Articles | Volume 26, issue 16
https://doi.org/10.5194/acp-26-11785-2026
© 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-26-11785-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Measurement report
| 
20 Aug 2026
Measurement report |
| 20 Aug 2026
| 20 Aug 2026
Measurement Report: Quantitative analysis of aerosol acidity and its driving factors in Guanzhong area, Northwest China
Qian Wang
State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
University of Chinese Academy of Sciences, Beijing, China
Xiao Guo
State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
Minxia Shen
State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
Yali Liu
Xi'an Institute for Innovative Earth Environment Research, Xi'an, China
Yifan Zhang
Xi'an Institute for Innovative Earth Environment Research, Xi'an, China
Lu Li
State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
Weining Qi
State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
University of Chinese Academy of Sciences, Beijing, China
Yue Cao
Xi'an Institute for Innovative Earth Environment Research, Xi'an, China
Shicong Li
State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
Zhuoer Dong
State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
University of Chinese Academy of Sciences, Beijing, China
Wenting Dai
State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
National Field Observation and Research Station (Shaanxi) for Ecological and Environment Changes and Integrated Management in the Guanzhong Plain Region, Xi'an, China
State Key Laboratory of Loess Science, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
National Field Observation and Research Station (Shaanxi) for Ecological and Environment Changes and Integrated Management in the Guanzhong Plain Region, Xi'an, China
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Cited articles
Brook, R., Wiebe, A. H., Woodhouse, A., Audette, V., Piechowski, M., Dabek-Zlotorzynska, E., and Dloughy, F.: Temporal and spatial relationships in fine particle strong acidity, sulphate, PM10, and PM2.5 across multiple Canadian locations, Atmos. Environ., 31, 4223–4236, https://doi.org/10.1016/S1352-2310(97)00248-3, 1997.
Chen, G., Fan, X., Lin, Z., Ji, X., Chen, Z., Xu, L., and Chen, J.: Driving factors and photochemical impacts of Cl2 in coastal atmosphere of southeast China, npj Clim. Atmos. Sci., 8, 135, https://doi.org/10.1038/s41612-025-01022-y, 2025.
Clegg, S. L., Brimblecombe, P., and Wexler, A. S.: Thermodynamic model of the system H+-NH
Cui, H., Du, Y., Zhang, H., Deng, M., Zhang, Q., Chen, W., Su, S., Li, X., Sarkar, S., Yang, L., Wang, X., and Jia, S.: A quantitative study on the influencing pathways of aerosol acidity: the non-neglectable role of non-ideality, Atmos. Environ., 354, 121256, https://doi.org/10.1016/j.atmosenv.2025.121256, 2025.
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.
Du, C., Yang, H., Wang, N., Pang, S., and Zhang, Y.: pH effect on the release of NH3 from the internally mixed sodium succinate and ammonium sulfate aerosols, Atmos. Environ., 220, 117101, https://doi.org/10.1016/j.atmosenv.2019.117101, 2020.
Feng, Q., Liu, H., Dai, W., Cao, Y., Shen, M., Liu, Y., Qi, W., Chen, Y., Guo, X., Zhang, Y., Li, L., Zhou, B., and Li, J.: Comparison of chemical composition and acidity of size-resolved inorganic aerosols at the top and foot of mt. Hua, northwest China: the role of the gas-particle distribution of ammonia, Sci. Total Environ., 905, 166985, https://doi.org/10.1016/j.scitotenv.2023.166985, 2023.
Fountoukis, C. and Nenes, A.: ISORROPIA II: a computationally efficient thermodynamic equilibrium model for K+–Ca2+–Mg2+–NH
Fu, Z., Cheng, L., Ye, X., Ma, Z., Wang, R., Duan, Y., Tao, J., and Cheng, J.: Characteristics of aerosol chemistry and acidity in shanghai after PM2.5 satisfied national guideline: Insight into future emission control, Sci. Total Environ., 827, 154319, https://doi.org/10.1016/j.scitotenv.2022.154319, 2022.
