-2019, 2019.
Fang, T., Guo, H. Y., Zeng, L. H., Verma, V., Nenes, A., and Weber, R. J.: Highly Acidic Ambient Particles, Soluble Metals, and Oxidative Potential: A Link between Sulfate and Aerosol Toxicity, Environ. Sci. Technol., 51, 2611–2620, https://doi.org/10.1021/acs.est.6b06151, 2017.
Farren, N. J., Dunmore, R. E., Mead, M. I., Mohd Nadzir, M. S., Samah, A. A., Phang, S.-M., Bandy, B. J., Sturges, W. T., and Hamilton, J. F.: Chemical characterisation of water-soluble ions in atmospheric particulate matter on the east coast of Peninsular Malaysia, Atmos. Chem. Phys., 19, 1537–1553, https://doi.org/10.5194/acp-19-1537-2019, 2019.
Gao, J., Wei, Y. T., Wang, H. Q., Song, S. J., Xu, H., Feng, Y. C., Shi, G. L., and Russell, A. G.: Multiphase Buffering: A Mechanistic Regulator of Aerosol Sulfate Formation and Its Dominant Pathways, Environ. Sci. Technol., 59, 8073–8084, https://doi.org/10.1021/acs.est.4c13744, 2025.
Guo, H., Xu, L., Bougiatioti, A., Cerully, K. M., Capps, S. L., Hite Jr., J. R., Carlton, A. G., Lee, S.-H., Bergin, M. H., Ng, N. L., Nenes, A., and Weber, R. J.: Fine-particle water and pH in the southeastern United States, Atmos. Chem. Phys., 15, 5211–5228, https://doi.org/10.5194/acp-15-5211-2015, 2015.
Guo, H., Otjes, R., Schlag, P., Kiendler-Scharr, A., Nenes, A., and Weber, R. J.: Effectiveness of ammonia reduction on control of fine particle nitrate, Atmos. Chem. Phys., 18, 12241–12256, https://doi.org/10.5194/acp-18-12241-2018, 2018.
Hennigan, C. J., Izumi, J., Sullivan, A. P., Weber, R. J., and Nenes, A.: A critical evaluation of proxy methods used to estimate the acidity of atmospheric particles, Atmos. Chem. Phys., 15, 2775–2790, https://doi.org/10.5194/acp-15-2775-2015, 2015.
Jacobson, M. Z., Tabazadeh, A., and Turco, R. P.: Simulating equilibrium within aerosols and nonequilibrium between gases and aerosols, J. Geophys. Res.-Atmos., 101, 9079–9091, https://doi.org/10.1029/96jd00348, 1996.
Karydis, V. A., Tsimpidi, A. P., Pozzer, A., and Lelieveld, J.: How alkaline compounds control atmospheric aerosol particle acidity, Atmos. Chem. Phys., 21, 14983–15001, https://doi.org/10.5194/acp-21-14983-2021, 2021.
Li, W. H. and Kuwata, M.: Detecting pH of Sub-Micrometer Aerosol Particles Using Fluorescent Probes, Environ. Sci. Technol., 57, 8701–8707, https://doi.org/10.1021/acs.est.3c01517, 2023.
Liu, Y., Wu, Z., Huang, X., Shen, H., Bai, Y., Qiao, K., Meng, X., Hu, W., Tang, M., and He, L.: Aerosol Phase State and Its Link to Chemical Composition and Liquid Water Content in a Subtropical Coastal Megacity, Environ. Sci. Technol., 53, 5027–5033, https://doi.org/10.1021/acs.est.9b01196, 2019.
Longo, A. F., Feng, Y., Lai, B., Landing, W. M., Shelley, R. U., Nenes, A., Mihalopoulos, N., Violaki, K., and Ingall, E. D.: Influence of Atmospheric Processes on the Solubility and Composition of Iron in Saharan Dust, Environ. Sci. Technol., 50, 6912–6920, https://doi.org/10.1021/acs.est.6b02605, 2016.
