Articles | Volume 23, issue 18
https://doi.org/10.5194/acp-23-10313-2023
© Author(s) 2023. 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-23-10313-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
15 Sep 2023
Research article |
| 15 Sep 2023
| 15 Sep 2023
Reduction in vehicular emissions attributable to the Covid-19 lockdown in Shanghai: insights from 5 years of monitoring-based machine learning
Meng Wang
Department of Civil and Environmental Engineering, The Hong Kong
Polytechnic University, Hung Hom, Hong Kong SAR, China
Yusen Duan
Shanghai Environmental Monitoring Center, Shanghai, China
Zhuozhi Zhang
Department of Civil and Environmental Engineering, The Hong Kong
Polytechnic University, Hung Hom, Hong Kong SAR, China
Qi Yuan
Department of Civil and Environmental Engineering, The Hong Kong
Polytechnic University, Hung Hom, Hong Kong SAR, China
Xinwei Li
Department of Civil and Environmental Engineering, The Hong Kong
Polytechnic University, Hung Hom, Hong Kong SAR, China
Shuwen Han
Department of Civil and Environmental Engineering, The Hong Kong
Polytechnic University, Hung Hom, Hong Kong SAR, China
Juntao Huo
Shanghai Environmental Monitoring Center, Shanghai, China
Jia Chen
Shanghai Environmental Monitoring Center, Shanghai, China
Yanfen Lin
Shanghai Environmental Monitoring Center, Shanghai, China
Shanghai Environmental Monitoring Center, Shanghai, China
Department of Civil and Environmental Engineering, The Hong Kong
Polytechnic University, Hung Hom, Hong Kong SAR, China
Junji Cao
State Key Laboratory of Loess and Quaternary Geology, Institute of
Earth Environment, Chinese Academy of Sciences, Xi'an 710061,
China
Laboratory for Middle Atmosphere and Global Environment
Observation, Institute of Atmospheric Physics, Chinese Academy
of Sciences,
Beijing 100029, China
Shun-cheng Lee
CORRESPONDING AUTHOR
Department of Civil and Environmental Engineering, The Hong Kong
Polytechnic University, Hung Hom, Hong Kong SAR, China
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Zhouxing Zou, Qianjie Chen, Men Xia, Qi Yuan, Yi Chen, Yanan Wang, Enyu Xiong, Zhe Wang, and Tao Wang
Atmos. Chem. Phys., 23, 7057–7074, https://doi.org/10.5194/acp-23-7057-2023, https://doi.org/10.5194/acp-23-7057-2023, 2023
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Yuting Wang, Yong-Feng Ma, Domingo Muñoz-Esparza, Jianing Dai, Cathy Wing Yi Li, Pablo Lichtig, Roy Chun-Wang Tsang, Chun-Ho Liu, Tao Wang, and Guy Pierre Brasseur
Atmos. Chem. Phys., 23, 5905–5927, https://doi.org/10.5194/acp-23-5905-2023, https://doi.org/10.5194/acp-23-5905-2023, 2023
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Air quality in urban areas is difficult to simulate in coarse-resolution models. This work exploits the WRF (Weather Research and Forecasting) model coupled with a large-eddy simulation (LES) component and online chemistry to perform high-resolution (33.3 m) simulations of air quality in a large city. The evaluation of the simulations with observations shows that increased model resolution improves the representation of the chemical species near the pollution sources.
Yizhen Wu, Juntao Huo, Gan Yang, Yuwei Wang, Lihong Wang, Shijian Wu, Lei Yao, Qingyan Fu, and Lin Wang
Atmos. Chem. Phys., 23, 2997–3014, https://doi.org/10.5194/acp-23-2997-2023, https://doi.org/10.5194/acp-23-2997-2023, 2023
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Yu Han, Tao Wang, Rui Li, Hongbo Fu, Yusen Duan, Song Gao, Liwu Zhang, and Jianmin Chen
Atmos. Chem. Phys., 23, 2877–2900, https://doi.org/10.5194/acp-23-2877-2023, https://doi.org/10.5194/acp-23-2877-2023, 2023
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Jie Tian, Qiyuan Wang, Yongyong Ma, Jin Wang, Yongming Han, and Junji Cao
Atmos. Chem. Phys., 23, 1879–1892, https://doi.org/10.5194/acp-23-1879-2023, https://doi.org/10.5194/acp-23-1879-2023, 2023
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We investigated the light absorption properties of brown carbon (BrC) in the Tibetan Plateau (TP). BrC made a substantial contribution to the submicron aerosol absorption, which is related to the cross-border transport of biomass burning emission and secondary aerosol from Southeast Asia. The radiative effect of BrC was half that of black carbon, which can remarkably affect the radiative balance of the TP.
Changqin Yin, Jianming Xu, Wei Gao, Liang Pan, Yixuan Gu, Qingyan Fu, and Fan Yang
Atmos. Chem. Phys., 23, 1329–1343, https://doi.org/10.5194/acp-23-1329-2023, https://doi.org/10.5194/acp-23-1329-2023, 2023
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The particle matter (PM2.5) at the top of the 632 m high Shanghai Tower was found to be higher than the surface from June to October due to unexpected larger PM2.5 levels during early to middle afternoon at Shanghai Tower. We suppose the significant chemical production of secondary species existed in the mid-upper planetary boundary layer. We found a high nitrate concentration at the tower site for both daytime and nighttime in winter, implying efficient gas-phase and heterogeneous formation.
Xiaofei Qin, Shengqian Zhou, Hao Li, Guochen Wang, Cheng Chen, Chengfeng Liu, Xiaohao Wang, Juntao Huo, Yanfen Lin, Jia Chen, Qingyan Fu, Yusen Duan, Kan Huang, and Congrui Deng
Atmos. Chem. Phys., 22, 15851–15865, https://doi.org/10.5194/acp-22-15851-2022, https://doi.org/10.5194/acp-22-15851-2022, 2022
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Using artificial neural network modeling and an explainable analysis approach, natural surface emissions (NSEs) were identified as a main driver of gaseous elemental mercury (GEM) variations during the COVID-19 lockdown. A sharp drop in GEM concentrations due to a significant reduction in anthropogenic emissions may disrupt the surface–air exchange balance of Hg, leading to increases in NSEs. This implies that NSEs may pose challenges to the future control of Hg pollution.
