Articles | Volume 21, issue 3
https://doi.org/10.5194/acp-21-1717-2021
© Author(s) 2021. 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-21-1717-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
09 Feb 2021
Research article |
| 09 Feb 2021
| 09 Feb 2021
Atmospheric-methane source and sink sensitivity analysis using Gaussian process emulation
School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK
Luke M. Western
School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK
Tomás Sherwen
Wolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York, YO10 5DD, UK
National Centre for Atmospheric Science, University of York, York, YO10 5DD, UK
School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK
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Guus J. M. Velders, John S. Daniel, Stephen A. Montzka, Isaac Vimont, Matthew Rigby, Paul B. Krummel, Jens Muhle, Simon O'Doherty, Ronald G. Prinn, Ray F. Weiss, and Dickon Young
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Jens Mühle, Lambert J. M. Kuijpers, Kieran M. Stanley, Matthew Rigby, Luke M. Western, Jooil Kim, Sunyoung Park, Christina M. Harth, Paul B. Krummel, Paul J. Fraser, Simon O'Doherty, Peter K. Salameh, Roland Schmidt, Dickon Young, Ronald G. Prinn, Ray H. J. Wang, and Ray F. Weiss
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Jan C. Minx, William F. Lamb, Robbie M. Andrew, Josep G. Canadell, Monica Crippa, Niklas Döbbeling, Piers M. Forster, Diego Guizzardi, Jos Olivier, Glen P. Peters, Julia Pongratz, Andy Reisinger, Matthew Rigby, Marielle Saunois, Steven J. Smith, Efisio Solazzo, and Hanqin Tian
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Atmos. Chem. Phys., 21, 16257–16276, https://doi.org/10.5194/acp-21-16257-2021, https://doi.org/10.5194/acp-21-16257-2021, 2021
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Daniel Say, Alistair J. Manning, Luke M. Western, Dickon Young, Adam Wisher, Matthew Rigby, Stefan Reimann, Martin K. Vollmer, Michela Maione, Jgor Arduini, Paul B. Krummel, Jens Mühle, Christina M. Harth, Brendan Evans, Ray F. Weiss, Ronald G. Prinn, and Simon O'Doherty
Atmos. Chem. Phys., 21, 2149–2164, https://doi.org/10.5194/acp-21-2149-2021, https://doi.org/10.5194/acp-21-2149-2021, 2021
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Perfluorocarbons (PFCs) are potent greenhouse gases with exceedingly long lifetimes. We used atmospheric measurements from a global monitoring network to track the accumulation of these gases in the atmosphere. In the case of the two most abundant PFCs, recent measurements indicate that global emissions are increasing. In Europe, we used a model to estimate regional PFC emissions. Our results show that there was no significant decline in northwest European PFC emissions between 2010 and 2019.
Rachel L. Tunnicliffe, Anita L. Ganesan, Robert J. Parker, Hartmut Boesch, Nicola Gedney, Benjamin Poulter, Zhen Zhang, Jošt V. Lavrič, David Walter, Matthew Rigby, Stephan Henne, Dickon Young, and Simon O'Doherty
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This study quantifies Brazil’s emissions of a potent atmospheric greenhouse gas, methane. This is in the field of atmospheric modelling and uses remotely sensed data and surface measurements of methane concentrations as well as an atmospheric transport model to interpret the data. Because of Brazil’s large emissions from wetlands, agriculture and biomass burning, these emissions affect global methane concentrations and thus are of global significance.
Guillaume Monteil, Grégoire Broquet, Marko Scholze, Matthew Lang, Ute Karstens, Christoph Gerbig, Frank-Thomas Koch, Naomi E. Smith, Rona L. Thompson, Ingrid T. Luijkx, Emily White, Antoon Meesters, Philippe Ciais, Anita L. Ganesan, Alistair Manning, Michael Mischurow, Wouter Peters, Philippe Peylin, Jerôme Tarniewicz, Matt Rigby, Christian Rödenbeck, Alex Vermeulen, and Evie M. Walton
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Swaleha Inamdar, Liselotte Tinel, Rosie Chance, Lucy J. Carpenter, Prabhakaran Sabu, Racheal Chacko, Sarat C. Tripathy, Anvita U. Kerkar, Alok K. Sinha, Parli Venkateswaran Bhaskar, Amit Sarkar, Rajdeep Roy, Tomás Sherwen, Carlos Cuevas, Alfonso Saiz-Lopez, Kirpa Ram, and Anoop S. Mahajan
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Iodine chemistry is generating a lot of interest because of its impacts on the oxidising capacity of the marine boundary and depletion of ozone. However, one of the challenges has been predicting the right levels of iodine in the models, which depend on parameterisations for emissions from the sea surface. This paper discusses the different parameterisations available and compares them with observations, showing that our current knowledge is still insufficient, especially on a regional scale.
Katherine R. Travis, Colette L. Heald, Hannah M. Allen, Eric C. Apel, Stephen R. Arnold, Donald R. Blake, William H. Brune, Xin Chen, Róisín Commane, John D. Crounse, Bruce C. Daube, Glenn S. Diskin, James W. Elkins, Mathew J. Evans, Samuel R. Hall, Eric J. Hintsa, Rebecca S. Hornbrook, Prasad S. Kasibhatla, Michelle J. Kim, Gan Luo, Kathryn McKain, Dylan B. Millet, Fred L. Moore, Jeffrey Peischl, Thomas B. Ryerson, Tomás Sherwen, Alexander B. Thames, Kirk Ullmann, Xuan Wang, Paul O. Wennberg, Glenn M. Wolfe, and Fangqun Yu
Atmos. Chem. Phys., 20, 7753–7781, https://doi.org/10.5194/acp-20-7753-2020, https://doi.org/10.5194/acp-20-7753-2020, 2020
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Atmospheric models overestimate the rate of removal of trace gases by the hydroxyl radical (OH). This is a concern for studies of the climate and air quality impacts of human activities. Here, we evaluate the performance of a commonly used model of atmospheric chemistry against data from the NASA Atmospheric Tomography Mission (ATom) over the remote oceans where models have received little validation. The model is generally successful, suggesting that biases in OH may be a concern over land.