Metzger, S., Mihalopoulos, N., and Lelieveld, J.: Importance of mineral cations and organics in gas-aerosol partitioning of reactive nitrogen compounds: case study based on MINOS results, Atmos. Chem. Phys., 6, 2549–2567, https://doi.org/10.5194/acp-6-2549-2006, 2006.
Nenes, A., Pandis, S. N., and Pilinis, C.: ISORROPIA: A new thermodynamic equilibrium model for multiphase multicomponent inorganic aerosols, Aquatic Geochemistry, 4, 123–152, https://doi.org/10.1023/a:1009604003981, 1998.
Nenes, A., Pandis, S. N., and Pilinis, C.: Continued development and testing of a new thermodynamic aerosol module for urban and regional air quality models, Atmos. Environ., 33, 1553–1560, https://doi.org/10.1016/s1352-2310(98)00352-5, 1999.
Pathak, R. K., Yao, X. H., and Chan, C. K.: Sampling artifacts of acidity and ionic species in PM2.5, Environ. Sci. Technol., 38, 254–259, https://doi.org/10.1021/es0342244, 2004.
Pilinis, C. and Seinfeld, J. H.: Continued development of a general equilibrium-model for inorganic multicomponent atmospheric aerosols, Atmos. Environ., 21, 2453–2466, https://doi.org/10.1016/0004-6981(87)90380-5, 1987.
Pye, H. O. T., Zuend, A., Fry, J. L., Isaacman-VanWertz, G., Capps, S. L., Appel, K. W., Foroutan, H., Xu, L., Ng, N. L., and Goldstein, A. H.: Coupling of organic and inorganic aerosol systems and the effect on gas–particle partitioning in the southeastern US, Atmos. Chem. Phys., 18, 357–370, https://doi.org/10.5194/acp-18-357-2018, 2018.
Pye, H. O. T., Nenes, A., Alexander, B., Ault, A. P., Barth, M. C., Clegg, S. L., Collett Jr., J. L., Fahey, K. M., Hennigan, C. J., Herrmann, H., Kanakidou, M., Kelly, J. T., Ku, I.-T., McNeill, V. F., Riemer, N., Schaefer, T., Shi, G., Tilgner, A., Walker, J. T., Wang, T., Weber, R., Xing, J., Zaveri, R. A., and Zuend, A.: The acidity of atmospheric particles and clouds, Atmos. Chem. Phys., 20, 4809–4888, https://doi.org/10.5194/acp-20-4809-2020, 2020.
Saxena, P., Hudischewskyj, A. B., Seigneur, C., and Seinfeld, J. H.: A Comparative-study of equilibrium approaches to the chemical characterization of secondary aerosols, Atmos. Environ., 20, 1471–1483, https://doi.org/10.1016/0004-6981(86)90019-3, 1986.
Song, S., Gao, M., Xu, W., Shao, J., Shi, G., Wang, S., Wang, Y., Sun, Y., and McElroy, M. B.: Fine-particle pH for Beijing winter haze as inferred from different thermodynamic equilibrium models, Atmos. Chem. Phys., 18, 7423–7438, https://doi.org/10.5194/acp-18-7423-2018, 2018.
Song, X. W., Wu, D., Chen, X., Ma, Z. Z., Li, Q., and Chen, J. M.: Toxic Potencies of Particulate Matter from Typical Industrial Plants Mediated with Acidity via Metal Dissolution, Environ. Sci. Technol., 58, 6736–6743, https://doi.org/10.1021/acs.est.4c00929, 2024.
Surratt, J. D., Lewandowski, M., Offenberg, J. H., Jaoui, M., Kleindienst, T. E., Edney, E. O., and Seinfeld, J. H.: Effect of acidity on secondary organic aerosol formation from isoprene, Environ. Sci. Technol., 41, 5363–5369, https://doi.org/10.1021/es0704176, 2007.
