• Aman, M. A., M. S. Salman and A. P. Yunus: COVID-19 and its impact on environment: Improved pollution levels during the lockdown period – A case from Ahmedabad, India. Remote Sensing Applications: Society and Environment, 20, 100382, https://doi.org/10.1016/j.rsase.2020.100382, 2020.
  • Agarwal, A., A. Kaushik, S. Kumar and R. K. Mishra: Comparative study on air quality status in Indian and Chinese cities before and during the COVID-19 lockdown period. Air Quality, Atmosphere and Health 13, 1167-1178, https://dx.doi.org/10.1007%2Fs11869-020-00881-z, 2020.
  • Al-qaness, M. et al.: Improved ANFIS model for forecasting Wuhan City Air Quality and analysis COVID-19 lockdown impacts on air quality. Environmental Research, 194, 110607, https://doi.org/10.1016/j.envres.2020.110607, 2021.
  • Barré, J., H. Petetin, A. Colette, M. Guevara, V.-H. Peuch, L. Rouil et al.: Estimating lockdown induced European NO2 changes. Atmospheric Chemistry and Physicshttps://doi.org/10.5194/acp-2020-995, 2020.
  • Bashir, M. F., B. J. MA, Bilal, B. Komal, M. A. Bashir, T.. H. Farooq, N. Iqbal, M. Bashir: Correlation between environmental pollution indicators and COVID-19 pandemic: A brief study in Californian context. Environmental Research, 187, 109652, https://doi.org/10.1016/j.envres.2020.109652, 2020.
  • Bassani, C. et al.: Nitrogen dioxide reductions from satellite and surface observations during COVID-19 mitigation in Rome (Italy). Environmental Science and Pollution Research, https://doi.org/10.1007/s11356-020-12141-9, 2021.
  • Bauwens, M. S. Compernolle, T. Stavrakou, J.-F. Müller, J. van Gent, H. Eskes, P. F. Levelt, R. van der A, J. P. Veefkind, J. Vlietinck, H. Yu, C. Zehner: Impact of coronavirus outbreak on NO2 pollution assessed using TROPOMI and OMI observations. Geophysical Research Letters, https://doi.org/10.1029/2020GL087978, 2020.
  • Bedi, J. S., P. Dhaka, D. Vijay, R. S. Aulakh and J. P. S. Gill: Assessment of Air Quality Changes in the Four Metropolitan Cities of India during COVID-19 Pandemic Lockdown. Aerosol and Air Quality Research, 20, https://doi.org/10.4209/aaqr.2020.05.0209, 2020.
  • Biswal, A., V. Singh, S. Singh, A. P. Kesarkar, K. Ravindra, R. S. Sokhl, M. P. Chipperfield, S. S. Dhomse, R. J. Pope, T. Singh and S. Mor: COVID-19 lockdown induced changes in NO2 levels across India observed by multi-satellite and surface observationsAtmospheric Chemistry and Physics, https://doi.org/10.5194/acp-2020-1023, 2020.
  • Biswas, M. S. and A. D. Choudhury: Impact of COVID-19 Control Measures on Trace Gases (NO2, HCHO and SO2) and Aerosols over India during Pre-monsoon of 2020. Aerosol and Air Quality Research, https://doi.org/10.4209/aaqr.2020.06.0306, 2020.
  • Brimblecombe, P. and Lai, Y.: Effect of Fireworks, Chinese New Year and the COVID-19 Lockdown on Air Pollution and Public Attitudes. Aerosol Air Quality Research, 20: 2318–2331. https://doi.org/10.4209/aaqr.2020.06.0299, 2020.

  • Brimblecombe, P. and Lai, Y.: Diurnal and weekly patterns of primary pollutants in Beijing under COVID-19 restrictions. Faraday Discussions, DOI: 10.1039/D0FD00082E, 2020.

  • Briz-Redón, A., C. Belenguer-Sapiña and A. Serrano-Aroca: Changes in air pollution during COVID-19 lockdown in Spain: A multi-city studyJournal of Environmental Sciences, 101, https://doi.org/10.1016/j.jes.2020.07.029, 2021.
  • Broomandi, P., F. Karaca, A. Nikfal, A. Jahanbakhshi, M. Tamjidi, J. R. Kim: Impact of COVID-19 event on the air quality in Iran. Aerosol and Air Quality Research, 20, https://doi.org/10.4209/aaqr.2020.05.0205, 2020.
  • Buchwitz, M., M. Reuter, S. Noël, K. Bramstedt, O. Schneising, M. Hilker, B. F. Andrade, H. Bovensmann, J. P. Burrows et al.: Can a regional-scale reduction of atmospheric CO2 during the COVID-19 pandemic be detected from space? A case study for East China using satellite XCO2 retrievals. Atmospheric Measurement Techniques, https://doi.org/10.5194/amt-2020-386, 2020.
  • Cazorla, M., E. Herrera, E. Palomeque and N. Saud: What the COVID-19 lockdown revealed about photochemistry and ozone production in Quito, Ecuador. Atmospheric Pollution Research https://doi.org/10.1016/j.apr.2020.08.028, 2020.
  • Chang, Y., R.-J. Huang, X. Ge, X. Huang, J. Hu, Y. Duan, Z. Zhou, X. Liu, M. F. Lehmann: Puzzling haze events during the coronavirus (COVID-19) shutdown. Geophysical Research Letters, https://doi.org/10.1029/2020GL088533, 2020.
  • Chatterjee, A., S. Mukherjee, M. Dutta, A. Ghosh, S. K. Ghosh and A. Roy: High rise in carbonaceous aerosols under very low anthropogenic emissions over eastern Himalaya, India: Impact of lockdown for COVID-19 outbreak. Atmospheric Environment 244, 117947, https://doi.org/10.1016/j.atmosenv.2020.117947, 2021.
  • Chen, Q. X., Huang, C.L., Yuan, Y. and Tan, H.P.: Influence of COVID-19 Event on air quality and their association in mainland China. Aerosol Air Quality Research, 20: 1541–1551, https://doi.org/10.4209/aaqr.2020.05.0224, 2020.
  • Chen, Y., Senthilkuma, N., Shen, H., and Shen, G.: Environmental inequality deapened during the COVID-19 in the developing world. Environmental Science and Technology, https://doi.org/10.1021/acs.est.0c06193, 2020.
  • Chevallier, F., Zheng, B., Broquet, G., Ciais, P., Liu, Z., Davis, S. J., et al.: Local anomalies in the column-averaged dry air mole fractions of carbon dioxide across the globe during the first months of the coronavirus recession. Geophysical Research Letters, 47.https://doi.org/10.1029/2020GL090244, 2020.
  • Chu, B., S. Zhang, J. Liu, Q. Ma and H. He: Significant concurrent decrease in PM2.5 and NO2 concentrations in China during COVID-19 epidemic. Journal of Environmental Science, 99, 346-353, https://doi.org/10.1016/j.jes.2020.06.031, 2020.