Yue Tan and Tao Wang
Atmos. Chem. Phys., 22, 14455–14466, https://doi.org/10.5194/acp-22-14455-2022, https://doi.org/10.5194/acp-22-14455-2022, 2022
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We present a timely analysis of the effects of the recent lockdown in Shanghai on ground-level ozone (O3). Despite a huge reduction in human activity, O3 concentrations frequently exceeded the O3 air quality standard during the 2-month lockdown, implying that future emission reductions similar to those that occurred during the lockdown will not be sufficient to eliminate O3 pollution in many urban areas without the imposition of additional VOC controls or substantial decreases in NOx emissions.
Meng Wang, Yusen Duan, Wei Xu, Qiyuan Wang, Zhuozhi Zhang, Qi Yuan, Xinwei Li, Shuwen Han, Haijie Tong, Juntao Huo, Jia Chen, Shan Gao, Zhongbiao Wu, Long Cui, Yu Huang, Guangli Xiu, Junji Cao, Qingyan Fu, and Shun-cheng Lee
Atmos. Chem. Phys., 22, 12789–12802, https://doi.org/10.5194/acp-22-12789-2022, https://doi.org/10.5194/acp-22-12789-2022, 2022
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In this study, we report the long-term measurement of organic carbon (OC) and elementary carbon (EC) in PM2.5 with hourly time resolution conducted at a regional site in Shanghai from 2016 to 2020. The results from this study provide critical information about the long-term trend of carbonaceous aerosol, in particular secondary OC, in one of the largest megacities in the world and are helpful for developing pollution control measures from a long-term planning perspective.
Huikun Liu, Qiyuan Wang, Suixin Liu, Bianhong Zhou, Yao Qu, Jie Tian, Ting Zhang, Yongming Han, and Junji Cao
Atmos. Chem. Phys., 22, 11739–11757, https://doi.org/10.5194/acp-22-11739-2022, https://doi.org/10.5194/acp-22-11739-2022, 2022
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Atmospheric motions play an important role in the mass concentration and the direct radiative effect (DRE) of black carbon (BC). The finding from this study elaborated the impacts of different scales of atmospheric motion on source-specific BC and its DREs, which revealed the nonlinear change between BC mass concentration and its DREs and emphasizes the importance of regionally transported BC for potential climatic effects.
Jie Tian, Qiyuan Wang, Huikun Liu, Yongyong Ma, Suixin Liu, Yong Zhang, Weikang Ran, Yongming Han, and Junji Cao
Atmos. Chem. Phys., 22, 8369–8384, https://doi.org/10.5194/acp-22-8369-2022, https://doi.org/10.5194/acp-22-8369-2022, 2022
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We investigated aerosol optical properties and the direct radiative effect (DRE) at an urban site in China before and during the COVID-19 lockdown. The total light extinction coefficient (bext) decreased under emission control measures; however, bext from biomass burning increased due to the undiminished need for residential cooking and heating. Biomass burning, rather than traffic-related emissions, became the largest positive effect contributor to aerosol DRE in the lockdown.
Han Zang, Yue Zhao, Juntao Huo, Qianbiao Zhao, Qingyan Fu, Yusen Duan, Jingyuan Shao, Cheng Huang, Jingyu An, Likun Xue, Ziyue Li, Chenxi Li, and Huayun Xiao
Atmos. Chem. Phys., 22, 4355–4374, https://doi.org/10.5194/acp-22-4355-2022, https://doi.org/10.5194/acp-22-4355-2022, 2022
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Particulate nitrate plays an important role in wintertime haze pollution in eastern China, yet quantitative constraints on detailed nitrate formation mechanisms remain limited. Here we quantified the contributions of the heterogeneous N2O5 hydrolysis (66 %) and gas-phase OH + NO2 reaction (32 %) to nitrate formation in this region and identified the atmospheric oxidation capacity (i.e., availability of O3 and OH radicals) as the driving factor of nitrate formation from both processes.
Yuting Zhang, Hang Liu, Shandong Lei, Wanyun Xu, Yu Tian, Weijie Yao, Xiaoyong Liu, Qi Liao, Jie Li, Chun Chen, Yele Sun, Pingqing Fu, Jinyuan Xin, Junji Cao, Xiaole Pan, and Zifa Wang
Atmos. Chem. Phys., 21, 17631–17648, https://doi.org/10.5194/acp-21-17631-2021, https://doi.org/10.5194/acp-21-17631-2021, 2021
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In this study, the authors used a single-particle soot photometer (SP2) to characterize the particle size, mixing state, and optical properties of black carbon aerosols in rural areas of the North China Plain in winter. Relatively warm and high-RH environments (RH > 50 %, −4° < T < 4 °) were more favorable to rBC aging than dry and cold environments (RH < 60 %, T < −8°). The paper emphasizes the importance of meteorological parameters in the mixing state of black carbon.
Men Xia, Xiang Peng, Weihao Wang, Chuan Yu, Zhe Wang, Yee Jun Tham, Jianmin Chen, Hui Chen, Yujing Mu, Chenglong Zhang, Pengfei Liu, Likun Xue, Xinfeng Wang, Jian Gao, Hong Li, and Tao Wang
Atmos. Chem. Phys., 21, 15985–16000, https://doi.org/10.5194/acp-21-15985-2021, https://doi.org/10.5194/acp-21-15985-2021, 2021
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ClNO2 is an important precursor of chlorine radical that affects photochemistry. However, its production and impact are not well understood. Our study presents field observations of ClNO2 at three sites in northern China. These observations provide new insights into nighttime processes that produce ClNO2 and the significant impact of ClNO2 on secondary pollutions during daytime. The results improve the understanding of photochemical pollution in the lower part of the atmosphere.
Thierno Doumbia, Claire Granier, Nellie Elguindi, Idir Bouarar, Sabine Darras, Guy Brasseur, Benjamin Gaubert, Yiming Liu, Xiaoqin Shi, Trissevgeni Stavrakou, Simone Tilmes, Forrest Lacey, Adrien Deroubaix, and Tao Wang
Earth Syst. Sci. Data, 13, 4191–4206, https://doi.org/10.5194/essd-13-4191-2021, https://doi.org/10.5194/essd-13-4191-2021, 2021
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Most countries around the world have implemented control measures to combat the spread of the COVID-19 pandemic, resulting in significant changes in economic and personal activities. We developed the CONFORM (COvid-19 adjustmeNt Factors fOR eMissions) dataset to account for changes in emissions during lockdowns. This dataset was created with the intention of being directly applicable to existing global and regional inventories used in chemical transport models.
