Articles | Volume 24, issue 23
https://doi.org/10.5194/acp-24-13151-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-24-13151-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Measurement report
| 
29 Nov 2024
Measurement report |
| 29 Nov 2024
| 29 Nov 2024
Measurement report: Long-term measurements of surface ozone and trends in semi-natural sub-Saharan African ecosystems
Hagninou Elagnon Venance Donnou
CORRESPONDING AUTHOR
Laboratoire de Physique du Rayonnement, Faculté des Sciences et Techniques, Université d'Abomey-Calavi, Cotonou, 01 B.P. 526, Benin
Aristide Barthélémy Akpo
Laboratoire de Physique du Rayonnement, Faculté des Sciences et Techniques, Université d'Abomey-Calavi, Cotonou, 01 B.P. 526, Benin
Money Ossohou
Department of Physics, University of Man, Man, Côte d'Ivoire
Laboratoire des Sciences de la Matière, de l'Environnement et de l'Energie Solaire, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire
Claire Delon
Laboratoire d'Aérologie, Université Toulouse III – Paul Sabatier, CNRS, Toulouse, 31400, France
Véronique Yoboué
Laboratoire des Sciences de la Matière, de l'Environnement et de l'Energie Solaire, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire
Dungall Laouali
Laboratoire de Climat-Environnement et Matériaux-Rayonnement, Faculté des Sciences et Techniques, Université Abdou Moumouni, Niamey, BP 10662, Niger
Marie Ouafo-Leumbe
Department of Earth Sciences, Faculty of Sciences, University of Douala, Douala, P.O. Box 2701, Cameroon
Pieter Gideon Van Zyl
Atmospheric Chemistry Research Group, Chemical Resource Beneficiation, North-West University, Potchefstroom, 2520, South Africa
Ousmane Ndiaye
Centre de Recherches Zootechniques de Dahra, Institut Sénégalais de Recherches Agricoles, Dahra, Senegal
Eric Gardrat
Laboratoire d'Aérologie, Université Toulouse III – Paul Sabatier, CNRS, Toulouse, 31400, France
Maria Dias-Alves
Laboratoire d'Aérologie, Université Toulouse III – Paul Sabatier, CNRS, Toulouse, 31400, France
Corinne Galy-Lacaux
CORRESPONDING AUTHOR
Laboratoire d'Aérologie, Université Toulouse III – Paul Sabatier, CNRS, Toulouse, 31400, France
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Arya Mukherjee, Anni Hartikainen, Markus Somero, Viljami Luostari, Mika Ihalainen, Christopher P. Rüger, Timo Kekäläinen, Ville H. Nissinen, Luis M. F. Barreira, Hanna Koponen, Tuukka Kokkola, Delun Li, Lejish Vettikkat, Pasi Yli-Pirilä, Muhammad Shahzaib, Meri M. Ruppel, Ville Vakkari, Kerneels Jaars, Stefan J. Siebert, Angela Buchholz, Kajar Köster, Pieter G. van Zyl, Hilkka Timonen, Niko Kinnunen, Janne Jänis, Annele Virtanen, Aki Virkkula, and Olli Sippula
EGUsphere, https://doi.org/10.5194/egusphere-2025-2759, https://doi.org/10.5194/egusphere-2025-2759, 2025
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Warming climate is predicted to increase boreal and peatland fires in Northern Eurasia. Limited studies have characterized light absorbing aerosol emissions from these biomasses, thus necessitating this work. Brown carbon (BrC) emitted from laboratory-scale biomass burning had weak light absorptivities based on their complex refractive index values. A combustion temperature dependent light absorptivity continuum existed for emitted BrC. Photochemical aging decreased BrC light absorptivity.
