Articles | Volume 25, issue 14
https://doi.org/10.5194/acp-25-7777-2025
© Author(s) 2025. 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-25-7777-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Measurement report: Diurnal variability in NO2 and HCHO lower-tropospheric vertical profiles in southeastern Los Angeles
Department of Chemistry, Whittier College, Whittier, CA, USA
Lisa F. Hernandez
Department of Chemistry, Whittier College, Whittier, CA, USA
Leslie Tanaka
Department of Chemistry, Whittier College, Whittier, CA, USA
Alejandro Dunnick
Department of Chemistry, Whittier College, Whittier, CA, USA
Related authors
Nathaniel Brockway, Peter K. Peterson, Katja Bigge, Kristian D. Hajny, Paul B. Shepson, Kerri A. Pratt, Jose D. Fuentes, Tim Starn, Robert Kaeser, Brian H. Stirm, and William R. Simpson
Atmos. Chem. Phys., 24, 23–40, https://doi.org/10.5194/acp-24-23-2024, https://doi.org/10.5194/acp-24-23-2024, 2024
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Bromine monoxide (BrO) strongly affects atmospheric chemistry in the springtime Arctic, yet there are still many uncertainties around its sources and recycling, particularly in the context of a rapidly changing Arctic. In this study, we observed BrO as a function of altitude above the Alaskan Arctic. We found that BrO was often most concentrated near the ground, confirming the ability of snow to produce and recycle reactive bromine, and identified four common vertical distributions of BrO.
William R. Simpson, Peter K. Peterson, Udo Frieß, Holger Sihler, Johannes Lampel, Ulrich Platt, Chris Moore, Kerri Pratt, Paul Shepson, John Halfacre, and Son V. Nghiem
Atmos. Chem. Phys., 17, 9291–9309, https://doi.org/10.5194/acp-17-9291-2017, https://doi.org/10.5194/acp-17-9291-2017, 2017
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We investigated Arctic atmospheric bromine chemistry during March–April 2012 to improve understanding of the role of sea ice and cracks in sea ice (leads) in this phenomenon. We find that leads vertically redistribute reactive bromine but that open/re-freezing leads are not major direct reactive halogen sources. Surface ozone depletion affects the vertical distribution and amount of reactive halogens, and aerosol particles are necessary but not sufficient to maintain reactive bromine aloft.
Peter K. Peterson, Denis Pöhler, Holger Sihler, Johannes Zielcke, Stephan General, Udo Frieß, Ulrich Platt, William R. Simpson, Son V. Nghiem, Paul B. Shepson, Brian H. Stirm, Suresh Dhaniyala, Thomas Wagner, Dana R. Caulton, Jose D. Fuentes, and Kerri A. Pratt
Atmos. Chem. Phys., 17, 7567–7579, https://doi.org/10.5194/acp-17-7567-2017, https://doi.org/10.5194/acp-17-7567-2017, 2017
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High-spatial-resolution aircraft measurements in the Arctic showed the sustained transport of reactive bromine in a lofted layer via heterogeneous reactions on aerosol particles. This process provides an explanation for free tropospheric reactive bromine and the significant spatial extent of satellite-observed bromine monoxide. The knowledge gained herein improves our understanding of the fate and transport of atmospheric pollutants in the Arctic.
P. K. Peterson, W. R. Simpson, K. A. Pratt, P. B. Shepson, U. Frieß, J. Zielcke, U. Platt, S. J. Walsh, and S. V. Nghiem
Atmos. Chem. Phys., 15, 2119–2137, https://doi.org/10.5194/acp-15-2119-2015, https://doi.org/10.5194/acp-15-2119-2015, 2015
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We developed methods to measure the vertical distribution of bromine monoxide, a gas that oxidizes pollutants, above sea ice based upon MAX-DOAS observations from Barrow, Alaska, and find that atmospheric stability exerts a strong control on BrO's vertical distribution. Specifically, more stable (temperature inversion) situations result in BrO being closer to the ground while more neutral (not inverted) atmospheres allow BrO to ascend further aloft and grow to larger column abundance.
J. W. Halfacre, T. N. Knepp, P. B. Shepson, C. R. Thompson, K. A. Pratt, B. Li, P. K. Peterson, S. J. Walsh, W. R. Simpson, P. A. Matrai, J. W. Bottenheim, S. Netcheva, D. K. Perovich, and A. Richter
Atmos. Chem. Phys., 14, 4875–4894, https://doi.org/10.5194/acp-14-4875-2014, https://doi.org/10.5194/acp-14-4875-2014, 2014
Nathaniel Brockway, Peter K. Peterson, Katja Bigge, Kristian D. Hajny, Paul B. Shepson, Kerri A. Pratt, Jose D. Fuentes, Tim Starn, Robert Kaeser, Brian H. Stirm, and William R. Simpson
Atmos. Chem. Phys., 24, 23–40, https://doi.org/10.5194/acp-24-23-2024, https://doi.org/10.5194/acp-24-23-2024, 2024
Short summary
Short summary
Bromine monoxide (BrO) strongly affects atmospheric chemistry in the springtime Arctic, yet there are still many uncertainties around its sources and recycling, particularly in the context of a rapidly changing Arctic. In this study, we observed BrO as a function of altitude above the Alaskan Arctic. We found that BrO was often most concentrated near the ground, confirming the ability of snow to produce and recycle reactive bromine, and identified four common vertical distributions of BrO.
William R. Simpson, Peter K. Peterson, Udo Frieß, Holger Sihler, Johannes Lampel, Ulrich Platt, Chris Moore, Kerri Pratt, Paul Shepson, John Halfacre, and Son V. Nghiem
Atmos. Chem. Phys., 17, 9291–9309, https://doi.org/10.5194/acp-17-9291-2017, https://doi.org/10.5194/acp-17-9291-2017, 2017
Short summary
Short summary
We investigated Arctic atmospheric bromine chemistry during March–April 2012 to improve understanding of the role of sea ice and cracks in sea ice (leads) in this phenomenon. We find that leads vertically redistribute reactive bromine but that open/re-freezing leads are not major direct reactive halogen sources. Surface ozone depletion affects the vertical distribution and amount of reactive halogens, and aerosol particles are necessary but not sufficient to maintain reactive bromine aloft.
Peter K. Peterson, Denis Pöhler, Holger Sihler, Johannes Zielcke, Stephan General, Udo Frieß, Ulrich Platt, William R. Simpson, Son V. Nghiem, Paul B. Shepson, Brian H. Stirm, Suresh Dhaniyala, Thomas Wagner, Dana R. Caulton, Jose D. Fuentes, and Kerri A. Pratt
Atmos. Chem. Phys., 17, 7567–7579, https://doi.org/10.5194/acp-17-7567-2017, https://doi.org/10.5194/acp-17-7567-2017, 2017
Short summary
Short summary
High-spatial-resolution aircraft measurements in the Arctic showed the sustained transport of reactive bromine in a lofted layer via heterogeneous reactions on aerosol particles. This process provides an explanation for free tropospheric reactive bromine and the significant spatial extent of satellite-observed bromine monoxide. The knowledge gained herein improves our understanding of the fate and transport of atmospheric pollutants in the Arctic.
