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1. A synergistic ozone-climate control to address emerging ozone pollution challenges

Author

Lyu, Xiaopu, Li, Ke, Guo, Hai, Morawska, Lidia, Zhou, Beining, Zeren, Yangzong, Jiang, Fei, Chen, Changhong, Goldstein, Allen H., Xu, Xiaobin, Wang, Tao, Lu, Xiao, Zhu, Tong, Querol, Xavier, Chatani, Satoru, Latif, Mohd Talib, Schuch, Daniel, Sinha, Vinayak, Kumar, Prashant, Mullins, Benjamin, Seguel, Rodrigo, Shao, Min, Xue, Likun, Wang, Nan, Chen, Jianmin, Gao, Jian, Chai, Fahe, Simpson, Isobel, Sinha, Baerbel, and Blake, Donald R.

Published
2023
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3. Tropospheric ozone precursors: global and regional distributions, trends, and variability.

Author

Elshorbany, Yasin, Ziemke, Jerald R., Strode, Sarah, Petetin, Hervé, Miyazaki, Kazuyuki, De Smedt, Isabelle, Pickering, Kenneth, Seguel, Rodrigo J., Worden, Helen, Emmerichs, Tamara, Taraborrelli, Domenico, Cazorla, Maria, Fadnavis, Suvarna, Buchholz, Rebecca R., Gaubert, Benjamin, Rojas, Néstor Y., Nogueira, Thiago, Salameh, Thérèse, and Huang, Min

Abstract

Tropospheric ozone results from in situ chemical formation and stratosphere–troposphere exchange (STE), with the latter being more important in the middle and upper troposphere than in the lower troposphere. Ozone photochemical formation is nonlinear and results from the oxidation of methane and non-methane hydrocarbons (NMHCs) in the presence of nitrogen oxide (NO x= NO + NO2). Previous studies showed that O3 short- and long-term trends are nonlinearly controlled by near-surface anthropogenic emissions of carbon monoxide (CO), volatile organic compounds (VOCs), and nitrogen oxides, which may also be impacted by the long-range transport (LRT) of O3 and its precursors. In addition, several studies have demonstrated the important role of STE in enhancing ozone levels, especially in the midlatitudes. In this article, we investigate tropospheric ozone spatial variability and trends from 2005 to 2019 and relate 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 (TrC-O3) and its precursors, nitrogen dioxide (TrC-NO2), formaldehyde (TrC-HCHO), and total column CO (TC-CO), as well as ozonesonde data and model simulations. Our results indicate a complex relationship between tropospheric ozone column levels, surface ozone levels, and ozone precursors. While the increasing trends of near-surface ozone concentrations can largely be explained by variations in VOC and NOx concentration under different regimes, TrC-O3 may also be affected by other variables such as tropopause height and STE as well as LRT. Decreasing or increasing trends in TrC-NO2 have varying effects on TrC-O3, which is related to the different local chemistry in each region. We also shed light on the contribution of NOx lightning and soil NO and nitrous acid (HONO) emissions to trends of tropospheric ozone on regional and global scales. [ABSTRACT FROM AUTHOR]

Published
2024
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6. Changes in South American surface ozone trends: exploring the influences of precursors and extreme events.

Author

Seguel, Rodrigo J., Castillo, Lucas, Opazo, Charlie, Rojas, Néstor Y., Nogueira, Thiago, Cazorla, María, Gavidia-Calderón, Mario, Gallardo, Laura, Garreaud, René, Carrasco-Escaff, Tomás, and Elshorbany, Yasin

Abstract

In this study, trends of 21st-century ground-level ozone and ozone precursors were examined across South America, a less-studied region where trend estimates have rarely been comprehensively addressed. Therefore, we provided an updated regional analysis based on validated surface observations. We tested the hypothesis that the recent increasing ozone trends, mostly in urban environments, resulted from intense wildfires driven by extreme meteorological events impacting cities where preexisting volatile organic compound (VOC)-limited regimes dominate. We applied the quantile regression method based on monthly anomalies to estimate trends, quantify their uncertainties and detect trend change points. Additionally, the maximum daily 8 h average (MDA8) and peak-season metrics were used to assess short- and long-term exposure levels, respectively, for the present day (2017–2021). Our results showed lower levels in tropical cities (Bogotá and Quito), varying between 39 and 43 nmol mol -1 for short-term exposure and between 26 and 27 nmol mol -1 for long-term exposure. In contrast, ozone mixing ratios were higher in extratropical cities (Santiago and São Paulo), with a short-term exposure level of 61 nmol mol -1 and long-term exposure levels varying between 40 and 41 nmol mol -1. Santiago (since 2017) and São Paulo (since 2008) exhibited positive trends of 0.6 and 0.3 nmol mol -1 yr -1 , respectively, with very high certainty. We attributed these upward trends, or no evidence of variation, such as in Bogotá and Quito, to a well-established VOC-limited regime. However, we attributed the greater increase in the extreme percentile trends (≥ 90th) to heat waves and, in the case of southwestern South America, to wildfires associated with extreme meteorological events. [ABSTRACT FROM AUTHOR]

Published
2024
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8. Predicting Stock Prices Using Neural Models Based on Financial Textual Information.

Author

Alvarez, Pablo, Morales, Andrés, Seguel, Rodrigo, and Atkinson, John

Subjects
STOCK prices, STOCK exchanges, MACHINE learning, SOCIAL media, INVESTMENTS
Abstract

The investment market has evolved with the integration of information technologies and the creation of new assets and strategies. Machine learning techniques have been used in finance to develop efficient applications. Furthermore, social media platforms have a significant impact on the market, with studies showing a strong correlation between stock prices and opinions on social media. Hence, machine learning techniques have been used to predict stock behavior based on the implicit sentiment in social media opinions. Accordingly, this article proposes a combined model for stock price prediction that uses natural language processing techniques and neural time-series prediction models based on long short-term memory. The approach combines stock price data from a week with related social media sentiments and uses natural language processing techniques based on pretrained transformers for the financial sector and predictors based on long short-term memory networks. Additionally, a convolutional neural network–based classifier is designed to analyze sentiments and determine a bullish or bearish factor based on polarity. The experiments with real stocks from the NYSE demonstrate that polarity prediction can improve stock price prediction by 26% compared to traditional predictive models. [ABSTRACT FROM AUTHOR]

Published
2024
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12. A synergistic ozone-climate control to address emerging ozone pollution challenges