Natalie M. Mahowald, Longlei Li, Julius Vira, Marje Prank, Douglas S. Hamilton, Hitoshi Matsui, Ron L. Miller, P. Louis Lu, Ezgi Akyuz, Daphne Meidan, Peter Hess, Heikki Lihavainen, Christine Wiedinmyer, Jenny Hand, Maria Grazia Alaimo, Célia Alves, Andres Alastuey, Paulo Artaxo, Africa Barreto, Francisco Barraza, Silvia Becagli, Giulia Calzolai, Shankararaman Chellam, Ying Chen, Patrick Chuang, David D. Cohen, Cristina Colombi, Evangelia Diapouli, Gaetano Dongarra, Konstantinos Eleftheriadis, Johann Engelbrecht, Corinne Galy-Lacaux, Cassandra Gaston, Dario Gomez, Yenny González Ramos, Roy M. Harrison, Chris Heyes, Barak Herut, Philip Hopke, Christoph Hüglin, Maria Kanakidou, Zsofia Kertesz, Zbigniew Klimont, Katriina Kyllönen, Fabrice Lambert, Xiaohong Liu, Remi Losno, Franco Lucarelli, Willy Maenhaut, Beatrice Marticorena, Randall V. Martin, Nikolaos Mihalopoulos, Yasser Morera-Gómez, Adina Paytan, Joseph Prospero, Sergio Rodríguez, Patricia Smichowski, Daniela Varrica, Brenna Walsh, Crystal L. Weagle, and Xi Zhao
Atmos. Chem. Phys., 25, 4665–4702, https://doi.org/10.5194/acp-25-4665-2025, https://doi.org/10.5194/acp-25-4665-2025, 2025
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Aerosol particles are an important part of the Earth system, but their concentrations are spatially and temporally heterogeneous, as well as being variable in size and composition. Here, we present a new compilation of PM2.5 and PM10 aerosol observations, focusing on the spatial variability across different observational stations, including composition, and demonstrate a method for comparing the data sets to model output.
Eric Martial Yao, Fabien Solmon, Marcellin Adon, Claire Delon, Corinne Galy-Lacaux, Graziano Giuliani, Bastien Sauvage, and Véronique Yoboue
EGUsphere, https://doi.org/10.5194/egusphere-2024-3179, https://doi.org/10.5194/egusphere-2024-3179, 2025
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As climate change and human activities intensify in Africa, understanding how air pollution, climate, and natural cycles interact is crucial. This study explores how nitrogen oxide emissions from African soils, especially in dry regions, contribute to atmospheric pollution. By using a climate-chemistry model, we show that considering these emissions improves predictions of nitrogen dioxide, nitric acid and ozone, although some discrepancies remain compared to observations.
Marie Lothon, François Gheusi, Fabienne Lohou, Véronique Pont, Serge Soula, Corinne Jambert, Solène Derrien, Yannick Bezombes, Emmanuel Leclerc, Gilles Athier, Antoine Vial, Alban Philibert, Bernard Campistron, Frédérique Saïd, Jeroen Sonke, Julien Amestoy, Erwan Bargain, Pierre Bosser, Damien Boulanger, Guillaume Bret, Renaud Bodichon, Laurent Cabanas, Guylaine Canut, Jean-Bernard Estrampes, Eric Gardrat, Zaida Gomez Kuri, Jérémy Gueffier, Fabienne Guesdon, Morgan Lopez, Olivier Masson, Pierre-Yves Meslin, Yves Meyerfeld, Nicolas Pascal, Eric Pique, Michel Ramonet, Felix Starck, and Romain Vidal
Atmos. Meas. Tech., 17, 6265–6300, https://doi.org/10.5194/amt-17-6265-2024, https://doi.org/10.5194/amt-17-6265-2024, 2024
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The Pyrenean Platform for Observation of the Atmosphere (P2OA) is a coupled plain–mountain instrumented platform in southwestern France for the monitoring of climate variables and the study of meteorological processes in a mountainous region. A comprehensive description of this platform is presented for the first time: its instrumentation, the associated dataset, and a meteorological characterization the site. The potential of the P2OA is illustrated through several examples of process studies.