P. K. Peterson, W. R. Simpson, K. A. Pratt, P. B. Shepson, U. Frieß, J. Zielcke, U. Platt, S. J. Walsh, and S. V. Nghiem
Atmos. Chem. Phys., 15, 2119–2137, https://doi.org/10.5194/acp-15-2119-2015, https://doi.org/10.5194/acp-15-2119-2015, 2015
Short summary
Short summary
We developed methods to measure the vertical distribution of bromine monoxide, a gas that oxidizes pollutants, above sea ice based upon MAX-DOAS observations from Barrow, Alaska, and find that atmospheric stability exerts a strong control on BrO's vertical distribution. Specifically, more stable (temperature inversion) situations result in BrO being closer to the ground while more neutral (not inverted) atmospheres allow BrO to ascend further aloft and grow to larger column abundance.
J. W. Halfacre, T. N. Knepp, P. B. Shepson, C. R. Thompson, K. A. Pratt, B. Li, P. K. Peterson, S. J. Walsh, W. R. Simpson, P. A. Matrai, J. W. Bottenheim, S. Netcheva, D. K. Perovich, and A. Richter
Atmos. Chem. Phys., 14, 4875–4894, https://doi.org/10.5194/acp-14-4875-2014, https://doi.org/10.5194/acp-14-4875-2014, 2014
Related subject area
Subject: Gases | Research Activity: Remote Sensing | Altitude Range: Troposphere | Science Focus: Chemistry (chemical composition and reactions)
Biosphere–atmosphere related processes influence trace-gas and aerosol satellite–model biases
Estimation of diurnal emissions of CO2 from thermal power plants using spaceborne integrated path differential absorption (IPDA) lidar
Increase in carbon monoxide (CO) and aerosol optical depth (AOD) observed by satellites in the Northern Hemisphere over the summers of 2008–2023, linked to an increase in wildfires
Monitoring of total and off-road NOx emissions from Canadian oil sands surface mining using the Ozone Monitoring Instrument
Large reductions in satellite-derived and modelled European lower-tropospheric ozone during and after the COVID-19 pandemic (2020–2022)
Air quality trends and regimes in South Korea inferred from 2015–2023 surface and satellite observations
What can we learn about tropospheric OH from satellite observations of methane?
Identifying missing sources and reducing NOx emissions uncertainty over China using daily satellite data and a mass-conserving method
Feasibility of robust estimates of ozone production rates using a synergy of satellite observations, ground-based remote sensing, and models
Satellite Detection of NO2 Distributions and Comparison with Ground-Based Concentrations
Global Patterns and Trends in Ground-Level Ozone Chemical Formation Regimes from 1996 to 2022
Upper-tropospheric pollutants observed by MIPAS: geographic and seasonal variations
Comparing space-based to reported carbon monoxide emission estimates for Europe's iron and steel plants
Unleashing the potential of geostationary satellite observations in air quality forecasting through artificial intelligence techniques
Tropical upper-tropospheric trends in ozone and carbon monoxide (2005–2020): observational and model results
Global seasonal urban, industrial, and background NO2 estimated from TROPOMI satellite observations
Ground-based Tropospheric Ozone Measurements: Regional tropospheric ozone column trends from the TOAR-II/ HEGIFTOM homogenized datasets
Opposing trends in the peak and low ozone concentrations in eastern China: anthropogenic and meteorological influences
Quantifying biases in TROPESS AIRS, CrIS, and joint AIRS+OMI tropospheric ozone products using ozonesondes
Vertical profiles of global tropospheric nitrogen dioxide (NO2) obtained by cloud slicing the TROPOspheric Monitoring Instrument (TROPOMI)
Opinion: Beyond global means – novel space-based approaches to indirectly constrain the concentrations of and trends and variations in the tropospheric hydroxyl radical (OH)
Satellite-observed relationships between land cover, burned area, and atmospheric composition over the southern Amazon
Ammonia emission estimates using CrIS satellite observations over Europe
Insights into the long-term (2005–2021) spatiotemporal evolution of summer ozone production sensitivity in the Northern Hemisphere derived with the Ozone Monitoring Instrument (OMI)
Tropical tropospheric ozone distribution and trends from in situ and satellite data
Estimation of ground-level NO2 and its spatiotemporal variations in China using GEMS measurements and a nested machine learning model
Investigation of the impact of satellite vertical sensitivity on long-term retrieved lower-tropospheric ozone trends
Quantifying the diurnal variation in atmospheric NO2 from Geostationary Environment Monitoring Spectrometer (GEMS) observations
State-wide California 2020 Carbon Dioxide Budget Estimated with OCO-2 and OCO-3 satellite data
Ammonia in the upper troposphere–lower stratosphere (UTLS): GLORIA airborne measurements for CAMS model evaluation in the Asian monsoon and in biomass burning plumes above the South Atlantic
A lightweight NO2-to-NOx conversion model for quantifying NOx emissions of point sources from NO2 satellite observations
Towards a sector-specific CO∕CO2 emission ratio: satellite-based observations of CO release from steel production in Germany
Monitoring European anthropogenic NOx emissions from space
Global carbon emission accounting: national-level assessment of wildfire CO2 emission – a case study of China
Pyrogenic HONO seen from space: insights from global IASI observations
First evaluation of the GEMS formaldehyde product against TROPOMI and ground-based column measurements during the in-orbit test period
High-resolution mapping of nitrogen oxide emissions in large US cities from TROPOMI retrievals of tropospheric nitrogen dioxide columns
Quantifying the tropospheric ozone radiative effect and its temporal evolution in the satellite era
A satellite chronology of plumes from the April 2021 eruption of La Soufrière, St Vincent
Investigation of spatial and temporal variability in lower tropospheric ozone from RAL Space UV–Vis satellite products
Two years of satellite-based carbon dioxide emission quantification at the world's largest coal-fired power plants
Tropical tropospheric ozone and carbon monoxide distributions: characteristics, origins, and control factors, as seen by IAGOS and IASI
Investigation of the summer 2018 European ozone air pollution episodes using novel satellite data and modelling
Bridging the spatial gaps of the Ammonia Monitoring Network using satellite ammonia measurements
A roadmap to estimating agricultural ammonia volatilization over Europe using satellite observations and simulation data
Investigation of meteorological conditions and BrO during ozone depletion events in Ny-Ålesund between 2010 and 2021
Quantification of carbon monoxide emissions from African cities using TROPOMI
Nitrogen oxides emissions from selected cities in North America, Europe, and East Asia observed by the TROPOspheric Monitoring Instrument (TROPOMI) before and after the COVID-19 pandemic
Remotely sensed and surface measurement- derived mass-conserving inversion of daily NOx emissions and inferred combustion technologies in energy-rich northern China
Examining TROPOMI formaldehyde to nitrogen dioxide ratios in the Lake Michigan region: implications for ozone exceedances
Emma Sands, Ruth M. Doherty, Fiona M. O'Connor, Richard J. Pope, James Weber, and Daniel P. Grosvenor
Atmos. Chem. Phys., 25, 7269–7297, https://doi.org/10.5194/acp-25-7269-2025, https://doi.org/10.5194/acp-25-7269-2025, 2025
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We perform a detailed satellite–model comparison for isoprene, formaldehyde and aerosol optical depth in an Earth system model. We quantify the impacts of several processes that affect how biosphere–atmosphere interactions influence atmospheric chemistry and aerosols. Our findings highlight that the aerosol direct effect is sensitive to the processes studied. These results can inform future investigations of how the biosphere can affect atmospheric composition and climate.