  • Collivignarelli, M. C., A. Abba, G. Bertanza, R. Pedrazzani, P. Ricciardi, and M. C. Miino: Lockdown for Covid-2019 in Milan: What are the effects on air quality? Science of the Total Environment, 732 (139280), https://doi.org/10.1016/j.scitotenv.2020.139280, 2020.
  • Contincine E., B. Frediani, and D. Caro: Can atmospheric pollution be considered a co-factor in extremely high level of SARS-CoV-2 lethality in Northern Italy? Environmental Pollution, 261, 114465, https://doi.org/10.1016/j.envpol.2020.114465, 2020.
  • Dacre, H. F., A. H. Mortimer and L. S. Neal: How have surface NO2 concentrations changed as a result of the UK's COVID-19 travel restrictions? Environmental Research Letters 15, 10, https://doi.org/10.1088/1748-9326/abb6a2, 2020.
  • Dantas, G., B. Siciliano, B. B. Farca, C. M. da Silva, G. Arbilla: The impact of COVID-19 partial lockdown on the air quality of the city of Rio de Janeiro, Brazil. Science of the Total Environment, 729 (139085), https://doi.org/10.1016/j.scitotenv.2020.139085, 2020.
  • Datta et al.: Did the COVID‐19 lockdown in Delhi and Kolkata improve the ambient air quality of the two cities? Journal of Environmental Quality,  https://doi.org/10.1002/jeq2.20192, 2021.
  • Deroubaix, A. et al.: Response of surface ozone concentration to emission reduction and meteorology during the COVID-19 lockdown in Europe. Authorea, 10.22541/au.160513378.82834373/v1, 2020.
  • Dhaka, S. K., Chetna, V. Kumar, V. Panwar, A. P. Dimri, N. Singh, P. K. Patra, Y. Matsumi, M. Takigawa, T. Nakayama, K. Yamaji, M. Kajino, P. Misra and S. Hayashida: PM2.5 diminution and haze events over Delhi during the COVID-19 lockdown period: an interplay between the baseline pollution and meteorology. Scientific Reports, 10, 13442, https://doi.org/10.1038/s41598-020-70179-8, 2020.
  • Diamond, M. S. and R. Wood: Limited Regional Aerosol and Cloud Microphysical Changes Despite Unprecedented Decline in Nitrogen Oxide Pollution During the February 2020 COVID-19 Shutdown in China. Geophysical Research Letters, 47, https://doi.org/10.1029/2020GL088913, 2020.
  • Dias, F. L., M. Assumpção, P. S. Peixoto, M. B. Bianchi, B. Collaço and J. Calhau: Using Seismic Noise Levels to Monitor Social Isolation: An Example From Rio de Janeiro, Brazil. Geophysical Research Letters, 47, https://doi.org/10.1029/2020GL088748, 2020.
  • Ding, J., van der A, R. J., Eskes, H. J.,Mijling, B., Stavrakou, T., van Geffen, J. H. G. M. et al.: NOx emissions reduction and rebound in China due to the COVID-19 crisis. Geophysical Research Letters, 46, e2020GL089912. https://doi.org/10.1029/2020GL089912, 2020.
  • Doumbia, T., Granier, C., Elguindi, N., Bouarar, I., Darras, S., Brasseur, G., Gaubert, B., Liu, Y., Shi, X., Stavrakou, T., Tilmes, S., Lacey, F., Deroubaix, A., and Wang, T.: Changes in global air pollutant emissions during the COVID-19 pandemic: a dataset for atmospheric chemistry modeling, Earth System Science Data Discussions [preprint] https://doi.org/10.5194/essd-2020-348, in review, 2021.
  • Dutta, A., Jinsart, W.: Air Quality, Atmospheric Variables and Spread of COVID-19 in Delhi (India): An Analysis. Aerosol Air Quality Research, 21, 200417. https://doi.org/10.4209/aaqr.2020.07.0417, 2021.
  • Elshorbany et al.: The Status of Air Quality in the United States During the COVID-19 Pandemic: A Remote Sensing Perspective. Remote Sensing, 13(3), 369, https://doi.org/10.3390/rs13030369, 2021.
  • Faridi, S., Yousefian, F., Niazi, S., Ghalhari, M.R., Hassanvand, M.S. and Naddafi. K.: Impact of SARS-CoV-2 on ambient air particulate matter in Tehran. Aerosol Air Quality Research, https://doi.org/10.4209/aaqr.2020.05.0225, 2020.
  • Feng, S., F. Jiang, H. Wang, H. Wang, W. Ju, Y. Shen, Y. Zheng, Z. Wu and A. Ding: NOx Emission Changes Over China During the COVID‐19 Epidemic Inferred From Surface NO2 Observations. Geophysical Research Letters 47, https://doi.org/10.1029/2020GL090080, 2020.
  • Filonchyk, M., Hurynovich, V., Yan, H., Gusev, A. and Shpilevskaya, N.: Impact Assessment of COVID-19 on Variations of SO2, NO2, CO and AOD over East China. Aerosol Air Quality Research 20: 1530–1540. https://doi.org/10.4209/aaqr.2020.05.0226, 2020.
  • Forster, P. M., H. I. Forster, M. J. Evans, M. J. Gidden, C. D. Jones, C. A. Keller, R. D. Lamboll, C. Le Quéré, J. Rogelj, D. Rosen, C.-F. Schleussner, T. B. Richardson, C. J. Smith and S. T. Turnock: Current and future global climate impacts resulting from COVID-19. Nature Climate Change, https://doi.org/10.1038/s41558-020-0883-0, 2020.
  • Fuwape I. A., C. T. Okpalaonwuka and S. T. Ogunjo: Impact of COVID -19 pandemic lockdown on distribution of inorganic pollutants in selected cities of Nigeria. Air Quality, Atmosphere and Health, https://doi.org/10.1007/s11869-020-00921-8, 2020.
  • Garg, A. et al.: Impact of Lockdown on Ambient Air Quality in COVID-19 Affected Hotspot Cities of India: Need to Readdress Air Pollution Mitigation Policies. Environmental Claims Journal, 33, https://doi.org/10.1080/10406026.2020.1822615, 2021.
  • Gautam, S. P., A. Silwal, P. Poudel, A. Thapa, P. Sharma, M. Lamsal, R. Neupane: Comparative study of ambient air quality using air quality index in Kathmandu city, Nepal. IOSR Journal of Environmental Science, Toxicology and Food Technology, 14, 29-35, DOI:10.9790/2402-1405022935, 2020.
  • Goldberg, D. L., S. C. Anenberg, D. Griffin, C. A. McLinden, Z. Lu, D. G. Streets: Disentangling the Impact of the COVID‐19 Lockdowns on Urban NO2 From Natural Variability. Geophysical Research Letters, 47, https://doi.org/10.1029/2020GL089269, 2020.
