Articles | Volume 21, issue 5
https://doi.org/10.5194/acp-21-4025-2021
© Author(s) 2021. 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-21-4025-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
17 Mar 2021
Research article |
| 17 Mar 2021
| 17 Mar 2021
Impact of reduced anthropogenic emissions during COVID-19 on air quality in India
Mengyuan Zhang
Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
Arpit Katiyar
Department of Civil Engineering, Indian Institute of Technology, Delhi, 110016, India
Shengqiang Zhu
Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
Juanyong Shen
School of Environmental Science and Engineering, Shanghai Jiao Tong
University, Shanghai 200240, China
Department of Civil and Environmental Engineering, The Hong Kong
Polytechnic University, Hong Kong SAR, 99907, China
Jinlong Ma
Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
Sri Harsha Kota
Department of Civil Engineering, Indian Institute of Technology, Delhi, 110016, India
Department of Civil and Environmental Engineering, The Hong Kong
Polytechnic University, Hong Kong SAR, 99907, China
Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
Institute of Eco-Chongming (IEC), Shanghai 200062, China
Related authors
No articles found.
Jianing Dai, Guy P. Brasseur, Mihalis Vrekoussis, Maria Kanakidou, Kun Qu, Yijuan Zhang, Hongliang Zhang, and Tao Wang
Atmos. Chem. Phys., 24, 12943–12962, https://doi.org/10.5194/acp-24-12943-2024, https://doi.org/10.5194/acp-24-12943-2024, 2024
Short summary
Short summary
This paper employs a regional chemical transport model to quantify the sensitivity of air pollutants and photochemical parameters to specified emission reductions in China for representative winter and summer conditions. The study provides insights into further air quality control in China with reduced primary emissions.
Mingxue Li, Men Xia, Chunshui Lin, Yifan Jiang, Weihang Sun, Yurun Wang, Yingnan Zhang, Maoxia He, and Tao Wang
EGUsphere, https://doi.org/10.5194/egusphere-2024-3137, https://doi.org/10.5194/egusphere-2024-3137, 2024
Short summary
Short summary
Our field campaigns observed a strong diel pattern of chloroacetic acid as well as a strong correlation between its level and those of reactive chlorine species at a coastal site. Using quantum chemical calculations and box model simulation with updated MCM, we found that the formation pathway of chloroacetic acid involved multiphase processes. Our study deepens the understanding of atmospheric VOC-Cl chemistry and highlights the crucial role of multiphase reactions in atmospheric chemistry.
Shuai Wang, Mengyuan Zhang, Hui Zhao, Peng Wang, Sri Harsha Kota, Qingyan Fu, Cong Liu, and Hongliang Zhang
Earth Syst. Sci. Data, 16, 3565–3577, https://doi.org/10.5194/essd-16-3565-2024, https://doi.org/10.5194/essd-16-3565-2024, 2024
Short summary
Short summary
Long-term, open-source, gap-free daily ground-level PM2.5 and PM10 datasets for India (LongPMInd) were reconstructed using a robust machine learning model to support health assessment and air quality management.
Shuai Wang, Mengyuan Zhang, Yueqi Gao, Peng Wang, Qingyan Fu, and Hongliang Zhang
Geosci. Model Dev., 17, 3617–3629, https://doi.org/10.5194/gmd-17-3617-2024, https://doi.org/10.5194/gmd-17-3617-2024, 2024
Short summary
Short summary
Numerical models are widely used in air pollution modeling but suffer from significant biases. The machine learning model designed in this study shows high efficiency in identifying such biases. Meteorology (relative humidity and cloud cover), chemical composition (secondary organic components and dust aerosols), and emission sources (residential activities) are diagnosed as the main drivers of bias in modeling PM2.5, a typical air pollutant. The results will help to improve numerical models.
Bin Luo, Yuqiang Zhang, Tao Tang, Hongliang Zhang, Jianlin Hu, Jiangshan Mu, Wenxing Wang, and Likun Xue
EGUsphere, https://doi.org/10.5194/egusphere-2024-974, https://doi.org/10.5194/egusphere-2024-974, 2024
Short summary
Short summary
India is facing a severe air pollution crisis that poses significant health risks, particularly from PM2.5 and O3. Our study reveals rising levels of both pollutants from 1995 to 2014, leading to increased premature mortality. While anthropogenic emissions play a significant role, biomass burning also impacts air quality, in particular seasons and regions in India. This study highlights the urgent need for localized policies to protect public health amid escalating environmental challenges.
Yifan Jiang, Men Xia, Zhe Wang, Penggang Zheng, Yi Chen, and Tao Wang
Atmos. Chem. Phys., 23, 14813–14828, https://doi.org/10.5194/acp-23-14813-2023, https://doi.org/10.5194/acp-23-14813-2023, 2023
Short summary
Short summary
This study provides the first estimate of high rates of formic acid (HCOOH) production from the photochemical aging of real ambient particles and demonstrates the potential importance of this pathway in the formation of HCOOH under ambient conditions. Incorporating this pathway significantly improved the performance of a widely used chemical model. Our solution irradiation experiments demonstrated the importance of nitrate photolysis in HCOOH production via the production of oxidants.
Jianing Dai, Guy P. Brasseur, Mihalis Vrekoussis, Maria Kanakidou, Kun Qu, Yijuan Zhang, Hongliang Zhang, and Tao Wang
Atmos. Chem. Phys., 23, 14127–14158, https://doi.org/10.5194/acp-23-14127-2023, https://doi.org/10.5194/acp-23-14127-2023, 2023
Short summary
Short summary
In this study, we used a regional chemical transport model to characterize the different parameters of atmospheric oxidative capacity in recent chemical environments in China. These parameters include the production and destruction rates of ozone and other oxidants, the ozone production efficiency, the OH reactivity, and the length of the reaction chain responsible for the formation of ozone and ROx. They are also affected by the aerosol burden in the atmosphere.
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.
Xiaodong Xie, Jianlin Hu, Momei Qin, Song Guo, Min Hu, Dongsheng Ji, Hongli Wang, Shengrong Lou, Cheng Huang, Chong Liu, Hongliang Zhang, Qi Ying, Hong Liao, and Yuanhang Zhang
Atmos. Chem. Phys., 23, 10563–10578, https://doi.org/10.5194/acp-23-10563-2023, https://doi.org/10.5194/acp-23-10563-2023, 2023
Short summary
Short summary
The atmospheric age of particles reflects how long particles have been formed and suspended in the atmosphere, which is closely associated with the evolution processes of particles. An analysis of the atmospheric age of PM2.5 provides a unique perspective on the evolution processes of different PM2.5 components. The results also shed lights on how to design effective emission control actions under unfavorable meteorological conditions.
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
Short summary
Short summary
We present OH observation and model simulation results at a coastal site in Hong Kong. The model predicted the OH concentration under high-NOx well but overpredicted it under low-NOx conditions. This implies an insufficient understanding of OH chemistry under low-NOx conditions. We show evidence of missing OH sinks as a possible cause of the overprediction.
Yishuo Guo, Chenjuan Deng, Aino Ovaska, Feixue Zheng, Chenjie Hua, Junlei Zhan, Yiran Li, Jin Wu, Zongcheng Wang, Jiali Xie, Ying Zhang, Tingyu Liu, Yusheng Zhang, Boying Song, Wei Ma, Yongchun Liu, Chao Yan, Jingkun Jiang, Veli-Matti Kerminen, Men Xia, Tuomo Nieminen, Wei Du, Tom Kokkonen, and Markku Kulmala
Atmos. Chem. Phys., 23, 6663–6690, https://doi.org/10.5194/acp-23-6663-2023, https://doi.org/10.5194/acp-23-6663-2023, 2023
Short summary
Short summary
Using the comprehensive datasets, we investigated the long-term variations of air pollutants during winter in Beijing from 2019 to 2022 and analyzed the characteristics of atmospheric pollution cocktail during different short-term special events (e.g., Beijing Winter Olympics, COVID lockdown and Chinese New Year) associated with substantial emission reductions. Our results are useful in planning more targeted and sustainable long-term pollution control plans.
Jinlong Ma, Shengqiang Zhu, Siyu Wang, Peng Wang, Jianmin Chen, and Hongliang Zhang
Atmos. Chem. Phys., 23, 4311–4325, https://doi.org/10.5194/acp-23-4311-2023, https://doi.org/10.5194/acp-23-4311-2023, 2023
Short summary
Short summary
An updated version of the CMAQ model with biogenic volatile organic compound (BVOC) emissions from MEGAN was applied to study the impacts of different land cover inputs on O3 and secondary organic aerosol (SOA) in China. The estimated BVOC emissions ranged from 25.42 to 37.39 Tg using different leaf area index (LAI) and land cover (LC) inputs. Those differences further induced differences of 4.8–6.9 ppb in O3 concentrations and differences of 5.3–8.4 µg m−3 in SOA concentrations in China.
Peng Wang, Ruhan Zhang, Shida Sun, Meng Gao, Bo Zheng, Dan Zhang, Yanli Zhang, Gregory R. Carmichael, and Hongliang Zhang
Atmos. Chem. Phys., 23, 2983–2996, https://doi.org/10.5194/acp-23-2983-2023, https://doi.org/10.5194/acp-23-2983-2023, 2023
Short summary
Short summary
In China, the number of vehicles has jumped significantly in the last decade. This caused severe traffic congestion and aggravated air pollution. In this study, we developed a new temporal allocation approach to quantify the impacts of traffic congestion. We found that traffic congestion worsens air quality and the health burden across China, especially in the urban clusters. More effective and comprehensive vehicle emission control policies should be implemented to improve air quality in China.
Peng Wang, Juanyong Shen, Men Xia, Shida Sun, Yanli Zhang, Hongliang Zhang, and Xinming Wang
Atmos. Chem. Phys., 21, 10347–10356, https://doi.org/10.5194/acp-21-10347-2021, https://doi.org/10.5194/acp-21-10347-2021, 2021
Short summary
Short summary
Ozone (O3) pollution has received extensive attention due to worsening air quality and rising health risks. The Chinese National Day holiday (CNDH), which is associated with intensive commercial and tourist activities, serves as a valuable experiment to evaluate the O3 response during the holiday. We find sharply increasing trends of observed O3 concentrations throughout China during the CNDH, leading to 33 % additional total daily deaths.
Lian Zong, Yuanjian Yang, Meng Gao, Hong Wang, Peng Wang, Hongliang Zhang, Linlin Wang, Guicai Ning, Chao Liu, Yubin Li, and Zhiqiu Gao
Atmos. Chem. Phys., 21, 9105–9124, https://doi.org/10.5194/acp-21-9105-2021, https://doi.org/10.5194/acp-21-9105-2021, 2021
Short summary
Short summary
In recent years, summer O3 pollution over eastern China has become more serious, and it is even the case that surface O3 and PM2.5 pollution can co-occur. However, the synoptic weather pattern (SWP) related to this compound pollution remains unclear. Regional PM2.5 and O3 compound pollution is characterized by various SWPs with different dominant factors. Our findings provide insights into the regional co-occurring high PM2.5 and O3 levels via the effects of certain meteorological factors.
Jinlong Ma, Juanyong Shen, Peng Wang, Shengqiang Zhu, Yu Wang, Pengfei Wang, Gehui Wang, Jianmin Chen, and Hongliang Zhang
Atmos. Chem. Phys., 21, 7343–7355, https://doi.org/10.5194/acp-21-7343-2021, https://doi.org/10.5194/acp-21-7343-2021, 2021
Short summary
Short summary
Due to the reduced anthropogenic emissions during the COVID-19 lockdown, mainly from the transportation and industrial sectors, PM2.5 decreased significantly in the whole Yangtze River Delta (YRD) and its major cities. However, the contributions and relative importance of different source sectors and regions changed differently, indicating that control strategies should be adjusted accordingly for further pollution control.