Xuanye Zhang, Hailong Yang, Lingbing Bu, Zengchang Fan, Wei Xiao, Binglong Chen, Lu Zhang, Sihan Liu, Zhongting Wang, Jiqiao Liu, Weibiao Chen, and Xuhui Lee
Atmos. Chem. Phys., 25, 6725–6740, https://doi.org/10.5194/acp-25-6725-2025, https://doi.org/10.5194/acp-25-6725-2025, 2025
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This study utilized the IPDA (integrated path differential absorption) lidar on board the DQ-1 satellite to monitor emissions from localized strong point sources and, for the first time, observed the diurnal variation in CO2 emissions from a high-latitude power plant. Overall, power plant CO2 emissions were largely consistent with local electricity consumption patterns, with most plants emitting less at night than during the day and with higher emissions in winter compared to spring and autumn.
Antoine Ehret, Solène Turquety, Maya George, Juliette Hadji-Lazaro, and Cathy Clerbaux
Atmos. Chem. Phys., 25, 6365–6394, https://doi.org/10.5194/acp-25-6365-2025, https://doi.org/10.5194/acp-25-6365-2025, 2025
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Biomass burning has a considerable effect on the chemical composition of the atmosphere and climate, due to the emission of trace gases and aerosols. We examine the relationship between fire variability and the values of carbon monoxide and aerosol optical depth observed by satellites. The observed increase in wildfires has led to a corresponding rise in the mean and extreme values of carbon monoxide and aerosol optical depth during the summer and early autumn across the Northern Hemisphere.
Chris A. McLinden, Debora Griffin, Vitali Fioletov, Junhua Zhang, Enrico Dammers, Cristen Adams, Mallory Loria, Nickolay Krotkov, and Lok N. Lamsal
Atmos. Chem. Phys., 25, 6093–6120, https://doi.org/10.5194/acp-25-6093-2025, https://doi.org/10.5194/acp-25-6093-2025, 2025
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The Ozone Monitoring Instrument (OMI) was used to understand the evolution of NOx emissions from the Canadian oil sands. OMI NO2 combined with winds and reported stack emissions found emissions from the heavy-hauler mine fleet have remained flat since 2005, whereas the total oil sands mined have more than doubled. This difference is a result of emissions standards that limit NOx emissions becoming more stringent over this period, confirming the efficacy of the policy enacting these standards.
Matilda A. Pimlott, Richard J. Pope, Brian J. Kerridge, Richard Siddans, Barry G. Latter, Lucy J. Ventress, Wuhu Feng, and Martyn P. Chipperfield
Atmos. Chem. Phys., 25, 4391–4401, https://doi.org/10.5194/acp-25-4391-2025, https://doi.org/10.5194/acp-25-4391-2025, 2025
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Globally, lockdowns were implemented to limit the spread of COVID-19, leading to a decrease in emissions of key air pollutants. Here, we use novel satellite data and a chemistry model to investigate the impact of the pandemic on tropospheric ozone (O3), a key pollutant, in 2020. Overall, we found substantial decreases of up to 20 %, two-thirds of which came from emission reductions, while one-third was due to a decrease in the stratospheric O3 flux into the troposphere.
Yujin J. Oak, Daniel J. Jacob, Drew C. Pendergrass, Ruijun Dang, Nadia K. Colombi, Heesung Chong, Seoyoung Lee, Su Keun Kuk, and Jhoon Kim
Atmos. Chem. Phys., 25, 3233–3252, https://doi.org/10.5194/acp-25-3233-2025, https://doi.org/10.5194/acp-25-3233-2025, 2025
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We analyze 2015–2023 air quality trends in South Korea using surface and satellite observations. Primary pollutants have decreased, consistent with emissions reductions. Surface O3 continues to increase and PM2.5 has decreased overall, but the nitrate component has not. O3 and PM2.5 nitrate depend on nonlinear responses from precursor emissions. Satellite data indicate a recent shift to NOx-sensitive O3 and nitrate formation, where further NOx reductions will benefit both O3 and PM2.5 pollution.
Elise Penn, Daniel J. Jacob, Zichong Chen, James D. East, Melissa P. Sulprizio, Lori Bruhwiler, Joannes D. Maasakkers, Hannah Nesser, Zhen Qu, Yuzhong Zhang, and John Worden
Atmos. Chem. Phys., 25, 2947–2965, https://doi.org/10.5194/acp-25-2947-2025, https://doi.org/10.5194/acp-25-2947-2025, 2025
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The hydroxyl radical (OH) destroys many air pollutants, including methane. Global-mean OH cannot be directly measured, and thus it is inferred with the methyl chloroform (MCF) proxy. MCF is decreasing, and a replacement is needed. We use satellite observations of methane in two spectral ranges as a proxy for OH. We find shortwave infrared observations can characterize yearly OH and its seasonality but not the latitudinal distribution. Thermal infrared observations add little information.
Lingxiao Lu, Jason Blake Cohen, Kai Qin, Xiaolu Li, and Qin He
Atmos. Chem. Phys., 25, 2291–2309, https://doi.org/10.5194/acp-25-2291-2025, https://doi.org/10.5194/acp-25-2291-2025, 2025
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This study applies an approach that assimilates NO2 vertical column densities from TROPOMI in a mass-conserving manner and inverts daily NOx emissions, presented over rapidly changing regions in China. Source attribution is quantified by the local thermodynamics of the combustion temperature (NOx/NO2). Emission results identify sources which do not exist in the a priori datasets, especially medium industrial sources located next to the Yangtze River.