  • Guevara, M., O. Jorba, A. Soret, H. Petetin, D. Bowdalo, K. Serradell, C. Tena, H. Denier van der Gon, J. Kuenen, V.-H. Peuch, C. P. Garcia-Pando, Time-resolved emission reductions for atmospheric chemistry modelling in Europe during hte COVID-19 lockdowns. Atmospheric Chemistry and Physics, https://doi.org/10.5194/acp-2020-686, 2020.
  • Griffith, S. M., W.-S. Huang, C.-C. Lin, Y.C. Chen, et al.: Long-range air pollution transport in East Asia during the first week of the COVID-19  lockdown in China. Science of the Total Environment, 741 (140214), https://doi.org/10.1016/j.scitotenv.2020.140214, 2020.
  • He, C. et al.: Global, continental, and national variation in PM2.5, O3, and NO2 concentrations during the early 2020 COVID-19 lockdown. Atmospheric Pollution Research, 12 (3), https://doi.org/10.1016/j.apr.2021.02.002, 2021.
  • Huang, G. and K. Sun: Non-negligible impacts of clean air regulations on the reduction of tropospheric NO2 over East China during the COVID-19 pandemic observed by OMI and TROPOMI. Science of the Total Environment 745, 141023, https://doi.org/10.1016/j.scitotenv.2020.141023, 2020.
  • Huang, L., Z. Liu, H. Li, Y. Wang, Y. Li, Y. Zhu, M. C. G. Ooi, J. An, Y. Shang, D. Zhang, A. Chan and L. Li: The Silver Lining of COVID-19: Estimation of Short-Term Health Impacts Due to Lockdown in the Yangtze River Delta Region, China. GeoHealth, 4, https://doi.org/10.1029/2020GH000272, 2020.
  • Huang, X., A. Ding, J. Gao, B. Zheng, D. Zhou, X. Qi, R. Tang, J. Wang, C. Ren, et al.: Enhanced secondary pollution offset reduction of primary emissions during COVID-19 lockdown in China. National Science Review, https://doi.org/10.1093/nsr/nwaa137, 2020.
  • Huang, Y., J. L. Zhou, Y. Yu, W.-C. Mok, C. F. C. Lee and Y.-S. Yam: Uncertainty in the Impact of the COVID-19 Pandemic on Air Quality in Hong Kong, China. Atmosphere, 11, 914, https://doi.org/10.3390/atmos11090914, 2020.
  • Hudda, N., M. C. Simon, A. P. Patton and J. L. Durant: Reductions in traffic-related black carbon and ultrafine particle number concentrations in an urban neighborhood during the COVID-19 pandemicScience of the Total Environment, 742, 140931, https://doi.org/10.1016/j.scitotenv.2020.140931, 2020.
  • Islam, M.S., Rahman, M., Tusher, T.R., Roy, S., Razi, M.A.: Assessing the Relationship between COVID-19, Air Quality, and Meteorological Variables: A Case Study of Dhaka City in Bangladesh. Aerosol Air Quality Research, https://doi.org/10.4209/aaqr.200609, 2021.
  • Jain, S. and T. Sharma: Social and Travel Lockdown Impact Considering Coronavirus Disease (COVID-19) on Air Quality in Megacities of India: Present Benefits, Future Challenges and Way Forward. Aerosol Air Quality Research, 20: 1222–1236, https://doi.org/10.4209/aaqr.2020.04.0171, 2020.
  • Jiang, Z., Shi, H., Zhao, B., Gu, Y., Zhu, Y., Miyazaki, K., Zhang, Y., Bowman, K. W., Sekiya, T., and Liou, K.-N.: Modeling the Impact of COVID-19 on Air Quality in Southern California: Implications for Future Control Policies. Atmospheric Chemistry and Physics Discussions [preprint] https://doi.org/10.5194/acp-2020-1197, in review, 2020.
  • Karegar, M. A., and Kusche, J.: Imprints of COVID-19 lockdown on GNSS observations: An initial demonstration using GNSS interferometric reflectometry. Geophysical Research Letters, 47,e2020GL089647. https://doi.org/10.1029/2020GL089647, 2020.
  • Kerimray, A., N. Baimatova, O. P. Ibragimova, B. Bukenov, B. Kenessov, P. Plotitsyn, F. Karaca: Assessing air quality changes in large cities during COVID-19 lockdowns: the impacts of traffic-free urban conditions in Almaty, Kazakhstan. Science of the Total Environment, 730 (139179), https://doi.org/10.1016/j.scitotenv.2020.139179, 2020.
  • Koukouli, M.-E., Skoulidou, I., Karavias, A., Parcharidis, I., Balis, D., Manders, A., Segers, A., Eskes, H., and van Geffen, J.: Sudden changes in nitrogen dioxide emissions over Greece due to lockdown after the outbreak of COVID-19. Atmospheric Chemistry and Physics, 21, 1759–1774, https://doi.org/10.5194/acp-21-1759-2021, 2021.
  • Krecl, P., A. C. Targino, G. Y. Oukawa and R. P. Cassino Junior: Drop in urban air pollution from COVID-19 pandemic: Policy implications for the megacity of São Paulo. Environmental Pollution, 265, 114883, https://doi.org/10.1016/j.envpol.2020.114883, 2020.
  • Kumar, P., S. Hama, H. Omidvarborna, A. Sharma, J. Sahani, K. V. Abhijith, S. E. Debele, J. C. Zavala-Reyes, Y. Barwise and A. Tiwari: Temporary reduction in fine particulate matter due to ‘anthropogenic emissions switch-off’ during COVID-19 lockdown in Indian citiesSustainable Cities and Society, 62, 102382, https://doi.org/10.1016/j.scs.2020.102382, 2020.
  • Kumari, P. and D. Toshniwal: Impact of lockdown measures during COVID-19 on air quality– A case study of India. International Journal of Environmental Health Research,  https://doi.org/10.1080/09603123.2020.1778646, 2020.
  • Lal, P., Kumar, A., Bharti, S., Saikia, P., Adhikari, D., Khan, M.L.: Lockdown to Contain the COVID-19 Pandemic: An Opportunity to Create a Less Polluted Environment in India. Aerosol Air Quality Research 21, 200229, https://doi.org/10.4209/aaqr.2020.05.0229, 2021.
  • Lamboll, R. D., Jones, C. D., Skeie, R. B., Fiedler, S., Samset, B. H., Gillett, N. P., Rogelj, J., and Forster, P. M.: Modifying emission scenario projections to account for the effects of COVID-19: protocol for Covid-MIP. Geoscientific Model Devevelopment Discussions [preprint] https://doi.org/10.5194/gmd-2020-373, in review, 2020. 