Author

0000-0002-7996-7294, Lyu, Xiaopu, Li, Ke, Guo, Hai, Morawska, Lidia, Zhou, Beining, Zeren, Yangzong, Jiang, Fei, Chen, Changhong, Goldstein, Allen H., Xu, Xiaobin, Wang, Tao, Lu, Xiao, Zhu, Tong, Querol, Xavier, Chatani, Satoru, Latif, Mohd Talib, Schuch, Daniel, Sinha, Vinayak, Kumar, Prashant, Mullins, Benjamin, Seguel, Rodrigo, Shao, Min, Xue, Likun, Wang, Nan, Chen, Jianmin, Gao, Jian, Chai, Fahe, Simpson, Isobel, Sinha, Baerbel, Blake, Donald R., 0000-0002-7996-7294, Lyu, Xiaopu, Li, Ke, Guo, Hai, Morawska, Lidia, Zhou, Beining, Zeren, Yangzong, Jiang, Fei, Chen, Changhong, Goldstein, Allen H., Xu, Xiaobin, Wang, Tao, Lu, Xiao, Zhu, Tong, Querol, Xavier, Chatani, Satoru, Latif, Mohd Talib, Schuch, Daniel, Sinha, Vinayak, Kumar, Prashant, Mullins, Benjamin, Seguel, Rodrigo, Shao, Min, Xue, Likun, Wang, Nan, Chen, Jianmin, Gao, Jian, Chai, Fahe, Simpson, Isobel, Sinha, Baerbel, and Blake, Donald R.

Abstract

Tropospheric ozone threatens human health and crop yields, exacerbates global warming, and fundamentally changes atmospheric chemistry. Evidence has pointed toward widespread ozone increases in the troposphere, and particularly surface ozone is chemically complex and difficult to abate. Despite past successes in some regions, a solution to new challenges of ozone pollution in a warming climate remains unexplored. In this perspective, by compiling surface measurements at ∼4,300 sites worldwide between 2014 and 2019, we show the emerging global challenge of ozone pollution, featuring the unintentional rise in ozone due to the uncoordinated emissions reduction and increasing climate penalty. On the basis of shared emission sources, interactive chemical mechanisms, and synergistic health effects between ozone pollution and climate warming, we propose a synergistic ozone-climate control strategy incorporating joint control of ozone and fine particulate matter. This new solution presents an opportunity to alleviate tropospheric ozone pollution in the forthcoming low-carbon transition.

Published
2023

13. Surface ozone trends and precursor attribution in South America

Author

Seguel, Rodrigo, primary, Castillo, Lucas, additional, Opazo, Charlie, additional, Rojas, Néstor, additional, Nogueira, Thiago, additional, Cazorla, María, additional, Gavidia, Mario, additional, Gallardo, Laura, additional, Elshorbany, Yasin, additional, and Menares, Camilo, additional

Published
2023
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16. A global observational analysis to understand changes in air quality during exceptionally low anthropogenic emission conditions

Author

Sokhi, Ranjeet S., Singh, Vikas, Querol, Xavier, Finardi, Sandro, Targino, Admir Créso, Andrade, Maria de Fatima, Pavlovic, Radenko, Garland, Rebecca M., Massagué, Jordi, Kong, Shaofei, Baklanov, Alexander, Ren, Lu, Tarasova, Oksana, Carmichael, Greg, Peuch, Vincent-Henri, Anand, Vrinda, Arbilla, Graciela, Badali, Kaitlin, Beig, Gufran, Belalcazart, Luis Carlos, Bolignano, Andrea, Brimblecombe, Peter, Camacho, Patricia, Casallas, Alejandro, Charland, Jean-Pierre, Choi, Jason, Chourdakis, Eleftherios, Coll, Isabelle, Collins, Marty, Cyrys, Josef, Cleyton, Martins, da Silva, Cleyton Martins, Di Giosa, Alessandro Domenico, Di Leo, Anna, Ferro, Camilo, Gavidia-Calderon, Mario, Gayen, Amiya, Ginzburg, Alexander, Godefroy, Fabrice, Gonzalez, Yuri Alexandra, Guevara-Luna, Marco, Haque, Mafizul, Havenga, Henno, Herod, Dennis, Horrak, Urmas, Hussein, Tareq, Ibarra, Sergio, Jaimes, Monica, Kaasik, Marko, Khaiwal, Ravindra, Kim, Jhoon, Kousa, Anu, Kukkonen, Jaakko, Kulmala, Markku, Kuula, Joel, La Violette, Nathalie, Lanzani, Guido, Liu, Xi, MacDougall, Stephanie, Manseau, Patrick M., Marchegiani, Giada, McDonald, Brian, Vardhan Mishra, Swasti, Molina, Luisa T., Mooibroek, Dennis, Mor, Suman, Moussiopoulos, Nicolas, Murena, Fabio, Niemi, Jarkko V., Noe, Steffen, Nogueira, Thiago, Norman, Michael, Pérez-Camaño, Juan Luis, Petajä, Tuukka, Piketh, Stuart, Rathod, Aditi, Reid, Ken, Retama, Armando, Rivera, Olivia, Rojas, Néstor Y., Rojas Quincho, Jhojan Pool, San José, Roberto, Sanchez, Odón R., Seguel, Rodrigo J., Sillanpää, Salla, Su, Yushan, Tapper, Nigel, Terrazas, Antonio, Timonen, Hilkka, Toscano, Domenico, Tsegas, George, Velders, Guus J.M., Vlachokostas, Christos, von Schneidemesser, Erika, VpM, Rajasree, Ravi, Yadav, Zalakeviciute, Rasa, Zavala, Miguel, Querol, Xavier, Air quality research group, Institute for Atmospheric and Earth System Research (INAR), Querol, Xavier [0000-0002-6549-9899], Sokhi, Ranjeet S, Singh, Vika, Finardi, Sandro, Targino, Admir Créso, Andrade, Maria de Fatima, Pavlovic, Radenko, Garland, Rebecca M, Massagué, Jordi, Kong, Shaofei, Baklanov, Alexander, Ren, Lu, Tarasova, Oksana, Carmichael, Greg, Peuch, Vincent-Henri, Anand, Vrinda, Arbilla, Graciela, Badali, Kaitlin, Beig, Gufran, Belalcazar, Luis Carlo, Bolignano, Andrea, Brimblecombe, Peter, Camacho, Patricia, Casallas, Alejandro, Charland, Jean-Pierre, Choi, Jason, Chourdakis, Eleftherio, Coll, Isabelle, Collins, Marty, Cyrys, Josef, da Silva, Cleyton Martin, Di Giosa, Alessandro Domenico, Di Leo, Anna, Ferro, Camilo, Gavidia-Calderon, Mario, Gayen, Amiya, Ginzburg, Alexander, Godefroy, Fabrice, Gonzalez, Yuri Alexandra, Guevara-Luna, Marco, Haque, Sk Mafizul, Havenga, Henno, Herod, Denni, Hõrrak, Urma, Hussein, Tareq, Ibarra, Sergio, Jaimes, Monica, Kaasik, Marko, Khaiwal, Ravindra, Kim, Jhoon, Kousa, Anu, Kukkonen, Jaakko, Kulmala, Markku, Kuula, Joel, La Violette, Nathalie, Lanzani, Guido, Liu, Xi, Macdougall, Stephanie, Manseau, Patrick M, Marchegiani, Giada, Mcdonald, Brian, Mishra, Swasti Vardhan, Molina, Luisa T, Mooibroek, Denni, Mor, Suman, Moussiopoulos, Nicola, Murena, Fabio, Niemi, Jarkko V, Noe, Steffen, Nogueira, Thiago, Norman, Michael, Pérez-Camaño, Juan Lui, Petäjä, Tuukka, Piketh, Stuart, Rathod, Aditi, Reid, Ken, Retama, Armando, Rivera, Olivia, Rojas, Néstor Y, Rojas-Quincho, Jhojan P, San José, Roberto, Sánchez, Odón, Seguel, Rodrigo J, Sillanpää, Salla, Su, Yushan, Tapper, Nigel, Terrazas, Antonio, Timonen, Hilkka, Toscano, Domenico, Tsegas, George, Velders, Guus J M, Vlachokostas, Christo, von Schneidemesser, Erika, Vpm, Rajasree, Yadav, Ravi, Zalakeviciute, Rasa, Zavala, Miguel, and Universitat Politècnica de Catalunya. Doctorat en Recursos Naturals i Medi Ambient