Amir H. Souri, Gonzalo González Abad, Glenn M. Wolfe, Tijl Verhoelst, Corinne Vigouroux, Gaia Pinardi, Steven Compernolle, Bavo Langerock, Bryan N. Duncan, and Matthew S. Johnson
Atmos. Chem. Phys., 25, 2061–2086, https://doi.org/10.5194/acp-25-2061-2025, https://doi.org/10.5194/acp-25-2061-2025, 2025
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We establish a simple yet robust relationship between ozone production rates and geophysical parameters obtained from several intensive atmospheric composition campaigns. We show that satellite remote sensing data can effectively constrain these parameters, enabling us to produce the first global maps of ozone production rates with unprecedented resolution.
Summer Joy Acker, Tracey Holloway, and Monica K. Harkey
EGUsphere, https://doi.org/10.5194/egusphere-2025-226, https://doi.org/10.5194/egusphere-2025-226, 2025
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Nitrogen dioxide (NO2) is a harmful air pollutant linked to heart and lung diseases, regulated in the U.S. through annual and 1-hour standards. Most areas lack ground monitors, so satellites can help fill this gap. While past studies showed satellites capture annual NO2 patterns well, we assess their ability to reflect 1-hour pollution levels. We find satellites perform best farther from roads and in winter. TEMPO, a new satellite taking hourly measurements, improves the detection of higher NO2.
Yu Tian, Siyi Wang, and Xiaomeng Jin
EGUsphere, https://doi.org/10.5194/egusphere-2025-368, https://doi.org/10.5194/egusphere-2025-368, 2025
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We leverage over two-decade ground-based ozone observations alongside space-based observations of ozone precursors (NO2 and formaldehyde) to study the long-term evolution in ozone chemical regimes across global source regions. We find a global trend towards NOx-limited regimes, supported by increasing satellite-based HCHO/NO2 and a diminishing ozone weekend effect.
Norbert Glatthor, Gabriele P. Stiller, Thomas von Clarmann, Bernd Funke, Sylvia Kellmann, and Andrea Linden
Atmos. Chem. Phys., 25, 1175–1208, https://doi.org/10.5194/acp-25-1175-2025, https://doi.org/10.5194/acp-25-1175-2025, 2025
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We present global upper-tropospheric distributions of the pollutants HCN, CO, C2H2, C2H6, PAN, and HCOOH, observed between 2002 and 2012 by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on the Environmental Satellite (Envisat). By comparing the spatial distributions of their volume mixing ratios and by global correlation and regression analyses, we draw conclusions on their sources, such as biomass burning, anthropogenic sources, and biogenic release.
Gijs Leguijt, Joannes D. Maasakkers, Hugo A. C. Denier van der Gon, Arjo J. Segers, Tobias Borsdorff, Ivar R. van der Velde, and Ilse Aben
Atmos. Chem. Phys., 25, 555–574, https://doi.org/10.5194/acp-25-555-2025, https://doi.org/10.5194/acp-25-555-2025, 2025
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The production of steel coincides with large emissions of greenhouse gases and air pollutants including carbon monoxide. European facilities are required to report their emissions, which are estimated using a variety of methods. We evaluate these estimates using carbon monoxide concentrations measured via satellite. We find generally good agreement between our values and those reported but also identify some uncertainties, showing that satellites can provide insights into these emissions.
Chengxin Zhang, Xinhan Niu, Hongyu Wu, Zhipeng Ding, Ka Lok Chan, Jhoon Kim, Thomas Wagner, and Cheng Liu
Atmos. Chem. Phys., 25, 759–770, https://doi.org/10.5194/acp-25-759-2025, https://doi.org/10.5194/acp-25-759-2025, 2025
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This research utilizes hourly air pollution observations from the world’s first geostationary satellite to develop a spatiotemporal neural network model for full-coverage surface NO2 pollution prediction over the next 24 hours, achieving outstanding forecasting performance and efficacy. These results highlight the profound impact of geostationary satellite observations in advancing air quality forecasting models, thereby contributing to future models for health exposure to air pollution.
Lucien Froidevaux, Douglas E. Kinnison, Benjamin Gaubert, Michael J. Schwartz, Nathaniel J. Livesey, William G. Read, Charles G. Bardeen, Jerry R. Ziemke, and Ryan A. Fuller
Atmos. Chem. Phys., 25, 597–624, https://doi.org/10.5194/acp-25-597-2025, https://doi.org/10.5194/acp-25-597-2025, 2025
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We compare observed changes in ozone (O3) and carbon monoxide (CO) in the tropical upper troposphere (10–15 km altitude) for 2005–2020 to predictions from model simulations that track the evolution of natural and industrial emissions transported to this region. An increasing trend in measured upper-tropospheric O3 is well matched by model trends. We find that changes in modeled industrial CO surface emissions lead to better model agreement with observed slight decreases in upper-tropospheric CO.
Vitali Fioletov, Chris A. McLinden, Debora Griffin, Xiaoyi Zhao, and Henk Eskes
Atmos. Chem. Phys., 25, 575–596, https://doi.org/10.5194/acp-25-575-2025, https://doi.org/10.5194/acp-25-575-2025, 2025
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Satellite data were used to estimate urban per capita emissions for 261 major cities worldwide. Three components in tropospheric NO2 data (background NO2, NO2 from urban sources, and NO2 from industrial point sources) were isolated, and then each of these components was analyzed separately. The largest per capita emissions were found in the Middle East and the smallest in India and southern Africa. Urban weekend emissions are 20 %–50 % less than workday emissions for all regions except China.
Roeland Van Malderen, Zhou Zang, Kai-Lan Chang, Robin Björklund, Owen R. Cooper, Jane Liu, Eliane Maillard Barras, Corinne Vigouroux, Irina Petropavlovskikh, Thierry Leblanc, Valérie Thouret, Pawel Wolff, Peter Effertz, Audrey Gaudel, David W. Tarasick, Herman G. J. Smit, Anne M. Thompson, Ryan M. Stauffer, Debra E. Kollonige, Deniz Poyraz, Gérard Ancellet, Marie-Renée De Backer, Matthias M. Frey, James W. Hannigan, José L. Hernandez, Bryan J. Johnson, Nicholas Jones, Rigel Kivi, Emmanuel Mahieu, Isamu Morino, Glen McConville, Katrin Müller, Isao Murata, Justus Notholt, Ankie Piters, Maxime Prignon, Richard Querel, Vincenzo Rizi, Dan Smale, Wolfgang Steinbrecht, Kimberly Strong, and Ralf Sussmann
EGUsphere, https://doi.org/10.5194/egusphere-2024-3745, https://doi.org/10.5194/egusphere-2024-3745, 2025
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Tropospheric ozone is an important greenhouse gas and an air pollutant, whose distribution and time variability is mainly governed by anthropogenic emissions and dynamics. In this paper, we assess regional trends of tropospheric ozone column amounts, based on two different approaches of merging or synthesizing ground-based observations and their trends within specific regions. Our findings clearly demonstrate regional trend differences, but also consistently higher pre- than post-COVID trends.