  • Le, T., Y. Wang, L. Liu, J. Yang, Y. L. Yung, G. Li, J. H. Seinfeld: Unexpected air pollution with marked emissions reductions during the COVID-19 outbreak in China. Science, https://doi.org/10.1126/science.abb7431, 2020.
  • Le, V.V et al.: A remarkable review of the effect of lockdowns during COVID-19 pandemic on global PM emissions. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, https://doi.org/10.1080/15567036.2020.1853854, 2020.
  • Lee, J. D., W. S. Drysdale, D. P. Finch, S. E. Wilde and P. I. Palmer: UK surface NO2 levels dropped by 42 % during the COVID-19 lockdown: impact on surface O3. Atmospheric Chemistry and Physics, https://doi.org/10.5194/acp-2020-838, 2020.
  • Le Quéré, C., R. B. Jackson, M. W. Jones, A. J. P. Smith, S. Abernethy, R. M. Andrew, A. J. De-Gol, D. R. Willis, Y. Shan, J. G. Canadell, P. Friedlingstein, F. Creutzig and G. P. Peters: Temporary reduction in daily global CO2 emisisons during the COVID-19 forced confinement. Nature Climate Change, https://doi.org/10.1038/s41558-020-0797-x, 2020.
  • Li, J., Yang, H., Zha, S., Nu, Y., Liu, X., Sun, R.: Effects of COVID-19 Emergency Response Levels on Air Quality in the Guangdong-Hong Kong-Macao Greater Bay Area, China. Aerosol Air Quality Research, 21, 200416. https://doi.org/10.4209/aaqr.2020.07.0416, 2021.
  • Li, L. Q. Li, L. Huang, Q. Wang, A. Zhu, et al.: Air quality changes during the COVID-19 lockdown over the Yangtze River Delta Region: an insight into the impact of human activity pattern changes in air pollution variation. Science of the Total Environment 732, 139282, https://doi.org/10.1016/j.scitotenv.2020.139282, 2020.
  • Li, R., Zhao, Y., and Fu, H.: Substantial changes of gaseous pollutants and chemical compositions in fine particles in North China Plain during COVID-19 lockdown period: anthropogenic vs meteorological influences, Atmospheric Chemistry and Physics Discussions [preprint] https://doi.org/10.5194/acp-2020-1199, in review, 2021.
  • Li, Z., J. Meng, L. Zhou, R. Zhou, M. Fu, Y. Wang, Y. Yi, A. Song, Q. Guo, Z. Hou, L. Yan: Impact of the COVID-19 event on the characteristics of atmospheric signle particle in the Northern China. Aerosol and AIr Quality Research, https://doi.org/10.4209/aaqr.2020.06.0321, 2020.
  • Lian, X., J. Huang, R. Huang, C. Liu, L. Wang and T. Zhang: Impact of city lockdown on the air quality of COVID-19-hit of Wuhan city. Science of the Total Environment  742, 140556, https://doi.org/10.1016/j.scitotenv.2020.140556, 2020.
  • Lin, S., D. Wei, Y. Sun, K. Chen, L. Yang, B. Liu, Q. Huang, M. M. B. Paoliello, H. Li and S. Wu: Region-specific air pollutants and meteorological parameters influence COVID-19: A study from mainland China. Ecotoxicology and Environmental Safety, 204, 111035,  https://doi.org/10.1016/j.ecoenv.2020.111035, 2020.
  • Liu, F., A. Page, S. A. Strode, Y. Yoshida, S. Choi, B. Zheng, L. N. Lamsal, C. Li, N. A. Krotkov, H. Eskes, R. van der A, P. Veefkind, P. F. Levelt, O. P. Hauser, J. Joiner: Abrupt decline in tropospheric nitrogen dioxide over China after the outbreak of COVID-19. Science Advanceshttps://doi.org/10.1126/sciadv.abc2992, 2020.
  • Liu, Q., J. T. Harris, L. S. Chiu, D. Sun, P. R. Houser, M. Yu, D. Q. Duffy, M. M. Little, C. Yang: Spatiotemporal impacts of COVID-19 on air pollution in California, USA. Science of the Total Environment, 750, 141592, https://doi.org/10.1016/j.scitotenv.2020.141592, 2021.
  • Liu, Q., D. Sha, W. Liu, P. Houser, L. Zhang, R. Hou, H. Lan, C. Flynn, M. Lu, T. Hu and C. Yang: Spatiotemporal Patterns of COVID-19 Impact on Human Activities and Environment in Mainland China Using Nighttime Light and Air Quality Data. Remote Sensing, 12(10), 1576, https://doi.org/10.3390/rs12101576, 2020.
  • Liu, Y., S. Ni, T. Jiang, S. Xing, Y. Zhang, X. Bao, Z. Feng, X. Fan, L. Zhang and H. Feng: Influence of Chinese New Year overlapping COVID-19 lockdown on HONO sources in Shijiazhuang. Science of the Total Environment 745, 141025, https://doi.org/10.1016/j.scitotenv.2020.141025, 2020.
  • Liu, Z., P. Ciais, Z. Deng, R. Lei, S. J. Davis, S. Feng et al.: Near-real-time monitoring of global CO2 emissions reveals the effects of the COVID-19 pandemic. Nature Communications 11, 5172, https://doi.org/10.1038/s41467-020-18922-7, 2020.
  • Ljubenkov, I., S. Haddout, K. L. Priya, A. M. Hoguane: SARS-CoV-2 epidemic: changes in air quality during the lockdown in Zagreb (Republic of Croatia). Toxicological & Environmental Chemistry, https://doi.org/10.1080/02772248.2020.1778703, 2020.
  • Lv, Z. et al.: Source–Receptor Relationship Revealed by the Halted Traffic and Aggravated Haze in Beijing during the COVID-19 Lockdown. Environmental Science and Technology, 54 (24), https://doi.org/10.1021/acs.est.0c04941, 2020.
  • Lyon, D. R. et al.: Concurrent variation in oil and gas methane emissions and oil price during the COVID-19 pandemic, Atmospheric Chemistry and Physics Discussions [preprint] https://doi.org/10.5194/acp-2020-1175, in review, 2020.
  • Ma, C.-J., and G.-U. Kang: Air quality variation in Wuhan, Daegu, and Tokyo during the explosive outbreak of COVID-19 and its health effects. Environmental Research and Public Health, 17 (11), 4119, https://doi.org/10.3390/ijerph17114119, 2020.
  • Ma, J., Shen, J., Wang, P., Zhu, S., Wang, Y., Wang, P., Wang, G., Chen, J., and Zhang, H.: Changes in source contributions of particulate matter during COVID-19 pandemic in the Yangtze River Delta, China, Atmospheric Chemistry and Physics Discussions [preprint] https://doi.org/10.5194/acp-2020-953, in review, 2021.