Kai Wang, Ru-Jin Huang, Martin Brüggemann, Yun Zhang, Lu Yang, Haiyan Ni, Jie Guo, Meng Wang, Jiajun Han, Merete Bilde, Marianne Glasius, and Thorsten Hoffmann
Atmos. Chem. Phys., 21, 9089–9104, https://doi.org/10.5194/acp-21-9089-2021, https://doi.org/10.5194/acp-21-9089-2021, 2021
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Here we present the detailed molecular composition of the organic aerosol collected in three eastern Chinese cities from north to south, Changchun, Shanghai and Guangzhou, by applying LC–Orbitrap analysis. Accordingly, the aromaticity degree of chemical compounds decreases from north to south, while the oxidation degree increases from north to south, which can be explained by the different anthropogenic emissions and photochemical oxidation processes.
Jianing Dai and Tao Wang
Atmos. Chem. Phys., 21, 8747–8759, https://doi.org/10.5194/acp-21-8747-2021, https://doi.org/10.5194/acp-21-8747-2021, 2021
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We used the WRF–Chem model with the latest HONO and ClNO2 processes to investigate their effects on the concentrations of ROx radicals, O3, and PM2.5 in Asia during summer. The results show that the ship-derived HONO and ClNO2 increased the ROx radical concentration by 2–3 times and subsequently increased the O3 and PM2.5 concentrations in marine areas. These findings indicate the importance of these nitrogen processes in the evaluation of the impact of ship emissions on air quality.
Kun Zhang, Ling Huang, Qing Li, Juntao Huo, Yusen Duan, Yuhang Wang, Elly Yaluk, Yangjun Wang, Qingyan Fu, and Li Li
Atmos. Chem. Phys., 21, 5905–5917, https://doi.org/10.5194/acp-21-5905-2021, https://doi.org/10.5194/acp-21-5905-2021, 2021
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Recently, high O3 concentrations were frequently observed in rural areas of the Yangtze River Delta (YRD) region under stagnant conditions. Using an online measurement and observation-based model, we investigated the budget of ROx radicals and the influence of isoprene chemistry on O3 formation. Our results underline that isoprene chemistry in the rural atmosphere becomes important with the participation of anthropogenic NOx.
Yuting Wang, Yong-Feng Ma, Domingo Muñoz-Esparza, Cathy W. Y. Li, Mary Barth, Tao Wang, and Guy P. Brasseur
Atmos. Chem. Phys., 21, 3531–3553, https://doi.org/10.5194/acp-21-3531-2021, https://doi.org/10.5194/acp-21-3531-2021, 2021
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Large-eddy simulations (LESs) were performed in the mountainous region of the island of Hong Kong to investigate the degree to which the rates of chemical reactions between two reactive species are reduced due to the segregation of species within the convective boundary layer. We show that the inhomogeneity in emissions plays an important role in the segregation effect. Topography also has a significant influence on the segregation locally.
Yujiao Zhu, Likun Xue, Jian Gao, Jianmin Chen, Hongyong Li, Yong Zhao, Zhaoxin Guo, Tianshu Chen, Liang Wen, Penggang Zheng, Ye Shan, Xinfeng Wang, Tao Wang, Xiaohong Yao, and Wenxing Wang
Atmos. Chem. Phys., 21, 1305–1323, https://doi.org/10.5194/acp-21-1305-2021, https://doi.org/10.5194/acp-21-1305-2021, 2021
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This work investigates the long-term changes in new particle formation (NPF) events under reduced SO2 emissions at the summit of Mt. Tai during seven campaigns from 2007 to 2018. We found the NPF intensity increased 2- to 3-fold in 2018 compared to 2007. In contrast, the probability of new particles growing to CCN size largely decreased. Changes to biogenic VOCs and anthropogenic emissions are proposed to explain the distinct NPF characteristics.
Rui Li, Qiongqiong Wang, Xiao He, Shuhui Zhu, Kun Zhang, Yusen Duan, Qingyan Fu, Liping Qiao, Yangjun Wang, Ling Huang, Li Li, and Jian Zhen Yu
Atmos. Chem. Phys., 20, 12047–12061, https://doi.org/10.5194/acp-20-12047-2020, https://doi.org/10.5194/acp-20-12047-2020, 2020
Zhenhao Ling, Qianqian Xie, Min Shao, Zhe Wang, Tao Wang, Hai Guo, and Xuemei Wang
Atmos. Chem. Phys., 20, 11451–11467, https://doi.org/10.5194/acp-20-11451-2020, https://doi.org/10.5194/acp-20-11451-2020, 2020
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The observation data from a receptor site in the Pearl River Delta region were analyzed by a photochemical box model with near-explicit chemical mechanisms (i.e., the Master Chemical Mechanism, MCM), improvements with reversible and irreversible heterogeneous processes of glyoxal and methylglyoxal, and the gas-particle partitioning of oxidation products in the present study.
Xiaofei Qin, Leiming Zhang, Guochen Wang, Xiaohao Wang, Qingyan Fu, Jian Xu, Hao Li, Jia Chen, Qianbiao Zhao, Yanfen Lin, Juntao Huo, Fengwen Wang, Kan Huang, and Congrui Deng
Atmos. Chem. Phys., 20, 10985–10996, https://doi.org/10.5194/acp-20-10985-2020, https://doi.org/10.5194/acp-20-10985-2020, 2020
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The uncertainties in mercury emissions are much larger from natural sources than anthropogenic sources. A method was developed to quantify the contributions of natural surface emissions to ambient GEM based on PMF modeling. The annual GEM concentration in eastern China showed a decreasing trend from 2015 to 2018, while the relative contribution of natural surface emissions increased significantly from 41 % in 2015 to 57 % in 2018, gradually surpassing those from anthropogenic sources.