Zhuang Wang, Chune Shi, Hao Zhang, Xianguang Ji, Yizhi Zhu, Congzi Xia, Xiaoyun Sun, Xinfeng Lin, Shaowei Yan, Suyao Wang, Yuan Zhou, Chengzhi Xing, Yujia Chen, and Cheng Liu
Atmos. Chem. Phys., 25, 347–366, https://doi.org/10.5194/acp-25-347-2025, https://doi.org/10.5194/acp-25-347-2025, 2025
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This study attempts to explain the surface ozone background and typical and peak trends in eastern China by combining a large number of ground-based and satellite observations. We found diametrically opposed trends in peak (decreasing) and low (increasing) ozone concentrations. Anthropogenic emissions primarily drive trends in low and peak ozone concentrations in eastern China, though meteorological effects also play a role.
Elyse A. Pennington, Gregory B. Osterman, Vivienne H. Payne, Kazuyuki Miyazaki, Kevin W. Bowman, and Jessica L. Neu
EGUsphere, https://doi.org/10.5194/egusphere-2024-3701, https://doi.org/10.5194/egusphere-2024-3701, 2024
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Tropospheric ozone is a harmful pollutant & powerful greenhouse gas. For satellite products to accurately quantify trends in tropospheric ozone, they must have low bias compared to a reliable source of data. This study compares 3 TROPESS satellite products – CrIS, AIRS, & AIRSOMI – to ozonesonde data. They have low global measurement bias & thus can be used to detect global tropospheric ozone trends, but the measurement bias should be considered in certain regions & time periods.
Rebekah P. Horner, Eloise A. Marais, Nana Wei, Robert G. Ryan, and Viral Shah
Atmos. Chem. Phys., 24, 13047–13064, https://doi.org/10.5194/acp-24-13047-2024, https://doi.org/10.5194/acp-24-13047-2024, 2024
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Nitrogen oxides (NOx ≡ NO + NO2) affect tropospheric ozone and the hydroxyl radical, influencing climate and atmospheric oxidation. To address the lack of routine observations of NOx, we cloud slice satellite observations of NO2 to derive a new dataset of global vertical profiles of NO2. We evaluate our data against in situ aircraft observations and use these data to critique the contemporary understanding of tropospheric NOx, as simulated by the GEOS-Chem model.
Bryan N. Duncan, Daniel C. Anderson, Arlene M. Fiore, Joanna Joiner, Nickolay A. Krotkov, Can Li, Dylan B. Millet, Julie M. Nicely, Luke D. Oman, Jason M. St. Clair, Joshua D. Shutter, Amir H. Souri, Sarah A. Strode, Brad Weir, Glenn M. Wolfe, Helen M. Worden, and Qindan Zhu
Atmos. Chem. Phys., 24, 13001–13023, https://doi.org/10.5194/acp-24-13001-2024, https://doi.org/10.5194/acp-24-13001-2024, 2024
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Trace gases emitted to or formed within the atmosphere may be chemically or physically removed from the atmosphere. One trace gas, the hydroxyl radical (OH), is responsible for initiating the chemical removal of many trace gases, including some greenhouse gases. Despite its importance, scientists have not been able to adequately measure OH. In this opinion piece, we discuss promising new methods to indirectly constrain OH using satellite data of trace gases that control the abundance of OH.
Emma Sands, Richard J. Pope, Ruth M. Doherty, Fiona M. O'Connor, Chris Wilson, and Hugh Pumphrey
Atmos. Chem. Phys., 24, 11081–11102, https://doi.org/10.5194/acp-24-11081-2024, https://doi.org/10.5194/acp-24-11081-2024, 2024
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Changes in vegetation alongside biomass burning impact regional atmospheric composition and air quality. Using satellite remote sensing, we find a clear linear relationship between forest cover and isoprene and a pronounced non-linear relationship between burned area and nitrogen dioxide in the southern Amazon, a region of substantial deforestation. These quantified relationships can be used for model evaluation and further exploration of biosphere-atmosphere interactions in Earth System Models.
Jieying Ding, Ronald van der A, Henk Eskes, Enrico Dammers, Mark Shephard, Roy Wichink Kruit, Marc Guevara, and Leonor Tarrason
Atmos. Chem. Phys., 24, 10583–10599, https://doi.org/10.5194/acp-24-10583-2024, https://doi.org/10.5194/acp-24-10583-2024, 2024
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Here we applied the existing Daily Emissions Constrained by Satellite Observations (DECSO) inversion algorithm to NH3 observations from the CrIS satellite instrument to estimate NH3 emissions. As NH3 in the atmosphere is influenced by NOx, we implemented DECSO to estimate NOx and NH3 emissions simultaneously. The emissions are derived over Europe for 2020 at a spatial resolution of 0.2° using daily observations from CrIS and TROPOMI. Results are compared to bottom-up emission inventories.
Matthew S. Johnson, Sajeev Philip, Scott Meech, Rajesh Kumar, Meytar Sorek-Hamer, Yoichi P. Shiga, and Jia Jung
Atmos. Chem. Phys., 24, 10363–10384, https://doi.org/10.5194/acp-24-10363-2024, https://doi.org/10.5194/acp-24-10363-2024, 2024
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Satellites, like the Ozone Monitoring Instrument (OMI), retrieve proxy species of ozone (O3) formation (formaldehyde and nitrogen dioxide) and the ratios (FNRs) which can define O3 production sensitivity regimes. Here we investigate trends of OMI FNRs from 2005 to 2021, and they have increased in major cities, suggesting a transition from radical- to NOx-limited regimes. OMI also observed the impact of reduced emissions during the 2020 COVID-19 lockdown that resulted in increased FNRs.
Audrey Gaudel, Ilann Bourgeois, Meng Li, Kai-Lan Chang, Jerald Ziemke, Bastien Sauvage, Ryan M. Stauffer, Anne M. Thompson, Debra E. Kollonige, Nadia Smith, Daan Hubert, Arno Keppens, Juan Cuesta, Klaus-Peter Heue, Pepijn Veefkind, Kenneth Aikin, Jeff Peischl, Chelsea R. Thompson, Thomas B. Ryerson, Gregory J. Frost, Brian C. McDonald, and Owen R. Cooper
Atmos. Chem. Phys., 24, 9975–10000, https://doi.org/10.5194/acp-24-9975-2024, https://doi.org/10.5194/acp-24-9975-2024, 2024
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The study examines tropical tropospheric ozone changes. In situ data from 1994–2019 display increased ozone, notably over India, Southeast Asia, and Malaysia and Indonesia. Sparse in situ data limit trend detection for the 15-year period. In situ and satellite data, with limited sampling, struggle to consistently detect trends. Continuous observations are vital over the tropical Pacific Ocean, Indian Ocean, western Africa, and South Asia for accurate ozone trend estimation in these regions.