  • Mendez-Espinosa, J. F., N. Y. Rojas, J. Varags, J. E. Pachón, L. C. Belalcazar and O. Ramírez: Air quality variations in Northern South America during the COVID-19 lockdownScience of the Total Environment, 749, 141621, https://doi.org/10.1016/j.scitotenv.2020.141621, 2020.
  • Menut, L., B. Bessagnet, G. Siour, S. Mailler, R. Pennel, A. Cholaklan: Impact of lockdown measures to combat Covid-19 on air quality in western Europe. Science of the Total Environment, 741 (140426), https://doi.org/10.1016/j.scitotenv.2020.140426, 2020.
  • Metiya, A., P. Dagupta, S. Halder, S. Chakraborty, Y. K. Tiwari: COVID-19 lockdowns imporve air quality in the South-East Asian regions, as seen by the remote sensing satellites. Aerosol Air Quality Research https://doi.org/10.4209/aaqr.2020.05.0240, 2020.
  • Mesas-Carracosa, F.-J., F. P. Porras, P. Trivino-Tarradas, A. Garcia-Ferrer, J. E. Merono-Larriva: Effect of lockdown measures on atmospheric nitrogen dioxide during SARS-CoV-2 in Spain. Remote Sensing, 12 (14), 2210, https://doi.org/10.3390/rs12142210, 2020.
  • Mishra, M., Kulshrestha, U.C.: A Brief Review on Changes in Air Pollution Scenario over South Asia during COVID-19 Lockdown. Aerosol Air Quality Research, https://doi.org/10.4209/aaqr.200541, 2021.
  • Mitra, A., T. R. Chaudhuri, A. Mitra, P. Pramanick, and S. Zaman: Impact of COVID-19 related shutdown on atmospheric carbon dioxide level in the city of Kolkata. Parana Journal of Science and Education, 6 (3), 84-92, 2020.
  • Miyazaki, K., K. Bowman, T. Sekiya, Z. Jiang, X. Chen, H. Eskes, M. Ru, Y. Zhang and D. Shindell: Air Quality Response in China Linked to the 2019 Novel Coronavirus (COVID-19) Lockdown. Geophysical Research Letters, 47, https://doi.org/10.1029/2020GL089252, 2020.
  • Mostafa, M. K., G. Gamal and A. Wafiq: The impact of COVID 19 on air pollution levels and other environmental indicators - A case study of Egypt. Journal of Environmental Management, 227, 111496, https://doi.org/10.1016/j.jenvman.2020.111496, 2021.
  • Nakada, L. Y. K. and R. C. Urban: COVID-19 pandemic: Impacts on the air quality during the partial lockdown in Sao Paulo state, Brazil. Science of the Total Environment, 730 (139087), https://doi.org/10.1016/j.scitotenv.2020.139087, 2020.
  • Navinya, C. G. Patidar, H. C. Phuleria: Examininf effects of the COVID-19 national lockdown on ambient air quality across urban India. Aerosol Air Quality Research https://doi.org/10.4209/aaqr.2020.05.0256, 2020.
  • Oo, T.K., Arunrat, N., Kongsurakan, P., Sereenonchai, S., Wang, C.: Nitrogen Dioxide (NO2) Level Changes during the Control of COVID-19 Pandemic in Thailand. Aerosol Air Quality Research, https://doi.org/10.4209/aaqr.200440, 2021.
  • Otmani, A., A. Benchrif, M. Tahri, M. Bounakhla, E. M. Chakir, M. El Bouch and M. Krombi: Impact of Covid-19 lockdown on PM10, SO2 and NO2 concentrations in Salé City (Morocco). Science of The Total Environment, 735 (139541), https://doi.org/10.1016/j.scitotenv.2020.139541, 2020.
  • Park, H., Jeong, S., Koo, J.H., Sim, S., Bae, Y., Kim, Y., Park, C., Bang, J.: Lessons from COVID-19 and Seoul: Effects of Reduced Human Activity from Social Distancing on Urban CO2 Concentration and Air Quality. Aerosol Air Quality Research 21, 200376. https://doi.org/10.4209/aaqr.2020.07.037, 2021.

  • Parker, H. A., Hasheminasseb, S., Crouse, J. D., Roehl, C. M., and Wennberg, P. O.: Impacts of traffic reductions associated with Covid-19 on Southern California air quality. Geophysical Research Letters, https://doi.org/10.1029/2020GL090164, 2020.
  • Pei, S., Dahl, K. A., Yamana, T. K., Licker, R., & Shaman, J.: Compound risks of hurricane evacuation amid the COVID-19 pandemic in the United States. GeoHealth, 4. https://doi.org/10.1029/2020GH000319, 2020.
  • Petetin, H., Bowdalo, D., Soret, A., Guevara, M., Jorba, O., Serradell, K., and Pérez García-Pando, C.: Meteorology-normalized impact of the COVID-19 lockdown upon NO2 pollution in Spain. Atmospheric Chemistry and Physics, 20, 11119–11141, https://doi.org/10.5194/acp-20-11119-2020, 2020.
  • Piccoli, A. et al.: Modeling the Effect of COVID-19 Lockdown on Mobility and NO2 Concentration in the Lombardy Region. Atmosphere, 11(12), 1319, https://doi.org/10.3390/atmos11121319, 2020.
  • Qiu, Y., Ma, Z., Li, K., Lin, W., Tang, Y., Dong, F. and Liao, H.: Markedly enhanced levels of peroxyacetyl nitrate (PAN) during COVID-19 in Beijing. Geophysical Research Letters, 47,e2020GL089623. https://doi.org/10.1029/2020GL089623, 2020.
  • Razzaq, A., A. Sharif, N. Aziz, M. Irfan and K. Jermsittiparsert: Asymmetric link between environmental pollution and COVID-19 in the top ten affected states of US: A novel estimations from quantile-on-quantile approachEnvironmental Research, 191, 110189, https://doi.org/10.1016/j.envres.2020.110189, 2020.
  • Represa, N.S., Della Ceca, L.S., Abril, G., García Ferreyra, M.F., Scavuzzo, C.M.: Atmospheric Pollutants Assessment during the COVID-19 Lockdown Using Remote Sensing and Ground-based Measurements in Buenos Aires, Argentina. Aerosol Air Quality Research, https://doi.org/10.4209/aaqr.2020.07.0486, 2021.
  • Rodriguez-Urrego, D., and L. Rodriguez-Urrego: Air quality during the COVID-19: PM2.5 analysis in the 50 most polluted capital cities in the world. Environmental Pollution 266, 115042, https://doi.org/10.1016/j.envpol.2020.115042, 2020.
  • Roman-Gonzalez et al.: Air Pollution Monitoring in Peru Using Satellite Data During the Quarantine Due to COVID-19. IEEE Aerospace and Electronic Systems Magazine, 35 (12), DOI: 10.1109/MAES.2020.3018895, 2020.