Jiayue Huang, Lyatt Jaeglé, Qianjie Chen, Becky Alexander, Tomás Sherwen, Mat J. Evans, Nicolas Theys, and Sungyeon Choi
Atmos. Chem. Phys., 20, 7335–7358, https://doi.org/10.5194/acp-20-7335-2020, https://doi.org/10.5194/acp-20-7335-2020, 2020
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Large-scale enhancements of tropospheric BrO and the depletion of surface ozone are often observed in the springtime Arctic. Here, we use a chemical transport model to examine the role of sea salt aerosol from blowing snow in explaining these phenomena. We find that our simulation can account for the spatiotemporal variability of satellite observations of BrO. However, the model has difficulty in producing the magnitude of observed ozone depletion events.
Peter G. Simmonds, Matthew Rigby, Alistair J. Manning, Sunyoung Park, Kieran M. Stanley, Archie McCulloch, Stephan Henne, Francesco Graziosi, Michela Maione, Jgor Arduini, Stefan Reimann, Martin K. Vollmer, Jens Mühle, Simon O'Doherty, Dickon Young, Paul B. Krummel, Paul J. Fraser, Ray F. Weiss, Peter K. Salameh, Christina M. Harth, Mi-Kyung Park, Hyeri Park, Tim Arnold, Chris Rennick, L. Paul Steele, Blagoj Mitrevski, Ray H. J. Wang, and Ronald G. Prinn
Atmos. Chem. Phys., 20, 7271–7290, https://doi.org/10.5194/acp-20-7271-2020, https://doi.org/10.5194/acp-20-7271-2020, 2020
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Sulfur hexafluoride (SF6) is a potent greenhouse gas which is regulated under the Kyoto Protocol. From a 40-year record of measurements, collected at five global monitoring sites and archived air samples, we show that its concentration in the atmosphere has steadily increased. Using modelling techniques, we estimate that global emissions have increased by about 24 % over the past decade. We find that this increase is driven by the demand for SF6-insulated switchgear in developing countries.
Luke M. Western, Zhe Sha, Matthew Rigby, Anita L. Ganesan, Alistair J. Manning, Kieran M. Stanley, Simon J. O'Doherty, Dickon Young, and Jonathan Rougier
Geosci. Model Dev., 13, 2095–2107, https://doi.org/10.5194/gmd-13-2095-2020, https://doi.org/10.5194/gmd-13-2095-2020, 2020
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Assessments of greenhouse gas emissions using atmospheric measurements and meteorological models, or
top-downmethods, are important to verify national inventories or produce a stand-alone estimate where no inventory exists. We present a novel top-down method to estimate emissions. This approach uses a fast method called an integrated nested Laplacian approximation to estimate how these emissions are correlated with other emissions in different locations and at different times.
Ryan J. Pound, Tomás Sherwen, Detlev Helmig, Lucy J. Carpenter, and Mat J. Evans
Atmos. Chem. Phys., 20, 4227–4239, https://doi.org/10.5194/acp-20-4227-2020, https://doi.org/10.5194/acp-20-4227-2020, 2020
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Ozone is an important pollutant with impacts on health and the environment. Ozone is lost to plants, land and the oceans. Loss to the ocean is slow compared to all other types of land cover and has not received as much attention. We build on previous work to more accurately model ozone loss to the ocean. We find changes in the concentration of ozone over the oceans, notably the Southern Ocean, which improves model performance.
Becky Alexander, Tomás Sherwen, Christopher D. Holmes, Jenny A. Fisher, Qianjie Chen, Mat J. Evans, and Prasad Kasibhatla
Atmos. Chem. Phys., 20, 3859–3877, https://doi.org/10.5194/acp-20-3859-2020, https://doi.org/10.5194/acp-20-3859-2020, 2020
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Nitrogen oxides are important for the formation of tropospheric oxidants and are removed from the atmosphere mainly through the formation of nitrate. We compare observations of the oxygen isotopes of nitrate with a global model to test our understanding of the chemistry nitrate formation. We use the model to quantify nitrate formation pathways in the atmosphere and identify key uncertainties and their relevance for the oxidation capacity of the atmosphere.
Angelina Wenger, Katherine Pugsley, Simon O'Doherty, Matt Rigby, Alistair J. Manning, Mark F. Lunt, and Emily D. White
Atmos. Chem. Phys., 19, 14057–14070, https://doi.org/10.5194/acp-19-14057-2019, https://doi.org/10.5194/acp-19-14057-2019, 2019
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We present 14CO2 observations at a background site in Ireland and a tall tower site in the UK. These data have been used to calculate the contribution of fossil fuel sources to atmospheric CO2 mole fractions from the UK and Ireland. 14CO2 emissions from nuclear industry sites in the UK cause a higher uncertainty in the results compared to observations in other locations. The observed ffCO2 at the site was not significantly different from simulated values based on the bottom-up inventory.