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., Sullivan, A. P., Campuzano-Jost, P., Schroder, J. C., Lopez-Hilfiker, F. D., Dibb, J. E., Jimenez, J. L., Thornton, J. A., Brown, S. S., Nenes, A., and Weber, R. J.: Fine particle pH and the partitioning of nitric acid during winter in the northeastern united states, J. Geophys. Res.-Atmos., 121, https://doi.org/10.1002/2016JD025311, 2016.
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.
Huang, R., Zhang, Y., Bozzetti, C., Ho, K., Cao, J., Han, Y., Daellenbach, K. R., Slowik, J. G., Platt, S. M., Canonaco, F., Zotter, P., Wolf, R., Pieber, S. M., Bruns, E. A., Crippa, M., Ciarelli, G., Piazzalunga, A., Schwikowski, M., Abbaszade, G., Schnelle-Kreis, J., Zimmermann, R., An, Z., Szidat, S., Baltensperger, U., Haddad, I. E., and Prévôt, A. S. H.: High secondary aerosol contribution to particulate pollution during haze events in China, Nature, 514, 218–222, https://doi.org/10.1038/nature13774, 2014.
Jia, S., Chen, W., Zhang, Q., Krishnan, P., Mao, J., Zhong, B., Huang, M., Fan, Q., Zhang, J., Chang, M., Yang, L., and Wang, X.: A quantitative analysis of the driving factors affecting seasonal variation of aerosol pH in Guangzhou, China, Sci. Total Environ., 725, 138228, https://doi.org/10.1016/j.scitotenv.2020.138228, 2020.
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.
Krotkov, N. A., McLinden, C. A., Li, C., Lamsal, L. N., Celarier, E. A., Marchenko, S. V., Swartz, W. H., Bucsela, E. J., Joiner, J., Duncan, B. N., Boersma, K. F., Veefkind, J. P., Levelt, P. F., Fioletov, V. E., Dickerson, R. R., He, H., Lu, Z., and Streets, D. G.: Aura OMI observations of regional SO2 and NO2 pollution changes from 2005 to 2015, Atmos. Chem. Phys., 16, 4605–4629, https://doi.org/10.5194/acp-16-4605-2016, 2016.
Li, K., Jacob, D. J., Liao, H., Qiu, Y., Shen, L., Zhai, S., Bates, K. H., Sulprizio, M. P., Song, S., Lu, X., Zhang, Q., Zheng, B., Zhang, Y., Zhang, J., Lee, H. C., and Kuk, S. K.: Ozone pollution in the north China plain spreading into the late-winter haze season, P. Natl. Acad. Sci. USA, 118, e2015797118, https://doi.org/10.1073/pnas.2015797118, 2021.
Liu, H., Feng, Q., Huang, Y., Wu, F., Liu, Y., Shen, M., Guo, X., Dai, W., Qi, W., Zhang, Y., Li, L., Wang, Q., Zhou, B., and Li, J.: Composition and size distribution of wintertime inorganic aerosols at ground and alpine regions of northwest China, Chinese Chem. Lett., 35, 109636, https://doi.org/10.1016/j.cclet.2024.109636, 2024.
Liu, M., Song, Y., Zhou, T., Xu, Z., Yan, C., Zheng, M., Wu, Z., Hu, M., Wu, Y., and Zhu, T.: Fine particle pH during severe haze episodes in northern China, Geophys. Res. Lett., 44, 5213–5221, https://doi.org/10.1002/2017GL073210, 2017.