Sarah Tinorua, Cyrielle Denjean, Pierre Nabat, Véronique Pont, Mathilde Arnaud, Thierry Bourrianne, Maria Dias Alves, and Eric Gardrat
Atmos. Meas. Tech., 17, 3897–3915, https://doi.org/10.5194/amt-17-3897-2024, https://doi.org/10.5194/amt-17-3897-2024, 2024
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The three most widely used techniques for measuring black carbon (BC) have been deployed continuously for 2 years at a French high-altitude research station. Despite a similar temporal variation in the BC load, we found significant biases by up to a factor of 8 between the three instruments. This study raises questions about the relevance of using these instruments for specific background sites, as well as the processing of their data, which can vary according to the atmospheric conditions.
Yélognissè Agbohessou, Claire Delon, Manuela Grippa, Eric Mougin, Daouda Ngom, Espoir Koudjo Gaglo, Ousmane Ndiaye, Paulo Salgado, and Olivier Roupsard
Biogeosciences, 21, 2811–2837, https://doi.org/10.5194/bg-21-2811-2024, https://doi.org/10.5194/bg-21-2811-2024, 2024
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Emissions of greenhouse gases in the Sahel are not well represented because they are considered weak compared to the rest of the world. However, natural areas in the Sahel emit carbon dioxide and nitrous oxides, which need to be assessed because of extended surfaces. We propose an assessment of such emissions in Sahelian silvopastoral systems and of how they are influenced by environmental characteristics. These results are essential to inform climate change strategies in the region.
Natalie M. Mahowald, Longlei Li, Julius Vira, Marje Prank, Douglas S. Hamilton, Hitoshi Matsui, Ron L. Miller, Louis Lu, Ezgi Akyuz, Daphne Meidan, Peter Hess, Heikki Lihavainen, Christine Wiedinmyer, Jenny Hand, Maria Grazia Alaimo, Célia Alves, Andres Alastuey, Paulo Artaxo, Africa Barreto, Francisco Barraza, Silvia Becagli, Giulia Calzolai, Shankarararman Chellam, Ying Chen, Patrick Chuang, David D. Cohen, Cristina Colombi, Evangelia Diapouli, Gaetano Dongarra, Konstantinos Eleftheriadis, Corinne Galy-Lacaux, Cassandra Gaston, Dario Gomez, Yenny González Ramos, Hannele Hakola, Roy M. Harrison, Chris Heyes, Barak Herut, Philip Hopke, Christoph Hüglin, Maria Kanakidou, Zsofia Kertesz, Zbiginiw Klimont, Katriina Kyllönen, Fabrice Lambert, Xiaohong Liu, Remi Losno, Franco Lucarelli, Willy Maenhaut, Beatrice Marticorena, Randall V. Martin, Nikolaos Mihalopoulos, Yasser Morera-Gomez, Adina Paytan, Joseph Prospero, Sergio Rodríguez, Patricia Smichowski, Daniela Varrica, Brenna Walsh, Crystal Weagle, and Xi Zhao
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2024-1, https://doi.org/10.5194/essd-2024-1, 2024
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Aerosol particles can interact with incoming solar radiation and outgoing long wave radiation, change cloud properties, affect photochemistry, impact surface air quality, and when deposited impact surface albedo of snow and ice, and modulate carbon dioxide uptake by the land and ocean. Here we present a new compilation of aerosol observations including composition, a methodology for comparing the datasets to model output, and show the implications of these results using one model.
Money Ossohou, Jonathan Edward Hickman, Lieven Clarisse, Pierre-François Coheur, Martin Van Damme, Marcellin Adon, Véronique Yoboué, Eric Gardrat, Maria Dias Alvès, and Corinne Galy-Lacaux
Atmos. Chem. Phys., 23, 9473–9494, https://doi.org/10.5194/acp-23-9473-2023, https://doi.org/10.5194/acp-23-9473-2023, 2023
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The updated analyses of ground-based concentrations and satellite total vertical columns of atmospheric ammonia help us to better understand 21st century ammonia dynamics in sub-Saharan Africa. We conclude that the drivers of trends are agriculture in the dry savanna of Katibougou, Mali; air temperature and agriculture in the wet savanna of Djougou, Benin, and Lamto, Côte d'Ivoire; and leaf area index, air temperature, residential, and agriculture in forests of Bomassa, Republic of Congo.