Tomás Sherwen, Rosie J. Chance, Liselotte Tinel, Daniel Ellis, Mat J. Evans, and Lucy J. Carpenter
Earth Syst. Sci. Data, 11, 1239–1262, https://doi.org/10.5194/essd-11-1239-2019, https://doi.org/10.5194/essd-11-1239-2019, 2019
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Iodine plays an important role in the Earth system, as a nutrient to the biosphere and by changing the concentrations of climate and air-quality species. However, there are uncertainties on the magnitude of iodine’s role, and a key uncertainty is our understanding of iodide in the global sea-surface. Here we take a data-driven approach using a machine learning algorithm to convert a sparse set of sea-surface iodide observations into a spatially and temporally resolved dataset for use in models.
Jens Mühle, Cathy M. Trudinger, Luke M. Western, Matthew Rigby, Martin K. Vollmer, Sunyoung Park, Alistair J. Manning, Daniel Say, Anita Ganesan, L. Paul Steele, Diane J. Ivy, Tim Arnold, Shanlan Li, Andreas Stohl, Christina M. Harth, Peter K. Salameh, Archie McCulloch, Simon O'Doherty, Mi-Kyung Park, Chun Ok Jo, Dickon Young, Kieran M. Stanley, Paul B. Krummel, Blagoj Mitrevski, Ove Hermansen, Chris Lunder, Nikolaos Evangeliou, Bo Yao, Jooil Kim, Benjamin Hmiel, Christo Buizert, Vasilii V. Petrenko, Jgor Arduini, Michela Maione, David M. Etheridge, Eleni Michalopoulou, Mike Czerniak, Jeffrey P. Severinghaus, Stefan Reimann, Peter G. Simmonds, Paul J. Fraser, Ronald G. Prinn, and Ray F. Weiss
Atmos. Chem. Phys., 19, 10335–10359, https://doi.org/10.5194/acp-19-10335-2019, https://doi.org/10.5194/acp-19-10335-2019, 2019
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We discuss atmospheric concentrations and emissions of the strong greenhouse gas perfluorocyclobutane. A large fraction of recent emissions stem from China, India, and Russia, probably as a by-product from the production of fluoropolymers and fluorochemicals. Most historic emissions likely stem from developed countries. Total emissions are higher than what is being reported. Clearly, more measurements and better reporting are needed to understand emissions of this and other greenhouse gases.
Daniel Say, Anita L. Ganesan, Mark F. Lunt, Matthew Rigby, Simon O'Doherty, Christina Harth, Alistair J. Manning, Paul B. Krummel, and Stephane Bauguitte
Atmos. Chem. Phys., 19, 9865–9885, https://doi.org/10.5194/acp-19-9865-2019, https://doi.org/10.5194/acp-19-9865-2019, 2019
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Despite its emergence as a global economic power, very little information exists regarding India's halocarbon (CFC, HCFC, HFC and chlorocarbon) emissions. We report atmospheric measurements of these gases from above India, and use them to estimate India's emissions. Our results are consistent with the emissions profile of a developing country, with large emissions of HCFCs, HFCs and chlorocarbons not regulated under the Montreal Protocol, but little evidence for ongoing CFC consumption.
Lei Zhu, Daniel J. Jacob, Sebastian D. Eastham, Melissa P. Sulprizio, Xuan Wang, Tomás Sherwen, Mat J. Evans, Qianjie Chen, Becky Alexander, Theodore K. Koenig, Rainer Volkamer, L. Gregory Huey, Michael Le Breton, Thomas J. Bannan, and Carl J. Percival
Atmos. Chem. Phys., 19, 6497–6507, https://doi.org/10.5194/acp-19-6497-2019, https://doi.org/10.5194/acp-19-6497-2019, 2019
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We quantify the effect of sea salt aerosol on tropospheric bromine chemistry with a new mechanistic description of the halogen chemistry in a global atmospheric chemistry model. For the first time, we are able to reproduce the observed levels of bromide activation from the sea salt aerosol in a manner consistent with bromine oxide radical measured from various platforms. Sea salt aerosol plays a far more complex role in global tropospheric chemistry than previously recognized.
Emily D. White, Matthew Rigby, Mark F. Lunt, T. Luke Smallman, Edward Comyn-Platt, Alistair J. Manning, Anita L. Ganesan, Simon O'Doherty, Ann R. Stavert, Kieran Stanley, Mathew Williams, Peter Levy, Michel Ramonet, Grant L. Forster, Andrew C. Manning, and Paul I. Palmer
Atmos. Chem. Phys., 19, 4345–4365, https://doi.org/10.5194/acp-19-4345-2019, https://doi.org/10.5194/acp-19-4345-2019, 2019
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Understanding carbon dioxide (CO2) fluxes from the terrestrial biosphere on a national scale is important for evaluating land use strategies to mitigate climate change. We estimate emissions of CO2 from the UK biosphere using atmospheric data in a top-down approach. Our findings show that bottom-up estimates from models of biospheric fluxes overestimate the amount of CO2 uptake in summer. This suggests these models wrongly estimate or omit key processes, e.g. land disturbance due to harvest.
Xuan Wang, Daniel J. Jacob, Sebastian D. Eastham, Melissa P. Sulprizio, Lei Zhu, Qianjie Chen, Becky Alexander, Tomás Sherwen, Mathew J. Evans, Ben H. Lee, Jessica D. Haskins, Felipe D. Lopez-Hilfiker, Joel A. Thornton, Gregory L. Huey, and Hong Liao
Atmos. Chem. Phys., 19, 3981–4003, https://doi.org/10.5194/acp-19-3981-2019, https://doi.org/10.5194/acp-19-3981-2019, 2019
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Chlorine radicals have a broad range of implications for tropospheric chemistry, air quality, and climate. We present a comprehensive simulation of tropospheric chlorine in a global 3-D model, which includes explicit accounting of chloride mobilization from sea salt aerosol. We find the chlorine chemistry contributes 1.0 % of the global oxidation of methane and decreases global burdens of tropospheric ozone by 7 % and OH by 3 % through the associated bromine radical chemistry.