Subjects
010504 meteorology & atmospheric sciences, Air pollution, Sulphur dioxide, 010501 environmental sciences, medicine.disease_cause, Atmospheric sciences, NO2, 01 natural sciences, COVID-19 (Malaltia), COVID-19 (Disease), Environmental Science(all), 11. Sustainability, Environmental monitoring, Ozó atmosfèric, GE1-350, COVID-19 LOCKDOWN, Carbon monoxide, General Environmental Science, Nitrogen dioxide, Air Pollutants, Carbon Monoxide, Air pollutant concentrations, AEROSOL, Particulates, Matemàtiques i estadística::Estadística aplicada [Àrees temàtiques de la UPC], FINE PARTICULATE MATTER, Environmental Monitoring, Nitrogen Dioxide, Climate change, PM2.5, purl.org/pe-repo/ocde/ford#1.05.08 [https], URBAN, 114 Physical sciences, 12. Responsible consumption, Ozone, POLLUTION, Air Pollution, medicine, Humans, East Asia, Cities, Pandemics, Air quality index, 0105 earth and related environmental sciences, Pollutant, SARS-CoV-2, Aire -- Qualitat, COVID-19, 15. Life on land, Atmospheric ozone, TRENDS, Environmental sciences, CLIMATE, 13. Climate action, COVID-19, Carbon monoxide, Nitrogen dioxide, Ozone, Particulate matter, Sulphur dioxide, Cities, Communicable Disease Control, Environmental Monitoring, Humans, Pandemics, Particulate Matter, SARS-CoV-2, Air Pollutants, Air Pollution, Communicable Disease Control, Air quality, Environmental science, Particulate Matter, Particulate matter, Desenvolupament humà i sostenible::Degradació ambiental::Contaminació atmosfèrica [Àrees temàtiques de la UPC]
Abstract