Matti Räsänen, Mika Aurela, Ville Vakkari, Johan P. Beukes, Juha-Pekka Tuovinen, Pieter G. Van Zyl, Miroslav Josipovic, Stefan J. Siebert, Tuomas Laurila, Markku Kulmala, Lauri Laakso, Janne Rinne, Ram Oren, and Gabriel Katul
Hydrol. Earth Syst. Sci., 26, 5773–5791, https://doi.org/10.5194/hess-26-5773-2022, https://doi.org/10.5194/hess-26-5773-2022, 2022
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The productivity of semiarid grazed grasslands is linked to the variation in rainfall and transpiration. By combining carbon dioxide and water flux measurements, we show that the annual transpiration is nearly constant during wet years while grasses react quickly to dry spells and drought, which reduce transpiration. The planning of annual grazing strategies could consider the early-season rainfall frequency that was linked to the portion of annual transpiration.
Mohamed Lamine Kassamba-Diaby, Corinne Galy-Lacaux, Veronique Yoboué, Jonathan E. Hickman, Kerneels Jaars, Sylvain Gnamien, Richmond Konan, Eric Gardrat, and Siele Silué
EGUsphere, https://doi.org/10.5194/egusphere-2022-994, https://doi.org/10.5194/egusphere-2022-994, 2022
Preprint archived
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This work presents the chemical composition of precipitation from 2018 to 2020 at three sites representative of a south-north transect in Côte d'Ivoire. It includes two urban sites (Abidjan and Korhogo) and one rural site (Lamto). Measured rain chemical content and wet deposition fluxes highlights different dominant sources contributions i.e anthropogenic sources (traffic, construction, industry) at urban sites and biomass burning at the rural site.
Flossie Brown, Gerd A. Folberth, Stephen Sitch, Susanne Bauer, Marijn Bauters, Pascal Boeckx, Alexander W. Cheesman, Makoto Deushi, Inês Dos Santos Vieira, Corinne Galy-Lacaux, James Haywood, James Keeble, Lina M. Mercado, Fiona M. O'Connor, Naga Oshima, Kostas Tsigaridis, and Hans Verbeeck
Atmos. Chem. Phys., 22, 12331–12352, https://doi.org/10.5194/acp-22-12331-2022, https://doi.org/10.5194/acp-22-12331-2022, 2022
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Surface ozone can decrease plant productivity and impair human health. In this study, we evaluate the change in surface ozone due to climate change over South America and Africa using Earth system models. We find that if the climate were to change according to the worst-case scenario used here, models predict that forested areas in biomass burning locations and urban populations will be at increasing risk of ozone exposure, but other areas will experience a climate benefit.
Constance K. Segakweng, Pieter G. van Zyl, Cathy Liousse, Johan P. Beukes, Jan-Stefan Swartz, Eric Gardrat, Maria Dias-Alves, Brigitte Language, Roelof P. Burger, and Stuart J. Piketh
Atmos. Chem. Phys., 22, 10291–10317, https://doi.org/10.5194/acp-22-10291-2022, https://doi.org/10.5194/acp-22-10291-2022, 2022
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A detailed size-resolved assessment of the chemical characteristics of outdoor and indoor aerosols collected in low-income urban settlements in South Africa indicated the significance of household combustion for cooking and space heating – an important source of pollutants in the developing world – to atmospheric chemical composition. The regional impact of industrial sources in the highly industrialised and densely populated north-eastern interior of South Africa was also evident.