Alba Badia, Claire E. Reeves, Alex R. Baker, Alfonso Saiz-Lopez, Rainer Volkamer, Theodore K. Koenig, Eric C. Apel, Rebecca S. Hornbrook, Lucy J. Carpenter, Stephen J. Andrews, Tomás Sherwen, and Roland von Glasow
Atmos. Chem. Phys., 19, 3161–3189, https://doi.org/10.5194/acp-19-3161-2019, https://doi.org/10.5194/acp-19-3161-2019, 2019
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The oceans have an impact on the composition and reactivity of the troposphere through the emission of gases and particles. Thus, a quantitative understanding of the marine atmosphere is crucial to examine the oxidative capacity and climate forcing. This study investigates the impact of halogens in the tropical troposphere and explores the sensitivity of this to uncertainties in the fluxes and their chemical processing. Our modelled tropospheric Ox loss due to halogens ranges from 20 % to 60 %.
Kieran Brophy, Heather Graven, Alistair J. Manning, Emily White, Tim Arnold, Marc L. Fischer, Seongeun Jeong, Xinguang Cui, and Matthew Rigby
Atmos. Chem. Phys., 19, 2991–3006, https://doi.org/10.5194/acp-19-2991-2019, https://doi.org/10.5194/acp-19-2991-2019, 2019
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We investigate potential errors and uncertainties related to the spatial and temporal prior representation of emissions and modelled atmospheric transport for the inversion of California's fossil fuel CO2 emissions. Our results indicate that uncertainties in posterior total state fossil fuel CO2 estimates arising from the choice of prior emissions or atmospheric transport model are on the order of 15 % or less for the ground-based network in California we consider.
Daniel Say, Anita L. Ganesan, Mark F. Lunt, Matthew Rigby, Simon O'Doherty, Chris Harth, Alistair J. Manning, Paul B. Krummel, and Stephane Bauguitte
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2018-1287, https://doi.org/10.5194/acp-2018-1287, 2019
Publication in ACP not foreseen
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India is a potentially significant source of chlorocarbons, gases typically used as solvents and feedstocks. Given the potential for these species to deplete stratospheric ozone, understanding their sources is important. We use flask measurements collected from an aircraft to infer India's chlorocarbon emissions. We link emissions of carbon tetrachloride to the industrial production of other chloromethanes, and provide evidence for rapid growth in India's emissions of dichloromethane.
Lu Hu, Christoph A. Keller, Michael S. Long, Tomás Sherwen, Benjamin Auer, Arlindo Da Silva, Jon E. Nielsen, Steven Pawson, Matthew A. Thompson, Atanas L. Trayanov, Katherine R. Travis, Stuart K. Grange, Mat J. Evans, and Daniel J. Jacob
Geosci. Model Dev., 11, 4603–4620, https://doi.org/10.5194/gmd-11-4603-2018, https://doi.org/10.5194/gmd-11-4603-2018, 2018
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We present a full-year online global simulation of tropospheric chemistry at 12.5 km resolution. To the best of our knowledge, such a resolution in a state-of-the-science global simulation of tropospheric chemistry is unprecedented. This simulation will serve as the Nature Run for observing system simulation experiments to support the future geostationary satellite constellation for tropospheric chemistry, and can also be used for various air quality applications.
Qianjie Chen, Tomás Sherwen, Mathew Evans, and Becky Alexander
Atmos. Chem. Phys., 18, 13617–13637, https://doi.org/10.5194/acp-18-13617-2018, https://doi.org/10.5194/acp-18-13617-2018, 2018
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Uncertainty in the natural tropospheric sulfur cycle represents the largest source of uncertainty in radiative forcing estimates of sulfate aerosol. This study investigates the natural sulfur cycle in the marine troposphere using the GEOS-Chem model. We found that BrO is important for DMS oxidation and multiphase chemistry is important for MSA production and loss, which have implications for the yield of SO2 and MSA from DMS oxidation and the radiative effect of DMS-derived sulfate aerosol.
Paul I. Palmer, Simon O'Doherty, Grant Allen, Keith Bower, Hartmut Bösch, Martyn P. Chipperfield, Sarah Connors, Sandip Dhomse, Liang Feng, Douglas P. Finch, Martin W. Gallagher, Emanuel Gloor, Siegfried Gonzi, Neil R. P. Harris, Carole Helfter, Neil Humpage, Brian Kerridge, Diane Knappett, Roderic L. Jones, Michael Le Breton, Mark F. Lunt, Alistair J. Manning, Stephan Matthiesen, Jennifer B. A. Muller, Neil Mullinger, Eiko Nemitz, Sebastian O'Shea, Robert J. Parker, Carl J. Percival, Joseph Pitt, Stuart N. Riddick, Matthew Rigby, Harjinder Sembhi, Richard Siddans, Robert L. Skelton, Paul Smith, Hannah Sonderfeld, Kieran Stanley, Ann R. Stavert, Angelina Wenger, Emily White, Christopher Wilson, and Dickon Young
Atmos. Chem. Phys., 18, 11753–11777, https://doi.org/10.5194/acp-18-11753-2018, https://doi.org/10.5194/acp-18-11753-2018, 2018
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This paper provides an overview of the Greenhouse gAs Uk and Global Emissions (GAUGE) experiment. GAUGE was designed to quantify nationwide GHG emissions of the UK, bringing together measurements and atmospheric transport models. This novel experiment is the first of its kind. We anticipate it will inform the blueprint for countries that are building a measurement infrastructure in preparation for global stocktakes, which are a key part of the Paris Agreement.