This global study, which has been coordinated by the World Meteorological Organization Global Atmospheric Watch (WMO/GAW) programme, aims to understand the behaviour of key air pollutant species during the COVID-19 pandemic period of exceptionally low emissions across the globe. We investigated the effects of the differences in both emissions and regional and local meteorology in 2020 compared with the period 2015–2019. By adopting a globally consistent approach, this comprehensive observational analysis focuses on changes in air quality in and around cities across the globe for the following air pollutants PM2.5, PM10, PMC (coarse fraction of PM), NO2, SO2, NOx, CO, O3 and the total gaseous oxidant (OX = NO2 + O3) during the pre-lockdown, partial lockdown, full lockdown and two relaxation periods spanning from January to September 2020. The analysis is based on in situ ground-based air quality observations at over 540 traffic, background and rural stations, from 63 cities and covering 25 countries over seven geographical regions of the world. Anomalies in the air pollutant concentrations (increases or decreases during 2020 periods compared to equivalent 2015–2019 periods) were calculated and the possible effects of meteorological conditions were analysed by computing anomalies from ERA5 reanalyses and local observations for these periods. We observed a positive correlation between the reductions in NO2 and NOx concentrations and peoples’ mobility for most cities. A correlation between PMC and mobility changes was also seen for some Asian and South American cities. A clear signal was not observed for other pollutants, suggesting that sources besides vehicular emissions also substantially contributed to the change in air quality. As a global and regional overview of the changes in ambient concentrations of key air quality species, we observed decreases of up to about 70% in mean NO2 and between 30% and 40% in mean PM2.5 concentrations over 2020 full lockdown compared to the same period in 2015–2019. However, PM2.5 exhibited complex signals, even within the same region, with increases in some Spanish cities, attributed mainly to the long-range transport of African dust and/or biomass burning (corroborated with the analysis of NO2/CO ratio). Some Chinese cities showed similar increases in PM2.5 during the lockdown periods, but in this case, it was likely due to secondary PM formation. Changes in O3 concentrations were highly heterogeneous, with no overall change or small increases (as in the case of Europe), and positive anomalies of 25% and 30% in East Asia and South America, respectively, with Colombia showing the largest positive anomaly of ~70%. The SO2 anomalies were negative for 2020 compared to 2015–2019 (between ~25 to 60%) for all regions. For CO, negative anomalies were observed for all regions with the largest decrease for South America of up to ~40%. The NO2/CO ratio indicated that specific sites (such as those in Spanish cities) were affected by biomass burning plumes, which outweighed the NO2 decrease due to the general reduction in mobility (ratio of ~60%). Analysis of the total oxidant (OX = NO2 + O3) showed that primary NO2 emissions at urban locations were greater than the O3 production, whereas at background sites, OX was mostly driven by the regional contributions rather than local NO2 and O3 concentrations. The present study clearly highlights the importance of meteorology and episodic contributions (e.g., from dust, domestic, agricultural biomass burning and crop fertilizing) when analysing air quality in and around cities even during large emissions reductions. There is still the need to better understand how the chemical responses of secondary pollutants to emission change under complex meteorological conditions, along with climate change and socio-economic drivers may affect future air quality. The implications for regional and global policies are also significant, as our study clearly indicates that PM2.5 concentrations would not likely meet the World Health Organization guidelines in many parts of the world, despite the drastic reductions in mobility. Consequently, revisions of air quality regulation (e.g., the Gothenburg Protocol) with more ambitious targets that are specific to the different regions of the world may well be required., World Meteorological Organization Global Atmospheric Watch programme is gratefully acknowledged for initiating and coordinating this study and for supporting this publication. We acknowledge the following projects for supporting the analysis contained in this article: Air Pollution and Human Health for an Indian Megacity project PROMOTE funded by UK NERC and the Indian MOES, Grant reference number NE/P016391/1; Regarding project funding from the European Commission, the sole responsibility of this publication lies with the authors. The European Commission is not responsible for any use that may be made of the information contained therein. This project has received funding from the European Commission’s Horizon 2020 research and innovation program under grant agreement No 874990 (EMERGE project). European Regional Development Fund (project MOBTT42) under the Mobilitas Pluss programme; Estonian Research Council (project PRG714); Estonian Research Infrastructures Roadmap project Estonian Environmental Observatory (KKOBS, project 2014-2020.4.01.20-0281). European network for observing our changing planet project (ERA-PLANET, grant agreement no. 689443) under the European Union’s Horizon 2020 research and innovation program, Estonian Ministry of Sciences projects (grant nos. P180021, P180274), and the Estonian Research Infrastructures Roadmap project Estonian Environmental Observatory (3.2.0304.11-0395). Eastern Mediterranean and Middle East—Climate and Atmosphere Research (EMME-CARE) project, which has received funding from the European Union’s Horizon 2020 Research and Innovation Programme (grant agreement no. 856612) and the Government of Cyprus. INAR acknowledges support by the Russian government (grant number 14.W03.31.0002), the Ministry of Science and Higher Education of the Russian Federation (agreement 14.W0331.0006), and the Russian Ministry of Education and Science (14.W03.31.0008). We are grateful to to the following agencies for providing access to data used in our analysis: A.M. Obukhov Institute of Atmospheric Physics Russian Academy of Sciences; Agenzia Regionale per la Protezione dell’Ambiente della Campania (ARPAC); Air Quality and Climate Change, Parks and Environment (MetroVancouver, Government of British Columbia); Air Quality Monitoring & Reporting, Nova Scotia Environment (Government of Nova Scotia); Air Quality Monitoring Network (SIMAT) and Emission Inventory, Mexico City Environment Secretariat (SEDEMA); Airparif (owner & provider of the Paris air pollution data); ARPA Lazio, Italy; ARPA Lombardia, Italy; Association Agréée de Surveillance de la Qualité de l’Air en Île-de-France AIRPARIF / Atmo-France; Bavarian Environment Agency, Germany; Berlin Senatsverwaltung für Umwelt, Verkehr und Klimaschutz, Germany; California Air Resources Board; Central Pollution Control Board (CPCB), India; CETESB: Companhia Ambiental do Estado de São Paulo, Brazil. China National Environmental Monitoring Centre; Chandigarh Pollution Control Committee (CPCC), India. DCMR Rijnmond Environmental Service, the Netherlands. Department of Labour Inspection, Cyprus; Department of Natural Resources Management and Environmental Protection of Moscow. Environment and Climate Change Canada; Environmental Monitoring and Science Division Alberta Environment and Parks (Government of Alberta); Environmental Protection Authority Victoria (Melbourne, Victoria, Australia); Estonian Environmental Research Centre (EERC); Estonian University of Life Sciences, SMEAR Estonia; European Regional Development Fund (project MOBTT42) under the Mobilitas Pluss programme; Finnish Meteorological Institute; Helsinki Region Environmental Services Authority; Haryana Pollution Control Board (HSPCB), IndiaLondon Air Quality Network (LAQN) and the Automatic Urban and Rural Network (AURN) supported by the Department of Environment, Food and Rural Affairs, UK Government; Madrid Municipality; Met Office Integrated Data Archive System (MIDAS); Meteorological Service of Canada; Ministère de l'Environnement et de la Lutte contre les changements climatiques (Gouvernement du Québec); Ministry of Environment and Energy, Greece; Ministry of the Environment (Chile) and National Weather Service (DMC); Moscow State Budgetary Environmental Institution MOSECOMONITORING. Municipal Department of the Environment SMAC, Brazil; Municipality of Madrid public open data service; National institute of environmental research, Korea; National Meteorology and Hydrology Service (SENAMHI), Peru; New York State Department of Environmental Conservation; NSW Department of Planning, Industry and Environment; Ontario Ministry of the Environment, Conservation and Parks, Canada; Public Health Service of Amsterdam (GGD), the Netherlands. Punjab Pollution Control Board (PPCB), India. Réseau de surveillance de la qualité de l'air (RSQA) (Montréal); Rosgydromet. Mosecomonitoring, Institute of Atmospheric Physics, Russia; Russian Foundation for Basic Research (project 20–05–00254) SAFAR-IITM-MoES, India; São Paulo State Environmental Protection Agency, CETESB; Secretaria de Ambiente, DMQ, Ecuador; Secretaría Distrital de Ambiente, Bogotá, Colombia. Secretaria Municipal de Meio Ambiente Rio de Janeiro; Mexico City Atmospheric Monitoring System (SIMAT); Mexico City Secretariat of Environment, Secretaría del Medio Ambiente (SEDEMA); SLB-analys, Sweden; SMEAR Estonia station and Estonian University of Life Sciences (EULS); SMEAR stations data and Finnish Center of Excellence; South African Weather Service and Department of Environment, Forestry and Fisheries through SAAQIS; Spanish Ministry for the Ecological Transition and the Demographic Challenge (MITECO); University of Helsinki, Finland; University of Tartu, Tahkuse air monitoring station; Weather Station of the Institute of Astronomy, Geophysics and Atmospheric Science of the University of São Paulo; West Bengal Pollution Control Board (WBPCB).