Junjun Deng, Hao Guo, Hongliang Zhang, Jialei Zhu, Xin Wang, and Pingqing Fu
Atmos. Chem. Phys., 20, 14419–14435, https://doi.org/10.5194/acp-20-14419-2020, https://doi.org/10.5194/acp-20-14419-2020, 2020
Short summary
Short summary
One-year source apportionment of BC aerosols in a coastal city in China was conducted with the light-absorption observation-based method and source-oriented model. Source contributions identified by the two source apportionment methods were compared. Temporal variability, potential sources and transport pathways of BC from fossil fuel and biomass burning were characterized. Significant influence of biomass burning in North and East–Central China on BC in the region was highlighted.
Zhihao Shi, Lin Huang, Jingyi Li, Qi Ying, Hongliang Zhang, and Jianlin Hu
Atmos. Chem. Phys., 20, 13455–13466, https://doi.org/10.5194/acp-20-13455-2020, https://doi.org/10.5194/acp-20-13455-2020, 2020
Short summary
Short summary
Meteorological conditions play important roles in the formation of O3 and PM2.5 pollution in China. O3 is most sensitive to temperature and the sensitivity is dependent on the O3 chemistry formation or loss regime. PM2.5 is negatively sensitive to temperature, wind speed, and planetary boundary layer height and positively sensitive to humidity. The results imply that air quality in certain regions of China is sensitive to climate changes.
Shengqiang Zhu, Lei Li, Shurong Wang, Mei Li, Yaxi Liu, Xiaohui Lu, Hong Chen, Lin Wang, Jianmin Chen, Zhen Zhou, Xin Yang, and Xiaofei Wang
Atmos. Meas. Tech., 13, 4111–4121, https://doi.org/10.5194/amt-13-4111-2020, https://doi.org/10.5194/amt-13-4111-2020, 2020
Short summary
Short summary
Single-particle aerosol mass spectrometry (SPAMS) is widely used to detect chemical compositions and sizes of individual aerosol particles. However, it has a major issue: the mass accuracy of high-resolution SPAMS is relatively low. Here we developed an automatic linear calibration method to greatly improve the mass accuracy of SPAMS spectra so that the elemental compositions of organic peaks, such as Cx, CxHy, CxHyOz and CxHyNO peaks, can be directly identified just based on their m / z values.
Meng Gao, Jinhui Gao, Bin Zhu, Rajesh Kumar, Xiao Lu, Shaojie Song, Yuzhong Zhang, Beixi Jia, Peng Wang, Gufran Beig, Jianlin Hu, Qi Ying, Hongliang Zhang, Peter Sherman, and Michael B. McElroy
Atmos. Chem. Phys., 20, 4399–4414, https://doi.org/10.5194/acp-20-4399-2020, https://doi.org/10.5194/acp-20-4399-2020, 2020
Short summary
Short summary
A regional fully coupled meteorology–chemistry model, Weather Research and Forecasting model with Chemistry (WRF-Chem), was employed to study the seasonality of ozone (O3) pollution and its sources in both China and India.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Xue Qiao, Hao Guo, Ya Tang, Pengfei Wang, Wenye Deng, Xing Zhao, Jianlin Hu, Qi Ying, and Hongliang Zhang
Atmos. Chem. Phys., 19, 5791–5803, https://doi.org/10.5194/acp-19-5791-2019, https://doi.org/10.5194/acp-19-5791-2019, 2019
Short summary
Short summary
A source-oriented version of the CMAQ model was used to quantify contributions from nine regions to PM2.5 and its components in the 18 cities within Sichuan Basin. Nonlocal emissions contribute 39–66 % and 25–52 % to the citywide average PM2.5 concentrations of 45–126 and 14–31 µg m3 in the winter and summer, respectively. This study demonstrates the importance of joint emission control efforts among cities within the SCB and neighboring regions to the east.
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
Short summary
Short summary
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
Short summary
Short summary
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.
Hao Guo, Sri Harsha Kota, Kaiyu Chen, Shovan Kumar Sahu, Jianlin Hu, Qi Ying, Yuan Wang, and Hongliang Zhang
Atmos. Chem. Phys., 18, 15219–15229, https://doi.org/10.5194/acp-18-15219-2018, https://doi.org/10.5194/acp-18-15219-2018, 2018
Short summary
Short summary
A total of 1.04 million premature mortalities and up to 2 years of life lost (YLL) per person were estimated in India in 2015 due to PM2.5. Premature mortality due to cerebrovascular disease (CEVD) was the highest (0.44 million), followed by ischaemic heart disease (IHD, 0.40 million). The residential sector was the largest contributor, followed by industry, agriculture and energy. Reducing PM2.5 concentrations would lead to a significant reduction in premature mortality and YLL.
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
Short summary
Short summary
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.
Mingjie Kang, Pingqing Fu, Kimitaka Kawamura, Fan Yang, Hongliang Zhang, Zhengchen Zang, Hong Ren, Lujie Ren, Ye Zhao, Yele Sun, and Zifa Wang
Atmos. Chem. Phys., 18, 13947–13967, https://doi.org/10.5194/acp-18-13947-2018, https://doi.org/10.5194/acp-18-13947-2018, 2018
Short summary
Short summary
Molecular characterization and spatial distribution of biogenic primary organic aerosol (POA) and secondary organic aerosol (SOA) in the marine atmosphere are not well known. Here, we analysed the organic molecular composition of marine aerosols collected during a marine cruise in the East China Sea during May–June 2014. Our results suggest that the Asian continent can be a natural emitter of biogenic POA and SOA, which can be transported to the downwind marine atmosphere.
Congbo Song, Yan Liu, Shida Sun, Luna Sun, Yanjie Zhang, Chao Ma, Jianfei Peng, Qian Li, Jinsheng Zhang, Qili Dai, Baoshuang Liu, Peng Wang, Yi Zhang, Ting Wang, Lin Wu, Min Hu, and Hongjun Mao
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2018-387, https://doi.org/10.5194/acp-2018-387, 2018
Revised manuscript not accepted
Short summary
Short summary
Vehicular emission is a key contributor to ambient volatile organic compounds (VOCs) and NOx in Chinese megacities. Information on real-world emission factors (EFs) for a typical urban fleet is still limited. We found that improvement of fuel quality can significantly reduce feet-average EFs of VOCs (especially for BTEX). Our study provided implications for O3 control in China from the view of primary emission, and highlighted the importance of further control of evaporative emissions.
Jianlin Hu, Xun Li, Lin Huang, Qi Ying, Qiang Zhang, Bin Zhao, Shuxiao Wang, and Hongliang Zhang
Atmos. Chem. Phys., 17, 13103–13118, https://doi.org/10.5194/acp-17-13103-2017, https://doi.org/10.5194/acp-17-13103-2017, 2017
Short summary
Short summary
The model performance of CMAQ with WRF using four different emission inventories in China was validated and compared to obtain the best air pollutants prediction for health effect studies of severe air pollution. The differences in performance of chemical transport model were analyzed for different months and regions in the vast part of China and ensemble predictions were firstly obtained from different inventories for health analysis with minimized errors for pollutants including PM2.5 and O3.
Jianlin Hu, Shantanu Jathar, Hongliang Zhang, Qi Ying, Shu-Hua Chen, Christopher D. Cappa, and Michael J. Kleeman
Atmos. Chem. Phys., 17, 5379–5391, https://doi.org/10.5194/acp-17-5379-2017, https://doi.org/10.5194/acp-17-5379-2017, 2017
Short summary
Short summary
Organic aerosol is a major constituent of ultrafine particulate matter (PM0.1). In this study, a source-oriented air quality model was used to simulate the concentrations and sources of primary and secondary organic aerosols in PM0.1 in California for a 9-year modeling period to provide useful information for epidemiological studies to further investigate the associations with health outcomes.
Jianlin Hu, Peng Wang, Qi Ying, Hongliang Zhang, Jianjun Chen, Xinlei Ge, Xinghua Li, Jingkun Jiang, Shuxiao Wang, Jie Zhang, Yu Zhao, and Yingyi Zhang
Atmos. Chem. Phys., 17, 77–92, https://doi.org/10.5194/acp-17-77-2017, https://doi.org/10.5194/acp-17-77-2017, 2017
Short summary
Short summary
An annual simulation of secondary organic aerosol (SOA) concentrations in China with updated SOA formation pathways reveals that SOA can be a significant contributor to PM2.5 in major urban areas. Summer SOA is dominated by emissions from biogenic sources, while winter SOA is dominated by anthropogenic emissions such as alkanes and aromatic compounds. Reactive surface uptake of dicarbonyls throughout the year and isoprene epoxides in summer is the most important contributor.
Jianlin Hu, Jianjun Chen, Qi Ying, and Hongliang Zhang
Atmos. Chem. Phys., 16, 10333–10350, https://doi.org/10.5194/acp-16-10333-2016, https://doi.org/10.5194/acp-16-10333-2016, 2016
Short summary
Short summary
A yearlong (2013) air-quality simulation was conducted to provide detailed temporal and spatial information of ozone, PM2.5 total and chemical components. The paper firstly compared the simulated air pollutants in China with country-wide public available observations for a whole year. It proves the ability of CMAQ in reproducing severe air pollution in China, shows directions that need to be improved, and benefits future source apportionment and human exposure studies.
Hsiang-He Lee, Shu-Hua Chen, Michael J. Kleeman, Hongliang Zhang, Steven P. DeNero, and David K. Joe
Atmos. Chem. Phys., 16, 8353–8374, https://doi.org/10.5194/acp-16-8353-2016, https://doi.org/10.5194/acp-16-8353-2016, 2016
Short summary
Short summary
A source-oriented CCN module was implemented in a source-oriented chemistry model to study the effect of aerosol mixing state on fog formation. The fraction of aerosols activating into CCN at a supersaturation of 0.5 % in the Central Valley decreased from 94 % in the internal mixture model to 80 % in the source-oriented model. The internal mixture model predicted greater CCN activation than the source-oriented model due to artificial coating of hydrophobic particles with hygroscopic components.
J. Hu, H. Zhang, Q. Ying, S.-H. Chen, F. Vandenberghe, and M. J. Kleeman
Atmos. Chem. Phys., 15, 3445–3461, https://doi.org/10.5194/acp-15-3445-2015, https://doi.org/10.5194/acp-15-3445-2015, 2015
Short summary
Short summary
Air quality model simulations have been conducted for California from 2000 to 2009 with 4km spatial resolution to provide exposure data for health effect studies. Comprehensive analysis shows that predicted concentrations for many pollutants are in agreement with measurements at monitoring stations, building confidence that the fields may be useful at times and locations where measurements are not available. Data can be downloaded for free at http://faculty.engineering.ucdavis.edu/kleeman/.