  • Roșu A, Constantin D-E, Voiculescu M, Arseni M, Roșu B, Merlaud A, Van Roozendael M, Georgescu PL. Assessment of NO2 Pollution Level during the COVID-19 Lockdown in a Romanian City. International Journal of Environmental Research and Public Health, 18(2):544. https://doi.org/10.3390/ijerph18020544, 2021.
  • Safarian, S., R. Unnthorsson, C. Richter: Effect of Coronavirus Disease 2019 on CO2 Emission in the World. Aerosol Air Quality Research, 20: 1197–1203. https://doi.org/10.4209/aaqr.2020.0.0151, 2020.
  • Sahin, U. A.: The Effects of COVID-19 Measures on Air Pollutant Concentrations at Urban and Traffic Sites in Istanbul. Aerosol and Air Quality Research, 20, https://doi.org/10.4209/aaqr.2020.05.0239, 2020.
  • Salini et al.: Probable Relationship between COVID-19, Pollutants and Meteorology: A Case Study at Santiago, Chile. Aerosol Air Quality Research, https://doi.org/10.4209/aaqr.200434, 2021.
  • Salma, I. et al.: What can we learn about urban air quality with regard to the first outbreak of the COVID-19 pandemic? A case study from central Europe.
    Atmospheric Chemistry and Physics, 20, 15725–15742, https://doi.org/10.5194/acp-20-15725-2020, 2020.
  • Sannino, A., D’Emilio, M., Castellano, P., Amoruso, S., Boselli, A.: Analysis of Air Quality during the COVID-19 Pandemic Lockdown in Naples (Italy). Aerosol Air Quality Research, 21, 200381. https://doi.org/10.4209/aaqr.2020.07.0381, 2021.
  • Sarfraz, M., K. Shehzad and A. Farid: Gauging the air quality of New York: a non-linear Nexus between COVID-19 and nitrogen dioxide emission. Air Quality, Atmosphere and Health, 13, https://doi.org/10.1007/s11869-020-00870-2, 2020.
  • Schumann, U., Poll, I., Teoh, R., Koelle, R., Spinielli, E., Molloy, J., Koudis, G. S., Baumann, R., Bugliaro, L., Stettler, M., and Voigt, C.: Air traffic and contrail changes during COVID-19 over Europe: A model study, Atmospheric Chemistry and Physics Discussions [preprint] https://doi.org/10.5194/acp-2021-62, in review, 2021.
  • Shakoor, A., X. Chen, T. H. Farooq, U. Shahzad, F. Ashraf, A. Rehman, N. e Sahar and W. Yan: Fluctuations in environmental pollutants and air quality during the lockdown in the USA and China: two sides of COVID-19 pandemic. Air Quality, Atmosphere and Health, https://doi.org/10.1007/s11869-020-00888-6, 2020.
  • Sharma, M., S. Jain and B. Y. Lamba: Epigrammatic study on the effect of lockdown amid Covid-19 pandemic on air quality of most polluted cities of Rajasthan (India)Air Quality, Atmosphere and Health, 13, https://doi.org/10.1007/s11869-020-00879-7, 2020.
  • Sharma, S., M. Zhang, Anshika, J. Gao, H. Zhang, S. H. Kota: Effect of restricted emissions during COVID-19 on air quality in India. Science of the Total Environment, 728 (138878), https://doi.org/10.1016/j.scitotenv.2020.138878, 2020.
  • Shi, X. and  G. P. Brasseur: The response in air quality to the reduction of Chinese Economic Activities during the COVID-19 Outbreak. Geophysical Research Letters, https://doi.org/10.1029/2020GL088070, 2020.
  • Sicard, P., A. De Marco, E. Agathokleous, Z. Feng, X. Xu, E. Paoletti, J. J. D. Rodriguez and V. Calatayud: Amplified ozone pollution in cities during the COVID-19 lockdown. Science of the Total Environment, 735 (139542), https://doi.org/10.1016/j.scitotenv.2020.139542, 2020.
  • Siciliano, B., G. Carvalho, C. M. da Silva, G. Arbilla: The impact of COVID-19 partial lockdown on primary pollutant concentrations in the atmosphere of Rio de Janeiro and Sao Paulo megacities (Brazil). Bulletin of Environmental Contamination and Toxicology 105, 2-8, https://doi.org/10.1007/s00128-020-02907-9, 2020.
  • Siciliano, B., G. Dantas, C. M. da Silva and G. Arbilla: Increased ozone levels during the COVID-19 lockdown: Analysis for the city of Rio de Janeiro, Brazil. Science of the Total Environment, 737, 139765, https://doi.org/10.1016/j.scitotenv.2020.139765, 2020.
  • Siddiqui, A., S. Halder, P. Chauhan and P. Kumar: COVID-19 Pandemic and City-Level Nitrogen Dioxide (NO2) Reduction for Urban Centres of India. Journal of the Indian Society of Remote Sensing, 48, https://doi.org/10.1007/s12524-020-01130-7, 2020.
  • Silver, B., X. He, S. R. Arnold and D. V. Spracklen: The impact of COVID-19 control measures on air quality in China. Environmental Research Letters, 15 084021, https://doi.org/10.1088/1748-9326/aba3a2, 2020.
  • Singh, J., Tyagi, B.: Transformation of Air Quality over a Coastal Tropical Station Chennai during COVID-19 Lockdown in India. Aerosol Air Quality Research, https://doi.org/10.4209/aaqr.200490, 2021.
  • Singh, V. S. Singh, A. Biswal, A. P. Kesarkar, S. Mor, and K. Ravindra: Diurnal and temporal changes in air pollution during Covid-19 strict locldown over different regions in India. Environmental Pollution, 266, 115368, https://doi.org/10.1016/j.envpol.2020.115368, 2020.
  • Soni, M., Verma, S., Jethava, H., Payra, S., Lamsal, L., Gupta, P., Singh, J.: mpact of COVID-19 on the Air Quality over China and India Using Long-term (2009-2020) Multi-Satellite Data. Aerosol Air Quality Research, https://doi.org/10.4209/aaqr.2020.06.0295, 2020.
  • Su, M., S. Peng, L. Chen, B. Wang, Y. Wang, X. Fan and Z. Dong: A warm summer is unlikely to stop transmission of COVID-19 naturally. GeoHealth, https://doi.org/10.1029/2020GH000292, 2020.
  • Su, T., Z. Li, Y. Zheng, Q. Luan and J. Guo: Abnormally Shallow Boundary Layer Associated With Severe Air Pollution During the COVID‐19 Lockdown in China. Geophysical Research Letters, 47, https://doi.org/10.1029/2020GL090041, 2020.
  • Suhaimi, N.F., Jalaludin, J. and Latif, M.T.: Demystifying a Possible Relationship between COVID-19, Air Quality and Meteorological Factors: Evidence from Kuala Lumpur, Malaysia. Aerosol Air Quality Research 20: 1520–1529. https://doi.org/10.4209/aaqr.2020.05.0218, 2020.