Published
2021

19. Exploring Alternatives and Designing the Next Generation of Real-Time Control System for Astronomical Observatories

Author

Shen, Tzu-Chiang, Augsburger, Rodrigo, Carrasco, Sebastian, Galeas, Patricio, Huenupan, Fernando, Seguel, Rodrigo, and Sepulveda, Jorge

Subjects
Control System Infrastructure, Accelerator Physics
Abstract

The ALMA Observatory was inaugurated in 2013, after the 8 years of successful operation, obsolescence has started to emerge in different areas. One of the most critical areas is the control bus of the hardware devices located the antenna, which is based on a customized version of CAN bus. Initial studies were performed to explore alternatives, and one of the candidates could be a solution based on EtherCAT. In this paper, the existing architecture will be presented and new architecture will be proposed, which would not only be compatible with the existing hardware devices but also allow prepared the ground for new subsystems that come with ALMA 2030 initiatives. This document reports the progress achieved in a proof of concept project that explores the possibility to embed the existing ALMA monitor control data structure into EtherCAT frames and use EtherCAT as the main communication protocol to control hardware devices in all the subsystems that comprise the ALMA telescope., Proceedings of the 18th International Conference on Accelerator and Large Experimental Physics Control Systems, ICALEPCS2021, Shanghai, China

Published
2022
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21. Photochemical sensitivity to emissions and local meteorology in Bogotá, Santiago, and São Paulo

Author

Seguel, Rodrigo J., primary, Gallardo, Laura, additional, Osses, Mauricio, additional, Rojas, Néstor Y., additional, Nogueira, Thiago, additional, Menares, Camilo, additional, de Fatima Andrade, Maria, additional, Belalcázar, Luis C., additional, Carrasco, Paula, additional, Eskes, Henk, additional, Fleming, Zoë L., additional, Huneeus, Nicolas, additional, Ibarra-Espinosa, Sergio, additional, Landulfo, Eduardo, additional, Leiva, Manuel, additional, Mangones, Sonia C., additional, Morais, Fernando G., additional, Moreira, Gregori A., additional, Pantoja, Nicolás, additional, Parraguez, Santiago, additional, Rojas, Jhojan P., additional, Rondanelli, Roberto, additional, da Silva Andrade, Izabel, additional, Toro, Richard, additional, and Yoshida, Alexandre C., additional

Published
2022
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23. TOAR-II kickoff meeting, January - February 2021

Author

Cooper, Owen R., Schultz, Martin G., Emberson, Lisa, Kanaya, Yugo, Moolla, Raeesa, Rudich, Ynon, Von Schneidemesser, Erika, Seguel, Rodrigo, Sinha, Bärbel, Worden, Helen, Zhang, Lin, Palmer, Paul, and Neu, Jessica

Subjects
tropospheric ozone, global air quality, air quality monitoring, 3.2.4 → Chemistry → Atmospheric chemistry
Abstract

The Tropospheric Ozone Assessment Report (TOAR) is an initiative of the International Global Atmospheric Chemistry (IGAC) project. TOAR-II is the second phase of TOAR. It builds on the successful completion of the first comprehensive assessment on tropospheric ozone and will last from 2020 to 2024. This data publication contains a summary report and slides from the TOAR-II kickoff workshop from Jan, 25th, 2021 to February, 3rd, 2021. This workshop was held globally in virtual format and attracted up to 177 participants from ?? countries. More information about TOAR-II can be found at https://igacproject.org/activities/TOAR/TOAR-II .

Published
2021
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24. Archived material from the TOAR-II Manuscript Scoping Event, Nov 16 - 18, 2021

Author

Cooper, Owen R., Schultz, Martin G., Emberson, Lisa, Kanaya, Yugo, Moolla, Raeesa, Rudich, Ynon, Von Schneidemesser, Erika, Seguel, Rodrigo, Sinha, B��rbel, Worden, Helen, and Zhang, Lin

Subjects
tropospheric ozone, global air quality, air quality monitoring, 3.2.4 ��� Chemistry ��� Atmospheric chemistry
Abstract

The Tropospheric Ozone Assessment Report (TOAR) is an initiative of the International Global Atmospheric Chemistry (IGAC) project. TOAR-II is the second phase of TOAR. It builds on the successful completion of the first comprehensive assessment on tropospheric ozone and will last from 2020 to 2024. This data publication contains a summary report and slides from the TOAR-II Manuscript Scoping Event from Nov, 16th, 2021 to Nov, 18th, 2021. This 3-day workshop was held globally in virtual format and attracted over 100 participants. The aim was to identify the papers that will be submitted to the TOAR-II Community Special Issue by September 2023. More information about TOAR-II can be found at https://igacproject.org/activities/TOAR/TOAR-II .

Published
2021
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25. A global observational analysis to understand changes in air quality during exceptionally low anthropogenic emission conditions

Author

Querol, Xavier [0000-0002-6549-9899], Sokhi, Ranjeet S., Querol, Xavier, Massagué, Jordi, Ibarra, Sergio, Molina, Luisa, T., Pérez-Camaño, Juan Luis, Retama, Armando, Rivera, Olivia, Rojas, Néstor Y., San José, Roberto, Sánchez, Odón, Seguel, Rodrigo J., Terrazas, Antonio, Zavala, Miguel, Querol, Xavier [0000-0002-6549-9899], Sokhi, Ranjeet S., Querol, Xavier, Massagué, Jordi, Ibarra, Sergio, Molina, Luisa, T., Pérez-Camaño, Juan Luis, Retama, Armando, Rivera, Olivia, Rojas, Néstor Y., San José, Roberto, Sánchez, Odón, Seguel, Rodrigo J., Terrazas, Antonio, and Zavala, Miguel

Abstract

This global study, which has been coordinated by the World Meteorological Organization Global Atmospheric Watch (WMO/GAW) programme, aims to understand the behaviour of key air pollutant species during the COVID-19 pandemic period of exceptionally low emissions across the globe. We investigated the effects of the differences in both emissions and regional and local meteorology in 2020 compared with the period 2015–2019. By adopting a globally consistent approach, this comprehensive observational analysis focuses on changes in air quality in and around cities across the globe for the following air pollutants PM2.5, PM10, PMC (coarse fraction of PM), NO2, SO2, NOx, CO, O3 and the total gaseous oxidant (OX = NO2 + O3) during the pre-lockdown, partial lockdown, full lockdown and two relaxation periods spanning from January to September 2020. The analysis is based on in situ ground-based air quality observations at over 540 traffic, background and rural stations, from 63 cities and covering 25 countries over seven geographical regions of the world. Anomalies in the air pollutant concentrations (increases or decreases during 2020 periods compared to equivalent 2015–2019 periods) were calculated and the possible effects of meteorological conditions were analysed by computing anomalies from ERA5 reanalyses and local observations for these periods. We observed a positive correlation between the reductions in NO2 and NOx concentrations and peoples’ mobility for most cities. A correlation between PMC and mobility changes was also seen for some Asian and South American cities. A clear signal was not observed for other pollutants, suggesting that sources besides vehicular emissions also substantially contributed to the change in air quality. As a global and regional overview of the changes in ambient concentrations of key air quality species, we observed decreases of up to about 70% in mean NO2 and between 30% and 40% in mean PM2.5 concentrations over 2020 full lockdown compared