Prasad Kasibhatla, Tomás Sherwen, Mathew J. Evans, Lucy J. Carpenter, Chris Reed, Becky Alexander, Qianjie Chen, Melissa P. Sulprizio, James D. Lee, Katie A. Read, William Bloss, Leigh R. Crilley, William C. Keene, Alexander A. P. Pszenny, and Alma Hodzic
Atmos. Chem. Phys., 18, 11185–11203, https://doi.org/10.5194/acp-18-11185-2018, https://doi.org/10.5194/acp-18-11185-2018, 2018
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Recent measurements of NOx and HONO suggest that photolysis of particulate nitrate in sea-salt aerosols is important in terms of marine boundary layer oxidant chemistry. We present the first global-scale assessment of the significance of this new chemical pathway for NOx, O3, and OH in the marine boundary layer. We also present a preliminary assessment of the potential impact of photolysis of particulate nitrate associated with other aerosol types on continental boundary layer chemistry.
Ronald G. Prinn, Ray F. Weiss, Jgor Arduini, Tim Arnold, H. Langley DeWitt, Paul J. Fraser, Anita L. Ganesan, Jimmy Gasore, Christina M. Harth, Ove Hermansen, Jooil Kim, Paul B. Krummel, Shanlan Li, Zoë M. Loh, Chris R. Lunder, Michela Maione, Alistair J. Manning, Ben R. Miller, Blagoj Mitrevski, Jens Mühle, Simon O'Doherty, Sunyoung Park, Stefan Reimann, Matt Rigby, Takuya Saito, Peter K. Salameh, Roland Schmidt, Peter G. Simmonds, L. Paul Steele, Martin K. Vollmer, Ray H. Wang, Bo Yao, Yoko Yokouchi, Dickon Young, and Lingxi Zhou
Earth Syst. Sci. Data, 10, 985–1018, https://doi.org/10.5194/essd-10-985-2018, https://doi.org/10.5194/essd-10-985-2018, 2018
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We present the data and accomplishments of the multinational global atmospheric measurement program AGAGE (Advanced Global Atmospheric Gases Experiment). At high frequency and at multiple sites, AGAGE measures all the important chemicals in the Montreal Protocol for the protection of the ozone layer and the non-carbon-dioxide gases assessed by the Intergovernmental Panel on Climate Change. AGAGE uses these data to estimate sources and sinks of all these gases and has operated since 1978.
Mike J. Newland, Andrew R. Rickard, Tomás Sherwen, Mathew J. Evans, Luc Vereecken, Amalia Muñoz, Milagros Ródenas, and William J. Bloss
Atmos. Chem. Phys., 18, 6095–6120, https://doi.org/10.5194/acp-18-6095-2018, https://doi.org/10.5194/acp-18-6095-2018, 2018
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Stabilised Criegee intermediates (SCIs) are formed in the reaction of alkenes with ozone, both of which are ubiquitous throughout the troposphere. We determine the fate and global distribution of SCI from monoterpene ozonolysis. One major fate of SCI is reaction with H2O, but for a fraction of SCIs, unimolecular reactions dominate. Concentrations of SCIs are high enough regionally to play a key role in the conversion of sulfur dioxide to aerosol, affecting air quality and climate.
Peter G. Simmonds, Matthew Rigby, Archie McCulloch, Martin K. Vollmer, Stephan Henne, Jens Mühle, Simon O'Doherty, Alistair J. Manning, Paul B. Krummel, Paul J. Fraser, Dickon Young, Ray F. Weiss, Peter K. Salameh, Christina M. Harth, Stefan Reimann, Cathy M. Trudinger, L. Paul Steele, Ray H. J. Wang, Diane J. Ivy, Ronald G. Prinn, Blagoj Mitrevski, and David M. Etheridge
Atmos. Chem. Phys., 18, 4153–4169, https://doi.org/10.5194/acp-18-4153-2018, https://doi.org/10.5194/acp-18-4153-2018, 2018
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Recent measurements of the potent greenhouse gas HFC-23, a by-product of HCFC-22 production, show a 28 % increase in the atmospheric mole fraction from 2009 to 2016. A minimum in the atmospheric abundance of HFC-23 in 2009 was attributed to abatement of HFC-23 emissions by incineration under the Clean Development Mechanism (CDM). Our results indicate that the recent increase in HFC-23 emissions is driven by failure of mitigation under the CDM to keep pace with increased HCFC-22 production.
Daniel Stone, Tomás Sherwen, Mathew J. Evans, Stewart Vaughan, Trevor Ingham, Lisa K. Whalley, Peter M. Edwards, Katie A. Read, James D. Lee, Sarah J. Moller, Lucy J. Carpenter, Alastair C. Lewis, and Dwayne E. Heard
Atmos. Chem. Phys., 18, 3541–3561, https://doi.org/10.5194/acp-18-3541-2018, https://doi.org/10.5194/acp-18-3541-2018, 2018
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Halogen chemistry in the troposphere impacts oxidising capacity, but model studies assessing the nature of these impacts can vary according to the model framework used. In this work we present simulations of OH and HO2 radicals using both box and global model frameworks, and compare to observations made at the Cape Verde Atmospheric Observatory. We highlight, and rationalise, differences between the model frameworks.