Liu, M., Huang, X., Song, Y., Tang, J., Cao, J., Zhang, X., Zhang, Q., Wang, S., Xu, T., Kang, L., Cai, X., Zhang, H., Yang, F., Wang, H., Yu, J. Z., Lau, A. K., He, L., Huang, X., Duan, L., Ding, A., Xue, L., Gao, J., Liu, B., and Zhu, T.: Ammonia emission control in China would mitigate haze pollution and nitrogen deposition, but worsen acid rain, P. Natl. Acad. Sci. USA, 116, 7760–7765, https://doi.org/10.1073/pnas.1814880116, 2019.
Liu, M., Liu, Z., Wang, J., Chen, W., Feng, T., Pan, T., Yuan, B., Huang, S., Shao, M., Hu, M., Wang, X., and Hu, W.: The variation, source, and environmental impact of chloride across China: summarized field results based on the aerosol mass spectrometer (AMS), J. Geophys. Res.-Atmos., 130, e2024JD043275, https://doi.org/10.1029/2024JD043275, 2025a.
Liu, P., Zhao, X., Zhang, C., Chen, H., Wang, J., Xue, L., Chen, J., and Mu, Y.: Fine particle pH and its influencing factors during summer at Mt. Tai: comparison between mountain and urban sites, Atmos. Environ., 261, 118607, https://doi.org/10.1016/j.atmosenv.2021.118607, 2021.
Liu, P., Chen, H., Song, Y., Xue, C., Ye, C., Zhao, X., Zhang, C., Liu, J., and Mu, Y.: Atmospheric ammonia in the rural North China Plain during wintertime: Variations, sources, and implications for HONO heterogeneous formation, Sci. Total Environ., 861, 160768, https://doi.org/10.1016/j.scitotenv.2022.160768, 2023.
Liu, Y., Guo, X., Zhang, Y., Cao, Y., Jiang, Y., Qi, W., Shen, M., Li, L., Wang, Q., Dai, W., and Li, J.: Chemical characteristics of wintertime PM2.5 in background region of northwest China during urban emission reduction, Iscience, 28, 113528, https://doi.org/10.1016/j.isci.2025.113528, 2025b.
Mao, I., Lin, C, Lin, C., Chen, Y., Sung, F., and Chen, M.: Exposure of acid aerosol for schoolchildren in metropolitan Taipei, Atmos. Environ., 43, 5622–5629, https://doi.org/10.1016/j.atmosenv.2009.07.054, 2009.
Mao, M., Rao, L., Jiang, H., He, S., and Zhang, X.: Air pollutants in metropolises of eastern coastal China, Int. J. Env. Res. Pub. He., 19, 15332, https://doi.org/10.3390/ijerph192215332, 2022.
Meng, Z., Xu, X., Lin, W., Ge, B., Xie, Y., Song, B., Jia, S., Zhang, R., Peng, W., Wang, Y., Cheng, H., Yang, W., and Zhao, H.: Role of ambient ammonia in particulate ammonium formation at a rural site in the North China Plain, Atmos. Chem. Phys., 18, 167–184, https://doi.org/10.5194/acp-18-167-2018, 2018.
Nah, T., Lam, Y. H., Yang, J., and Yang, L.: Long-term trends and sensitivities of PM2.5 pH and aerosol liquid water to chemical composition changes and meteorological parameters in Hong Kong, south China: insights from 10-year records from three urban sites, Atmos. Environ., 302, 119725, https://doi.org/10.1016/j.atmosenv.2023.119725, 2023.
Nenes, A., Pandis, S. N., and Pilinis, C.: ISORROPIA: A new thermodynamic equilibrium model for multiphase multicomponent inorganic aerosols, Aquat. Geochem., 4, 123–152, https://doi.org/10.1023/A:1009604003981, 1998.
Niu, X., Cao, J., Shen, Z., Ho, S. S. H., Tie, X., Zhao, S., Xu, H., Zhang, T., and Huang, R.: PM2.5 from the Guanzhong Plain: chemical composition and implications for emission reductions, Atmos. Environ., 147, 458–469, https://doi.org/10.1016/j.atmosenv.2016.10.029, 2016.