Wei Pu, Zhouxing Zou, Weihao Wang, David Tanner, Zhe Wang, and Tao Wang
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-252, https://doi.org/10.5194/amt-2020-252, 2020
Revised manuscript not accepted
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The hydroxyl radical (OH) is responsible for the degradation of trace gases and plays key roles in major environmental issues such as photochemical pollution. However, the measurement of atmospheric OH radical is a huge challenge due to its high reactivity. Our study provides systematic optimization of a chemical ionization mass spectrometer (CIMS) for OH measurement as a reference for other CIMS users. The ambient result demonstrates the capability of the CIMS for ambient OH measurement.
Jian Xu, Jia Chen, Na Zhao, Guochen Wang, Guangyuan Yu, Hao Li, Juntao Huo, Yanfen Lin, Qingyan Fu, Hongyu Guo, Congrui Deng, Shan-Hu Lee, Jianmin Chen, and Kan Huang
Atmos. Chem. Phys., 20, 7259–7269, https://doi.org/10.5194/acp-20-7259-2020, https://doi.org/10.5194/acp-20-7259-2020, 2020
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This study provided evidence that gas-particle partitioning of ammonia, as opposed to ammonia concentration, plays a critical role in the haze formation. A reduction in ammonia emissions alone may not reduce air pollution effectively, at least at rural agricultural sites in China.
Yiming Liu and Tao Wang
Atmos. Chem. Phys., 20, 6305–6321, https://doi.org/10.5194/acp-20-6305-2020, https://doi.org/10.5194/acp-20-6305-2020, 2020
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This study revealed the effects of changes in meteorology and anthropogenic emissions on the summer ozone variations from 2013 to 2017 across China by conducting numerical experiments. We highlighted the important but varying roles of meteorology in ozone variations attributed to the synergistic or counteracting effects from individual meteorological factors. Developing future ozone pollution mitigation policies should consider the counteracting impact of meteorological changes.
Yiming Liu and Tao Wang
Atmos. Chem. Phys., 20, 6323–6337, https://doi.org/10.5194/acp-20-6323-2020, https://doi.org/10.5194/acp-20-6323-2020, 2020
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Surface ozone levels in urban areas of China were increasing despite the implementation of stringent emission control measures since 2013. Our modeling results show that the decrease in NOx, SO2, and PM emissions and increase in VOC emissions contributed to the urban ozone increases due to the nonlinear ozone chemistry and complex aerosol affects. VOC reduction measures should be implemented in the current and future policies to achieve the goal of improving the overall air quality.
Men Xia, Xiang Peng, Weihao Wang, Chuan Yu, Peng Sun, Yuanyuan Li, Yuliang Liu, Zhengning Xu, Zhe Wang, Zheng Xu, Wei Nie, Aijun Ding, and Tao Wang
Atmos. Chem. Phys., 20, 6147–6158, https://doi.org/10.5194/acp-20-6147-2020, https://doi.org/10.5194/acp-20-6147-2020, 2020
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ClNO2 and Cl2 can be photolyzed by sunlight to produce a highly reactive Cl atom which affects air quality and climate. We observed high ClNO2 and Cl2 concentrations during a recent field study in east China. We analyzed the data and proposed a new hypothesis on the Cl2 production mechanism. Yields of ClNO2 and Cl2 from N2O2 uptake were parameterized using observational constraints, and they can be used in air quality models to improve simulations of atmospheric photochemistry and air quality.
Yonggang Xue, Yu Huang, Steven Sai Hang Ho, Long Chen, Liqin Wang, Shuncheng Lee, and Junji Cao
Atmos. Chem. Phys., 20, 5425–5436, https://doi.org/10.5194/acp-20-5425-2020, https://doi.org/10.5194/acp-20-5425-2020, 2020
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Particulate active metallic oxides in dust were proposed to influence the photochemical reactions of ambient volatile organic compounds (VOCs). A case study investigated the origin and transformation of VOCs during a windblown dust-to-haze pollution episode. In the dust event, a sharp decrease in VOC loading and aging of their components was observed. An increase in Ti and Fe and a fast decrease in trans-/cis-2-butene ratios demonstrated that dust can accelerate the oxidation of ambient VOCs.
Wei Yuan, Ru-Jin Huang, Lu Yang, Jie Guo, Ziyi Chen, Jing Duan, Ting Wang, Haiyan Ni, Yongming Han, Yongjie Li, Qi Chen, Yang Chen, Thorsten Hoffmann, and Colin O'Dowd
Atmos. Chem. Phys., 20, 5129–5144, https://doi.org/10.5194/acp-20-5129-2020, https://doi.org/10.5194/acp-20-5129-2020, 2020
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We characterized light-absorbing properties, chromophore composition and sources of brown carbon (BrC) in Xi'an; identified three groups of light-absorbing organics; and quantified their contribution to overall BrC absorption. Our results showed that vehicle emissions and secondary formation are major sources of BrC in spring, coal combustion and vehicle emissions are major sources in fall, biomass burning and coal combustion become major sources in winter, and secondary BrC dominates in summer.
Havala O. T. Pye, Athanasios Nenes, Becky Alexander, Andrew P. Ault, Mary C. Barth, Simon L. Clegg, Jeffrey L. Collett Jr., Kathleen M. Fahey, Christopher J. Hennigan, Hartmut Herrmann, Maria Kanakidou, James T. Kelly, I-Ting Ku, V. Faye McNeill, Nicole Riemer, Thomas Schaefer, Guoliang Shi, Andreas Tilgner, John T. Walker, Tao Wang, Rodney Weber, Jia Xing, Rahul A. Zaveri, and Andreas Zuend
Atmos. Chem. Phys., 20, 4809–4888, https://doi.org/10.5194/acp-20-4809-2020, https://doi.org/10.5194/acp-20-4809-2020, 2020
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Acid rain is recognized for its impacts on human health and ecosystems, and programs to mitigate these effects have had implications for atmospheric acidity. Historical measurements indicate that cloud and fog droplet acidity has changed in recent decades in response to controls on emissions from human activity, while the limited trend data for suspended particles indicate acidity may be relatively constant. This review synthesizes knowledge on the acidity of atmospheric particles and clouds.