Martin K. Vollmer, Dickon Young, Cathy M. Trudinger, Jens Mühle, Stephan Henne, Matthew Rigby, Sunyoung Park, Shanlan Li, Myriam Guillevic, Blagoj Mitrevski, Christina M. Harth, Benjamin R. Miller, Stefan Reimann, Bo Yao, L. Paul Steele, Simon A. Wyss, Chris R. Lunder, Jgor Arduini, Archie McCulloch, Songhao Wu, Tae Siek Rhee, Ray H. J. Wang, Peter K. Salameh, Ove Hermansen, Matthias Hill, Ray L. Langenfelds, Diane Ivy, Simon O'Doherty, Paul B. Krummel, Michela Maione, David M. Etheridge, Lingxi Zhou, Paul J. Fraser, Ronald G. Prinn, Ray F. Weiss, and Peter G. Simmonds
Atmos. Chem. Phys., 18, 979–1002, https://doi.org/10.5194/acp-18-979-2018, https://doi.org/10.5194/acp-18-979-2018, 2018
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We measured the three chlorofluorocarbons (CFCs) CFC-13, CFC-114, and CFC-115 in the atmosphere because they are important in stratospheric ozone depletion. These compounds should have decreased in the atmosphere because they are banned by the Montreal Protocol but we find the opposite. Emissions over the last decade have not declined on a global scale. We use inverse modeling and our observations to find that a large part of the emissions originate in the Asian region.
Theodore K. Koenig, Rainer Volkamer, Sunil Baidar, Barbara Dix, Siyuan Wang, Daniel C. Anderson, Ross J. Salawitch, Pamela A. Wales, Carlos A. Cuevas, Rafael P. Fernandez, Alfonso Saiz-Lopez, Mathew J. Evans, Tomás Sherwen, Daniel J. Jacob, Johan Schmidt, Douglas Kinnison, Jean-François Lamarque, Eric C. Apel, James C. Bresch, Teresa Campos, Frank M. Flocke, Samuel R. Hall, Shawn B. Honomichl, Rebecca Hornbrook, Jørgen B. Jensen, Richard Lueb, Denise D. Montzka, Laura L. Pan, J. Michael Reeves, Sue M. Schauffler, Kirk Ullmann, Andrew J. Weinheimer, Elliot L. Atlas, Valeria Donets, Maria A. Navarro, Daniel Riemer, Nicola J. Blake, Dexian Chen, L. Gregory Huey, David J. Tanner, Thomas F. Hanisco, and Glenn M. Wolfe
Atmos. Chem. Phys., 17, 15245–15270, https://doi.org/10.5194/acp-17-15245-2017, https://doi.org/10.5194/acp-17-15245-2017, 2017
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Tropospheric inorganic bromine (BrO and Bry) shows a C-shaped profile over the tropical western Pacific Ocean, and supports previous speculation that marine convection is a source for inorganic bromine from sea salt to the upper troposphere. The Bry profile in the tropical tropopause layer (TTL) is complex, suggesting that the total Bry budget in the TTL is not closed without considering aerosol bromide. The implications for atmospheric composition and bromine sources are discussed.
Peter G. Simmonds, Matthew Rigby, Archie McCulloch, Simon O'Doherty, Dickon Young, Jens Mühle, Paul B. Krummel, Paul Steele, Paul J. Fraser, Alistair J. Manning, Ray F. Weiss, Peter K. Salameh, Chris M. Harth, Ray H. J. Wang, and Ronald G. Prinn
Atmos. Chem. Phys., 17, 4641–4655, https://doi.org/10.5194/acp-17-4641-2017, https://doi.org/10.5194/acp-17-4641-2017, 2017
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This paper reports how long-term atmospheric measurements demonstrate that the Montreal Protocol has been effective in controlling production and consumption of the hydrochlorofluorocarbons, a group of industrial chemicals that have detrimental effects on the ozone layer and also contribute to global warming as greenhouse gases and their hydrofluorocarbon substitutes which are also potent greenhouse gases but do not materially affect the ozone layer.
Chris Reed, Mathew J. Evans, Leigh R. Crilley, William J. Bloss, Tomás Sherwen, Katie A. Read, James D. Lee, and Lucy J. Carpenter
Atmos. Chem. Phys., 17, 4081–4092, https://doi.org/10.5194/acp-17-4081-2017, https://doi.org/10.5194/acp-17-4081-2017, 2017
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The source of ozone-depleting compounds in the remote troposphere has been thought to be long-range transport of secondary pollutants such as organic nitrates. Processing of organic nitrates to nitric acid and subsequent deposition on surfaces in the atmosphere was thought to remove these nitrates from the ozone–NOx–HOx cycle. We found through observation of NOx in the remote tropical troposphere at the Cape Verde Observatory that surface nitrates can be released back into the atmosphere.
Tomás Sherwen, Mat J. Evans, Lucy J. Carpenter, Johan A. Schmidt, and Loretta J. Mickley
Atmos. Chem. Phys., 17, 1557–1569, https://doi.org/10.5194/acp-17-1557-2017, https://doi.org/10.5194/acp-17-1557-2017, 2017
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We model pre-industrial to present day changes using the GEOS-Chem global chemical transport model with halogens (Cl, Br, I). The model better captures pre-industrial O3 observations with halogens included. Halogens buffer the tropospheric forcing of O3 (RFTO3) from pre-industrial to present day, reducing RFTO3 by 0.087 Wm−2. This reduction is greater than that from halogens on stratospheric O3 (−0.05 Wm−2). This suggests that models that do not include halogens will overestimate RFTO3by ~ 25%.