H. Zhang, S. P. DeNero, D. K. Joe, H.-H. Lee, S.-H. Chen, J. Michalakes, and M. J. Kleeman
Atmos. Chem. Phys., 14, 485–503, https://doi.org/10.5194/acp-14-485-2014, https://doi.org/10.5194/acp-14-485-2014, 2014
Related subject area
Subject: Gases | Research Activity: Atmospheric Modelling and Data Analysis | Altitude Range: Troposphere | Science Focus: Chemistry (chemical composition and reactions)
Insights into ozone pollution control in urban areas by decoupling meteorological factors based on machine learning
Quantification of regional net CO2 flux errors in the Orbiting Carbon Observatory-2 (OCO-2) v10 model intercomparison project (MIP) ensemble using airborne measurements
Reactive nitrogen in and around the northeastern and mid-Atlantic US: sources, sinks, and connections with ozone
Preindustrial-to-present-day changes in atmospheric carbon monoxide: agreement and gaps between ice archives and global model reconstructions
Investigating processes influencing simulation of local Arctic wintertime anthropogenic pollution in Fairbanks, Alaska, during ALPACA-2022
Urban ozone formation and sensitivities to volatile chemical products, cooking emissions, and NOx upwind of and within two Los Angeles Basin cities
Causes of growing middle-to-upper tropospheric ozone over the northwest Pacific region
Impact of introducing electric vehicles on ground-level O3 and PM2.5 in the Greater Tokyo Area: yearly trends and the importance of changes in the urban heat island effect
A CO2–Δ14CO2 inversion setup for estimating European fossil CO2 emissions
Maximum ozone concentrations in the southwestern US and Texas: implications of the growing predominance of the background contribution
Derivation of atmospheric reaction mechanisms for volatile organic compounds by the SAPRC mechanism generation system (MechGen)
Seasonal, regional, and vertical characteristics of high-carbon-monoxide plumes along with their associated ozone anomalies, as seen by IAGOS between 2002 and 2019
The potential of drone observations to improve air quality predictions by 4D-Var
Process analysis of elevated concentrations of organic acids at Whiteface Mountain, New York
Ozone source attribution in polluted European areas during summer 2017 as simulated with MECO(n)
Opinion: Challenges and needs of tropospheric chemical mechanism development
The atmospheric oxidizing capacity in China – Part 2: Sensitivity to emissions of primary pollutants
Role of chemical production and depositional losses on formaldehyde in the Community Regional Atmospheric Chemistry Multiphase Mechanism (CRACMM)
Review of source analyses of ambient volatile organic compounds considering reactive losses: methods of reducing loss effects, impacts of losses, and sources
Interpreting summertime hourly variation of NO2 columns with implications for geostationary satellite applications
An investigation into atmospheric nitrous acid (HONO) processes in South Korea
Performance evaluation of UKESM1 for surface ozone across the pan-tropics
Constraining light dependency in modeled emissions through comparison to observed biogenic volatile organic compound (BVOC) concentrations in a southeastern US forest
A global re-analysis of regionally resolved emissions and atmospheric mole fractions of SF6 for the period 2005–2021
Tropospheric ozone precursors: global and regional distributions, trends, and variability
The contribution of transport emissions to ozone mixing ratios and methane lifetime in 2015 and 2050 in the Shared Socioeconomic Pathways (SSPs)
Ether and ester formation from peroxy radical recombination: a qualitative reaction channel analysis
ACEIC: a comprehensive anthropogenic chlorine emission inventory for China
Impact of methane and other precursor emission reductions on surface ozone in Europe: scenario analysis using the European Monitoring and Evaluation Programme (EMEP) Meteorological Synthesizing Centre – West (MSC-W) model
Investigating the response of China’s surface ozone concentration to the future changes of multiple factors
Chemistry-climate feedback of atmospheric methane in a methane emission flux driven chemistry-climate model
Natural emissions of VOC and NOx over Africa constrained by TROPOMI HCHO and NO2 data using the MAGRITTEv1.1 model
Verifying national inventory-based combustion emissions of CO2 across the UK and mainland Europe using satellite observations of atmospheric CO and CO2
Revisiting the high tropospheric ozone over Southern Africa: overestimated biomass burning and underestimated anthropogenic emissions
Enhanced understanding of atmospheric blocking modulation on ozone dynamics within a high-resolution Earth system model
Estimating the variability of NOx emissions from Wuhan with TROPOMI NO2 data during 2018 to 2023
An improved estimate of inorganic iodine emissions from the ocean using a coupled surface microlayer box model
Technical note: A comparative study of chemistry schemes for volcanic sulfur dioxide in Lagrangian transport simulations: a case study of the 2019 Raikoke eruption
Impact of improved representation of volatile organic compound emissions and production of NOx reservoirs on modeled urban ozone production
The effect of different climate and air quality policies in China on in situ ozone production in Beijing
Assessing the relative impacts of satellite ozone and its precursor observations to improve global tropospheric ozone analysis using multiple chemical reanalysis systems
Evaluating present-day and future impacts of agricultural ammonia emissions on atmospheric chemistry and climate
Enhancing long-term trend simulation of the global tropospheric hydroxyl (TOH) and its drivers from 2005 to 2019: a synergistic integration of model simulations and satellite observations
Intercomparison of GEOS-Chem and CAM-chem tropospheric oxidant chemistry within the Community Earth System Model version 2 (CESM2)
Development of a detailed gaseous oxidation scheme of naphthalene for secondary organic aerosol (SOA) formation and speciation
Air pollution satellite-based CO2 emission inversion: system evaluation, sensitivity analysis, and future perspective
Anthropogenic emission controls reduce summertime ozone-temperature sensitivity in the United States
Large contributions of soil emissions to the atmospheric nitrogen budget and their impacts on air quality and temperature rise in North China
Why did ozone concentrations remain high during Shanghai's static management? A statistical and radical-chemistry perspective
Revising VOC emissions speciation improves the simulation of global background ethane and propane
Yuqing Qiu, Xin Li, Wenxuan Chai, Yi Liu, Mengdi Song, Xudong Tian, Qiaoli Zou, Wenjun Lou, Wangyao Zhang, Juan Li, and Yuanhang Zhang
Atmos. Chem. Phys., 25, 1749–1763, https://doi.org/10.5194/acp-25-1749-2025, https://doi.org/10.5194/acp-25-1749-2025, 2025
Short summary
Short summary
The chemical reactions of ozone (O3) formation are related to meteorology and local emissions. Here, a random forest approach was used to eliminate the effects of meteorological factors (dispersion or transport) on O3 and its precursors. Variations in the sensitivity of O3 formation and the apportionment of emission sources were revealed after meteorological normalization. Our results suggest that meteorological variations should be considered when diagnosing O3 formation.
Jeongmin Yun, Junjie Liu, Brendan Byrne, Brad Weir, Lesley E. Ott, Kathryn McKain, Bianca C. Baier, Luciana V. Gatti, and Sebastien C. Biraud
Atmos. Chem. Phys., 25, 1725–1748, https://doi.org/10.5194/acp-25-1725-2025, https://doi.org/10.5194/acp-25-1725-2025, 2025
Short summary
Short summary
This study quantifies errors in regional net surface–atmosphere CO2 flux estimates from an inverse model ensemble using airborne CO2 measurements. Our results show that flux error estimates based on observations significantly exceed those computed from the ensemble spread of flux estimates in regions with high fossil fuel emissions. This finding suggests the presence of systematic biases in the inversion estimates, associated with errors in the fossil fuel emissions common to all models.
Min Huang, Gregory R. Carmichael, Kevin W. Bowman, Isabelle De Smedt, Andreas Colliander, Michael H. Cosh, Sujay V. Kumar, Alex B. Guenther, Scott J. Janz, Ryan M. Stauffer, Anne M. Thompson, Niko M. Fedkin, Robert J. Swap, John D. Bolten, and Alicia T. Joseph
Atmos. Chem. Phys., 25, 1449–1476, https://doi.org/10.5194/acp-25-1449-2025, https://doi.org/10.5194/acp-25-1449-2025, 2025
Short summary
Short summary
We use model simulations along with multiplatform, multidisciplinary observations and a range of analysis methods to estimate and understand the distributions, temporal changes, and impacts of reactive nitrogen and ozone over the most populous US region that has undergone significant environmental changes. Deposition, biogenic emissions, and extra-regional sources have been playing increasingly important roles in controlling pollutant budgets in this area as local anthropogenic emissions drop.
Xavier Faïn, Sophie Szopa, Vaishali Naïk, Patricia Martinerie, David M. Etheridge, Rachael H. Rhodes, Cathy M. Trudinger, Vasilii V. Petrenko, Kévin Fourteau, and Philip Place
Atmos. Chem. Phys., 25, 1105–1119, https://doi.org/10.5194/acp-25-1105-2025, https://doi.org/10.5194/acp-25-1105-2025, 2025
Short summary
Short summary
Carbon monoxide (CO) plays a crucial role in the atmosphere's oxidizing capacity. In this study, we analyse how historical (1850–2014) [CO] outputs from state-of-the-art global chemistry–climate models over Greenland and Antarctica are able to capture both absolute values and trends recorded in multi-site ice archives. A disparity in [CO] growth rates emerges in the Northern Hemisphere between models and observations from 1920–1975 CE, possibly linked to uncertainties in CO emission factors.
Natalie Brett, Kathy S. Law, Steve R. Arnold, Javier G. Fochesatto, Jean-Christophe Raut, Tatsuo Onishi, Robert Gilliam, Kathleen Fahey, Deanna Huff, George Pouliot, Brice Barret, Elsa Dieudonné, Roman Pohorsky, Julia Schmale, Andrea Baccarini, Slimane Bekki, Gianluca Pappaccogli, Federico Scoto, Stefano Decesari, Antonio Donateo, Meeta Cesler-Maloney, William Simpson, Patrice Medina, Barbara D'Anna, Brice Temime-Roussel, Joel Savarino, Sarah Albertin, Jingqiu Mao, Becky Alexander, Allison Moon, Peter F. DeCarlo, Vanessa Selimovic, Robert Yokelson, and Ellis S. Robinson
Atmos. Chem. Phys., 25, 1063–1104, https://doi.org/10.5194/acp-25-1063-2025, https://doi.org/10.5194/acp-25-1063-2025, 2025
Short summary
Short summary
Processes influencing dispersion of local anthropogenic pollution in Arctic wintertime are investigated with Lagrangian dispersion modelling. Simulated power plant plume rise that considers temperature inversion layers improves results compared to observations (interior Alaska). Modelled surface concentrations are improved by representation of vertical mixing and emission estimates. Large increases in diesel vehicle emissions at temperatures reaching −35°C are required to reproduce observed NOx.
Chelsea E. Stockwell, Matthew M. Coggon, Rebecca H. Schwantes, Colin Harkins, Bert Verreyken, Congmeng Lyu, Qindan Zhu, Lu Xu, Jessica B. Gilman, Aaron Lamplugh, Jeff Peischl, Michael A. Robinson, Patrick R. Veres, Meng Li, Andrew W. Rollins, Kristen Zuraski, Sunil Baidar, Shang Liu, Toshihiro Kuwayama, Steven S. Brown, Brian C. McDonald, and Carsten Warneke
Atmos. Chem. Phys., 25, 1121–1143, https://doi.org/10.5194/acp-25-1121-2025, https://doi.org/10.5194/acp-25-1121-2025, 2025
Short summary
Short summary
In urban areas, emissions from everyday products like paints, cleaners, and personal care products, along with non-traditional sources such as cooking, are increasingly important and impact air quality. This study uses a box model to evaluate how these emissions impact ozone in the Los Angeles Basin and quantifies the impact of gaseous cooking emissions. Accurate representation of these and other anthropogenic sources in inventories is crucial for informing effective air quality policies.
Xiaodan Ma, Jianping Huang, Michaela I. Hegglin, Patrick Jöckel, and Tianliang Zhao
Atmos. Chem. Phys., 25, 943–958, https://doi.org/10.5194/acp-25-943-2025, https://doi.org/10.5194/acp-25-943-2025, 2025
Short summary
Short summary
Our research explored changes in ozone levels in the northwest Pacific region over 30 years, revealing a significant increase in the middle-to-upper troposphere, especially during spring and summer. This rise is influenced by both stratospheric and tropospheric sources, which affect climate and air quality in East Asia. This work underscores the need for continued study to understand underlying mechanisms.
Hiroo Hata, Norifumi Mizushima, and Tomohiko Ihara
Atmos. Chem. Phys., 25, 1037–1061, https://doi.org/10.5194/acp-25-1037-2025, https://doi.org/10.5194/acp-25-1037-2025, 2025
Short summary
Short summary
The introduction of battery electric vehicles (BEVs) is expected to reduce the primary air pollutants from vehicular exhaust and evaporative emissions while reducing the anthropogenic heat produced by vehicles, ultimately mitigating the urban heat island (UHI) effect. This study revealed the impact of introducing BEVs on the decrease in the UHI effect and the impact of BEVs on the formation of tropospheric ozone and fine particulate matter in the Greater Tokyo Area of Japan.