Chuan Yu, Zhe Wang, Men Xia, Xiao Fu, Weihao Wang, Yee Jun Tham, Tianshu Chen, Penggang Zheng, Hongyong Li, Ye Shan, Xinfeng Wang, Likun Xue, Yan Zhou, Dingli Yue, Yubo Ou, Jian Gao, Keding Lu, Steven S. Brown, Yuanhang Zhang, and Tao Wang
Atmos. Chem. Phys., 20, 4367–4378, https://doi.org/10.5194/acp-20-4367-2020, https://doi.org/10.5194/acp-20-4367-2020, 2020
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This study provides a holistic picture of N2O5 heterogeneous uptake on ambient aerosols and the influencing factors under various climatic and chemical conditions in China, and it proposes an observation-based empirical parameterization. The empirical parameterization can be used in air quality models to improve the prediction of PM2.5 and photochemical pollution in China and similar polluted regions of the world.
Jing Duan, Ru-Jin Huang, Yongjie Li, Qi Chen, Yan Zheng, Yang Chen, Chunshui Lin, Haiyan Ni, Meng Wang, Jurgita Ovadnevaite, Darius Ceburnis, Chunying Chen, Douglas R. Worsnop, Thorsten Hoffmann, Colin O'Dowd, and Junji Cao
Atmos. Chem. Phys., 20, 3793–3807, https://doi.org/10.5194/acp-20-3793-2020, https://doi.org/10.5194/acp-20-3793-2020, 2020
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We characterized secondary aerosol formation in Beijing. Our results showed that relative humidity (RH) and Ox have opposite effects on sulfate and nitrate formation in summer and winter. The wintertime more-oxidized OOA (MO-OOA) showed a good correlation with aerosol liquid water content (ALWC). Meanwhile, the dependence of less-oxidized OOA (LO-OOA) and the mass ratio of LO-OOA to MO-OOA in Ox both degraded when RH > 60 %, suggesting that RH or ALWC may also affect LO-OOA formation.
Tao Li, Zhe Wang, Yaru Wang, Chen Wu, Yiheng Liang, Men Xia, Chuan Yu, Hui Yun, Weihao Wang, Yan Wang, Jia Guo, Hartmut Herrmann, and Tao Wang
Atmos. Chem. Phys., 20, 391–407, https://doi.org/10.5194/acp-20-391-2020, https://doi.org/10.5194/acp-20-391-2020, 2020
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This work presents a field study of cloud water chemistry and interactions of cloud, gas, and aerosols in the polluted coastal boundary layer in southern China. Substantial dissolved organic matter in the acidic cloud water was observed, and the gas- and aqueous-phase partitioning of carbonyl compounds was investigated. The results demonstrated the significant role of cloud processing in altering aerosol properties, especially in producing aqueous organics and droplet-mode aerosols.
Jianming Xu, Xuexi Tie, Wei Gao, Yanfen Lin, and Qingyan Fu
Atmos. Chem. Phys., 19, 9017–9035, https://doi.org/10.5194/acp-19-9017-2019, https://doi.org/10.5194/acp-19-9017-2019, 2019
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The PM2.5 in China has decreased significantly in recent years as a result of the implementation of the Chinese Clean Air Action Plan in 2013, while the O3 pollution is getting worse, especially in megacities. The work aims to better understand the elevated O3 pollution in the megacity of Shanghai, China, and its response to emission changes, which is important for developing an effective emission control strategy in the future.
Lu Shen, Daniel J. Jacob, Xiong Liu, Guanyu Huang, Ke Li, Hong Liao, and Tao Wang
Atmos. Chem. Phys., 19, 6551–6560, https://doi.org/10.5194/acp-19-6551-2019, https://doi.org/10.5194/acp-19-6551-2019, 2019
Xinning Wang, Yin Shen, Yanfen Lin, Jun Pan, Yan Zhang, Peter K. K. Louie, Mei Li, and Qingyan Fu
Atmos. Chem. Phys., 19, 6315–6330, https://doi.org/10.5194/acp-19-6315-2019, https://doi.org/10.5194/acp-19-6315-2019, 2019
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Shipping emissions were measured online at Shanghai Port, and their impacts on local air quality at the port and in the surrounding area were quantitatively assessed. Ship emission plumes were readily detectable before they dissipated. We captured ship emission plumes using synchronized peaks of SO2 and vanadium particles. By measuring the pollutant concentrations during plumes and their occurrence frequency, we made quantitative estimations of ship emission impacts on port air quality.
Junlan Feng, Yan Zhang, Shanshan Li, Jingbo Mao, Allison P. Patton, Yuyan Zhou, Weichun Ma, Cong Liu, Haidong Kan, Cheng Huang, Jingyu An, Li Li, Yin Shen, Qingyan Fu, Xinning Wang, Juan Liu, Shuxiao Wang, Dian Ding, Jie Cheng, Wangqi Ge, Hong Zhu, and Katherine Walker
Atmos. Chem. Phys., 19, 6167–6183, https://doi.org/10.5194/acp-19-6167-2019, https://doi.org/10.5194/acp-19-6167-2019, 2019
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This study aims to estimate the emissions, air quality and population exposure impacts of shipping in 2015, prior to the implementation of the DECAs. It shows that ship emissions within 12 NM of the shore could account for over 55 % of the shipping impact on air pollution in the YRD in summer. Ships entering the Yangtze River and other inland waterways of Shanghai contribute 40–80 % of the ship-related air pollution and population exposure，which both have important implications regarding policy.
Xiaofei Qin, Xiaohao Wang, Yijie Shi, Guangyuan Yu, Na Zhao, Yanfen Lin, Qingyan Fu, Dongfang Wang, Zhouqing Xie, Congrui Deng, and Kan Huang
Atmos. Chem. Phys., 19, 5923–5940, https://doi.org/10.5194/acp-19-5923-2019, https://doi.org/10.5194/acp-19-5923-2019, 2019
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The seasonal pattern of atmospheric mercury species over a regional transport intersection zone in east China indicated impacts from both natural re-emissions and anthropogenic emissions. Quasi-local sources were more important than long-range transport for mercury, opposite from particles. Shipping activities were especially outstanding emissions. Abnormally high GOM was ascribed to the high oxidant levels. The gas–particle partition inhibited the formation of GOM under high particle levels.