Published
2021

27. TOAR-II quickstart event, 16-Sep-2020

Author

Cooper, Owen R., Schultz, Martin G., Emberson, Lisa, Yugo Kanaya, Raeesa Moolla, Rudich, Ynon, Schneidemesser, Erika Von, Seguel, Rodrigo, Sinha, Bärbel, Worden, Helen, Zhang, Lin, Palmer, Paul, and Neu, Jessica

Subjects
tropospheric ozone, global air quality, air quality monitoring, 3.2.4 → Chemistry → Atmospheric chemistry
Abstract

The Tropospheric Ozone Assessment Report (TOAR) is an initiative of the International Global Atmospheric Chemistry (IGAC) project. TOAR-II is the second phase of TOAR. It builds on the successful completion of the first comprehensive assessment on tropospheric ozone and will last from 2020 to 2024. A quickstart event was given via Blue Jeans on September, 16th, 2020 to inform the scientific community about the plans for TOAR-II. This publication contains all presentation files from this event together with the video and audio recording, a transcript of the question and answer session, and a synthetic snapshot picture assembled from screen snapshots taken during the event.

Published
2020
Full Text
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32. Tropospheric Ozone Assessment Report: Database and Metrics Data of Global Surface Ozone Observations

Author

Schultz, Martin G., Schröder, Sabine, Lyapina, Olga, Cooper, Owen, Galbally, Ian, Petropavlovskikh, Irina, von Schneidemesser, Erika, Tanimoto, Hiroshi, Elshorbany, Yasin, Naja, Ma, Seguel, Rodrigo, Dauert, Ute, Eckhardt, Paul, Feigenspahn, Stefan, Fiebig, Ma, Hjellbrekke, Anne-Gunn, Hong, You-Deog, Christian Kjeld, Peter, Koide, Hiroshi, Lear, Gary, Tarasick, David, Ueno, Mikio, Wallasch, Ma, Baumgardner, Darrel, Chuang, Ming-Tung, Gillett, Robert, Lee, Meehye, Molloy, Suzie, Moolla, Raeesa, Wang, Tao, Sharps, Katrina, Adame, Jose A., Ancellet, Gérard, Apadula, Francesco, Artaxo, Paul, Barlasina, Ma, Bogucka, Ma, Bonasoni, Paolo, Chang, Limseok, Colomb, Aurélie, Cuevas, Emilio, Cupeiro, Ma, Degorska, Anna, Ding, Aijun, Fröhlich, Ma, Frolova, Ma, Gadhavi, Harish, GHEUSI, François, Gilge, Stefan, Gonzalez, Ma, Gros, Valérie, Hamad, Samera H., Helmig, Detlev, Henriques, Diamantino, Hermansen, Ove, Holla, Robert, Huber, Jacques, Im, Ulas, Jaffe, Daniel A., Komala, Ninong, Kubistin, Dagmar, Lam, Ka-Se, Laurila, Tuomas, Lee, Haeyoung, Levy, Ilan, Mazzoleni, Claudio, Mazzoleni, Lynn, McClure-Begley, Audra, Mohamad, Maznorizan, Murovic, Marijana, Navarro-Comas, M., Nicodim, Florin, Parrish, David, Read, Katie A., Reid, Nick, Ries, Ludwig, Saxena, Pallavi, Schwab, James J., Scorgie, Yvonne, Senik, Irina, Simmonds, Peter, Sinha, Vinayak, Skorokhod, Andrey, Spain, Gerard, Spangl, Wolfgang, Spoor, Ronald, Springston, Stephen R., Steer, Kelvyn, Steinbacher, Martin, Suharguniyawan, Eka, Torre, Paul, Trickl, Thomas, Weili, Lin, Weller, Rolf, Xu, Xiaobin, Xue, Likun, Zhiqiang, Ma, Institut für Energie- und Klimaforschung - Troposphäre (IEK-8), Forschungszentrum Jülich GmbH | Centre de recherche de Juliers, Helmholtz-Gemeinschaft = Helmholtz Association-Helmholtz-Gemeinschaft = Helmholtz Association, Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado [Boulder]-National Oceanic and Atmospheric Administration (NOAA), CSIRO Climate Science Centre, Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA), Institute for Advanced Sustainability Studies [Potsdam] (IASS), National Institute for Environmental Studies (NIES), NASA Goddard Space Flight Center (GSFC), Aryabhatta Research Institute of Observational Sciences (ARIES), Centro Nacional de Medio Ambiente (CENMA), German Federal Environmental Agency / Umweltbundesamt (UBA), Norwegian Institute for Air Research (NILU), National Institute of Environmental Research [South Korea] (NIER), European Environmental Agency (EEA), Japan Meteorological Agency (JMA), Office of Air and Radiation (OAR), US Environmental Protection Agency (EPA), Environment and Climate Change Canada, Centro de Ciencias de la Atmosfera [Mexico], Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM), National Central University [Taiwan] (NCU), Department of Earth and Environmental Sciences [Korea], Korea University [Seoul], School of Geography, Archaeology and Environmental Studies [Johannesburg] (GAES), University of the Witwatersrand [Johannesburg] (WITS), Department of Civil and Environmental Engineering [Hong Kong] (CEE), The Hong Kong Polytechnic University [Hong Kong] (POLYU), Centre for Ecology and Hydrology [Bangor] (CEH), Natural Environment Research Council (NERC), Instituto Nacional de Técnica Aeroespacial (INTA), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Ricerca sul Sistema Energetico (RSE), Instituto de Fisica da Universidade de São Paulo (IFUSP), Universidade de São Paulo = University of São Paulo (USP), Servicio Meteorológico Nacional [Buenos Aires], Institute of Meteorology and Water Management - National Research Institute (IMGW - PIB), CNR Institute of Atmospheric Sciences and Climate (ISAC), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Laboratoire de Météorologie Physique (LaMP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Izaña Atmospheric Research Center (IARC), Agencia Estatal de Meteorología (AEMet), Iinstitute of Environmental Protection - National Research Institute (IOS-PIB), School of Atmospheric Sciences [Nanjing], Nanjing University (NJU), Umweltbundesamt GmbH = Environment Agency Austria, Latvian Environment Geology and Meteorology Centre (LEGMC), National Atmospheric Research Laboratory [Tirupati] (NARL), Indian Space Research Organisation (ISRO), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Zentrum für Medizin-Meteorologische Forschung (ZMMF), Deutscher Wetterdienst [Offenbach] (DWD), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Chimie Atmosphérique Expérimentale (CAE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), UMD School of Public Health, University of Maryland [College Park], University of Maryland System-University of Maryland System, Institute of Arctic Alpine Research [University of Colorado Boulder] (INSTAAR), University of Colorado [Boulder], Portuguese Institute for Sea and Atmosphere (IMPA), Norsk Institutt for Luftforskning (NILU), Meteorologisches Observatorium Hohenpeißenberg (MOHp), Department of Environmental Science [Roskilde] (ENVS), Aarhus University [Aarhus], School of Science, Technology, Engineering and Mathematics [Bothell] (STEM), University of Washington-Bothell, Indonesian National Institute of Aeronautics and Space (LAPAN), Finnish Meteorological Institute (FMI), National Institute of Meteorological Sciences (NIMS), Air Quality and Climate Change Division [Jerusalem], Israël Ministry of Environmental Protection, Michigan Technological University (MTU), Malaysian Meteorological Department (MetMalaysia), Ministry of Science, Technology and Innovation [Malaysia] (MOSTI), Slovenian Environment Agency, Administratia Nationala de Meteorologie, Department of Chemistry [York, UK], University of York [York, UK], Auckland Council, Jawaharlal Nehru University (JNU), Atmospheric Sciences Research Center (ASRC), University at Albany [SUNY], State University of New York (SUNY)-State University of New York (SUNY), New South Wales Office of Environment and Heritage, A.M.Obukhov Institute of Atmospheric Physics (IAP), Russian Academy of Sciences [Moscow] (RAS), School of Chemistry [Bristol], University of Bristol [Bristol], Indian Institute of Science Education and Research Mohali (IISER Mohali), National University of Ireland [Galway] (NUI Galway), National Institute for Public Health and the Environment [Bilthoven] (RIVM), Brookhaven National Laboratory [Upton, NY] (BNL), UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY)-U.S. Department of Energy [Washington] (DOE), South Australia Environment Protection Authority (EPA), Swiss Federal Laboratories for Materials Science and Technology [Thun] (EMPA), Indonesian Meteorological, Climatologicall and Geophysical Agency (BMKG), Environment Protection Authority Victoria (EPA ), Institut für Meteorologie und Klimaforschung - Atmosphärische Umweltforschung (IMK-IFU), Karlsruher Institut für Technologie (KIT), China Meteorological Administration (CMA), Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Shandong University, Universidad Nacional Autónoma de México (UNAM), Instituto de Fisica [Sao Paulo], Universidade de São Paulo (USP), Consiglio Nazionale delle Ricerche (CNR), Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Umweltbundesamt GmbH/Environment Agency Austria, National Atmospheric Research Laboratory [Tirupathi] (NARL), Météo France-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institute of Arctic and Alpine Research (INSTAAR), U.S. Department of Energy [Washington] (DOE)-UT-Battelle, LLC-Stony Brook University [SUNY] (SBU), and Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Centre National de la Recherche Scientifique (CNRS)