Carlos Gómez-Ortiz, Guillaume Monteil, Sourish Basu, and Marko Scholze
Atmos. Chem. Phys., 25, 397–424, https://doi.org/10.5194/acp-25-397-2025, https://doi.org/10.5194/acp-25-397-2025, 2025
Short summary
Short summary
In this paper, we test new implementations of our inverse modeling tool to estimate the weekly and regional CO2 emissions from fossil fuels in Europe. We use synthetic atmospheric observations of CO2 and radiocarbon (14CO2) to trace emissions to their sources, while separating the natural and fossil CO2. Our tool accurately estimates fossil CO2 emissions in densely monitored regions like western/central Europe. This approach aids in developing strategies for reducing CO2 emissions.
David D. Parrish, Ian C. Faloona, and Richard G. Derwent
Atmos. Chem. Phys., 25, 263–289, https://doi.org/10.5194/acp-25-263-2025, https://doi.org/10.5194/acp-25-263-2025, 2025
Short summary
Short summary
Observation-based estimates of contributions to maximum ozone (O3) concentrations show that background O3 can exceed the air quality standard of 70 ppb in the southwestern US, precluding standard attainment. Over the past 4 decades, US anthropogenic O3 has decreased by a factor of ~ 6.3, while wildfire contributions have increased, so that the background now dominates maximum concentrations, even in Los Angeles, and the occurrence of maximum O3 has shifted from the eastern to the western US.
William P. L. Carter, Jia Jiang, John J. Orlando, and Kelley C. Barsanti
Atmos. Chem. Phys., 25, 199–242, https://doi.org/10.5194/acp-25-199-2025, https://doi.org/10.5194/acp-25-199-2025, 2025
Short summary
Short summary
This paper describes the scientific basis for gas-phase atmospheric chemical mechanisms derived using the SAPRC mechanism generation system, MechGen. It can derive mechanisms for most organic compounds with C, H, O, or N atoms, including initial reactions of organics with OH, O3, NO3, and O3P or by photolysis, as well as the reactions of the various types of intermediates that are formed. The paper includes a description of areas of uncertainty where additional research and updates are needed.
Thibaut Lebourgeois, Bastien Sauvage, Pawel Wolff, Béatrice Josse, Virginie Marécal, Yasmine Bennouna, Romain Blot, Damien Boulanger, Hannah Clark, Jean-Marc Cousin, Philippe Nedelec, and Valérie Thouret
Atmos. Chem. Phys., 24, 13975–14004, https://doi.org/10.5194/acp-24-13975-2024, https://doi.org/10.5194/acp-24-13975-2024, 2024
Short summary
Short summary
Our study examines intense-carbon-monoxide (CO) pollution events measured by commercial aircraft from the In-service Aircraft for a Global Observing System (IAGOS) research infrastructure. We combine these measurements with the SOFT-IO model to trace the origin of the observed CO. A comprehensive analysis of the geographical origin, source type, seasonal variation, and ozone levels of these pollution events is provided.
Hassnae Erraji, Philipp Franke, Astrid Lampert, Tobias Schuldt, Ralf Tillmann, Andreas Wahner, and Anne Caroline Lange
Atmos. Chem. Phys., 24, 13913–13934, https://doi.org/10.5194/acp-24-13913-2024, https://doi.org/10.5194/acp-24-13913-2024, 2024
Short summary
Short summary
Four-dimensional variational data assimilation allows for the simultaneous optimisation of initial values and emission rates by using trace-gas profiles from drone observations in a regional air quality model. Assimilated profiles positively impact the representation of air pollutants in the model by improving their vertical distribution and ground-level concentrations. This case study highlights the potential of drone data to enhance air quality analyses including local emission evaluation.
Christopher Lawrence, Mary Barth, John Orlando, Paul Casson, Richard Brandt, Daniel Kelting, Elizabeth Yerger, and Sara Lance
Atmos. Chem. Phys., 24, 13693–13713, https://doi.org/10.5194/acp-24-13693-2024, https://doi.org/10.5194/acp-24-13693-2024, 2024
Short summary
Short summary
This work uses chemical transport and box modeling to study the gas- and aqueous-phase production of organic acid concentrations measured in cloud water at the summit of Whiteface Mountain on 1 July 2018. Isoprene was the major source of formic, acetic, and oxalic acid. Gas-phase chemistry greatly underestimated formic and acetic acid, indicating missing sources, while cloud chemistry was a key source of oxalic acid. More studies of organic acids are required to better constrain their sources.
Markus Kilian, Volker Grewe, Patrick Jöckel, Astrid Kerkweg, Mariano Mertens, Andreas Zahn, and Helmut Ziereis
Atmos. Chem. Phys., 24, 13503–13523, https://doi.org/10.5194/acp-24-13503-2024, https://doi.org/10.5194/acp-24-13503-2024, 2024
Short summary
Short summary
Anthropogenic emissions are a major source of precursors of tropospheric ozone. As ozone formation is highly non-linear, we apply a global–regional chemistry–climate model with a source attribution method (tagging) to quantify the contribution of anthropogenic emissions to ozone. Our analysis shows that the contribution of European anthropogenic emissions largely increases during large ozone periods, indicating that emissions from these sectors drive ozone values.
Barbara Ervens, Andrew Rickard, Bernard Aumont, William P. L. Carter, Max McGillen, Abdelwahid Mellouki, John Orlando, Bénédicte Picquet-Varrault, Paul Seakins, William R. Stockwell, Luc Vereecken, and Timothy J. Wallington
Atmos. Chem. Phys., 24, 13317–13339, https://doi.org/10.5194/acp-24-13317-2024, https://doi.org/10.5194/acp-24-13317-2024, 2024
Short summary
Short summary
Chemical mechanisms describe the chemical processes in atmospheric models that are used to describe the changes in the atmospheric composition. Therefore, accurate chemical mechanisms are necessary to predict the evolution of air pollution and climate change. The article describes all steps that are needed to build chemical mechanisms and discusses the advances and needs of experimental and theoretical research activities needed to build reliable chemical mechanisms.
Jianing Dai, Guy P. Brasseur, Mihalis Vrekoussis, Maria Kanakidou, Kun Qu, Yijuan Zhang, Hongliang Zhang, and Tao Wang
Atmos. Chem. Phys., 24, 12943–12962, https://doi.org/10.5194/acp-24-12943-2024, https://doi.org/10.5194/acp-24-12943-2024, 2024
Short summary
Short summary
This paper employs a regional chemical transport model to quantify the sensitivity of air pollutants and photochemical parameters to specified emission reductions in China for representative winter and summer conditions. The study provides insights into further air quality control in China with reduced primary emissions.
T. Nash Skipper, Emma L. D'Ambro, Forwood C. Wiser, V. Faye McNeill, Rebecca H. Schwantes, Barron H. Henderson, Ivan R. Piletic, Colleen B. Baublitz, Jesse O. Bash, Andrew R. Whitehill, Lukas C. Valin, Asher P. Mouat, Jennifer Kaiser, Glenn M. Wolfe, Jason M. St. Clair, Thomas F. Hanisco, Alan Fried, Bryan K. Place, and Havala O.T. Pye
Atmos. Chem. Phys., 24, 12903–12924, https://doi.org/10.5194/acp-24-12903-2024, https://doi.org/10.5194/acp-24-12903-2024, 2024
Short summary
Short summary
We develop the Community Regional Atmospheric Chemistry Multiphase Mechanism (CRACMM) version 2 to improve predictions of formaldehyde in ambient air compared to satellite-, aircraft-, and ground-based observations. With the updated chemistry, we estimate the cancer risk from inhalation exposure to ambient formaldehyde across the contiguous USA and predict that 40 % of this risk is controllable through reductions in anthropogenic emissions of nitrogen oxides and reactive organic carbon.
Baoshuang Liu, Yao Gu, Yutong Wu, Qili Dai, Shaojie Song, Yinchang Feng, and Philip K. Hopke
Atmos. Chem. Phys., 24, 12861–12879, https://doi.org/10.5194/acp-24-12861-2024, https://doi.org/10.5194/acp-24-12861-2024, 2024
Short summary
Short summary
Reactive loss of volatile organic compounds (VOCs) is a long-term issue yet to be resolved in VOC source analyses. We assess common methods of, and existing issues in, reducing losses, impacts of losses, and sources in current source analyses. We offer a potential supporting role for solving issues of VOC conversion. Source analyses of consumed VOCs that reacted to produce ozone and secondary organic aerosols can play an important role in the effective control of secondary pollution in air.
Deepangsu Chatterjee, Randall V. Martin, Chi Li, Dandan Zhang, Haihui Zhu, Daven K. Henze, James H. Crawford, Ronald C. Cohen, Lok N. Lamsal, and Alexander M. Cede
Atmos. Chem. Phys., 24, 12687–12706, https://doi.org/10.5194/acp-24-12687-2024, https://doi.org/10.5194/acp-24-12687-2024, 2024
Short summary
Short summary
We investigate the hourly variation of NO2 columns and surface concentrations by applying the GEOS-Chem model to interpret aircraft and ground-based measurements over the US and Pandora sun photometer measurements over the US, Europe, and Asia. Corrections to the Pandora columns and finer model resolution improve the modeled representation of the summertime hourly variation of total NO2 columns to explain the weaker hourly variation in NO2 columns than at the surface.
Kiyeon Kim, Kyung Man Han, Chul Han Song, Hyojun Lee, Ross Beardsley, Jinhyeok Yu, Greg Yarwood, Bonyoung Koo, Jasper Madalipay, Jung-Hun Woo, and Seogju Cho
Atmos. Chem. Phys., 24, 12575–12593, https://doi.org/10.5194/acp-24-12575-2024, https://doi.org/10.5194/acp-24-12575-2024, 2024
Short summary
Short summary
We incorporated each HONO process into the current CMAQ modeling framework to enhance the accuracy of HONO mixing ratio predictions. These results expand our understanding of HONO photochemistry and identify crucial sources of HONO that impact the total HONO budget in Seoul, South Korea. Through this investigation, we contribute to resolving discrepancies in understanding chemical transport models, with implications for better air quality management and environmental protection in the region.
Flossie Brown, Gerd Folberth, Stephen Sitch, Paulo Artaxo, Marijn Bauters, Pascal Boeckx, Alexander W. Cheesman, Matteo Detto, Ninong Komala, Luciana Rizzo, Nestor Rojas, Ines dos Santos Vieira, Steven Turnock, Hans Verbeeck, and Alfonso Zambrano
Atmos. Chem. Phys., 24, 12537–12555, https://doi.org/10.5194/acp-24-12537-2024, https://doi.org/10.5194/acp-24-12537-2024, 2024
Short summary
Short summary
Ozone is a pollutant that is detrimental to human and plant health. Ozone monitoring sites in the tropics are limited, so models are often used to understand ozone exposure. We use measurements from the tropics to evaluate ozone from the UK Earth system model, UKESM1. UKESM1 is able to capture the pattern of ozone in the tropics, except in southeast Asia, although it systematically overestimates it at all sites. This work highlights that UKESM1 can capture seasonal and hourly variability.
Namrata Shanmukh Panji, Deborah F. McGlynn, Laura E. R. Barry, Todd M. Scanlon, Manuel T. Lerdau, Sally E. Pusede, and Gabriel Isaacman-VanWertz
Atmos. Chem. Phys., 24, 12495–12507, https://doi.org/10.5194/acp-24-12495-2024, https://doi.org/10.5194/acp-24-12495-2024, 2024
Short summary
Short summary
Climate change will bring about changes in parameters that are currently used in global-scale models to calculate biogenic emissions. This study seeks to understand the factors driving these models by comparing long-term datasets of biogenic compounds to modeled emissions. We note that the light-dependent fractions currently used in models do not accurately represent regional observations. We provide evidence for the time-dependent variation in this parameter for future modifications to models.