Julius Vira, Peter Hess, Money Ossohou, and Corinne Galy-Lacaux
Atmos. Chem. Phys., 22, 1883–1904, https://doi.org/10.5194/acp-22-1883-2022, https://doi.org/10.5194/acp-22-1883-2022, 2022
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Ammonia is one of the main components of nitrogen deposition. Here we use a new model to assess the ammonia emissions from agriculture, the largest anthropogenic source of ammonia. The model results are consistent with earlier estimates over industrialized regions in agreement with observations. However, the model predicts much higher emissions over sub-Saharan Africa compared to earlier estimates. Available observations from surface stations and satellites support these higher emissions.
Clémence Rose, Martine Collaud Coen, Elisabeth Andrews, Yong Lin, Isaline Bossert, Cathrine Lund Myhre, Thomas Tuch, Alfred Wiedensohler, Markus Fiebig, Pasi Aalto, Andrés Alastuey, Elisabeth Alonso-Blanco, Marcos Andrade, Begoña Artíñano, Todor Arsov, Urs Baltensperger, Susanne Bastian, Olaf Bath, Johan Paul Beukes, Benjamin T. Brem, Nicolas Bukowiecki, Juan Andrés Casquero-Vera, Sébastien Conil, Konstantinos Eleftheriadis, Olivier Favez, Harald Flentje, Maria I. Gini, Francisco Javier Gómez-Moreno, Martin Gysel-Beer, Anna Gannet Hallar, Ivo Kalapov, Nikos Kalivitis, Anne Kasper-Giebl, Melita Keywood, Jeong Eun Kim, Sang-Woo Kim, Adam Kristensson, Markku Kulmala, Heikki Lihavainen, Neng-Huei Lin, Hassan Lyamani, Angela Marinoni, Sebastiao Martins Dos Santos, Olga L. Mayol-Bracero, Frank Meinhardt, Maik Merkel, Jean-Marc Metzger, Nikolaos Mihalopoulos, Jakub Ondracek, Marco Pandolfi, Noemi Pérez, Tuukka Petäjä, Jean-Eudes Petit, David Picard, Jean-Marc Pichon, Veronique Pont, Jean-Philippe Putaud, Fabienne Reisen, Karine Sellegri, Sangeeta Sharma, Gerhard Schauer, Patrick Sheridan, James Patrick Sherman, Andreas Schwerin, Ralf Sohmer, Mar Sorribas, Junying Sun, Pierre Tulet, Ville Vakkari, Pieter Gideon van Zyl, Fernando Velarde, Paolo Villani, Stergios Vratolis, Zdenek Wagner, Sheng-Hsiang Wang, Kay Weinhold, Rolf Weller, Margarita Yela, Vladimir Zdimal, and Paolo Laj
Atmos. Chem. Phys., 21, 17185–17223, https://doi.org/10.5194/acp-21-17185-2021, https://doi.org/10.5194/acp-21-17185-2021, 2021
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Aerosol particles are a complex component of the atmospheric system the effects of which are among the most uncertain in climate change projections. Using data collected at 62 stations, this study provides the most up-to-date picture of the spatial distribution of particle number concentration and size distribution worldwide, with the aim of contributing to better representation of aerosols and their interactions with clouds in models and, therefore, better evaluation of their impact on climate.
Jonathan E. Hickman, Niels Andela, Enrico Dammers, Lieven Clarisse, Pierre-François Coheur, Martin Van Damme, Courtney A. Di Vittorio, Money Ossohou, Corinne Galy-Lacaux, Kostas Tsigaridis, and Susanne E. Bauer
Atmos. Chem. Phys., 21, 16277–16291, https://doi.org/10.5194/acp-21-16277-2021, https://doi.org/10.5194/acp-21-16277-2021, 2021
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Ammonia (NH3) gas emitted from soils and biomass burning contributes to particulate air pollution. We used satellite observations of the atmosphere over Africa to show that declines in NH3 concentrations over South Sudan's Sudd wetland in 2008–2017 are related to variation in wetland extent. We also find NH3 concentrations increased in West Africa as a result of biomass burning and increased in the Lake Victoria region, likely due to agricultural expansion and intensification.