Naveed Ahmad, Changqing Lin, Alexis K. H. Lau, Jhoon Kim, Tianshu Zhang, Fangqun Yu, Chengcai Li, Ying Li, Jimmy C. H. Fung, and Xiang Qian Lao
Atmos. Chem. Phys., 24, 9645–9665, https://doi.org/10.5194/acp-24-9645-2024, https://doi.org/10.5194/acp-24-9645-2024, 2024
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This study developed a nested machine learning model to convert the GEMS NO2 column measurements into ground-level concentrations across China. The model directly incorporates the NO2 mixing height (NMH) into the methodological framework. The study underscores the importance of considering NMH when estimating ground-level NO2 from satellite column measurements and highlights the significant advantages of new-generation geostationary satellites in air quality monitoring.
Richard J. Pope, Fiona M. O'Connor, Mohit Dalvi, Brian J. Kerridge, Richard Siddans, Barry G. Latter, Brice Barret, Eric Le Flochmoen, Anne Boynard, Martyn P. Chipperfield, Wuhu Feng, Matilda A. Pimlott, Sandip S. Dhomse, Christian Retscher, Catherine Wespes, and Richard Rigby
Atmos. Chem. Phys., 24, 9177–9195, https://doi.org/10.5194/acp-24-9177-2024, https://doi.org/10.5194/acp-24-9177-2024, 2024
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Ozone is a potent air pollutant in the lower troposphere, with adverse impacts on human health. Satellite records of tropospheric ozone currently show large-scale inconsistencies in long-term trends. Our detailed study of the potential factors (e.g. satellite errors, where the satellite can observe ozone) potentially driving these inconsistencies found that, in North America, Europe, and East Asia, the underlying trends are typically small with large uncertainties.
David P. Edwards, Sara Martínez-Alonso, Duseong S. Jo, Ivan Ortega, Louisa K. Emmons, John J. Orlando, Helen M. Worden, Jhoon Kim, Hanlim Lee, Junsung Park, and Hyunkee Hong
Atmos. Chem. Phys., 24, 8943–8961, https://doi.org/10.5194/acp-24-8943-2024, https://doi.org/10.5194/acp-24-8943-2024, 2024
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Until recently, satellite observations of atmospheric pollutants at any location could only be obtained once a day. New geostationary satellites stare at a region of the Earth to make hourly measurements, and the Geostationary Environment Monitoring Spectrometer is the first looking at Asia. These data and model simulations show how the change seen for one important pollutant that determines air quality depends on a combination of pollution emissions, atmospheric chemistry, and meteorology.
Matthew S. Johnson, Sofia D. Hamilton, Seongeun Jeong, Yuyan Cui, Dien Wu, Alex Turner, and Marc Fischer
EGUsphere, https://doi.org/10.5194/egusphere-2024-2152, https://doi.org/10.5194/egusphere-2024-2152, 2024
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Satellites, such as NASA’s Orbiting Carbon Observatory-2 and -3 (OCO-2/3), retrieve carbon dioxide (CO2) concentrations which provide vital information for estimating surface CO2 emissions. Here we investigate the ability of OCO-2/3 retrievals to constrain CO2 emissions for the state of California for the major emission sectors (i.e., fossil fuels, net ecosystem exchange, wildfire).
Sören Johansson, Michael Höpfner, Felix Friedl-Vallon, Norbert Glatthor, Thomas Gulde, Vincent Huijnen, Anne Kleinert, Erik Kretschmer, Guido Maucher, Tom Neubert, Hans Nordmeyer, Christof Piesch, Peter Preusse, Martin Riese, Björn-Martin Sinnhuber, Jörn Ungermann, Gerald Wetzel, and Wolfgang Woiwode
Atmos. Chem. Phys., 24, 8125–8138, https://doi.org/10.5194/acp-24-8125-2024, https://doi.org/10.5194/acp-24-8125-2024, 2024
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We present airborne infrared limb sounding GLORIA measurements of ammonia (NH3) in the upper troposphere of air masses within the Asian monsoon and of those connected with biomass burning. Comparing CAMS (Copernicus Atmosphere Monitoring Service) model data, we find that the model reproduces the measured enhanced NH3 within the Asian monsoon well but not that within biomass burning plumes, where no enhanced NH3 is measured in the upper troposphere but considerable amounts are simulated by CAMS.
Sandro Meier, Erik F. M. Koene, Maarten Krol, Dominik Brunner, Alexander Damm, and Gerrit Kuhlmann
Atmos. Chem. Phys., 24, 7667–7686, https://doi.org/10.5194/acp-24-7667-2024, https://doi.org/10.5194/acp-24-7667-2024, 2024
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Nitrogen oxides (NOx = NO + NO2) are important air pollutants. This study addresses the challenge of accurately estimating NOx emissions from NO2 satellite observations. We develop a realistic model to convert NO2 to NOx by using simulated plumes from various power plants. We apply the model to satellite NO2 observations, significantly reducing biases in estimated NOx emissions. The study highlights the potential for a consistent, high-resolution estimation of NOx emissions using satellite data.
Oliver Schneising, Michael Buchwitz, Maximilian Reuter, Michael Weimer, Heinrich Bovensmann, John P. Burrows, and Hartmut Bösch
Atmos. Chem. Phys., 24, 7609–7621, https://doi.org/10.5194/acp-24-7609-2024, https://doi.org/10.5194/acp-24-7609-2024, 2024
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Large quantities of CO and CO2 are emitted during conventional steel production. As satellite-based estimates of CO2 emissions at the facility level are challenging, co-emitted CO can indicate the carbon footprint of steel plants. We estimate CO emissions for German steelworks and use CO2 emissions from emissions trading data to derive a sector-specific CO/CO2 emission ratio for the steel industry; it is a prerequisite to use CO as a proxy for CO2 emissions from similar steel production sites.
Ronald J. van der A, Jieying Ding, and Henk Eskes
Atmos. Chem. Phys., 24, 7523–7534, https://doi.org/10.5194/acp-24-7523-2024, https://doi.org/10.5194/acp-24-7523-2024, 2024
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Using observations of the Sentinel-5P satellite and the latest version of the inversion algorithm DECSO, anthropogenic NOx emissions are derived for Europe for the years 2019–2022 with a spatial resolution of 0.2°. The results are compared with European emissions of the Copernicus Atmosphere Monitoring Service.
Xuehong Gong, Zeyu Liu, Jie Tian, Qiyuan Wang, Guohui Li, Zhisheng An, and Yongming Han
EGUsphere, https://doi.org/10.5194/egusphere-2024-1684, https://doi.org/10.5194/egusphere-2024-1684, 2024
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Our study analyzed CO2 emissions from wildfires in China from 2001 to 2022. Cropland and forest fires contributed the most, while grassland fires were the least. Emissions from forest and shrub fires decreased significantly, while cropland fires increased. The highest emissions were in Heilongjiang and Inner Mongolia. China's effective policy management has reduced wildfire-related CO2 emissions, aiding global climate change efforts.