Martin Vojta, Andreas Plach, Saurabh Annadate, Sunyoung Park, Gawon Lee, Pallav Purohit, Florian Lindl, Xin Lan, Jens Mühle, Rona L. Thompson, and Andreas Stohl
Atmos. Chem. Phys., 24, 12465–12493, https://doi.org/10.5194/acp-24-12465-2024, https://doi.org/10.5194/acp-24-12465-2024, 2024
Short summary
Short summary
We constrain the global emissions of the very potent greenhouse gas sulfur hexafluoride (SF6) between 2005 and 2021. We show that SF6 emissions are decreasing in the USA and in the EU, while they are substantially growing in China, leading overall to an increasing global emission trend. The national reports for the USA, EU, and China all underestimated their SF6 emissions. However, stringent mitigation measures can successfully reduce SF6 emissions, as can be seen in the EU emission trend.
Yasin Elshorbany, Jerald R. Ziemke, Sarah Strode, Hervé Petetin, Kazuyuki Miyazaki, Isabelle De Smedt, Kenneth Pickering, Rodrigo J. Seguel, Helen Worden, Tamara Emmerichs, Domenico Taraborrelli, Maria Cazorla, Suvarna Fadnavis, Rebecca R. Buchholz, Benjamin Gaubert, Néstor Y. Rojas, Thiago Nogueira, Thérèse Salameh, and Min Huang
Atmos. Chem. Phys., 24, 12225–12257, https://doi.org/10.5194/acp-24-12225-2024, https://doi.org/10.5194/acp-24-12225-2024, 2024
Short summary
Short summary
We investigated tropospheric ozone spatial variability and trends from 2005 to 2019 and related those to ozone precursors on global and regional scales. We also investigate the spatiotemporal characteristics of the ozone formation regime in relation to ozone chemical sources and sinks. Our analysis is based on remote sensing products of the tropospheric column of ozone and its precursors, nitrogen dioxide, formaldehyde, and total column CO, as well as ozonesonde data and model simulations.
Mariano Mertens, Sabine Brinkop, Phoebe Graf, Volker Grewe, Johannes Hendricks, Patrick Jöckel, Anna Lanteri, Sigrun Matthes, Vanessa S. Rieger, Mattia Righi, and Robin N. Thor
Atmos. Chem. Phys., 24, 12079–12106, https://doi.org/10.5194/acp-24-12079-2024, https://doi.org/10.5194/acp-24-12079-2024, 2024
Short summary
Short summary
We quantified the contributions of land transport, shipping, and aviation emissions to tropospheric ozone; its radiative forcing; and the reductions of the methane lifetime using chemistry-climate model simulations. The contributions were analysed for the conditions of 2015 and for three projections for the year 2050. The results highlight the challenges of mitigating ozone formed by emissions of the transport sector, caused by the non-linearitiy of the ozone chemistry and the long lifetime.
Lauri Franzon, Marie Camredon, Richard Valorso, Bernard Aumont, and Theo Kurtén
Atmos. Chem. Phys., 24, 11679–11699, https://doi.org/10.5194/acp-24-11679-2024, https://doi.org/10.5194/acp-24-11679-2024, 2024
Short summary
Short summary
In this article we investigate the formation of large, sticky molecules from various organic compounds entering the atmosphere as primary emissions and the degree to which these processes may contribute to organic aerosol particle mass. More specifically, we qualitatively investigate a recently discovered chemical reaction channel for one of the most important short-lived radical compounds, peroxy radicals, and discover which of these reactions are most atmospherically important.
Siting Li, Yiming Liu, Yuqi Zhu, Yinbao Jin, Yingying Hong, Ao Shen, Yifei Xu, Haofan Wang, Haichao Wang, Xiao Lu, Shaojia Fan, and Qi Fan
Atmos. Chem. Phys., 24, 11521–11544, https://doi.org/10.5194/acp-24-11521-2024, https://doi.org/10.5194/acp-24-11521-2024, 2024
Short summary
Short summary
This study establishes an inventory of anthropogenic chlorine emissions in China in 2019 with expanded species (HCl, Cl-, Cl2, HOCl) and sources (41 specific sources). The inventory is validated by a modeling study against the observations. This study enhances the understanding of anthropogenic chlorine emissions in the atmosphere, identifies key sources, and provides scientific support for pollution control and climate change.
Willem E. van Caspel, Zbigniew Klimont, Chris Heyes, and Hilde Fagerli
Atmos. Chem. Phys., 24, 11545–11563, https://doi.org/10.5194/acp-24-11545-2024, https://doi.org/10.5194/acp-24-11545-2024, 2024
Short summary
Short summary
Methane in the atmosphere contributes to the production of ozone gas – an air pollutant and greenhouse gas. Our results highlight that simultaneous reductions in methane emissions help avoid offsetting the air pollution benefits already achieved by the already-approved precursor emission reductions by 2050 in the European Monitoring and Evaluation Programme region, while also playing an important role in bringing air pollution further down towards World Health Organization guideline limits.
Jinya Yang, Yutong Wang, Lei Zhang, and Yu Zhao
EGUsphere, https://doi.org/10.5194/egusphere-2024-2713, https://doi.org/10.5194/egusphere-2024-2713, 2024
Short summary
Short summary
We develop a modeling framework to predict future ozone concentrations (till 2060s) in China following an IPCC scenario. We further evaluate and separate the contributions of climatic, anthropogenic, and biogenic factors by season and region. We find persistent emission controls will alter the nonlinear response of ozone to its precursors, and dominate the declining ozone level. The outcomes highlight the importance of human actions even with a climate penalty on air quality in the future.
Laura Stecher, Franziska Winterstein, Patrick Jöckel, Michael Ponater, Mariano Mertens, and Martin Dameris
EGUsphere, https://doi.org/10.5194/egusphere-2024-2938, https://doi.org/10.5194/egusphere-2024-2938, 2024
Short summary
Short summary
Methane, the second most important anthropogenic greenhouse gas, is chemically decomposed in the atmosphere. The chemical sink of atmospheric methane is not constant, but depends on the temperature and on the abundance of its reaction partners. In this study, we use a global chemistry-climate model to assess the feedback of atmospheric methane induced by changes of the chemical sink in a warming climate, and its implications for the chemical composition and the surface air temperature change.
Beata Opacka, Trissevgeni Stavrakou, Jean-François Müller, Isabelle De Smedt, Jos van Geffen, Eloise A. Marais, Rebekah P. Horner, Dylan B. Millet, Kelly C. Wells, and Alex B. Guenther
EGUsphere, https://doi.org/10.5194/egusphere-2024-2912, https://doi.org/10.5194/egusphere-2024-2912, 2024
Short summary
Short summary
Vegetation releases biogenic volatile organic compounds, while soils and lightning contribute to the natural emissions of nitrogen oxides into the atmosphere. These gases interact in complex ways. Using satellite data and models, we developed a new method to simultaneously optimise these natural emissions over Africa in 2019. Our approach led to an increase in natural emissions that is supported by independent data showing that current estimates are underestimated.
Tia R. Scarpelli, Paul I. Palmer, Mark Lunt, Ingrid Super, and Arjan Droste
Atmos. Chem. Phys., 24, 10773–10791, https://doi.org/10.5194/acp-24-10773-2024, https://doi.org/10.5194/acp-24-10773-2024, 2024
Short summary
Short summary
Under the Paris Agreement, countries must track their anthropogenic greenhouse gas emissions. This study describes a method to determine self-consistent estimates for combustion emissions and natural fluxes of CO2 from atmospheric data. We report consistent estimates inferred using this approach from satellite data and ground-based data over Europe, suggesting that satellite data can be used to determine national anthropogenic CO2 emissions for countries where ground-based CO2 data are absent.
Yufen Wang, Ke Li, Xi Chen, Zhenjiang Yang, Minglong Tang, Pascoal M. D. Campos, Yang Yang, Xu Yue, and Hong Liao
EGUsphere, https://doi.org/10.5194/egusphere-2024-2576, https://doi.org/10.5194/egusphere-2024-2576, 2024
Short summary
Short summary
The impact of biomass burning and anthropogenic emissions on high tropospheric ozone was not well studied in Southern Africa. We combined the model simulation with recent observations at the surface and from space to quantify tropospheric ozone and its main drivers in Southern Africa. Our work focuses on the impact of emissions from different sources at different spatial scales, contributing to a comprehensive understanding of air pollution drivers and their uncertainties in Southern Africa.
Wenbin Kou, Yang Gao, Dan Tong, Xiaojie Guo, Xiadong An, Wenyu Liu, Mengshi Cui, Xiuwen Guo, Shaoqing Zhang, Huiwang Gao, and Lixin Wu
EGUsphere, https://doi.org/10.5194/egusphere-2024-2500, https://doi.org/10.5194/egusphere-2024-2500, 2024
Short summary
Short summary
Unlike traditional numerical studies, we apply a high-resolution Earth system model, improving simulations of ozone and large-scale circulations such as atmospheric blocking. In addition to local heatwave effects, we quantify the impact of atmospheric blocking on downstream ozone concentrations, which is closely associated with the blocking position. We identify three major pathways of Rossby wave propagation, stressing the critical role of large-scale circulation play in regional air quality.
Qianqian Zhang, K. Folkert Boersma, Chiel van der Laan, Alba Mols, Bin Zhao, Shengyue Li, and Yuepeng Pan
EGUsphere, https://doi.org/10.5194/egusphere-2024-2641, https://doi.org/10.5194/egusphere-2024-2641, 2024
Short summary
Short summary
Accurate NOx emission estimates are required to better understand air pollution. This study investigates and demonstrates the ability of the superposition column model in combination with TROPOMI tropospheric NO2 column data to estimate city-scale NOx emissions and lifetimes and their variabilities. The results of this work nevertheless confirm the strength of the superposition column model in estimating urban NOx emissions with reasonable accuracy.
Ryan J. Pound, Lucy V. Brown, Mat J. Evans, and Lucy J. Carpenter
Atmos. Chem. Phys., 24, 9899–9921, https://doi.org/10.5194/acp-24-9899-2024, https://doi.org/10.5194/acp-24-9899-2024, 2024
Short summary
Short summary
Iodine-mediated loss of ozone to the ocean surface and the subsequent emission of iodine species has a large effect on the troposphere. Here we combine recent experimental insights to develop a box model of the process, which we then parameterize and incorporate into the GEOS-Chem transport model. We find that these new insights have a small impact on the total emission of iodine but significantly change its distribution.
Mingzhao Liu, Lars Hoffmann, Jens-Uwe Grooß, Zhongyin Cai, Sabine Grießbach, and Yi Heng
EGUsphere, https://doi.org/10.5194/egusphere-2024-2596, https://doi.org/10.5194/egusphere-2024-2596, 2024
Short summary
Short summary
We studied the transport and chemical decomposition of volcanic SO2, focusing on the 2019 Raikoke event. By comparing two different chemistry modeling schemes, we found that including complex chemical reactions leads to a more accurate prediction of how long SO2 stays in the atmosphere. This research helps improve our understanding of volcanic pollution and its impact on air quality and climate, providing better tools for scientists to track and predict the movement of these pollutants.
Katherine R. Travis, Benjamin A. Nault, James H. Crawford, Kelvin H. Bates, Donald R. Blake, Ronald C. Cohen, Alan Fried, Samuel R. Hall, L. Gregory Huey, Young Ro Lee, Simone Meinardi, Kyung-Eun Min, Isobel J. Simpson, and Kirk Ullman
Atmos. Chem. Phys., 24, 9555–9572, https://doi.org/10.5194/acp-24-9555-2024, https://doi.org/10.5194/acp-24-9555-2024, 2024
Short summary
Short summary
Human activities result in the emission of volatile organic compounds (VOCs) that contribute to air pollution. Detailed VOC measurements were taken during a field study in South Korea. When compared to VOC inventories, large discrepancies showed underestimates from chemical products, liquefied petroleum gas, and long-range transport. Improved emissions and chemistry of these VOCs better described urban pollution. The new chemical scheme is relevant to urban areas and other VOC sources.