Tao, Y. and Murphy, J. G.: The sensitivity of PM2.5 acidity to meteorological parameters and chemical composition changes: 10-year records from six Canadian monitoring sites, Atmos. Chem. Phys., 19, 9309–9320, https://doi.org/10.5194/acp-19-9309-2019, 2019.
Tao, Y. and Murphy, J. G.: Simple Framework to Quantify the Contributions from Different Factors Influencing Aerosol pH Based on NHx Phase-Partitioning Equilibrium, Environ. Sci. Technol., 55, 10310–10319, https://doi.org/10.1021/acs.est.1c03103, 2021.
Tilgner, A., Schaefer, T., Alexander, B., Barth, M., Collett Jr., J. L., Fahey, K. M., Nenes, A., Pye, H. O. T., Herrmann, H., and McNeill, V. F.: Acidity and the multiphase chemistry of atmospheric aqueous particles and clouds, Atmos. Chem. Phys., 21, 13483–13536, https://doi.org/10.5194/acp-21-13483-2021, 2021.
Turnock, S. T., Mann, G. W., Woodhouse, M. T., Dalvi, M., O'Connor, F. M., Carslaw, K. S., and Spracklen, D. V.: The Impact of Changes in Cloud Water pH on Aerosol Radiative Forcing, Geophys. Res. Lett., 46, 4039–4048, https://doi.org/10.1029/2019gl082067, 2019.
Wang, G. C., Chen, J., Xu, J., Yun, L., Zhang, M. D., Li, H., Qin, X. F., Deng, C. R., Zheng, H. T., Gui, H. Q., Liu, J. G., and Huang, K.: Atmospheric Processing at the Sea-Land Interface Over the South China Sea: Secondary Aerosol Formation, Aerosol Acidity, and Role of Sea Salts, J. Geophys. Res.-Atmos., 127, https://doi.org/10.1029/2021jd036255, 2022a.
Wang, G. C., Tao, Y., Chen, J., Liu, C. F., Qin, X. F., Li, H., Yun, L., Zhang, M. D., Zheng, H. T., Gui, H. Q., Liu, J. G., Huo, J. T., Fu, Q. Y., Deng, C. R., and Huang, K.: Quantitative Decomposition of Influencing Factors to Aerosol pH Variation over the Coasts of the South China Sea, East China Sea, and Bohai Sea, Environmental Science & Technology Letters, 9, 815–821, https://doi.org/10.1021/acs.estlett.2c00527, 2022b.
Weber, R., Guo, H., Russell, A., and Nenes, A.: High aerosol acidity despite declining atmospheric sulfate concentrations over the past 15 years, Nat. Geosci., 9, 282, https://doi.org/10.1038/ngeo2665, 2016.
Wexler, A. S. and Clegg, S. L.: Atmospheric aerosol models for systems including the ions H+, NH4+, Na+, SO42−, NO3−, Cl−, Br−, and H2O, J. Geophys. Res. Atmos., 107, 4207, https://doi.org/10.1029/2001jd000451, 2002.
Wexler, A. S. and Seinfeld, J. H.: Second-generation inorganic aerosol model, Atmos. Environ., 25, 2731–2748, https://doi.org/10.1016/0960-1686(91)90203-J, 1991.
Xie, Y., Wang, G., Wang, X., Chen, J., Chen, Y., Tang, G., Wang, L., Ge, S., Xue, G., Wang, Y., and Gao, J.: Nitrate-dominated PM2.5 and elevation of particle pH observed in urban Beijing during the winter of 2017, Atmos. Chem. Phys., 20, 5019–5033, https://doi.org/10.5194/acp-20-5019-2020, 2020.