Paglione, M., Decesari, S., Rinaldi, M., Tarozzi, L., Manarini, F., Gilardoni, S., Facchini, M. C., Fuzzi, S., Bacco, D., Trentini, A., Pandis, S. N., and Nenes, A.: Historical changes in seasonal aerosol acidity in the po valley (Italy) as inferred from fog water and aerosol measurements, Environ. Sci. Technol., 55, 7307–7315, https://doi.org/10.1021/acs.est.1c00651, 2021.
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.
Rengarajan, R., Sudheer, A., and Sarin, M.: Aerosol acidity and secondary organic aerosol formation during wintertime over urban environment in western India, Atmos. Environ., 45, 1940–1945, https://doi.org/10.1016/j.atmosenv.2011.01.026, 2011.
Saraswati, Sharma, S., Saxena, M., and Mandal, T.: Characteristics of gaseous and particulate ammonia and their role in the formation of secondary inorganic particulate matter at Delhi, India, Atmos. Res., 218, 34–49, https://doi.org/10.1016/j.atmosres.2018.11.010, 2019.
Shah, V., Jaeglé, L., Thornton, J., Lopez-Hilfiker, F., Lee, B., Schroder, J., Campuzano-Jost, P., Jimenez, J., Guo, H., Sullivan, A., Weber, R., Green, J., Fiddler, M., Bililign, S., Campos, T., Stell, M., Weinheimer, A., Montzka, D., and Brown, S.: Chemical feedbacks weaken the wintertime response of particulate sulfate and nitrate to emissions reductions over the eastern United States, P. Natl. Acad. Sci. USA, 115, 8110–8115, https://doi.org/10.1073/pnas.1803295115, 2018.
Shen, M., Li, J., Liu, Y., Dai, W., Wang, G., Qi, W., Chen, Y., Guo, X., Zhang, Y., Li, L., Cao, Y., Feng, Q., Su, H., and Cao, J.: Comparison of acidity and chemical composition of summertime cloud water and aerosol at an alpine site in northwest China: Implications for the neutral property of clouds in the free troposphere, Sci. Total Environ., 925, 171775, https://doi.org/10.1016/j.scitotenv.2024.171775, 2024.
Shi, G., Xu, J., Shi, X., Liu, B., Bi, X., Xiao, Z., Chen, K., Wen, J., Dong, S., Tian, Y., Feng, Y., Yu, H., Song, S., Zhao, Q., Gao, J., and Russell, A. G.: Aerosol pH dynamics during haze periods in an urban environment in China: use of detailed, hourly, speciated observations to study the role of ammonia availability and secondary aerosol formation and urban environment, J. Geophys. Res.-Atmos., 124, 9730–9742, https://doi.org/10.1029/2018JD029976, 2019.
Shi, Z., Bonneville, S., Krom, M. D., Carslaw, K. S., Jickells, T. D., Baker, A. R., and Benning, L. G.: Iron dissolution kinetics of mineral dust at low pH during simulated atmospheric processing, Atmos. Chem. Phys., 11, 995–1007, https://doi.org/10.5194/acp-11-995-2011, 2011.
Song, S., Nenes, A., Gao, M., Zhang, Y., Liu, P., Shao, J., Ye, D., Xu, W., Sun, Y., Liu, B., and McElroy, M.: Thermodynamic Modeling Suggests Declines in Water Uptake and Acidity of Inorganic Aerosols in Beijing Winter Haze Events during 2014/2015–2018/2019, Environ. Sci. Technol., 6, 752–760, https://doi.org/10.1021/acs.estlett.9b00621, 2019.
Su, H., Zhang, T., Liu, S., Qu, Y., Li, H., Zhou, J., Zhao, Z., Wang, Q., Li, L., Shen, M., and Chen, S.: Growth of nitrate contribution to aerosol pollution during wintertime in Xi'an, northwest China: Formation mechanism and effects of NH3, Particuology, 87, 303–315, https://doi.org/10.1016/j.partic.2023.09.014, 2024.