  • Sun, W. et al.: Global Significant Changes in Formaldehyde (HCHO) Columns Observed from Space at the Early Stage of the COVID‐19 Pandemic. Geophysical Research Lettershttps://doi.org/10.1029/2020GL091265, 2021.
  • Sun, Y., L. Lei, W. Zhou, C. Chen, Y. He, J. Sun, Z. Li, W. Xu, Q. Wang, D. Ji, P. Fu, Z. Wang and D. R. Worsnop: A chemical cocktail during the COVID-19 outbreak in Beijing, China: Insights from six-year aerosol particle composition measurements during the Chinese New Year holiday. Science of the Total Environment, 742 (140739), https://doi.org/10.1016/j.scitotenv.2020.140739, 2020.
  • Sussmann, R. and M. Rettinger: Can We Measure a COVID-19-Related Slowdown in Atmospheric CO2 Growth? Sensitivity of Total Carbon Colomn Observations. Remote Sensing, 12(15), 2387, https://doi.org/10.3390/rs12152387, 2020.
  • Tanvir, A. et al.: Tropospheric NO2 and HCHO During COVID-19 Lockdown and Spring Festival Over Shanghai, China. Remote Sensing, 13(3), 488, https://doi.org/10.3390/rs13030488, 2021.
  • Tanzer-Gruener, R., J. Li, S. R. Eilenberg, A. L. Robinson and A. A. Presto: Impacts of Modifiable Factors on Ambient Air Pollution: A Case Study of COVID-19 ShutdownsEnvironmental Science & Technology Letters, 7,  https://doi.org/10.1021/acs.estlett.0c00365, 2020.
  • Topping, D., Watts, D., Coe, H., Evans, J., Bannan, T. J., Lowe, D., Jay, C., and Taylor, J. W.: Evaluating the use of Facebook's Prophet model v0.6 in forecasting concentrations of NO2 at single sites across the UK and in response to the COVID-19 lockdown in Manchester, England. Geoscientific Model Development Discussions [preprint], https://doi.org/10.5194/gmd-2020-270, in review, 2020.
  • Travaglio, M., Y. Yizhou, R. Popovic, L. Selley, N. Santos Leal, L. Miguel Martins: Links between air pollution and COVID-19 in England, Environmental Pollution, 268, https://doi.org/10.1016/j.envpol.2020.115859, 2021.
  • Turner, A. J., Kim, J., Fitzmaurice, H., Newman, C., Worthington, K., Chan, K., et. al.: Observed impacts of COVID-19 on urban CO2 emissions. Geophysical Research Letters, 47, e2020GL090037. https://doi.org/10.1029/2020GL090037, 2020.
  • Velásquez, R. M. A. and J. V. M. Lara: Gaussian approach for probability and correlation between the number of COVID-19 cases and the air pollution in Lima. Urban Climate, 33, 100664, https://doi.org/10.1016/j.uclim.2020.100664, 2020
  • Venkat Ratnam, M., Prasad, P., Akhil Raj, S.T., Hoteit, I.: Effect of Lockdown due to COVID-19 on the Aerosol and Trace Gases Spatial Distribution over India and Adjoining Regions. Aerosol Air Quality Research, 21, 200397, https://doi.org/10.4209/aaqr.2020.07.0397, 2021.
  • Venter, Z.S., K. Aunan, S. Chowdhury, and J. Lelieveld:CIVID-19 lockdowns cause global air pollution declines. Proceedings of the National Academy of Sciences of the United States of America (PNAS),
  • Wang, Y. Y. Yuan, Q. Wang, C. Liu, Q. Zhi, and J. Cao: Changes in air quality related to the control of coronavirus in China: Implications for traffic and industrial emissions. Science of the Total Environment, 731 (139133), https://doi.org/10.1016/j.scitotenv.2020.139133, 2020.
  • Wang, L., M. Li, S. Yu, X. Chen, Z. Li, Y. Zhang, L. Jiang, Y. Xia, J. Li, W. Liu, P. Li, E. Lichtfouse, D. Rosenfeld, J. Seinfeld: Unexpected rise of ozone in urban and rural areas, and sulfur dioxide in rural areas during the coronavirus city lockdown in Hangzhou, China: implications for air quality. Environmental Chemistry Letters, https://doi.org/10.1007/s10311-020-01028-3, 2020.
  • Wang, P., K. Chen, S. Zhu, P. Wang, and H. Zhang: Severe air pollution events not avoided by reduced anthropogenic activities during COVID-19 outbreak. Resources, Conservation and Recycling, 158 (104814), https://doi.org/10.1016/j.resconrec.2020.104814, 2020.
  • Wang, W., van der A, R., Ding, J., van Weele, M., and Cheng, T.: Spatial and temporal changes of the ozone sensitivity in China based on satellite and ground-based observations. Atmospheric Chemistry and Physics Discussions [preprint] https://doi.org/10.5194/acp-2020-1097, in review, 2020.
  • Wang, Y., Y. Wen, Y. Wang, S. Zhang, K. M. Zhang, H. Zheng, J. Xing, Y. Wu and J. Hao: Four-Month Changes in Air Quality during and after the COVID-19 Lockdown in Six Megacities in China. Environmental Science & Technology Letters, https://doi.org/10.1021/acs.estlett.0c00605, 2020.
  • Weber, J., Shin, Y. M., Staunton Sykes, J., Archer-Nicholls, S., Abraham, N. L. & Archibald, A. T.: Minimal climate impacts from short-lived climate forcers following emission reductions related to the COVID-19 pandemic. Geophysical Research Letters, 47, e2020GL090326. https://doi.org/10.1029/2020GL090326, 2020.
  • Wu, S. et al.: Spatiotemporal mapping and assessment of daily ground NO2 concentrations in China using high-resolution TROPOMI retrievals. Environmental Pollution, 273,116456, https://doi.org/10.1016/j.envpol.2021.116456, 2021.
  • Wu, X. et al.: Air pollution and COVID-19 mortality in the United States: Strengths and limitations of an ecological regression analysis. Science Advances, 6 (45), DOI: 10.1126/sciadv.abd4049, 2020.
  • Xing, J., Li, S., Jiang, Y., Wang, S., Ding, D., Dong, Z., Zhu, Y., and Hao, J.: Quantifying the emission changes and associated air quality impacts during the COVID-19 pandemic on the North China Plain: a response modeling study. Atmospheric Chemistry and Physics, 20, 14347–14359, https://doi.org/10.5194/acp-20-14347-2020, 2020.
  • Xu, J., Ge, X., Zhang, X., Zhao, W.,Zhang, R., & Zhang, Y.: COVID-19 impact on the concentration and composition of submicron particulate matter in a typical city of Northwest China. Geophysical Research Letters, 47, e2020GL089035 . https://doi.org/10.1029/2020GL089035, 2020.