Bruno Franco, Lieven Clarisse, Nicolas Theys, Juliette Hadji-Lazaro, Cathy Clerbaux, and Pierre Coheur
Atmos. Chem. Phys., 24, 4973–5007, https://doi.org/10.5194/acp-24-4973-2024, https://doi.org/10.5194/acp-24-4973-2024, 2024
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Using IASI global infrared measurements, we retrieve nitrous acid (HONO) in fire plumes from space. We detect large enhancements of pyrogenic HONO worldwide, especially from intense wildfires at Northern Hemisphere mid- and high latitudes. Predominance of IASI nighttime over daytime measurements sheds light on HONO's extended lifetime and secondary formation during long-range transport in smoke plumes. Our findings deepen the understanding of atmospheric HONO, crucial for air quality assessment.
Gitaek T. Lee, Rokjin J. Park, Hyeong-Ahn Kwon, Eunjo S. Ha, Sieun D. Lee, Seunga Shin, Myoung-Hwan Ahn, Mina Kang, Yong-Sang Choi, Gyuyeon Kim, Dong-Won Lee, Deok-Rae Kim, Hyunkee Hong, Bavo Langerock, Corinne Vigouroux, Christophe Lerot, Francois Hendrick, Gaia Pinardi, Isabelle De Smedt, Michel Van Roozendael, Pucai Wang, Heesung Chong, Yeseul Cho, and Jhoon Kim
Atmos. Chem. Phys., 24, 4733–4749, https://doi.org/10.5194/acp-24-4733-2024, https://doi.org/10.5194/acp-24-4733-2024, 2024
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This study evaluates the Geostationary Environment Monitoring Spectrometer (GEMS) HCHO product by comparing its vertical column densities (VCDs) with those of TROPOMI and ground-based observations. Based on some sensitivity tests, obtaining radiance references under clear-sky conditions significantly improves HCHO retrieval quality. GEMS HCHO VCDs captured seasonal and diurnal variations well during the first year of observation, showing consistency with TROPOMI and ground-based observations.
Fei Liu, Steffen Beirle, Joanna Joiner, Sungyeon Choi, Zhining Tao, K. Emma Knowland, Steven J. Smith, Daniel Q. Tong, Siqi Ma, Zachary T. Fasnacht, and Thomas Wagner
Atmos. Chem. Phys., 24, 3717–3728, https://doi.org/10.5194/acp-24-3717-2024, https://doi.org/10.5194/acp-24-3717-2024, 2024
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Using satellite data, we developed a coupled method independent of the chemical transport model to map NOx emissions across US cities. After validating our technique with synthetic data, we charted NOx emissions from 2018–2021 in 39 cities. Our results closely matched EPA estimates but also highlighted some inconsistencies in both magnitude and spatial distribution. This research can help refine strategies for monitoring and managing air quality.
Richard J. Pope, Alexandru Rap, Matilda A. Pimlott, Brice Barret, Eric Le Flochmoen, Brian J. Kerridge, Richard Siddans, Barry G. Latter, Lucy J. Ventress, Anne Boynard, Christian Retscher, Wuhu Feng, Richard Rigby, Sandip S. Dhomse, Catherine Wespes, and Martyn P. Chipperfield
Atmos. Chem. Phys., 24, 3613–3626, https://doi.org/10.5194/acp-24-3613-2024, https://doi.org/10.5194/acp-24-3613-2024, 2024
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Tropospheric ozone is an important short-lived climate forcer which influences the incoming solar short-wave radiation and the outgoing long-wave radiation in the atmosphere (8–15 km) where the balance between the two yields a net positive (i.e. warming) effect at the surface. Overall, we find that the tropospheric ozone radiative effect ranges between 1.21 and 1.26 W m−2 with a negligible trend (2008–2017), suggesting that tropospheric ozone influences on climate have remained stable with time.
Isabelle A. Taylor, Roy G. Grainger, Andrew T. Prata, Simon R. Proud, Tamsin A. Mather, and David M. Pyle
Atmos. Chem. Phys., 23, 15209–15234, https://doi.org/10.5194/acp-23-15209-2023, https://doi.org/10.5194/acp-23-15209-2023, 2023
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This study looks at sulfur dioxide (SO2) and ash emissions from the April 2021 eruption of La Soufrière on St Vincent. Using satellite data, 35 eruptive events were identified. Satellite data were used to track SO2 as it was transported around the globe. The majority of SO2 was emitted into the upper troposphere and lower stratosphere. Similarities with the 1979 eruption of La Soufrière highlight the value of studying these eruptions to be better prepared for future eruptions.
Richard J. Pope, Brian J. Kerridge, Richard Siddans, Barry G. Latter, Martyn P. Chipperfield, Wuhu Feng, Matilda A. Pimlott, Sandip S. Dhomse, Christian Retscher, and Richard Rigby
Atmos. Chem. Phys., 23, 14933–14947, https://doi.org/10.5194/acp-23-14933-2023, https://doi.org/10.5194/acp-23-14933-2023, 2023
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Ozone is a potent air pollutant, and we present the first study to investigate long-term changes in lower tropospheric column ozone (LTCO3) from space. We have constructed a merged LTCO3 dataset from GOME-1, SCIAMACHY and OMI between 1996 and 2017. Comparing LTCO3 between the 1996–2000 and 2013–2017 5-year averages, we find significant positive increases in the tropics/sub-tropics, while in the northern mid-latitudes, we find small-scale differences.
Daniel H. Cusworth, Andrew K. Thorpe, Charles E. Miller, Alana K. Ayasse, Ralph Jiorle, Riley M. Duren, Ray Nassar, Jon-Paul Mastrogiacomo, and Robert R. Nelson
Atmos. Chem. Phys., 23, 14577–14591, https://doi.org/10.5194/acp-23-14577-2023, https://doi.org/10.5194/acp-23-14577-2023, 2023
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Carbon dioxide (CO2) emissions from combustion sources are uncertain in many places across the globe. Satellites have the ability to detect and quantify emissions from large CO2 point sources, including coal-fired power plants. In this study, we tasked two satellites to routinely observe CO2 emissions at 30 coal-fired power plants between 2021 and 2022. These results present the largest dataset of space-based CO2 emission estimates to date.
Maria Tsivlidou, Bastien Sauvage, Yasmine Bennouna, Romain Blot, Damien Boulanger, Hannah Clark, Eric Le Flochmoën, Philippe Nédélec, Valérie Thouret, Pawel Wolff, and Brice Barret
Atmos. Chem. Phys., 23, 14039–14063, https://doi.org/10.5194/acp-23-14039-2023, https://doi.org/10.5194/acp-23-14039-2023, 2023
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The tropics are a region where the ozone increase has been most apparent since 1980 and where observations are sparse. Using aircraft, satellite, and model data, we document the characteristics of tropospheric ozone and CO over the whole tropics for the last 2 decades. We explore the origin of the observed CO anomalies and investigate transport processes driving the tropical CO and O3 distribution. Our study highlights the importance of anthropogenic emissions, mostly over the northern tropics.