Zhaofeng Tan, Keding Lu, Meiqing Jiang, Rong Su, Hongli Wang, Shengrong Lou, Qingyan Fu, Chongzhi Zhai, Qinwen Tan, Dingli Yue, Duohong Chen, Zhanshan Wang, Shaodong Xie, Limin Zeng, and Yuanhang Zhang
Atmos. Chem. Phys., 19, 3493–3513, https://doi.org/10.5194/acp-19-3493-2019, https://doi.org/10.5194/acp-19-3493-2019, 2019
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We evaluated the atmospheric oxidation capacity (AOC) in four Chinese megacities during photochemically polluted seasons. The chemical production of ozone and particle nitrate was diagnosed through a box model, which can be attributed to daytime radical chemistry. Our work highlights that the formation of both ozone and fine particles is largely driven by the atmospheric radical chemistry in China. Consequently, we suggest future pollution mitigation strategies should consider the role of AOC.
Xiao Fu, Tao Wang, Li Zhang, Qinyi Li, Zhe Wang, Men Xia, Hui Yun, Weihao Wang, Chuan Yu, Dingli Yue, Yan Zhou, Junyun Zheng, and Rui Han
Atmos. Chem. Phys., 19, 1–14, https://doi.org/10.5194/acp-19-1-2019, https://doi.org/10.5194/acp-19-1-2019, 2019
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This study has identified the major contributors to the observed high HONO levels during a severe winter pollution episode and highlighted the importance of HONO chemistry in the combined photochemical and haze pollution in a subtropical region. It also highlighted the critical need to include and update HONO sources in regional air quality models in order to predict ozone and other secondary pollutants better during heavy pollution events in southern China and similar regions.
Hui Yun, Weihao Wang, Tao Wang, Men Xia, Chuan Yu, Zhe Wang, Steven C. N. Poon, Dingli Yue, and Yan Zhou
Atmos. Chem. Phys., 18, 17515–17527, https://doi.org/10.5194/acp-18-17515-2018, https://doi.org/10.5194/acp-18-17515-2018, 2018
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Based on the data analysis of simultaneous measurement of N2O5 and ClNO2 in a severe winter haze in the Pearl River Delta, this study underscores the importance of N2O5 heterogeneous reactions in nitrate formation and calls for better parameterization of N2O5 heterogeneous chemistry in order to predict haze pollution in China.
Weihao Wang, Zhe Wang, Chuan Yu, Men Xia, Xiang Peng, Yan Zhou, Dingli Yue, Yubo Ou, and Tao Wang
Atmos. Meas. Tech., 11, 5643–5655, https://doi.org/10.5194/amt-11-5643-2018, https://doi.org/10.5194/amt-11-5643-2018, 2018
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This study introduces an in situ experimental approach to direct measurement of N2O5 heterogeneous reactivity in polluted environments. Laboratory tests, model simulations, and field deployment of the method at a polluted site in south China demonstrated its applicability in accurately measuring N2O5 uptake coefficient with high ambient pollutants levels and air mass changes. The introduced method is also applicable to in situ measurement of reactivity of other trace gases on ambient aerosols.
Yee Jun Tham, Zhe Wang, Qinyi Li, Weihao Wang, Xinfeng Wang, Keding Lu, Nan Ma, Chao Yan, Simonas Kecorius, Alfred Wiedensohler, Yuanhang Zhang, and Tao Wang
Atmos. Chem. Phys., 18, 13155–13171, https://doi.org/10.5194/acp-18-13155-2018, https://doi.org/10.5194/acp-18-13155-2018, 2018
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This study addresses the limited understanding of heterogeneous N2O5 uptake and ClNO2 production in the polluted environment of China. The results showed that N2O5 uptake and ClNO2 yield cannot be well explained by previous parameterizations and were largely influenced by factors like aerosol water content and biomass burning emission. Our findings illuminate the need to realistically parameterize these heterogeneous processes for better simulation of photochemical and haze pollution in China.
Michael Le Breton, Åsa M. Hallquist, Ravi Kant Pathak, David Simpson, Yujue Wang, John Johansson, Jing Zheng, Yudong Yang, Dongjie Shang, Haichao Wang, Qianyun Liu, Chak Chan, Tao Wang, Thomas J. Bannan, Michael Priestley, Carl J. Percival, Dudley E. Shallcross, Keding Lu, Song Guo, Min Hu, and Mattias Hallquist
Atmos. Chem. Phys., 18, 13013–13030, https://doi.org/10.5194/acp-18-13013-2018, https://doi.org/10.5194/acp-18-13013-2018, 2018
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We apply state-of-the-art chemical characterization to determine the chloride radical production in Beijing via measurement of inorganic halogens at a semi-rural site. The high concentration of inorganic halogens, namely nitryl chloride, enables the production of chlorinated volatile organic compounds which are measured in both the gas and particle phases simultaneously. This enables the secondary production of aerosols via chlorine oxidation to be directly observed in ambient air.
Liang Wen, Likun Xue, Xinfeng Wang, Caihong Xu, Tianshu Chen, Lingxiao Yang, Tao Wang, Qingzhu Zhang, and Wenxing Wang
Atmos. Chem. Phys., 18, 11261–11275, https://doi.org/10.5194/acp-18-11261-2018, https://doi.org/10.5194/acp-18-11261-2018, 2018
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We present the first piece of observational evidence of the increasing trend of fine nitrate aerosol in the North China Plain (NCP) during 2005–2015. The summertime nitrate formation mechanism is dissected with a multiphase chemical box model based on observations at three different sites. The nitrate formation is most sensitive to NO2 and to a lesser extent to O3. NH3 plays a significant role in prompting the nitrate formation, but it is usually in excess in summer in the NCP region.
Liwei Wang, Xinfeng Wang, Rongrong Gu, Hao Wang, Lan Yao, Liang Wen, Fanping Zhu, Weihao Wang, Likun Xue, Lingxiao Yang, Keding Lu, Jianmin Chen, Tao Wang, Yuanghang Zhang, and Wenxing Wang
Atmos. Chem. Phys., 18, 4349–4359, https://doi.org/10.5194/acp-18-4349-2018, https://doi.org/10.5194/acp-18-4349-2018, 2018
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This study presents concentrations, variation characteristics, sources and secondary formations of nitrated phenols, a major component of brown carbon, in typical seasons at four sites in northern China. The results highlight the strong influences and contributions of anthropogenic activities, in particular coal combustion and the aging processes, to the atmospheric nitrated phenols in this region.