  • Xu K., Cui, K., Young, L.H., Wang, Y.F., Hsieh, Y.K., Wan, S. and Zhang, J.: Air Quality Index, Indicatory Air Pollutants and Impact of COVID-19 Event on the Air Quality near Central China. Aerosol Air Quality Research 20: 1204–1221. https://doi.org/10.4209/aaqr.2020.04.0139, 2020.
  • Xu, L., Zhang, J., Sun, X., Xu, S., Shan, M., Yuan, Q., et al.: Variation in Concentration and Sources of Black Carbon in a Megacity of China during the COVID-19 pandemic. Geophysical Research Letters, 47. https://doi.org/10.1029/2020GL090444, 2020.
  • Yang, Y., L. Ren, H. Li, H. Wang, P. Wang, L. Chen, X. Yue and H. Liao: Fast Climate Responses to Aerosol Emission Reductions During the COVID‐19 Pandemic. Geophysical Research Letters 47, https://doi.org/10.1029/2020GL089788, 2020.
  • Yin Z. et al.: Evident PM2.5 drops in the east of China due to the COVID-19 quarantine measures in February. Atmospheric Chemistry and Physics, 21, 1581–1592, https://doi.org/10.5194/acp-21-1581-2021, 2021.
  • You, Y. and Pan, S.: Urban vegetation slows down the spread of coronavirus disease (COVID-19) in the United States. Geophysical Research Letters, 47, e2020GL089286. https://doi.org/10.1029/2020GL089286, 2020.
  • Yuan, Q., B. Qi, D. Hu, J. Wang, J. Zhang, H. Yang, S. Zhang, L. Liu, L. Xu and W. Li: Spatiotemporal variations and reduction of air pollutants during the COVID-19 pandemic in a megacity of Yangtze River Delta in China. Science of the Total Environment, 751, 141820, https://doi.org/10.1016/j.scitotenv.2020.141820, 2021.
  • Zalakuviciute, R., R. Vasquez, D. Bayas, A. Buenano, D. Mejia, R. Zegarra, A. Diaz, B. Lamb: Drastic improvements in air quality in Ecuador during the COVID-19 outbreak. Aerosol Air Quality Research 20: 1204–1221. https://doi.org/10.4209/aaqr.2020.05.0254, 2020.
  • Zambrano-Monserrate, M. A. Ruano: Has air quality improved in Ecuador during the COVID-19 pandemic? A parametric analysis. Air Quality, Atmosphere and Health 13, 929-938, https://doi.org/10.1007/s11869-020-00866-y, 2020.
  • Zhang, J., K. Cui, Y. Wang, J.-L. Wu, W.-S. Huang, S. Wan, K. Xu: Temporal variations in the air quality index and the impact of the COVID-19 event on air quality in Western China. Aerosol Air Quality Research 20: 1552–1568, https://doi.org/10.4209/aaqr.2020.06.0297, 2020.
  • Zhang, L., Yang, L., Zhou, Q., Zhang, X., Xing, W., Zhang, H., Toriba, A., Hayakawa, K. and Tang, N.: Impact of the COVID-19 Outbreak on the Long-range Transport of Particulate PAHs in East Asia. Aerosol Air Quality Research 20: 2035–2046. https://doi.org/10.4209/aaqr.2020.07.0388, 2020.
  • Zhang, M., A. Katiyar, S. Zhu, J. Shen, M. Xia, J. Ma, S. H. Kota, P. Wang and H. Zhang: Impact of reduced anthropogenic emissions during COVID-19 on air quality in India. Atmospheric Chemistry and Physics, https://doi.org/10.5194/acp-2020-903, 2020.
  • Zhang, R., Y. Zhang, H. Lin, X. Feng, T.-M. Fu, and Y. Wang: NOx Emission Reduction and Recovery during COVID-19 in East China. Atmosphere, 11 (4), 433, https://doi.org/10.3390/atmos11040433, 2020.
  • Zhang, Z., T. Xue and X. Jin: Effects of meteorological conditions and air pollution on COVID-19 transmission: Evidence from 219 Chinese citiesScience of the Total Environment 741 (140244), https://doi.org/10.1016/j.scitotenv.2020.140244, 2020.
  • Zhao, N., G. Wang, G. Li, J. Lang and H. Zhang: Air pollution episodes during the COVID-19 outbreak in the Beijing–Tianjin–Hebei region of China: An insight into the transport pathways and source distributionEnvironmental Pollution 267, 115617, https://doi.org/10.1016/j.envpol.2020.115617, 2020.
  • Zhao, Y., K. Zhang, X. Xu, H. Shen, X. Zhu, Y. Zhang, Y. Hu, and G. Shen: Substantial changes in nitrogen dioxide and ozone after excluding meteorological impacts during the COVID-19 outbreak in mainland China. Environmental Science and Technology Letters, https://doi.org/10.1021/acs.estlett.0c00304, 2020.
  • Zheng, B., Zhang, Q., Geng, G., Shi, Q., Lei, Y., and He, K.: Changes in China's anthropogenic emissions during the COVID-19 pandemic. Earth System Science Data Discussions [preprint] https://doi.org/10.5194/essd-2020-355, in review, 2020.
  • Zheng, H., S. Kong, N. Chen, Y. Yan, D. Liu, B. Zhu, K. Xu, W. Cao, Q. Ding, B. Lan, Z. Zhang, M. Zheng, Z. Fan, Y. Cheng, S. Zheng, L. Yao, Y. Bai, T. Zhao and S. Qi: Significant changes in the chemical compositions and sources of PM2.5 in Wuhan since the city lockdown as COVID-19. Science of the Total Environment 739 (140000), https://doi.org/10.1016/j.scitotenv.2020.140000, 2020.
  • Zhu, S., Q. Wang, L. Qiao, M. Zhou, S. Wang, S. Lou, D. Huang, Q. Wang, S. Jing, H. Wang, C. Chen, C. Huang and J. Z. Yu: Tracer-based Characterization of Source Variations of PM2.5 and Organic Carbon in Shanghai Influenced by the COVID-19 Lockdown. Faraday Discussions, https://doi.org/10.1039/D0FD00091D, 2020.
  •  Zhu, Y., J. Xie, F. Huang, L. Cao: Association between short-term exposure to air pollution and COVID-19 infection: Evidence from China. Science of the Total Environment, 727, 138704, https://doi.org/10.1016/j.scitotenv.2020.138704, 2020.
  • Zoran, M. R. Savastru, D. M. Savastru, M. N. Tautan: Assessing the relationship between surface levels of PM2.5 and PM10 particulate matter impact on COVID-19 in Milan, Italy. Science of the Total Environment, 738 (139825), https://doi.org/10.1016/j.scitotenv.2020.139825, 2020.