Martyn P. Chipperfield, Qing Liang, Matthew Rigby, Ryan Hossaini, Stephen A. Montzka, Sandip Dhomse, Wuhu Feng, Ronald G. Prinn, Ray F. Weiss, Christina M. Harth, Peter K. Salameh, Jens Mühle, Simon O'Doherty, Dickon Young, Peter G. Simmonds, Paul B. Krummel, Paul J. Fraser, L. Paul Steele, James D. Happell, Robert C. Rhew, James Butler, Shari A. Yvon-Lewis, Bradley Hall, David Nance, Fred Moore, Ben R. Miller, James W. Elkins, Jeremy J. Harrison, Chris D. Boone, Elliot L. Atlas, and Emmanuel Mahieu
Atmos. Chem. Phys., 16, 15741–15754, https://doi.org/10.5194/acp-16-15741-2016, https://doi.org/10.5194/acp-16-15741-2016, 2016
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Carbon tetrachloride (CCl4) is a compound which, when released into the atmosphere, can cause depletion of the stratospheric ozone layer. Its emissions are controlled under the Montreal Protocol, and its atmospheric abundance is slowly decreasing. However, this decrease is not as fast as expected based on estimates of its emissions and its atmospheric lifetime. We have used an atmospheric model to look at the uncertainties in the CCl4 lifetime and to examine the impact on its atmospheric decay.
Tomás Sherwen, Johan A. Schmidt, Mat J. Evans, Lucy J. Carpenter, Katja Großmann, Sebastian D. Eastham, Daniel J. Jacob, Barbara Dix, Theodore K. Koenig, Roman Sinreich, Ivan Ortega, Rainer Volkamer, Alfonso Saiz-Lopez, Cristina Prados-Roman, Anoop S. Mahajan, and Carlos Ordóñez
Atmos. Chem. Phys., 16, 12239–12271, https://doi.org/10.5194/acp-16-12239-2016, https://doi.org/10.5194/acp-16-12239-2016, 2016
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We present a simulation of tropospheric Cl, Br, I chemistry within the GEOS-Chem CTM. We find a decrease in tropospheric ozone burden of 18.6 % and a 8.2 % decrease in global mean OH concentrations. Cl oxidation of some VOCs range from 15 to 27 % of the total loss. Bromine plays a small role in oxidising oVOCs. Surface ozone, ozone sondes, and methane lifetime are in general improved by the inclusion of halogens. We argue that simulated bromine and chlorine represent a lower limit.
Cathy M. Trudinger, Paul J. Fraser, David M. Etheridge, William T. Sturges, Martin K. Vollmer, Matt Rigby, Patricia Martinerie, Jens Mühle, David R. Worton, Paul B. Krummel, L. Paul Steele, Benjamin R. Miller, Johannes Laube, Francis S. Mani, Peter J. Rayner, Christina M. Harth, Emmanuel Witrant, Thomas Blunier, Jakob Schwander, Simon O'Doherty, and Mark Battle
Atmos. Chem. Phys., 16, 11733–11754, https://doi.org/10.5194/acp-16-11733-2016, https://doi.org/10.5194/acp-16-11733-2016, 2016
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Perfluorocarbons (PFCs) are potent, long-lived and mostly man-made greenhouse gases released to the atmosphere mainly during aluminium production and semiconductor manufacture. Here we present the first continuous histories of three PFCs from 1800 to 2014, derived from measurements of these PFCs in the atmosphere and in air bubbles in polar ice. The records show how human actions have affected these important greenhouse gases over the past century.
Mark F. Lunt, Matt Rigby, Anita L. Ganesan, and Alistair J. Manning
Geosci. Model Dev., 9, 3213–3229, https://doi.org/10.5194/gmd-9-3213-2016, https://doi.org/10.5194/gmd-9-3213-2016, 2016
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Bayesian inversions can be used to estimate emissions of gases from atmospheric data. We present an inversion framework that objectively defines the basis functions, which describe regions of emissions. The framework allows for the uncertainty in the choice of basis functions to be propagated through to the posterior emissions distribution in a single-step process, and provides an alternative to using a single set of basis functions.
Joe McNorton, Martyn P. Chipperfield, Manuel Gloor, Chris Wilson, Wuhu Feng, Garry D. Hayman, Matt Rigby, Paul B. Krummel, Simon O'Doherty, Ronald G. Prinn, Ray F. Weiss, Dickon Young, Ed Dlugokencky, and Steve A. Montzka
Atmos. Chem. Phys., 16, 7943–7956, https://doi.org/10.5194/acp-16-7943-2016, https://doi.org/10.5194/acp-16-7943-2016, 2016
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Methane (CH4) is an important greenhouse gas. The growth of atmospheric CH4 stalled from 1999 to 2006, with current explanations focussed mainly on changing surface fluxes. We combine models with observations and meteorological data to assess the atmospheric contribution to CH4 changes. We find that variations in mean atmospheric hydroxyl concentration can explain part of the stall in growth. Our study highlights the role of multi-annual variability in atmospheric chemistry in global CH4 trends.
Luke M. Western, Peter N. Francis, I. Matthew Watson, and Shona Mackie
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2016-92, https://doi.org/10.5194/amt-2016-92, 2016
Revised manuscript has not been submitted
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This work aims to infer the size distribution of airborne volcanic ash using satellite measurements. The size distribution of volcanic ash is typically described using two parameters, of which one is normally assumed and one can be measured using satellites. This work shows that it is possible, using a satellite with high spectral resolution, to retrieve both parameters. This work has been done to reduce uncertainty in mass calculations for airspace management during volcanic unrest.
T. Sherwen, M. J. Evans, L. J. Carpenter, S. J. Andrews, R. T. Lidster, B. Dix, T. K. Koenig, R. Sinreich, I. Ortega, R. Volkamer, A. Saiz-Lopez, C. Prados-Roman, A. S. Mahajan, and C. Ordóñez
Atmos. Chem. Phys., 16, 1161–1186, https://doi.org/10.5194/acp-16-1161-2016, https://doi.org/10.5194/acp-16-1161-2016, 2016
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Using a global chemical transport model (GEOS-Chem) with additional iodine emissions, chemistry, and deposition we show that iodine is responsible for ~ 9 % of global ozone loss but has negligible impacts on global OH. Uncertainties are large in the chemistry and emissions and future research is needed in both. Measurements of iodine species (especially HOI) would be useful. We believe iodine chemistry should be considered in future chemistry-climate and in air quality modelling.