Qiongzhen Wang, Xinyi Dong, Joshua S. Fu, Jian Xu, Congrui Deng, Yilun Jiang, Qingyan Fu, Yanfen Lin, Kan Huang, and Guoshun Zhuang
Atmos. Chem. Phys., 18, 3505–3521, https://doi.org/10.5194/acp-18-3505-2018, https://doi.org/10.5194/acp-18-3505-2018, 2018
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A synergy of ground-based atmospheric chemistry observation, lidar, and numerical modeling was used to investigate a super dust event passing over Shanghai. The degree of dust that was modified by anthropogenic sources highly depended on the transport pathways. A community regional air quality model with improved dust scheme reproduced reasonable dust chemistry results. The chemical and optical properties of evolving dust are crucial for evaluating the climatic effects of dust.
Zhe Wang, Weihao Wang, Yee Jun Tham, Qinyi Li, Hao Wang, Liang Wen, Xinfeng Wang, and Tao Wang
Atmos. Chem. Phys., 17, 12361–12378, https://doi.org/10.5194/acp-17-12361-2017, https://doi.org/10.5194/acp-17-12361-2017, 2017
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This work addresses unclear roles of heterogeneous N2O5 reactions and chlorine activation processes in the polluted residual layer from a mountaintop measurement in northern China. The results revealed efficient ClNO2 production in the coal-fired plumes in this region, having large impacts on next-morning photochemistry. Fast heterogeneous N2O5 reactions dominate the nocturnal NOx loss and contribute to substantial nitrate formation, which may boost the haze pollution in northern China.
Li Zhang, Qinyi Li, Tao Wang, Ravan Ahmadov, Qiang Zhang, Meng Li, and Mengyao Lv
Atmos. Chem. Phys., 17, 9733–9750, https://doi.org/10.5194/acp-17-9733-2017, https://doi.org/10.5194/acp-17-9733-2017, 2017
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Little is known of the integrated impacts of HONO and ClNO2 on lower-tropospheric ozone so far. In this study, we updated WRF-Chem with the CBMZ_ReNOM module, which considers both the sources and chemistry of HONO and ClNO2. The revised model revealed that the two reactive nitrogen compounds significantly affected the oxidation capacity and ozone formation at the surface and within the lower troposphere over polluted regions and noticeably improved summertime O3 predictions over China.
Jiaping Wang, Aki Virkkula, Yuan Gao, Shuncheng Lee, Yicheng Shen, Xuguang Chi, Wei Nie, Qiang Liu, Zheng Xu, Xin Huang, Tao Wang, Long Cui, and Aijun Ding
Atmos. Chem. Phys., 17, 2653–2671, https://doi.org/10.5194/acp-17-2653-2017, https://doi.org/10.5194/acp-17-2653-2017, 2017
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Multi-year observations at a coastal station in Hong Kong reveals that aerosol optical properties showed clear temporal variations according to the dominant sources of aerosols. LPDM modeling and correlation analysis gave similar signals about the freshness of aerosols during different seasons. Fresh emissions of particles from nearby cities and ship exhausts affected light optical properties and particle size in summer and aged air mass in winter caused larger variability of light extinction.
Yee Jun Tham, Zhe Wang, Qinyi Li, Hui Yun, Weihao Wang, Xinfeng Wang, Likun Xue, Keding Lu, Nan Ma, Birger Bohn, Xin Li, Simonas Kecorius, Johannes Größ, Min Shao, Alfred Wiedensohler, Yuanhang Zhang, and Tao Wang
Atmos. Chem. Phys., 16, 14959–14977, https://doi.org/10.5194/acp-16-14959-2016, https://doi.org/10.5194/acp-16-14959-2016, 2016
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This work addresses the unclear global significance of chlorine activation processes in the troposphere. The first high-quality measurement data set of ClNO2 in northern China revealed strong ClNO2 production in the residual layers, and demonstrated its significant effects on radical budget and ozone production. Our findings imply the widespread effects of ClNO2 over the polluted regions of northern China, which may increase photochemical and haze pollution.
Qinyi Li, Li Zhang, Tao Wang, Yee Jun Tham, Ravan Ahmadov, Likun Xue, Qiang Zhang, and Junyu Zheng
Atmos. Chem. Phys., 16, 14875–14890, https://doi.org/10.5194/acp-16-14875-2016, https://doi.org/10.5194/acp-16-14875-2016, 2016
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The regional distributions and impacts of N2O5 and ClNO2 remain poorly understood. To address the problem, we developed a chemical transport model further and conducted the first high-resolution simulation of the distributions of the two species. Our research demonstrated the significant impacts of the two gases on the lifetime of nitrogen oxides, secondary nitrate production and ozone formation in southern China and highlighted the necessity of considering this chemistry in air quality models.
Lei Sun, Likun Xue, Tao Wang, Jian Gao, Aijun Ding, Owen R. Cooper, Meiyun Lin, Pengju Xu, Zhe Wang, Xinfeng Wang, Liang Wen, Yanhong Zhu, Tianshu Chen, Lingxiao Yang, Yan Wang, Jianmin Chen, and Wenxing Wang
Atmos. Chem. Phys., 16, 10637–10650, https://doi.org/10.5194/acp-16-10637-2016, https://doi.org/10.5194/acp-16-10637-2016, 2016
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We compiled the available observations of surface O3 at Mt. Tai – the highest mountain in the North China Plain, and found a significant increase of O3 concenrations from 2003 to 2015. The observed O3 increase was mainly due to the increase of O3 precursors, especially VOCs. Our analysis shows that controlling NOx alone, in the absence of VOC controls, is not sufficient to reduce regional O3 levels in North China in a short period.