Beth S. Nelson, Zhenze Liu, Freya A. Squires, Marvin Shaw, James R. Hopkins, Jacqueline F. Hamilton, Andrew R. Rickard, Alastair C. Lewis, Zongbo Shi, and James D. Lee
Atmos. Chem. Phys., 24, 9031–9044, https://doi.org/10.5194/acp-24-9031-2024, https://doi.org/10.5194/acp-24-9031-2024, 2024
Short summary
Short summary
The impact of combined air quality and carbon neutrality policies on O3 formation in Beijing was investigated. Emissions inventory data were used to estimate future pollutant mixing ratios relative to ground-level observations. O3 production was found to be most sensitive to changes in alkenes, but large reductions in less reactive compounds led to larger reductions in future O3 production. This study highlights the importance of understanding the emissions of organic pollutants.
Takashi Sekiya, Emanuele Emili, Kazuyuki Miyazaki, Antje Inness, Zhen Qu, R. Bradley Pierce, Dylan Jones, Helen Worden, William Y. Y. Cheng, Vincent Huijnen, and Gerbrand Koren
EGUsphere, https://doi.org/10.5194/egusphere-2024-2426, https://doi.org/10.5194/egusphere-2024-2426, 2024
Short summary
Short summary
Five global chemical reanalysis datasets were used to assess the relative impacts of assimilating satellite ozone and its precursors measurements on tropospheric ozone analyses for 2010. The multiple reanalysis system comparison allows for evaluating dependency of the impacts on different reanalysis systems. The results suggested the importance of satellite ozone and its precursor measurements for improving ozone analysis in the whole troposphere, with varying the magnitudes among the systems.
Maureen Beaudor, Didier Hauglustaine, Juliette Lathière, Martin Van Damme, Lieven Clarisse, and Nicolas Vuichard
EGUsphere, https://doi.org/10.5194/egusphere-2024-2022, https://doi.org/10.5194/egusphere-2024-2022, 2024
Short summary
Short summary
Agriculture is the biggest ammonia (NH3) source, impacting air quality, climate, and ecosystems. Because of food demand, NH3 emissions are projected to rise by 2100. Using a global model, we analyzed the impact of present and future NH3 emissions generated from a land model. Our results show improved ammonia patterns compared to a reference inventory. Future scenarios predict up to 70 % increase in global NH3 burden, significant changes in radiative forcing, and could significantly elevate N2O.
Amir H. Souri, Bryan N. Duncan, Sarah A. Strode, Daniel C. Anderson, Michael E. Manyin, Junhua Liu, Luke D. Oman, Zhen Zhang, and Brad Weir
Atmos. Chem. Phys., 24, 8677–8701, https://doi.org/10.5194/acp-24-8677-2024, https://doi.org/10.5194/acp-24-8677-2024, 2024
Short summary
Short summary
We explore a new method of using the wealth of information obtained from satellite observations of Aura OMI NO2, HCHO, and MERRA-2 reanalysis in NASA’s GEOS model equipped with an efficient tropospheric OH (TOH) estimator to enhance the representation of TOH spatial distribution and its long-term trends. This new framework helps us pinpoint regional inaccuracies in TOH and differentiate between established prior knowledge and newly acquired information from satellites on TOH trends.
Haipeng Lin, Louisa K. Emmons, Elizabeth W. Lundgren, Laura Hyesung Yang, Xu Feng, Ruijun Dang, Shixian Zhai, Yunxiao Tang, Makoto M. Kelp, Nadia K. Colombi, Sebastian D. Eastham, Thibaud M. Fritz, and Daniel J. Jacob
Atmos. Chem. Phys., 24, 8607–8624, https://doi.org/10.5194/acp-24-8607-2024, https://doi.org/10.5194/acp-24-8607-2024, 2024
Short summary
Short summary
Tropospheric ozone is a major air pollutant, a greenhouse gas, and a major indicator of model skill. Global atmospheric chemistry models show large differences in simulations of tropospheric ozone, but isolating sources of differences is complicated by different model environments. By implementing the GEOS-Chem model side by side to CAM-chem within a common Earth system model, we identify and evaluate specific differences between the two models and their impacts on key chemical species.
Victor Lannuque and Karine Sartelet
Atmos. Chem. Phys., 24, 8589–8606, https://doi.org/10.5194/acp-24-8589-2024, https://doi.org/10.5194/acp-24-8589-2024, 2024
Short summary
Short summary
Large uncertainties remain in understanding secondary organic aerosol (SOA) formation and speciation from naphthalene oxidation. This study details the development of the first near-explicit chemical scheme for naphthalene oxidation by OH, which includes kinetic and mechanistic data, and is able to reproduce most of the experimentally identified products in both gas and particle phases.
Hui Li, Jiaxin Qiu, and Bo Zheng
EGUsphere, https://doi.org/10.5194/egusphere-2024-1986, https://doi.org/10.5194/egusphere-2024-1986, 2024
Short summary
Short summary
We conduct a sensitivity analysis on various factors including prior, model resolution, satellite constraint, and inversion system configuration to assess the vulnerability of emission estimates across temporal, sectoral, and regional dimensions. Our analysis first reveals the robustness of emissions estimated by this air pollution satellite sensor-based CO2 emission inversion system, with relative change between tests and Base inversion below 4.0 % for national annual NOx and CO2 emissions.
Shuai Li, Xiao Lu, and Haolin Wang
EGUsphere, https://doi.org/10.5194/egusphere-2024-1889, https://doi.org/10.5194/egusphere-2024-1889, 2024
Short summary
Short summary
We report that the summertime ozone-temperature sensitivity decreased by 50 % from 3.0 ppbv/K in 1990 to 1.5 ppb/K in 2021 in the US. GEOS-Chem simulations show that anthropogenic NOx emission reduction is the dominant driver of the ozone-temperature sensitivity decline, through influencing both the temperature-direct and temperature-indirect processes. Reduced ozone-temperature sensitivity has decreased the ozone enhancement from low to high temperatures by an average of 6.8 ppbv across the US.
Tong Sha, Siyu Yang, Qingcai Chen, Liangqing Li, Xiaoyan Ma, Yan-Lin Zhang, Zhaozhong Feng, K. Folkert Boersma, and Jun Wang
Atmos. Chem. Phys., 24, 8441–8455, https://doi.org/10.5194/acp-24-8441-2024, https://doi.org/10.5194/acp-24-8441-2024, 2024
Short summary
Short summary
Using an updated soil reactive nitrogen emission scheme in the Unified Inputs for Weather Research and Forecasting coupled with Chemistry (UI-WRF-Chem) model, we investigate the role of soil NO and HONO (Nr) emissions in air quality and temperature in North China. Contributions of soil Nr emissions to O3 and secondary pollutants are revealed, exceeding effects of soil NOx or HONO emission. Soil Nr emissions play an important role in mitigating O3 pollution and addressing climate change.
Jian Zhu, Shanshan Wang, Chuanqi Gu, Zhiwen Jiang, Sanbao Zhang, Ruibin Xue, Yuhao Yan, and Bin Zhou
Atmos. Chem. Phys., 24, 8383–8395, https://doi.org/10.5194/acp-24-8383-2024, https://doi.org/10.5194/acp-24-8383-2024, 2024
Short summary
Short summary
In 2022, Shanghai implemented city-wide static management measures during the high-ozone season in April and May, providing a chance to study ozone pollution control. Despite significant emissions reductions, ozone levels increased by 23 %. Statistically, the number of days with higher ozone diurnal variation types increased during the lockdown period. The uneven decline in VOC and NO2 emissions led to heightened photochemical processes, resulting in the observed ozone level rise.
Matthew J. Rowlinson, Mat J. Evans, Lucy J. Carpenter, Katie A. Read, Shalini Punjabi, Adedayo Adedeji, Luke Fakes, Ally Lewis, Ben Richmond, Neil Passant, Tim Murrells, Barron Henderson, Kelvin H. Bates, and Detlev Helmig
Atmos. Chem. Phys., 24, 8317–8342, https://doi.org/10.5194/acp-24-8317-2024, https://doi.org/10.5194/acp-24-8317-2024, 2024
Short summary
Short summary
Ethane and propane are volatile organic compounds emitted from human activities which help to form ozone, a pollutant and greenhouse gas, and also affect the chemistry of the lower atmosphere. Atmospheric models tend to do a poor job of reproducing the abundance of these compounds in the atmosphere. By using regional estimates of their emissions, rather than globally consistent estimates, we can significantly improve the simulation of ethane in the model and make some improvement for propane.
Cited articles
Abdi, B.: The Economic Times, Coronavirus impact: Within ten days, 26 per cent fall in India's energy consumption, available at: https://energy.economictimes.indiatimes.com/news/power/, last access: 27 August 2020.
Ali, K., Inamdar, S. R., Beig, G., Ghude, S., and Peshin, S.: Surface ozone
scenario at Pune and Delhi during the decade of 1990s, J. Earth
Syst. Sci., 121, 373–383, https://doi.org/10.1007/s12040-012-0170-1,
2012.
Anderson, R. M., Heesterbeek, H., Klinkenberg, D., and Hollingsworth, T. D.:
How will country-based mitigation measures influence the course of the
COVID-19 epidemic?, Lancet, 395, 931–934,
https://doi.org/10.1016/s0140-6736(20)30567-5, 2020.
Apituley, A., Pedergnana, M., Sneep, M., Pepijn Veefkind, J., Loyola, D., Landgraf, J., and Borsdorff, T.: Sentinel-5 Precursor/TROPOMI Level 2 Product User Manual Carbon Monoxide, SRON-S5P-LEV2-MA-002, avaliable at: http://www.tropomi.eu/sites/default/files/files/Sentinel-5P-Level-2-Product-User-Manual-CarbonMonoxide_v1.00.02_20180613.pdf (last access: 7 February 2021), 2018.
Balakrishnan, K., Dey, S., Gupta, T., Dhaliwal, R. S., Brauer, M., Cohen, A.
J., Stanaway, J. D., Beig, G., Joshi, T. K., Aggarwal, A. N., Sabde, Y.,
Sadhu, H., Frostad, J., Causey, K., Godwin, W., Shukla, D. K., Kumar, G. A.,
Varghese, C. M., Muraleedharan, P., Agrawal, A., Anjana, R. M., Bhansali,
A., Bhardwaj, D., Burkart, K., Cercy, K., Chakma, J. K., Chowdhury, S.,
Christopher, D. J., Dutta, E., Furtado, M., Ghosh, S., Ghoshal, A. G.,
Glenn, S. D., Guleria, R., Gupta, R., Jeemon, P., Kant, R., Kant, S., Kaur,
T., Koul, P. A., Krish, V., Krishna, B., Larson, S. L., Madhipatla, K.,
Mahesh, P. A., Mohan, V., Mukhopadhyay, S., Mutreja, P., Naik, N., Nair, S.,
Nguyen, G., Odell, C. M., Pandian, J. D., Prabhakaran, D., Prabhakaran, P.,
Roy, A., Salvi, S., Sambandam, S., Saraf, D., Sharma, M., Shrivastava, A.,
Singh, V., Tandon, N., Thomas, N. J., Torre, A., Xavier, D., Yadav, G.,
Singh, S., Shekhar, C., Vos, T., Dandona, R., Reddy, K. S., Lim, S. S.,
Murray, C. J. L., Venkatesh, S., and Dandona, L.: The impact of air
pollution on deaths, disease burden, and life expectancy across the states
of India: the Global Burden of Disease Study 2017, Lancet Planet. Health, 3, e26–e39, https://doi.org/10.1016/S2542-5196(18)30261-4, 2019.
Banerjee, T., Kumar, M., Mall, R. K., and Singh, R. S.: Airing 'clean air'
in Clean India Mission, Environ. Sci. Pollut. Res., 24,
6399–6413, https://doi.org/10.1007/s11356-016-8264-y, 2017.
Bao, R. and Zhang, A.: Does lockdown reduce air pollution? Evidence from 44
cities in northern China, Sci. Total Environ., 731, 139052,
https://doi.org/10.1016/j.scitotenv.2020.139052, 2020.