Su, J., Zhao, P., Ge, S., and Ding, J.: Aerosol liquid water content of PM2.5 and its influencing factors in Beijing, China, Sci. Total Environ., 839, 156342, https://doi.org/10.1016/j.scitotenv.2022.156342, 2022.
Sun, Y. L., Wang, Z. F., Fu, P. Q., Yang, T., Jiang, Q., Dong, H. B., Li, J., and Jia, J. J.: Aerosol composition, sources and processes during wintertime in Beijing, China, Atmos. Chem. Phys., 13, 4577–4592, https://doi.org/10.5194/acp-13-4577-2013, 2013.
Tan, T., Hu, M., Li, M., Guo, Q., Wu, Y., Fang, X., Gu, F., Wang, Y., and Wu, Z.: New insight into PM2.5 pollution patterns in Beijing based on one-year measurement of chemical compositions, Sci. Total Environ., 621, 734–743, https://doi.org/10.1016/j.scitotenv.2017.11.208, 2018.
Tang, I.: Chemical and size effects of hygroscopic aerosols on light scattering coefficients. J. Geophys. Res.-Atmos., 101, 19245–19250, https://doi.org/10.1029/96JD03003, 1996.
Tao, J., Wu, Y., Deng, Y., Hu, B., and Zhou, Z.: Thermodynamic regulation of aerosol pH by temperature and humidity: the role of gas-particle partitioning of semi-volatile inorganic species in a subtropical region, Environ. Res., 286, 122727, https://doi.org/10.1016/j.envres.2025.122727, 2025.
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.
Wang, G., Zhang, R., Gomez, M., Yang, L., Levy Zamora, M., Hu, M., Lin, Y., Peng, J., Guo, S., Meng, J., Li, J., Cheng, C., Hu, T., Ren, Y., Wang, Y., Gao, J., Cao, J., An, Z., Zhou, W., Li, G., Wang, J., Tian, P., Marrero-Ortiz, W., Secrest, J., Du, Z., Zheng, J., Shang, D., Zeng, L., Shao, M., Wang, W., Huang, Y., Wang, Y., Zhu, Y., Li, Y., Hu, J., Pan, B., Cai, L., Cheng, Y., Ji, Y., Zhang, F., Rosenfeld, D., Liss, P., Duce, R., Kolb, C., and Molina, M.: Persistent sulfate formation from London fog to Chinese haze, P. Natl. Acad. Sci. USA, 113, 13630–13635, https://doi.org/10.1073/pnas.1616540113, 2016.
Wang, Q., Guo, Xiao., Shen, M., Liu, Y., Zhang, Y., Li, L., Qi, W., Cao, Y., Li, S., Dong, Z., and Dai, W.: Measurement report: quantitative analysis of aerosol acidity and its driving factors in guanzhong area, northwest China, Zenodo [data set], https://doi.org/10.5281/zenodo.18455742, 2026.
Wang, Z., Wang, R., Wang, J., Wang, Y., McPherson Donahue, N., Tang, R., Dong, Z., Li, X., Wang, L., Han, Y., and Cao, J.: The seasonal variation, characteristics and secondary generation of PM2.5 in Xi'an, China, especially during pollution events, Environ. Res., 212, 113388, https://doi.org/10.1016/j.envres.2022.113388, 2022.
Wei, Y., Wang, S., Jiang, N., Zhang, R., and Hao, Q.: Comparative multi-model study of PM2.5 acidity trend changes in ammonia-rich regions in winter: based on a new ammonia concentration assessment method, J. Hazard. Mater., 458, 131970, https://doi.org/10.1016/j.jhazmat.2023.131970, 2023.
