Articles | Volume 19, issue 9
https://doi.org/10.5194/amt-19-3063-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/amt-19-3063-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
08 May 2026
Research article |
| 08 May 2026
| 08 May 2026
Ground-based monitoring of nitrogen dioxide in Kumasi, Ghana, and its comparison with satellite observations
Royal Netherlands Meteorological Institute (KNMI), De Bilt, 3730 AE, the Netherlands
Benjamin Afotey
Department of Chemical Engineering, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, 00233, Ghana
Tim Henrik Eckert
Delft University of Technology (TU Delft), Delft, 2600 GA, the Netherlands
Magdalena Mairhofer
Delft University of Technology (TU Delft), Delft, 2600 GA, the Netherlands
Águeda Gil Pascual
Delft University of Technology (TU Delft), Delft, 2600 GA, the Netherlands
Emmanuel Yuorkuu
Department of Chemical Engineering, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, 00233, Ghana
Philip Darko
Department of Chemical Engineering, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, 00233, Ghana
Phiona Amakah
Department of Chemical Engineering, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, 00233, Ghana
Klaas Folkert Boersma
Royal Netherlands Meteorological Institute (KNMI), De Bilt, 3730 AE, the Netherlands
Wageningen University, Meteorology and Air Quality Group, Wageningen, 6700 AA, the Netherlands
Prince Junior Asilevi
Department of Meteorology and Climate Science, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, 00233, Ghana
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Suvarna Fadnavis, Yasin Elshorbany, Jerald Ziemke, Brice Barret, Alexandru Rap, P. R. Satheesh Chandran, Richard J. Pope, Vijay Sagar, Domenico Taraborrelli, Eric Le Flochmoen, Juan Cuesta, Catherine Wespes, Folkert Boersma, Isolde Glissenaar, Isabelle De Smedt, Michel Van Roozendael, Hervé Petetin, and Isidora Anglou
Atmos. Chem. Phys., 25, 8229–8254, https://doi.org/10.5194/acp-25-8229-2025, https://doi.org/10.5194/acp-25-8229-2025, 2025
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Atmos. Meas. Tech., 18, 1961–1979, https://doi.org/10.5194/amt-18-1961-2025, https://doi.org/10.5194/amt-18-1961-2025, 2025
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Atmos. Chem. Phys., 25, 3313–3326, https://doi.org/10.5194/acp-25-3313-2025, https://doi.org/10.5194/acp-25-3313-2025, 2025
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Tobias Christoph Valentin Werner Riess, Klaas Folkert Boersma, Ward Van Roy, Jos de Laat, Enrico Dammers, and Jasper van Vliet
Atmos. Meas. Tech., 16, 5287–5304, https://doi.org/10.5194/amt-16-5287-2023, https://doi.org/10.5194/amt-16-5287-2023, 2023
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Satellite retrievals of trace gases require prior knowledge of the vertical distribution of the pollutant, which is usually obtained from models. Using aircraft-measured vertical NO2 profiles over the North Sea in summer 2021, we evaluate the Transport Model 5 profiles used in the TROPOMI NO2 retrieval. We conclude that driven by the low horizontal resolution and the overestimated vertical mixing, resulting NO2 columns are 20 % too low. This has important implications for emission estimates.
John Douros, Henk Eskes, Jos van Geffen, K. Folkert Boersma, Steven Compernolle, Gaia Pinardi, Anne-Marlene Blechschmidt, Vincent-Henri Peuch, Augustin Colette, and Pepijn Veefkind
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Viral Shah, Daniel J. Jacob, Ruijun Dang, Lok N. Lamsal, Sarah A. Strode, Stephen D. Steenrod, K. Folkert Boersma, Sebastian D. Eastham, Thibaud M. Fritz, Chelsea Thompson, Jeff Peischl, Ilann Bourgeois, Ilana B. Pollack, Benjamin A. Nault, Ronald C. Cohen, Pedro Campuzano-Jost, Jose L. Jimenez, Simone T. Andersen, Lucy J. Carpenter, Tomás Sherwen, and Mat J. Evans
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Qianqian Zhang, K. Folkert Boersma, Bin Zhao, Henk Eskes, Cuihong Chen, Haotian Zheng, and Xingying Zhang
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We developed an improved superposition column model and used the latest released (v2.3.1) TROPOMI satellite NO2 observations to estimate daily city-scale NOx and CO2 emissions. The results are verified against bottom-up emissions and OCO-2 XCO2 observations. We obtained the day-to-day variation of city NOx and CO2 emissions, allowing policymakers to gain real-time information on spatial–temporal emission patterns and the effectiveness of carbon and nitrogen regulation in urban environments.