Beig, G., Chate, D. M., Ghude, S. D., Mahajan, A. S., Srinivas, R., Ali, K.,
Sahu, S. K., Parkhi, N., Surendran, D., and Trimbake, H. R.: Quantifying the
effect of air quality control measures during the 2010 Commonwealth Games at
Delhi, India, Atmos. Environ., 80, 455–463,
https://doi.org/10.1016/j.atmosenv.2013.08.012, 2013.
Binkowski, F. S. and Roselle, S. J.: Models-3 Community Multiscale Air Quality (CMAQ) model aerosol component 1. Model description, J. Geophys. Res.-Atmos., 108, 4183, https://doi.org/10.1029/2001JD001409, 2003.
Bujin, B., Joshua, S. A., Dylan, B. M., Allen, R., Kelley, C. W., and Julian, D. M.: PM2.5 and Ozone Air Pollution Levels Have Not Dropped Consistently Across the US Following Societal Covid Response, ChemRxiv [preprint], https://doi.org/10.26434/chemrxiv.12275603.v3, 2020.
Byun, D. and Schere, K. L.: Review of the governing equations,
computational algorithms, and other components of the models-3 Community
Multiscale Air Quality (CMAQ) modeling system, Appl. Mech. Rev.,
59, 51–77, https://doi.org/10.1115/1.2128636, 2006.
Carter, W. P. L.: SAPRC Atmospheric Chemical Mechanisms and VOC Reactivity
Scales, available at: https://intra.engr.ucr.edu/~carter/SAPRC/ (last access: 26 August 2020), 2011.
Chauhan, A. and Singh, R. P.: Decline in PM2.5 concentrations over
major cities around the world associated with COVID-19, Environ.
Res., 187, 109634, https://doi.org/10.1016/j.envres.2020.109634, 2020.
Chen, Z., Zhuang, Y., Xie, X., Chen, D., Cheng, N., Yang, L., and Li, R.:
Understanding long-term variations of meteorological influences on ground
ozone concentrations in Beijing During 2006–2016, Environ. Pollut.,
245, 29–37, https://doi.org/10.1016/j.envpol.2018.10.117, 2019.
Chintalapudi, N., Battineni, G., and Amenta, F.: COVID-19 virus outbreak
forecasting of registered and recovered cases after sixty day lockdown in
Italy: A data driven model approach, J. Microbiol. Immunol., 53, 396–403, https://doi.org/10.1016/j.jmii.2020.04.004, 2020.
Collivignarelli, M. C., Abba, A., Bertanza, G., Pedrazzani, R., Ricciardi,
P., and Carnevale Miino, M.: Lockdown for CoViD-2019 in Milan: What are the
effects on air quality?, Sci. Total Environ., 732, 139280,
https://doi.org/10.1016/j.scitotenv.2020.139280, 2020.
Dantas, G., Siciliano, B., Franca, B. B., da Silva, C. M., and Arbilla, G.:
The impact of COVID-19 partial lockdown on the air quality of the city of
Rio de Janeiro, Brazil, Sci. Total Environ., 729, 139085,
https://doi.org/10.1016/j.scitotenv.2020.139085, 2020.
Das, M., Das, A., Sarkar, R., Saha, S., and Mandal, A.: Examining the impact
of lockdown (due to COVID-19) on ambient aerosols (PM2.5): A study on
Indo-Gangetic Plain (IGP) Cities, India, Stoch. Env. Res. Risk A., 16, 1–17, https://doi.org/10.1007/s00477-020-01905-x, 2020.
David, L. M., Ravishankara, A. R., Kodros, J. K., Pierce, J. R.,
Venkataraman, C., and Sadavarte, P.: Premature Mortality Due to PM2.5
Over India: Effect of Atmospheric Transport and Anthropogenic Emissions,
Geohealth, 3, 2–10, https://doi.org/10.1029/2018GH000169, 2019.
Dominutti, P., Nogueira, T., Fornaro, A., and Borbon, A.: One decade of VOCs
measurements in São Paulo megacity: Composition, variability, and
emission evaluation in a biofuel usage context, Sci. Total
Environ., 738, 139790, https://doi.org/10.1016/j.scitotenv.2020.139790,
2020.
Ehrlich, H., McKenney, M., and Elkbuli, A.: Protecting our healthcare
workers during the COVID-19 pandemic, Am. J. Emerg.
Med., 38, 1527–1528, https://doi.org/10.1016/j.ajem.2020.04.024, 2020.
Emery, C., Tai, E., and Yarwood, G.: Enhanced Meteorological Modeling and Performance Evaluation for Two texas Episodes, Report to the Texas Natural Resources Conservation Commission, Prepared by ENVIRON, International Corp., Novato, CA, available at: http://www.tceq.state.tx.us/assets/public/implementation/air/am/contracts/reports/mm/EnhancedMetModelingAndPerformanceEvaluation.pdf (last access: 27 August 2020), 2001.
EPA: Guidance on the Use of Models and Other Analyses in Attainment Demonstrations for the 8-hour Ozone, NAAQSRep, available at: https://nepis.epa.gov/Exe/ZyPDF.cgi/P1006FPU.PDF?Dockey=P1006FPU.PDF, (last access: 27 August 2020), 2005.
EPA: Guidance on the use of models and other analyses for demonstrating attainment of air quality goals for ozone, PM2.5, and regional haze, US Environmental Protection Agency, Office of Air Quality Planning and Standards, available at: https://nepis.epa.gov/Exe/ZyPDF.cgi/P1009OL1.PDF?Dockey=P1009OL1.PDF (last access: 27 August 2020), 2007.
Eskes, K.-U. E., Lambert, J.-C., Loyola, D., Veefkind, J. P., Dehn, A., and Zehner, C.: S5P Mission Performance Centre Nitrogen Dioxide [L2_NO2_] Readme, available at: https://sentinel.esa.int/documents/247904/3541451/Sentinel-5P-Nitrogen-Dioxide-Level-2-Product-Readme-File (last access: 7 February 2021), 2020.
ET Bureau: The Economic Times, Move only essential items: Transport body to members, available at: https://economictimes.indiatimes.com/industry/transportation/shipping-/-transport/move-only-essential-items-transport-body-to-members/articleshow/75016374.cms?from=mdr, last access: 27 August 2020.
Feng, T., Zhao, S., Bei, N., Wu, J., Liu, S., Li, X., Liu, L., Qian, Y., Yang, Q., Wang, Y., Zhou, W., Cao, J., and Li, G.: Secondary organic aerosol enhanced by increasing atmospheric oxidizing capacity in Beijing–Tianjin–Hebei (BTH), China, Atmos. Chem. Phys., 19, 7429–7443, https://doi.org/10.5194/acp-19-7429-2019, 2019.
Fountoukis, C. and Nenes, A.: ISORROPIA II: a computationally efficient thermodynamic equilibrium model for K+–Ca2+–Mg2+–NH
Garaga, R., Gokhale, S., and Kota, S. H.: Source apportionment of
size-segregated atmospheric particles and the influence of particles
deposition in the human respiratory tract in rural and urban locations of
north-east India, Chemosphere, 255, 126980,
https://doi.org/10.1016/j.chemosphere.2020.126980, 2020.
Gautam, S.: The Influence of COVID-19 on Air Quality in India: A Boon or
Inutile, B. Environ. Contam. Tox., 104, 724–726, https://doi.org/10.1007/s00128-020-02877-y, 2020.
Gawhane, R. D., Rao, P. S. P., Budhavant, K. B., Waghmare, V., Meshram, D.
C., and Safai, P. D.: Seasonal variation of chemical composition and source
apportionment of PM2.5 in Pune, India, Environ. Sci.
Pollut. Res., 24, 21065–21072,
https://doi.org/10.1007/s11356-017-9761-3, 2017.
Guenther, A. B., Jiang, X., Heald, C. L., Sakulyanontvittaya, T., Duhl, T., Emmons, L. K., and Wang, X.: The Model of Emissions of Gases and Aerosols from Nature version 2.1 (MEGAN2.1): an extended and updated framework for modeling biogenic emissions, Geosci. Model Dev., 5, 1471–1492, https://doi.org/10.5194/gmd-5-1471-2012, 2012.
Guo, H., Kota, S. H., Sahu, S. K., Hu, J., Ying, Q., Gao, A., and Zhang, H.:
Source apportionment of PM2.5 in North India using source-oriented air
quality models, Environ. Pollut., 231, 426–436,
https://doi.org/10.1016/j.envpol.2017.08.016, 2017.
Gurjar, B. R., Ravindra, K., and Nagpure, A. S.: Air pollution trends over
Indian megacities and their local-to-global implications, Atmos.
Environ., 142, 475–495, https://doi.org/10.1016/j.atmosenv.2016.06.030,
2016.
Guttikunda, S. K., Nishadh, K. A., Gota, S., Singh, P., Chanda, A., Jawahar,
P., and Asundi, J.: Air quality, emissions, and source contributions
analysis for the Greater Bengaluru region of India, Atmos. Pollut.
Res., 10, 941–953, https://doi.org/10.1016/j.apr.2019.01.002, 2019.
Hu, J., Wu, L., Zheng, B., Zhang, Q., He, K., Chang, Q., Li, X., Yang, F.,
Ying, Q., and Zhang, H.: Source contributions and regional transport of
primary particulate matter in China, Environ. Pollut., 207, 31–42,
https://doi.org/10.1016/j.envpol.2015.08.037, 2015.
Hu, J., Chen, J., Ying, Q., and Zhang, H.: One-year simulation of ozone and particulate matter in China using WRF/CMAQ modeling system, Atmos. Chem. Phys., 16, 10333–10350, https://doi.org/10.5194/acp-16-10333-2016, 2016.
Isaifan, R. J.: The dramatic impact of Coronavirus outbreak on air quality:
Has it saved as much as it has killed so far?, Global J.
Environ. Sci. Manage., 6, 275–288,
https://doi.org/10.22034/gjesm.2020.03.01, 2020.
Jain, S., Sharma, S. K., Vijayan, N., and Mandal, T. K.: Seasonal
characteristics of aerosols (PM2.5 and PM10) and their source
apportionment using PMF: A four year study over Delhi, India, Environ.
Pollut., 262, 114337, https://doi.org/10.1016/j.envpol.2020.114337, 2020.
Kabiraj, S. and Gavli, N. V.: Impact of SARS-CoV-2 Pandemic Lockdown on Air
Quality Using Satellite Imagery with Ground Station Monitoring Data in Most
Polluted City Kolkata, India, Aerosol Sci. Eng., 4, 320–330,
10.1007/s41810-020-00077-z, 2020.
Karambelas, A., Holloway, T., Kiesewetter, G., and Heyes, C.: Constraining
the uncertainty in emissions over India with a regional air quality model
evaluation, Atmos. Environ., 174, 194–203,
https://doi.org/10.1016/j.atmosenv.2017.11.052, 2018.
Kitayama, K., Morino, Y., Yamaji, K., and Chatani, S.: Uncertainties in
O3 concentrations simulated by CMAQ over Japan using four chemical
mechanisms, Atmos. Environ., 198, 448–462,
https://doi.org/10.1016/j.atmosenv.2018.11.003, 2019.
Kota, S. H., Guo, H., Myllyvirta, L., Hu, J., Sahu, S. K., Garaga, R., Ying,
Q., Gao, A., Dahiya, S., Wang, Y., and Zhang, H.: Year-long simulation of
gaseous and particulate air pollutants in India, Atmos. Environ.,
180, 244–255, https://doi.org/10.1016/j.atmosenv.2018.03.003, 2018.
Kroll, J. H., Heald, C. L., Cappa, C. D., Farmer, D. K., Fry, J. L., Murphy,
J. G., and Steiner, A. L.: The complex chemical effects of COVID-19
shutdowns on air quality, Nat. Chem., 12, 777–779,
https://doi.org/10.1038/s41557-020-0535-z, 2020.
Kumar, P., Hama, S., Omidvarborna, H., Sharma, A., Sahani, J., Abhijith, K.