Wu, C., Wang, G., Li, J., Li, J., Cao, C., Ge, S., Xie, Y., Chen, J., Li, X., Xue, G., Wang, X., Zhao, Z., and Cao, F.: The characteristics of atmospheric brown carbon in Xi'an, inland China: sources, size distributions and optical properties, Atmos. Chem. Phys., 20, 2017–2030, https://doi.org/10.5194/acp-20-2017-2020, 2020.
Xie, Y., Lu, H., Yi, A., Zhang, Z., Zheng, N., Fang, X., and Xiao, H.: Characterization and source analysis of water–soluble ions in PM2.5 at a background site in central China, Atmos. Res., 239, 104881, https://doi.org/10.1016/j.atmosres.2020.104881, 2020.
Xu, K., Yin, L., Chen, Q., Liao, D., Ji, X., Zhang, K., Wu, Y., Xu, L., Li, M., Fan, X., Zhang, F., Huang, Z., Chen, J., and Hong, Y.: Quantitative analysis of influencing factors to aerosol pH and its responses to PM2.5 and O3 pollution in a coastal city, J. Environ. Sci., 151, 284–297, https://doi.org/10.1016/j.jes.2024.03.044, 2025.
Ye, X., Tao, Y., Liu, Y., Wang, R., Li, Q., Yang, X., and Chen, J.: Size-fractionated water-soluble ions during autumn and winter: Insights into volatile ammonium formation mechanisms in Shanghai, a megacity of China, Atmos. Environ., 2, 100011, https://doi.org/10.1016/j.aeaoa.2019.100011, 2019.
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, 2021a.
Zhang, Q., Shen, Z., Lei, Y., Zhang, T., and Zhang, R.: Optical properties and source identification of black carbon and brown carbon: Comparison of winter and summer haze episodes in Xi'an, northwest China, Environ. Sci.: Processes Impacts, 21, 2058–2069, 2019.
Zhang, R., Han, Y., Shi, A., Sun, X., Yan, X., Huang, Y., and Wang, Y.: Characteristics of ambient ammonia and its effects on particulate ammonium in winter of urban Beijing, China, Environ. Sci. Pollut. Res., 28, 62828–62838, https://doi.org/10.1007/s11356-021-14108-w, 2021b.
Zhang, T., Shen, Z., Su, H., Liu, S., Zhou, J., Zhao, Z., Wang, Q., Prévôt, A. S. H., and Cao, J. J.: Effects of aerosol water content on the formation of secondary inorganic aerosol during a winter heavy PM2.5 pollution episode in Xi'an, China, Atmos. Environ., 252, 118304, https://doi.org/10.1016/j.atmosenv.2021.118304, 2021c.
Zhang, Y., Cai, J., Wang, S., He, K., and Zheng, M.: Review of receptor-based source apportionment research of fine particulate matter and its challenges in China, Sci. Total Environ., 586, 917–929, https://doi.org/10.1016/j.scitotenv.2017.02.071, 2017.
Zheng, G., Su, H., Wang, S., Andreae, M., Pöschl, U., and Cheng, Y.: Multiphase buffer theory explains contrasts in atmospheric aerosol acidity, Science, 369, 1374–1377, https://doi.org/10.1126/science.aba3719, 2020.
Zheng, G., Su, H., and Cheng, Y.: Role of carbon dioxide, ammonia, and organic acids in buffering atmospheric acidity: The distinct contribution in clouds and aerosols, Environ. Sci. Technol., 57, 12571–12582, https://doi.org/10.1021/acs.est.2c09851, 2023.
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
We studied fine particle acidity over one year in northwest China. Average pH was 3.8, highest in winter, lowest in summer. Pollution made particles less acidic. Temperature drove seasonal changes; ammonia was key in autumn and winter, dust calcium in spring, and humidity in summer. Humidity had a non-linear effect around 60–85% relative humidity. Our results enhance the understanding of the contributions of various factors to aerosol pH.
We studied fine particle acidity over one year in northwest China. Average pH was 3.8, highest...
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