Likun Xue, Rongrong Gu, Tao Wang, Xinfeng Wang, Sandra Saunders, Donald Blake, Peter K. K. Louie, Connie W. Y. Luk, Isobel Simpson, Zheng Xu, Zhe Wang, Yuan Gao, Shuncheng Lee, Abdelwahid Mellouki, and Wenxing Wang
Atmos. Chem. Phys., 16, 9891–9903, https://doi.org/10.5194/acp-16-9891-2016, https://doi.org/10.5194/acp-16-9891-2016, 2016
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The chemical budgets and principal sources of ROx and NO3 radicals during a multi-day photochemical smog episode in Hong Kong are elucidated by an observation-constrained MCM model. NO3 was shown to be an important oxidant even during daytime in a pollution case when high aerosol loading attenuated the solar irradiation. This study suggests the potential important role of daytime NO3 chemistry in polluted atmospheres under conditions with the co-existence of abundant O3, NO2, VOCs, and aerosols.
L. K. Xue, S. M. Saunders, T. Wang, R. Gao, X. F. Wang, Q. Z. Zhang, and W. X. Wang
Geosci. Model Dev., 8, 3151–3162, https://doi.org/10.5194/gmd-8-3151-2015, https://doi.org/10.5194/gmd-8-3151-2015, 2015
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A detailed chemical mechanism including 205 reactions is developed for use in the Master Chemical Mechanism. With this new chlorine mechanism, it was found that the nocturnal formation of ClNO2 has high potential to perturb the next day's atmospheric photochemistry, by enhancing the radical production and cycling, VOC oxidation and O3 formation, in the polluted coastal environments.
T. Li, Y. Wang, W. J. Li, J. M. Chen, T. Wang, and W. X. Wang
Atmos. Chem. Phys., 15, 8987–9002, https://doi.org/10.5194/acp-15-8987-2015, https://doi.org/10.5194/acp-15-8987-2015, 2015
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Twelve trace elements in fine particles and clouds at a mountain site in southern China were investigated.
Long-range transport contributed the most to element concentrations, whereas the YRD and the area around Mt. Lushan exhibited the highest element solubility.
We demonstrated that cloud processing can enhance aerosol element solubility and increase sulfate concentration correspondingly, by irreversibly altering the morphology of metal particles in cloud droplet residues.
S. Xiao, M. Y. Wang, L. Yao, M. Kulmala, B. Zhou, X. Yang, J. M. Chen, D. F. Wang, Q. Y. Fu, D. R. Worsnop, and L. Wang
Atmos. Chem. Phys., 15, 1769–1781, https://doi.org/10.5194/acp-15-1769-2015, https://doi.org/10.5194/acp-15-1769-2015, 2015
L. K. Xue, T. Wang, J. Gao, A. J. Ding, X. H. Zhou, D. R. Blake, X. F. Wang, S. M. Saunders, S. J. Fan, H. C. Zuo, Q. Z. Zhang, and W. X. Wang
Atmos. Chem. Phys., 14, 13175–13188, https://doi.org/10.5194/acp-14-13175-2014, https://doi.org/10.5194/acp-14-13175-2014, 2014
X. Wang, T. Wang, C. Yan, Y. J. Tham, L. Xue, Z. Xu, and Q. Zha
Atmos. Meas. Tech., 7, 1–12, https://doi.org/10.5194/amt-7-1-2014, https://doi.org/10.5194/amt-7-1-2014, 2014
L. K. Xue, T. Wang, J. Gao, A. J. Ding, X. H. Zhou, D. R. Blake, X. F. Wang, S. M. Saunders, S. J. Fan, H. C. Zuo, Q. Z. Zhang, and W. X. Wang
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acpd-13-27243-2013, https://doi.org/10.5194/acpd-13-27243-2013, 2013
Revised manuscript not accepted
L. K. Xue, T. Wang, H. Guo, D. R. Blake, J. Tang, X. C. Zhang, S. M. Saunders, and W. X. Wang
Atmos. Chem. Phys., 13, 8551–8567, https://doi.org/10.5194/acp-13-8551-2013, https://doi.org/10.5194/acp-13-8551-2013, 2013
W. Nie, T. Wang, L. K. Xue, A. J. Ding, X. F. Wang, X. M. Gao, Z. Xu, Y. C. Yu, C. Yuan, Z. S. Zhou, R. Gao, X. H. Liu, Y. Wang, S. J. Fan, S. Poon, Q. Z. Zhang, and W. X. Wang
Atmos. Chem. Phys., 12, 11985–11995, https://doi.org/10.5194/acp-12-11985-2012, https://doi.org/10.5194/acp-12-11985-2012, 2012
Related subject area
Subject: Aerosols | Research Activity: Machine Learning | Altitude Range: Troposphere | Science Focus: Chemistry (chemical composition and reactions)
Capturing synoptic-scale variations in surface aerosol pollution using deep learning with meteorological data
Decoupling impacts of weather conditions on interannual variations in concentrations of criteria air pollutants in South China – constraining analysis uncertainties by using multiple analysis tools
Jin Feng, Yanjie Li, Yulu Qiu, and Fuxin Zhu
Atmos. Chem. Phys., 23, 375–388, https://doi.org/10.5194/acp-23-375-2023, https://doi.org/10.5194/acp-23-375-2023, 2023
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It is important to use weather data to estimate aerosol concentrations. Here, a weather index for aerosol concentration based on deep learning was developed, linking weather and short-term variations in aerosol concentrations over China. The index provides better performance than chemical transport model simulation and other data-based estimation approaches. It can be used as a robust tool for estimating daily variations in aerosol concentrations.
Yu Lin, Leiming Zhang, Qinchu Fan, He Meng, Yang Gao, Huiwang Gao, and Xiaohong Yao
Atmos. Chem. Phys., 22, 16073–16090, https://doi.org/10.5194/acp-22-16073-2022, https://doi.org/10.5194/acp-22-16073-2022, 2022
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In this study, we analyzed 7-year (from May 2014 to April 2021) concentration data of six criteria air pollutants (PM2.5, PM10, O3, NO2, CO and SO2) as well as the sum of NO2 and O3 in six cities in South China. Three different analysis methods were used to identify emission-driven interannual variations and perturbations from varying weather conditions. In addition, a self-developed method was further introduced to constrain analysis uncertainties.
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Short summary
Hourly elemental carbon (EC) and NOx were continuously measured for 5 years (2016–2020) at a sampling site near a highway in western Shanghai. We use a machine learning model to rebuild the measured EC and NOx, and a business-as-usual (BAU) scenario was assumed in 2020 and compared with the measured EC and NOx.
Hourly elemental carbon (EC) and NOx were continuously measured for 5 years (2016–2020) at a...
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