Srijana Lama, Sander Houweling, K. Folkert Boersma, Ilse Aben, Hugo A. C. Denier van der Gon, and Maarten C. Krol
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Jos van Geffen, Henk Eskes, Steven Compernolle, Gaia Pinardi, Tijl Verhoelst, Jean-Christopher Lambert, Maarten Sneep, Mark ter Linden, Antje Ludewig, K. Folkert Boersma, and J. Pepijn Veefkind
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Tobias Christoph Valentin Werner Riess, Klaas Folkert Boersma, Jasper van Vliet, Wouter Peters, Maarten Sneep, Henk Eskes, and Jos van Geffen
Atmos. Meas. Tech., 15, 1415–1438, https://doi.org/10.5194/amt-15-1415-2022, https://doi.org/10.5194/amt-15-1415-2022, 2022
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This paper reports on improved monitoring of ship nitrogen oxide emissions by TROPOMI. With its fantastic resolution we can identify lanes of ship nitrogen dioxide (NO2) pollution not detected from space before. The quality of TROPOMI NO2 data over sea is improved further by recent upgrades in cloud retrievals and the use of sun glint scenes. Lastly, we study the impact of COVID-19 on ship NO2 in European seas and compare the found reductions to emission estimates gained from ship-specific data.
Auke J. Visser, Laurens N. Ganzeveld, Ignacio Goded, Maarten C. Krol, Ivan Mammarella, Giovanni Manca, and K. Folkert Boersma
Atmos. Chem. Phys., 21, 18393–18411, https://doi.org/10.5194/acp-21-18393-2021, https://doi.org/10.5194/acp-21-18393-2021, 2021
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Isabelle De Smedt, Gaia Pinardi, Corinne Vigouroux, Steven Compernolle, Alkis Bais, Nuria Benavent, Folkert Boersma, Ka-Lok Chan, Sebastian Donner, Kai-Uwe Eichmann, Pascal Hedelt, François Hendrick, Hitoshi Irie, Vinod Kumar, Jean-Christopher Lambert, Bavo Langerock, Christophe Lerot, Cheng Liu, Diego Loyola, Ankie Piters, Andreas Richter, Claudia Rivera Cárdenas, Fabian Romahn, Robert George Ryan, Vinayak Sinha, Nicolas Theys, Jonas Vlietinck, Thomas Wagner, Ting Wang, Huan Yu, and Michel Van Roozendael
Atmos. Chem. Phys., 21, 12561–12593, https://doi.org/10.5194/acp-21-12561-2021, https://doi.org/10.5194/acp-21-12561-2021, 2021
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Jianfeng Li, Yuhang Wang, Ruixiong Zhang, Charles Smeltzer, Andrew Weinheimer, Jay Herman, K. Folkert Boersma, Edward A. Celarier, Russell W. Long, James J. Szykman, Ruben Delgado, Anne M. Thompson, Travis N. Knepp, Lok N. Lamsal, Scott J. Janz, Matthew G. Kowalewski, Xiong Liu, and Caroline R. Nowlan
Atmos. Chem. Phys., 21, 11133–11160, https://doi.org/10.5194/acp-21-11133-2021, https://doi.org/10.5194/acp-21-11133-2021, 2021
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Comprehensive evaluations of simulated diurnal cycles of NO2 and NOy concentrations, vertical profiles, and tropospheric vertical column densities at two different resolutions with various measurements during the DISCOVER-AQ 2011 campaign show potential distribution biases of NOx emissions in the National Emissions Inventory 2011 at both 36 and 4 km resolutions, providing another possible explanation for the overestimation of model results.
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Short summary
We established the first Palmes tube laboratory in Sub-Saharan Africa to monitor urban nitrogen dioxide (NO2) in Kumasi, Ghana. Our measurements reveal high surface NO2 levels that satellites underestimate, showing the importance of local measurements. This low-cost, scalable approach provides continuous local data and improves the interpretation of satellite observations, helping policymakers better understand and manage air quality in tropical cities.
We established the first Palmes tube laboratory in Sub-Saharan Africa to monitor urban nitrogen...