Richard J. Pope, Brian J. Kerridge, Martyn P. Chipperfield, Richard Siddans, Barry G. Latter, Lucy J. Ventress, Matilda A. Pimlott, Wuhu Feng, Edward Comyn-Platt, Garry D. Hayman, Stephen R. Arnold, and Ailish M. Graham
Atmos. Chem. Phys., 23, 13235–13253, https://doi.org/10.5194/acp-23-13235-2023, https://doi.org/10.5194/acp-23-13235-2023, 2023
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In the summer of 2018, Europe experienced several persistent large-scale ozone (O3) pollution episodes. Satellite tropospheric O3 and surface O3 data recorded substantial enhancements in 2018 relative to other years. Targeted model simulations showed that meteorological processes and emissions controlled the elevated surface O3, while mid-tropospheric O3 enhancements were dominated by stratospheric O3 intrusion and advection of North Atlantic O3-rich air masses into Europe.
Rui Wang, Da Pan, Xuehui Guo, Kang Sun, Lieven Clarisse, Martin Van Damme, Pierre-François Coheur, Cathy Clerbaux, Melissa Puchalski, and Mark A. Zondlo
Atmos. Chem. Phys., 23, 13217–13234, https://doi.org/10.5194/acp-23-13217-2023, https://doi.org/10.5194/acp-23-13217-2023, 2023
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Ammonia (NH3) is a key precursor for fine particulate matter (PM2.5) and a primary form of reactive nitrogen, yet it has sparse ground measurements. We perform the first comprehensive comparison between ground observations and satellite retrievals in the US, demonstrating that satellite NH3 data can help fill spatial gaps in the current ground monitoring networks. Trend analyses using both datasets highlight increasing NH3 trends across the US, including the NH3 hotspots and urban areas.
Rimal Abeed, Camille Viatte, William C. Porter, Nikolaos Evangeliou, Cathy Clerbaux, Lieven Clarisse, Martin Van Damme, Pierre-François Coheur, and Sarah Safieddine
Atmos. Chem. Phys., 23, 12505–12523, https://doi.org/10.5194/acp-23-12505-2023, https://doi.org/10.5194/acp-23-12505-2023, 2023
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Ammonia emissions from agricultural activities will inevitably increase with the rise in population. We use a variety of datasets (satellite, reanalysis, and model simulation) to calculate the first regional map of ammonia emission potential during the start of the growing season in Europe. We then apply our developed method using a climate model to show the effect of the temperature increase on future ammonia columns under two possible climate scenarios.
Bianca Zilker, Andreas Richter, Anne-Marlene Blechschmidt, Peter von der Gathen, Ilias Bougoudis, Sora Seo, Tim Bösch, and John Philip Burrows
Atmos. Chem. Phys., 23, 9787–9814, https://doi.org/10.5194/acp-23-9787-2023, https://doi.org/10.5194/acp-23-9787-2023, 2023
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During Arctic spring, near-surface ozone is depleted by bromine released from salty sea ice and/or snow-covered areas under certain meteorological conditions. To study this ozone depletion and the prevailing meteorological conditions, two ozone data sets from Ny-Ålesund, Svalbard, have been evaluated. We found that during ozone depletion events lower pressure over the Barents Sea and higher pressure in the Icelandic Low area led to a transport of cold polar air from the north to Ny-Ålesund.
Gijs Leguijt, Joannes D. Maasakkers, Hugo A. C. Denier van der Gon, Arjo J. Segers, Tobias Borsdorff, and Ilse Aben
Atmos. Chem. Phys., 23, 8899–8919, https://doi.org/10.5194/acp-23-8899-2023, https://doi.org/10.5194/acp-23-8899-2023, 2023
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We present a fast method to evaluate carbon monoxide emissions from cities in Africa. Carbon monoxide is important for climate change in an indirect way, as it is linked to ozone, methane, and carbon dioxide. Our measurements are made with a satellite that sees the entire globe every single day. This means that we can check from space whether the current knowledge of emission rates is up to date. We make the comparison and show that the emission rates in northern Africa are underestimated.
Chantelle R. Lonsdale and Kang Sun
Atmos. Chem. Phys., 23, 8727–8748, https://doi.org/10.5194/acp-23-8727-2023, https://doi.org/10.5194/acp-23-8727-2023, 2023
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The COVID-19 pandemic, which was caused by the SARS-CoV-2 virus, emerged in 2019, and its still evolving variants have resulted in unprecedented shifts in human activities and anthropogenic emissions into the Earth's atmosphere. We present monthly nitrogen oxide emissions over three major continents from May 2018 to January 2023 to capture variations before and after the COVID-19 pandemic. We focus on a diverse collection of 54 cities to quantify the post-COVID-19 perturbations.
Xiaolu Li, Jason Blake Cohen, Kai Qin, Hong Geng, Xiaohui Wu, Liling Wu, Chengli Yang, Rui Zhang, and Liqin Zhang
Atmos. Chem. Phys., 23, 8001–8019, https://doi.org/10.5194/acp-23-8001-2023, https://doi.org/10.5194/acp-23-8001-2023, 2023
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Remotely sensed NO2 and surface NOx are combined with a mathematical method to estimate daily NOx emissions. The results identify new sources and improve existing estimates. The estimation is driven by three flexible factors: thermodynamics of combustion, chemical loss, and atmospheric transport. The thermodynamic term separates power, iron, and cement from coking, boilers, and aluminum. This work finds three causes for the extremes: emissions, UV radiation, and transport.
Juanito Jerrold Mariano Acdan, Robert Bradley Pierce, Angela F. Dickens, Zachariah Adelman, and Tsengel Nergui
Atmos. Chem. Phys., 23, 7867–7885, https://doi.org/10.5194/acp-23-7867-2023, https://doi.org/10.5194/acp-23-7867-2023, 2023
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Ozone is an air pollutant that is harmful to human health. Near the surface of Earth, ozone is created when other pollutants react in the presence of sunlight. This study uses satellite data to investigate how ozone levels can be decreased in the Lake Michigan region of the United States. Our results indicate that ozone levels can be decreased by decreasing volatile organic compound emissions in urban areas and decreasing nitrogen oxide emissions in the region as a whole.
Cited articles
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Short summary
This work uses spectroscopy to examine the vertical distribution of nitrogen dioxide and formaldehyde in southeastern Los Angeles, USA, a region heavily impacted by ozone pollution. We examine how both the amount and vertical profile of the two species vary throughout the day, finding that differences between the two species impact the utilization of satellite-based measurements to diagnose ozone production chemistry and that these impacts are variable depending on the time of day.
This work uses spectroscopy to examine the vertical distribution of nitrogen dioxide and...
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