Sekou Keita, Catherine Liousse, Eric-Michel Assamoi, Thierno Doumbia, Evelyne Touré N'Datchoh, Sylvain Gnamien, Nellie Elguindi, Claire Granier, and Véronique Yoboué
Earth Syst. Sci. Data, 13, 3691–3705, https://doi.org/10.5194/essd-13-3691-2021, https://doi.org/10.5194/essd-13-3691-2021, 2021
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This inventory fills the gap in African regional inventories, providing biofuel and fossil fuel emissions that take into account African specificities. It could be used for air quality modeling. We show that all pollutant emissions are globally increasing during the period 1990–2015. Also, West Africa and East Africa emissions are largely due to domestic fire and traffic activities, while southern Africa and northern Africa emissions are largely due to industrial and power plant sources.
Maurin Zouzoua, Fabienne Lohou, Paul Assamoi, Marie Lothon, Véronique Yoboue, Cheikh Dione, Norbert Kalthoff, Bianca Adler, Karmen Babić, Xabier Pedruzo-Bagazgoitia, and Solène Derrien
Atmos. Chem. Phys., 21, 2027–2051, https://doi.org/10.5194/acp-21-2027-2021, https://doi.org/10.5194/acp-21-2027-2021, 2021
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Based on a field experiment conducted in June and July 2016, we analyzed the daytime breakup of continental low-level stratiform clouds over southern West Africa in order to provide complementary guidance for model evaluation during the monsoon season. Those clouds exhibit weaker temperature and moisture jumps at the top compared to marine stratiform clouds. Their lifetime and the transition towards shallow convective clouds during daytime hours depend on their coupling with the surface.
Jean-François Léon, Aristide Barthélémy Akpo, Mouhamadou Bedou, Julien Djossou, Marleine Bodjrenou, Véronique Yoboué, and Cathy Liousse
Atmos. Chem. Phys., 21, 1815–1834, https://doi.org/10.5194/acp-21-1815-2021, https://doi.org/10.5194/acp-21-1815-2021, 2021
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We have investigated the aerosol optical depth (AOD) and its relation to PM2.5 surface concentrations in southern West Africa based on in situ observations (2015–2017 period) and MODIS satellite data (2003–2019). MODIS AODs are validated using a regional network of handheld and automatic sun photometers. Satellite-derived PM2.5 shows an increasing trend during the short dry period that is possibly linked to the increase in anthropogenic emission over this area.
Jan-Stefan Swartz, Pieter G. van Zyl, Johan P. Beukes, Corinne Galy-Lacaux, Avishkar Ramandh, and Jacobus J. Pienaar
Atmos. Chem. Phys., 20, 10637–10665, https://doi.org/10.5194/acp-20-10637-2020, https://doi.org/10.5194/acp-20-10637-2020, 2020
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Statistical modelling of interdependencies between local, regional and global parameters on long-term trends of atmospheric SO2, NO2 and O2 within proximity of the pollution hotspot in South Africa indicated that changes in meteorological conditions and/or variances in source influences contributed to temporal variability. The impact of increased anthropogenic activities and energy demand was evident, while the El Niño–Southern Oscillation made a significant contribution to O3 levels.
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Short summary
Ozone is a secondary air pollutant that is detrimental to human and plant health. A better understanding of its chemical evolution is a challenge for Africa, where it is still undersampled. Out of 14 sites examined (1995–2020), high levels of O3 are reported in southern Africa. The dominant chemical processes leading to O3 formation are identified. A decrease in O3 is observed at Katibougou (Mali) and Banizoumbou (Niger), and an increase is found at Zoétélé (Cameroon) and Skukuza (South Africa).
Ozone is a secondary air pollutant that is detrimental to human and plant health. A better...
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