Xu, Y., Miyazaki, Y., Tachibana, E., Sato, K., Ramasamy, S., Mochizuki, T., Sadanaga, Y., Nakashima, Y., Sakamoto, Y., Matsuda, K., and Kajii, Y.: Aerosol Liquid Water Promotes the Formation of Water-Soluble Organic Nitrogen in Submicrometer Aerosols in a Suburban Forest, Environ. Sci. Technol., 54, 1406–1414, https://doi.org/10.1021/acs.est.9b05849, 2020.
Zhai, J., Zhang, Y., Liu, P., Zhang, Y., Zhang, A., Zeng, Y., Cai, B., Zhang, J., Xing, C., Yang, H., Wang, X., Ye, J., Wang, C., Fu, T.-M., Zhu, L., Shen, H., Tao, S., and Yang, X.: Source-dependent optical properties and molecular characteristics of atmospheric brown carbon, Atmos. Chem. Phys., 25, 7959–7972, https://doi.org/10.5194/acp-25-7959-2025, 2025a.
Zhai, J., Zhang, Y., Cai, B., Zeng, Y., Zhang, J., Ye, J., Wang, C., Fu, T.-M., Zhu, L., Shen, H., and Yang, X.: Divergent Drivers of Aerosol Acidity: Evidence for Shifting Regulatory Regimes in a Coastal Region, Zenodo [data set], https://doi.org/10.5281/zenodo.17207845, 2025b.
Zhang, A. T., Zeng, Y. L., Yang, X., Zhai, J. H., Wang, Y. X., Xing, C. B., Cai, B. H., Shi, S., Zhang, Y. J., Shen, Z. X., Fu, T. M., Zhu, L., Shen, H. Z., Ye, J. H., and Wang, C.: Organic Matrix Effect on the Molecular Light Absorption of Brown Carbon, Geophys. Res. Lett., 50, https://doi.org/10.1029/2023gl106541, 2023.
Zhang, B., Shen, H., Liu, P., Guo, H., Hu, Y., Chen, Y., Xie, S., Xi, Z., Skipper, T. N., and Russell, A. G.: Significant contrasts in aerosol acidity between China and the United States, Atmos. Chem. Phys., 21, 8341–8356, https://doi.org/10.5194/acp-21-8341-2021, 2021.
Zheng, G., Su, H., Wang, S., Pozzer, A., and Cheng, Y.: Impact of non-ideality on reconstructing spatial and temporal variations in aerosol acidity with multiphase buffer theory, Atmos. Chem. Phys., 22, 47–63, https://doi.org/10.5194/acp-22-47-2022, 2022a.
Zheng, G. J., Su, H., and Cheng, Y. F.: Revisiting the Key Driving Processes of the Decadal Trend of Aerosol Acidity in the U.S, ACS Environmental Au, 2, 346–353, https://doi.org/10.1021/acsenvironau.1c00055, 2022b.
Zheng, G. J., Su, H., Wang, S. W., Andreae, M. O., Pöschl, U., and Cheng, Y. F.: Multiphase buffer theory explains contrasts in atmospheric aerosol acidity, Science, 369, 1374, https://doi.org/10.1126/science.aba3719, 2020.
Zhou, M., Zheng, G., Wang, H., Qiao, L., Zhu, S., Huang, D., An, J., Lou, S., Tao, S., Wang, Q., Yan, R., Ma, Y., Chen, C., Cheng, Y., Su, H., and Huang, C.: Long-term trends and drivers of aerosol pH in eastern China, Atmos. Chem. Phys., 22, 13833–13844, https://doi.org/10.5194/acp-22-13833-2022, 2022.
Short summary
This work investigates the regulation of aerosol acidity in a coastal megacity under contrasting meteorological regimes. By integrating field observations with thermodynamic modeling, we show that ammonia and aerosol water dominate acidity control under typical conditions, whereas sea-salt cations prevail during typhoons. These findings reveal that extreme weather can alter the governing mechanisms of aerosol acidity, with implications for air quality and climate evaluation.
This work investigates the regulation of aerosol acidity in a coastal megacity under contrasting...
Altmetrics
Final-revised paper
Preprint