Subjects
lcsh:GE1-350, tropospheric ozone, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Monitoring, ground-level ozone, monitoring, database, Tropospheric ozone, Ecology and Environment, Atmospheric Sciences, Database, Earth sciences, ddc:550, Data and Information, Ground-level ozone, lcsh:Environmental sciences
Abstract

In support of the first Tropospheric Ozone Assessment Report (TOAR) a relational database of global surface ozone observations has been developed and populated with hourly measurement data and enhanced metadata. A comprehensive suite of ozone data products including standard statistics, health and vegetation impact metrics, and trend information, are made available through a common data portal and a web interface. These data form the basis of the TOAR analyses focusing on human health, vegetation, and climate relevant ozone issues, which are part of this special feature. Cooperation among many data centers and individual researchers worldwide made it possible to build the world’s largest collection of in-situ hourly surface ozone data covering the period from 1970 to 2015. By combining the data from almost 10,000 measurement sites around the world with global metadata information, new analyses of surface ozone have become possible, such as the first globally consistent characterisations of measurement sites as either urban or rural/remote. Exploitation of these global metadata allows for new insights into the global distribution, and seasonal and long-term changes of tropospheric ozone and they enable TOAR to perform the first, globally consistent analysis of present-day ozone concentrations and recent ozone changes with relevance to health, agriculture, and climate. Considerable effort was made to harmonize and synthesize data formats and metadata information from various networks and individual data submissions. Extensive quality control was applied to identify questionable and erroneous data, including changes in apparent instrument offsets or calibrations. Such data were excluded from TOAR data products. Limitations of a posteriori data quality assurance are discussed. As a result of the work presented here, global coverage of surface ozone data for scientific analysis has been significantly extended. Yet, large gaps remain in the surface observation network both in terms of regions without monitoring, and in terms of regions that have monitoring programs but no public access to the data archive. Therefore future improvements to the database will require not only improved data harmonization, but also expanded data sharing and increased monitoring in data-sparse regions. This work is part of the Tropospheric Ozone Assessment Report (TOAR) which was supported by the International Global Atmospheric Chemistry (IGAC) project, the National Oceanic and Atmospheric Administration (NOAA), Forschungszentrum Jülich, and the World Meteorological Organisation (WMO). Many institutions and agencies sup¬ported the implementation of the measurements, and the processing, quality assurance, and submission of the data contained in the TOAR database.

Published
2017

42. Tropospheric Ozone Assessment Report: Database and Metrics Data of Global Surface Ozone Observations

Author

Schultz, Martin G., Schröder, Sabine, Lyapina, Olga, Cooper, Owen, Galbally, Ian, Petropavlovskikh, Irina, Von Schneidemesser, Erika, Tanimoto, Hiroshi, Elshorbany, Yasin, Naja, Manish, Seguel, Rodrigo, Dauert, Ute, Eckhardt, Paul, Feigenspahn, Stefan, Fiebig, Markus, Hjellbrekke, Anne-Gunn, Hong, You-Deog, Christian Kjeld, Peter, Koide, Hiroshi, Lear, Gary, Tarasick, David, Ueno, Mikio, Wallasch, Markus, Baumgardner, Darrel, Chuang, Ming-Tung, Gillett, Robert, Lee, Meehye, Molloy, Suzie, Moolla, Raeesa, Wang, Tao, Sharps, Katrina, Adame, Jose A., Ancellet, Gerard, Apadula, Francesco, Artaxo, Paulo, Barlasina, Maria, Bogucka, Magdalena, Bonasoni, Paolo, Chang, Limseok, Colomb, Aurelie, Cuevas, Emilio, Cupeiro, Manuel, Degorska, Anna, Ding, Aijun, Fröhlich, Marina, Frolova, Marina, Gadhavi, Harish, Gheusi, Francois, Gilge, Stefan, Gonzalez, Margarita Y., Gros, Valerie, Hamad, Samera H., Helmig, Detlev, Henriques, Diamantino, Hermansen, Ove, Holla, Robert, Huber, Jacques, Im, Ulas, Jaffe, Daniel A., Komala, Ninong, Kubistin, Dagmar, Lam, Ka-Se, Laurila, Tuomas, Lee, Haeyoung, Levy, Ilan, Mazzoleni, Claudio, Mazzoleni, Lynn, McClure-Begley, Audra, Mohamad, Maznorizan, Murovic, Marijana, Navarro-Comas, M., Nicodim, Florin, Parrish, David, Read, Katie A., Reid, Nick, Ries, Ludwig, Saxena, Pallavi, Schwab, James J., Scorgie, Yvonne, Senik, Irina, Simmonds, Peter, Sinha, Vinayak, Skorokhod, Andrey, Spain, Gerard, Spangl, Wolfgang, Spoor, Ronald, Springston, Stephen R., Steer, Kelvyn, Steinbacher, Martin, Suharguniyawan, Eka, Torre, Paul, Trickl, Thomas, Weili, Lin, Weller, Rolf, Xu, Xiaobin, Xue, Likun, and Zhiqiang, Ma