V., Debele, S. E., Zavala-Reyes, J. C., Barwise, Y., and Tiwari, A.:
Temporary reduction in fine particulate matter due to `anthropogenic
emissions switch-off' during COVID-19 lockdown in Indian cities, Sustain.
Cities Soc., 62, 102382, https://doi.org/10.1016/j.scs.2020.102382,
2020.
Kumar, S.: Effect of meteorological parameters on spread of COVID-19 in
India and air quality during lockdown, Sci. Total Environ.,
745, 141021, https://doi.org/10.1016/j.scitotenv.2020.141021, 2020.
Kumari, P., and Toshniwal, D.: Impact of lockdown measures during COVID-19 on air quality – A case study of India, Int. J. Environ. Health Res., https://doi.org/10.1080/09603123.2020.1778646, in press, 2020.
Lal, S., Venkataramani, S., Naja, M., Kuniyal, J. C., Mandal, T. K., Bhuyan,
P. K., Kumari, K. M., Tripathi, S. N., Sarkar, U., Das, T., Swamy, Y. V.,
Gopal, K. R., Gadhavi, H., and Kumar, M. K. S.: Loss of crop yields in India
due to surface ozone: an estimation based on a network of observations,
Environ. Sci. Pollut. Res., 24, 20972–20981,
https://doi.org/10.1007/s11356-017-9729-3, 2017.
Le, T., Wang, Y., Liu, L., Yang, J., Yung, Y. L., Li, G., and Seinfeld, J. H.: Unexpected air pollution with marked emission reductions during the COVID-19 outbreak in China, Science, 369, 702–706, https://doi.org/10.1126/science.abb7431, 2020.
Mahajan, A. S., De Smedt, I., Biswas, M. S., Ghude, S., Fadnavis, S., Roy,
C., and van Roozendael, M.: Inter-annual variations in satellite
observations of nitrogen dioxide and formaldehyde over India, Atmos.
Environ., 116, 194–201, https://doi.org/10.1016/j.atmosenv.2015.06.004,
2015.
Mahato, S., Pal, S., and Ghosh, K. G.: Effect of lockdown amid COVID-19
pandemic on air quality of the megacity Delhi, India, Sci. Total
Environ., 730, 139086, https://doi.org/10.1016/j.scitotenv.2020.139086,
2020.
Mohan, M. and Gupta, M.: Sensitivity of PBL parameterizations on PM10
and ozone simulation using chemical transport model WRF-Chem over a
sub-tropical urban airshed in India, Atmos. Environ., 185, 53–63,
https://doi.org/10.1016/j.atmosenv.2018.04.054, 2018.
Mor, S., Kumar, S., Singh, T., Dogra, S., Pandey, V., and Ravindra, K.:
Impact of COVID-19 lockdown on air quality in Chandigarh, India:
Understanding the emission sources during controlled anthropogenic
activities, Chemosphere, 263, 127978,
https://doi.org/10.1016/j.chemosphere.2020.127978, 2021.
Mukherjee, K.: COVID-19 and lockdown: Insights from Mumbai, Indian J. Pub. Health, 64, 168–171,
https://doi.org/10.4103/ijph.IJPH_508_20,
2020.
Nakada, L. Y. K. and Urban, R. C.: COVID-19 pandemic: Impacts on the air
quality during the partial lockdown in Sao Paulo state, Brazil, Sci.
Total Environ., 730, 139087,
https://doi.org/10.1016/j.scitotenv.2020.139087, 2020.
Oksanen, E., Pandey, V., Pandey, A. K., Keski-Saari, S., Kontunen-Soppela,
S., and Sharma, C.: Impacts of increasing ozone on Indian plants,
Environ. Pollut., 177, 189–200,
https://doi.org/10.1016/j.envpol.2013.02.010, 2013.
Otmani, A., Benchrif, A., Tahri, M., Bounakhla, M., Chakir, E. M., El Bouch,
M., and Krombi, M.: Impact of Covid-19 lockdown on PM10, SO2 and
NO2 concentrations in Sale City (Morocco), Sci. Total
Environ., 735, 139541, https://doi.org/10.1016/j.scitotenv.2020.139541,
2020.
Pai, C., Bhaskar, A., and Rawoot, V.: Investigating the dynamics of COVID-19
pandemic in India under lockdown, Chaos Soliton. Fract., 138,
109988, https://doi.org/10.1016/j.chaos.2020.109988, 2020.
Palmer, P. I., Jacob, D. J., Fiore, A. M., Martin, R. V., Chance, K., and Kurosu, T. P.: Mapping isoprene emissions over North America using formaldehyde column observations from space, J. Geophys. Res.-Atmos., 108, 4180, https://doi.org/10.1029/2002JD002153, 2003.
Purohit, P., Amann, M., Kiesewetter, G., Rafaj, P., Chaturvedi, V.,
Dholakia, H. H., Koti, P. N., Klimont, Z., Borken-Kleefeld, J.,
Gomez-Sanabria, A., Schopp, W., and Sander, R.: Mitigation pathways towards
national ambient air quality standards in India, Environ. Int.,
133, 105147, https://doi.org/10.1016/j.envint.2019.105147, 2019.
Reuters, S. V.: UPDATE 1 – India's March Electricity Usage Falls 9.2 % as Lock-Down Bites, available at: https://uk.reuters.com/article/india-electricity-supply/update-1-indias-march-electricity-usage-falls-9-2-as-lockdown, last access: 26 August 2020.
Sahu, S. K., Sharma, S., Zhang, H., Chejarla, V., Guo, H., Hu, J., Ying, Q.,
Xing, J., and Kota, S. H.: Estimating ground level PM2.5 concentrations
and associated health risk in India using satellite based AOD and WRF
predicted meteorological parameters, Chemosphere, 255,
126969, https://doi.org/10.1016/j.chemosphere.2020.126969, 2020.
Schnell, J. L., Naik, V., Horowitz, L. W., Paulot, F., Mao, J., Ginoux, P., Zhao, M., and Ram, K.: Exploring the relationship between surface PM2.5 and meteorology in Northern India, Atmos. Chem. Phys., 18, 10157–10175, https://doi.org/10.5194/acp-18-10157-2018, 2018.
Selvam, S., Muthukumar, P., Venkatramanan, S., Roy, P. D., Manikanda
Bharath, K., and Jesuraja, K.: SARS-CoV-2 pandemic lockdown: Effects on air
quality in the industrialized Gujarat state of India, Sci. Total
Environ., 737, 140391, https://doi.org/10.1016/j.scitotenv.2020.140391,
2020.
Sharma, S., Chatani, S., Mahtta, R., Goel, A., and Kumar, A.: Sensitivity
analysis of ground level ozone in India using WRF-CMAQ models, Atmos.
Environ., 131, 29–40, https://doi.org/10.1016/j.atmosenv.2016.01.036,
2016.
Sharma, S., Zhang, M., Anshika, Gao, J., Zhang, H., and Kota, S. H.: Effect
of restricted emissions during COVID-19 on air quality in India, Sci. Total Environ., 728, 138878,
https://doi.org/10.1016/j.scitotenv.2020.138878, 2020.
Shehzad, K., Sarfraz, M., and Shah, S. G. M.: The impact of COVID-19 as a
necessary evil on air pollution in India during the lockdown, Environ.
Pollut., 266, 115080, https://doi.org/10.1016/j.envpol.2020.115080, 2020.
Sicard, P., De Marco, A., Agathokleous, E., Feng, Z., Xu, X., Paoletti, E.,
Rodriguez, J. J. D., and Calatayud, V.: Amplified ozone pollution in cities
during the COVID-19 lockdown, Sci. Total Environ., 735, 139542,
https://doi.org/10.1016/j.scitotenv.2020.139542, 2020.
Sillman, S.: The use of NOy, H2O2, and HNO3 as
indicators for ozone-NOx-hydrocarbon sensitivity in urban locations,
J. Geophys. Res.-Atmos., 100, 14175–14188,
https://doi.org/10.1029/94JD02953, 1995.
Sillman, S. and He, D.: Some theoretical results concerning
O3-NOx-VOC chemistry and NOx-VOC indicators, J.
Geophys. Res.-Atmos., 107, ACH 26-21–ACH 26-15,
https://doi.org/10.1029/2001JD001123, 2002.
Srivastava, S., Kumar, A., Bauddh, K., Gautam, A. S., and Kumar, S.: 21-Day
Lockdown in India Dramatically Reduced Air Pollution Indices in Lucknow and
New Delhi, India, B. Environ. Contam. Tox.,
105, 9–17, https://doi.org/10.1007/s00128-020-02895-w, 2020.
Steiner, A. L., Cohen, R. C., Harley, R. A., Tonse, S., Millet, D. B., Schade, G. W., and Goldstein, A. H.: VOC reactivity in central California: comparing an air quality model to ground-based measurements, Atmos. Chem. Phys., 8, 351–368, https://doi.org/10.5194/acp-8-351-2008, 2008.
Wang, D., Hu, J., Xu, Y., Lv, D., Xie, X., Kleeman, M., Xing, J., Zhang, H.,
and Ying, Q.: Source contributions to primary and secondary inorganic
particulate matter during a severe wintertime PM2.5 pollution episode
in Xi'an, China, Atmos. Environ., 97, 182–194,
https://doi.org/10.1016/j.atmosenv.2014.08.020, 2014.
Wang, P., Chen, K., Zhu, S., Wang, P., and Zhang, H.: Severe air pollution
events not avoided by reduced anthropogenic activities during COVID-19
outbreak, Resour. Conserv. Recy., 158, 104814,
https://doi.org/10.1016/j.resconrec.2020.104814, 2020.
WHO: Global urban ambient air pollution database (update 2016), available at: http://www.who.int/phe/health_topics/outdoorair/databases/cities/en/, (last access: 27 August 2020), 2016.
WHO: WHO Global Ambient Air Quality Database (Update 2018), available at: http://www.who.int/airpollution/data/cities/en/ (last access: 27 August 2020), 2018.
Wiedinmyer, C., Akagi, S. K., Yokelson, R. J., Emmons, L. K., Al-Saadi, J. A., Orlando, J. J., and Soja, A. J.: The Fire INventory from NCAR (FINN): a high resolution global model to estimate the emissions from open burning, Geosci. Model Dev., 4, 625–641, https://doi.org/10.5194/gmd-4-625-2011, 2011.
Zhang, H., Wang, Y., Hu, J., Ying, Q., and Hu, X. M.: Relationships between
meteorological parameters and criteria air pollutants in three megacities in
China, Environ. Res., 140, 242–254,
https://doi.org/10.1016/j.envres.2015.04.004, 2015.
Zhang, Q., Shao, M., Li, Y., Lu, S. H., Yuan, B., and Chen, W. T.: Increase
of ambient formaldehyde in Beijing and its implication for VOC reactivity,
Chinese Chem. Lett., 23, 1059–1062,
https://doi.org/10.1016/j.cclet.2012.06.015, 2012.
Zhao, B., Wu, W., Wang, S., Xing, J., Chang, X., Liou, K.-N., Jiang, J. H., Gu, Y., Jang, C., Fu, J. S., Zhu, Y., Wang, J., Lin, Y., and Hao, J.: A modeling study of the nonlinear response of fine particles to air pollutant emissions in the Beijing–Tianjin–Hebei region, Atmos. Chem. Phys., 17, 12031–12050, https://doi.org/10.5194/acp-17-12031-2017, 2017.
Short summary
We studied changes in air quality in India induced by the COVID-19 lockdown through both surface observations and the CMAQ model. Our results show that emission reductions improved the air quality across India during the lockdown. On average, the levels of PM2.5 and O3 decreased by 28 % and 15 %, indicating positive effects of lockdown measures. We suggest that more stringent and localized emission control strategies should be implemented in India to mitigate air pollutions.
We studied changes in air quality in India induced by the COVID-19 lockdown through both surface...
Altmetrics
Final-revised paper
Preprint