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Persistent sulfate formation from London Fog to Chinese haze

Wang, Gehui and Zhang, Renyi and Gomez, Mario E. and Yang, Lingxiao and Zamora, Misti Levy and Hu, Min and Lin, Yun and Peng, Jianfei and Guo, Song and Meng, Jingjing and Li, Jianjun and Cheng, Chunlei and Hu, Tafeng and Ren, Yanqin and Wang, Yuesi and Gao, Jian and Cao, Junji and An, Zhisheng and Zhou, Weijian and Li, Guohui and Wang, Jiayuan and Tian, Pengfei and Marrero-Ortiz, Wilmarie and Secrest, Jeremiah and Du, Zhuofei and Zheng, Jing and Shang, Dongjie and Zeng, Limin and Shao, Min and Wang, Weigang and Huang, Yao and Wang, Yuan and Zhu, Yujiao and Li, Yixin and Hu, Jiaxi and Pan, Bowen and Cai, Li and Cheng, Yuting and Ji, Yuemeng and Zhang, Fang and Rosenfeld, Daniel and Liss, Peter S. and Duce, Robert A. and Kolb, Charles E. and Molina, Mario J. (2016) Persistent sulfate formation from London Fog to Chinese haze. Proceedings of the National Academy of Sciences of the United States of America, 113 (48). pp. 13630-13635. ISSN 0027-8424. PMCID PMC5137769. doi:10.1073/pnas.1616540113.

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Sulfate aerosols exert profound impacts on human and ecosystem health, weather, and climate, but their formation mechanism remains uncertain. Atmospheric models consistently underpredict sulfate levels under diverse environmental conditions. From atmospheric measurements in two Chinese megacities and complementary laboratory experiments, we show that the aqueous oxidation of SO_2 by NO_2 is key to efficient sulfate formation but is only feasible under two atmospheric conditions: on fine aerosols with high relative humidity and NH_3 neutralization or under cloud conditions. Under polluted environments, this SO_2 oxidation process leads to large sulfate production rates and promotes formation of nitrate and organic matter on aqueous particles, exacerbating severe haze development. Effective haze mitigation is achievable by intervening in the sulfate formation process with enforced NH_3 and NO_2 control measures. In addition to explaining the polluted episodes currently occurring in China and during the 1952 London Fog, this sulfate production mechanism is widespread, and our results suggest a way to tackle this growing problem in China and much of the developing world.

Item Type:Article
Related URLs:
URLURL TypeDescription Information CentralArticle
Zhang, Renyi0000-0001-8708-3862
Lin, Yun0000-0001-8222-0346
Peng, Jianfei0000-0003-4753-087X
Cao, Junji0000-0003-1000-7241
Li, Guohui0000-0001-8868-7123
Wang, Weigang0000-0001-6911-1110
Wang, Yuan0000-0001-6657-8401
Li, Yixin0000-0001-7937-7385
Pan, Bowen0000-0002-4617-5936
Cai, Li0000-0002-6098-1168
Ji, Yuemeng0000-0002-8641-4276
Rosenfeld, Daniel0000-0002-0784-7656
Molina, Mario J.0000-0003-2339-3225
Additional Information:© 2016 National Academy of Sciences. Freely available online through the PNAS open access option. Contributed by Mario J. Molina, October 9, 2016 (sent for review July 8, 2016; reviewed by Zhanqing Li and Sasha Madronich). Published ahead of print November 14, 2016. G.W. acknowledges the National Natural Science Foundation of China and the Strategic Priority Research Program of the CAS for financial support (Grants 41325014, XDA05100103, and XDB05020401). This work was partially supported by the Robert A. Welch Foundation (Grant A-1417), the Ministry of Science and Technology of China (Grant 2013CB955800), a collaborative research program by Texas A&M University and the National Natural Science Foundation of China. M.H. acknowledges the National Basic Research Program, China Ministry of Science and Technology (Grant 2013CB228503), National Natural Science Foundation of China (Grant 21190052) and the China Ministry of Environmental Protection’s Special Funds for Scientific Research on Public Welfare (Grant 20130916). W.M.-O. was supported by the National Science Foundation Graduate Research Fellowship Program, and B.P. was supported by the NASA Earth and Space Science Fellowship Program. Author contributions: G.W. and R.Z. designed research; G.W., R.Z., M.E.G., L.Y., M.L.Z., M.H., Y. Lin, J.P., S.G., J.M., J.L., C.C., T.H., Y.R., Y.S.W., J.G., J.W., P.T., W.M.-O., J.S., Z.D., J.Z., Y.H., Y.W., Y.Z., Y. Li, J.H., B.P., Y.C., Y.J., F.Z., and M.J.M. performed research; G.W., R.Z., M.H., and M.J.M. contributed new reagents/analytic tools; G.W., R.Z., M.E.G., L.Y., M.L.Z., M.H., Y. Lin, J.P., J.C., Z.A., W.Z., G.L., D.S., L.Z., M.S., W.W., Y.W., L.C., D.R., P.S.L., R.A.D., C.E.K., and M.J.M. analyzed data; and G.W. and R.Z. wrote the paper. Reviewers: Z.L., University of Maryland; and S.M., National Center for Atmospheric Research. The authors declare no conflict of interest. This article contains supporting information online at
Funding AgencyGrant Number
National Natural Science Foundation of China41325014
National Natural Science Foundation of ChinaXDA05100103
National Natural Science Foundation of ChinaXDB05020401
Robert A. Welch FoundationA-1417
Ministry of Science and Technology (China)2013CB955800
Texas A&M UniversityUNSPECIFIED
Ministry of Science and Technology (China)2013CB228503
National Natural Science Foundation of China21190052
Ministry of Environmental Protection (China)20130916
NSF Graduate Research FellowshipUNSPECIFIED
NASA Earth and Space Science FellowshipUNSPECIFIED
Subject Keywords:sulfate aerosol; severe haze; pollution; human health; climate
Issue or Number:48
PubMed Central ID:PMC5137769
Record Number:CaltechAUTHORS:20161115-091115050
Persistent URL:
Official Citation:Gehui Wang, Renyi Zhang, Mario E. Gomez, Lingxiao Yang, Misti Levy Zamora, Min Hu, Yun Lin, Jianfei Peng, Song Guo, Jingjing Meng, Jianjun Li, Chunlei Cheng, Tafeng Hu, Yanqin Ren, Yuesi Wang, Jian Gao, Junji Cao, Zhisheng An, Weijian Zhou, Guohui Li, Jiayuan Wang, Pengfei Tian, Wilmarie Marrero-Ortiz, Jeremiah Secrest, Zhuofei Du, Jing Zheng, Dongjie Shang, Limin Zeng, Min Shao, Weigang Wang, Yao Huang, Yuan Wang, Yujiao Zhu, Yixin Li, Jiaxi Hu, Bowen Pan, Li Cai, Yuting Cheng, Yuemeng Ji, Fang Zhang, Daniel Rosenfeld, Peter S. Liss, Robert A. Duce, Charles E. Kolb, and Mario J. Molina Persistent sulfate formation from London Fog to Chinese haze PNAS 2016 113 (48) 13630-13635; published ahead of print November 14, 2016, doi:10.1073/pnas.1616540113
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:72023
Deposited By: Tony Diaz
Deposited On:15 Nov 2016 17:55
Last Modified:08 Apr 2022 18:14

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