Subjects
13. Climate action, 15. Life on land, 6. Clean water

43. A global observational analysis to understand changes in air quality during exceptionally low anthropogenic emission conditions.

Author

Sokhi RS, Singh V, Querol X, Finardi S, Targino AC, Andrade MF, Pavlovic R, Garland RM, Massagué J, Kong S, Baklanov A, Ren L, Tarasova O, Carmichael G, Peuch VH, Anand V, Arbilla G, Badali K, Beig G, Belalcazar LC, Bolignano A, Brimblecombe P, Camacho P, Casallas A, Charland JP, Choi J, Chourdakis E, Coll I, Collins M, Cyrys J, da Silva CM, Di Giosa AD, Di Leo A, Ferro C, Gavidia-Calderon M, Gayen A, Ginzburg A, Godefroy F, Gonzalez YA, Guevara-Luna M, Haque SM, Havenga H, Herod D, Hõrrak U, Hussein T, Ibarra S, Jaimes M, Kaasik M, Khaiwal R, Kim J, Kousa A, Kukkonen J, Kulmala M, Kuula J, La Violette N, Lanzani G, Liu X, MacDougall S, Manseau PM, Marchegiani G, McDonald B, Mishra SV, Molina LT, Mooibroek D, Mor S, Moussiopoulos N, Murena F, Niemi JV, Noe S, Nogueira T, Norman M, Pérez-Camaño JL, Petäjä T, Piketh S, Rathod A, Reid K, Retama A, Rivera O, Rojas NY, Rojas-Quincho JP, San José R, Sánchez O, Seguel RJ, Sillanpää S, Su Y, Tapper N, Terrazas A, Timonen H, Toscano D, Tsegas G, Velders GJM, Vlachokostas C, von Schneidemesser E, Vpm R, Yadav R, Zalakeviciute R, and Zavala M

Subjects
Cities, Communicable Disease Control, Environmental Monitoring, Humans, Pandemics, Particulate Matter analysis, SARS-CoV-2, Air Pollutants analysis, Air Pollution analysis, COVID-19
Abstract

This global study, which has been coordinated by the World Meteorological Organization Global Atmospheric Watch (WMO/GAW) programme, aims to understand the behaviour of key air pollutant species during the COVID-19 pandemic period of exceptionally low emissions across the globe. We investigated the effects of the differences in both emissions and regional and local meteorology in 2020 compared with the period 2015-2019. By adopting a globally consistent approach, this comprehensive observational analysis focuses on changes in air quality in and around cities across the globe for the following air pollutants PM 2.5 , PM 10 , PMC (coarse fraction of PM), NO 2 , SO 2 , NOx, CO, O 3 and the total gaseous oxidant (OX = NO 2  + O 3 ) during the pre-lockdown, partial lockdown, full lockdown and two relaxation periods spanning from January to September 2020. The analysis is based on in situ ground-based air quality observations at over 540 traffic, background and rural stations, from 63 cities and covering 25 countries over seven geographical regions of the world. Anomalies in the air pollutant concentrations (increases or decreases during 2020 periods compared to equivalent 2015-2019 periods) were calculated and the possible effects of meteorological conditions were analysed by computing anomalies from ERA5 reanalyses and local observations for these periods. We observed a positive correlation between the reductions in NO 2 and NOx concentrations and peoples' mobility for most cities. A correlation between PMC and mobility changes was also seen for some Asian and South American cities. A clear signal was not observed for other pollutants, suggesting that sources besides vehicular emissions also substantially contributed to the change in air quality. As a global and regional overview of the changes in ambient concentrations of key air quality species, we observed decreases of up to about 70% in mean NO 2 and between 30% and 40% in mean PM 2.5 concentrations over 2020 full lockdown compared to the same period in 2015-2019. However, PM 2.5 exhibited complex signals, even within the same region, with increases in some Spanish cities, attributed mainly to the long-range transport of African dust and/or biomass burning (corroborated with the analysis of NO 2 /CO ratio). Some Chinese cities showed similar increases in PM 2.5 during the lockdown periods, but in this case, it was likely due to secondary PM formation. Changes in O 3 concentrations were highly heterogeneous, with no overall change or small increases (as in the case of Europe), and positive anomalies of 25% and 30% in East Asia and South America, respectively, with Colombia showing the largest positive anomaly of ~70%. The SO 2 anomalies were negative for 2020 compared to 2015-2019 (between ~25 to 60%) for all regions. For CO, negative anomalies were observed for all regions with the largest decrease for South America of up to ~40%. The NO 2 /CO ratio indicated that specific sites (such as those in Spanish cities) were affected by biomass burning plumes, which outweighed the NO 2 decrease due to the general reduction in mobility (ratio of ~60%). Analysis of the total oxidant (OX = NO 2  + O 3 ) showed that primary NO 2 emissions at urban locations were greater than the O 3 production, whereas at background sites, OX was mostly driven by the regional contributions rather than local NO 2 and O 3 concentrations. The present study clearly highlights the importance of meteorology and episodic contributions (e.g., from dust, domestic, agricultural biomass burning and crop fertilizing) when analysing air quality in and around cities even during large emissions reductions. There is still the need to better understand how the chemical responses of secondary pollutants to emission change under complex meteorological conditions, along with climate change and socio-economic drivers may affect future air quality. The implications for regional and global policies are also significant, as our study clearly indicates that PM 2.5 concentrations would not likely meet the World Health Organization guidelines in many parts of the world, despite the drastic reductions in mobility. Consequently, revisions of air quality regulation (e.g., the Gothenburg Protocol) with more ambitious targets that are specific to the different regions of the world may well be required., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Published
2021
Full Text
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