P. G. Simmonds, M. Rigby, A. J. Manning, M. F. Lunt, S. O'Doherty, A. McCulloch, P. J. Fraser, S. Henne, M. K. Vollmer, J. Mühle, R. F. Weiss, P. K. Salameh, D. Young, S. Reimann, A. Wenger, T. Arnold, C. M. Harth, P. B. Krummel, L. P. Steele, B. L. Dunse, B. R. Miller, C. R. Lunder, O. Hermansen, N. Schmidbauer, T. Saito, Y. Yokouchi, S. Park, S. Li, B. Yao, L. X. Zhou, J. Arduini, M. Maione, R. H. J. Wang, D. Ivy, and R. G. Prinn
Atmos. Chem. Phys., 16, 365–382, https://doi.org/10.5194/acp-16-365-2016, https://doi.org/10.5194/acp-16-365-2016, 2016
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We report regional and global emissions estimates of HFC-152a using high frequency measurements from 11 observing sites and archived air samples dating back to 1978 together with atmospheric transport models. The "bottom-up" emissions of HFC-152a reported to the UNFCCC appear to significantly underestimate those reported here from observations. This discrepancy we suggest arises from largely underestimated USA and undeclared Asian emissions.
S. O'Doherty, M. Rigby, J. Mühle, D. J. Ivy, B. R. Miller, D. Young, P. G. Simmonds, S. Reimann, M. K. Vollmer, P. B. Krummel, P. J. Fraser, L. P. Steele, B. Dunse, P. K. Salameh, C. M. Harth, T. Arnold, R. F. Weiss, J. Kim, S. Park, S. Li, C. Lunder, O. Hermansen, N. Schmidbauer, L. X. Zhou, B. Yao, R. H. J. Wang, A. J. Manning, and R. G. Prinn
Atmos. Chem. Phys., 14, 9249–9258, https://doi.org/10.5194/acp-14-9249-2014, https://doi.org/10.5194/acp-14-9249-2014, 2014
E. Saikawa, R. G. Prinn, E. Dlugokencky, K. Ishijima, G. S. Dutton, B. D. Hall, R. Langenfelds, Y. Tohjima, T. Machida, M. Manizza, M. Rigby, S. O'Doherty, P. K. Patra, C. M. Harth, R. F. Weiss, P. B. Krummel, M. van der Schoot, P. J. Fraser, L. P. Steele, S. Aoki, T. Nakazawa, and J. W. Elkins
Atmos. Chem. Phys., 14, 4617–4641, https://doi.org/10.5194/acp-14-4617-2014, https://doi.org/10.5194/acp-14-4617-2014, 2014
A. L. Ganesan, M. Rigby, A. Zammit-Mangion, A. J. Manning, R. G. Prinn, P. J. Fraser, C. M. Harth, K.-R. Kim, P. B. Krummel, S. Li, J. Mühle, S. J. O'Doherty, S. Park, P. K. Salameh, L. P. Steele, and R. F. Weiss
Atmos. Chem. Phys., 14, 3855–3864, https://doi.org/10.5194/acp-14-3855-2014, https://doi.org/10.5194/acp-14-3855-2014, 2014
D. A. Belikov, S. Maksyutov, M. Krol, A. Fraser, M. Rigby, H. Bian, A. Agusti-Panareda, D. Bergmann, P. Bousquet, P. Cameron-Smith, M. P. Chipperfield, A. Fortems-Cheiney, E. Gloor, K. Haynes, P. Hess, S. Houweling, S. R. Kawa, R. M. Law, Z. Loh, L. Meng, P. I. Palmer, P. K. Patra, R. G. Prinn, R. Saito, and C. Wilson
Atmos. Chem. Phys., 13, 1093–1114, https://doi.org/10.5194/acp-13-1093-2013, https://doi.org/10.5194/acp-13-1093-2013, 2013
Related subject area
Subject: Gases | Research Activity: Atmospheric Modelling and Data Analysis | Altitude Range: Troposphere | Science Focus: Chemistry (chemical composition and reactions)
Modelling Arctic lower-tropospheric ozone: processes controlling seasonal variations
Influence of nitrogen oxides and volatile organic compounds emission changes on tropospheric ozone variability, trends and radiative effect
Tropospheric ozone trends and attributions over East and Southeast Asia in 1995–2019: an integrated assessment using statistical methods, machine learning models, and multiple chemical transport models
Characterization of reactive oxidized nitrogen in the global upper troposphere using recent and historic commercial and research aircraft campaigns and GEOS-Chem
Soil deposition of atmospheric hydrogen constrained using planetary-scale observations
Comparative ozone production sensitivity to NOx and VOCs in Quito, Ecuador, and Santiago, Chile
South Asia anthropogenic ammonia emission inversion through assimilating IASI observations
A new parameterization of photolysis rates for oxygenated volatile organic compounds (OVOCs)
Constraining the budget of NOx and volatile organic compounds at a remote tropical island using multi-platform observations and WRF-Chem model simulations
Multi-observational estimation of regional and sectoral emission contributions to the persistent high growth rate of atmospheric CH4 for 2020–2022
Representing improved tropospheric ozone distribution over the Northern Hemisphere by including lightning NOx emissions in CHIMERE
Assessing the ability to quantify the decrease in NOx anthropogenic emissions in 2019 compared to 2005 using OMI and TROPOMI satellite observations
Tracking daily NOx emissions from an urban agglomeration based on TROPOMI NO2 and a local ensemble transform Kalman filter
Evaluation of O3, H2O, CO, and NOy climatologies simulated by four global models in the upper troposphere–lower stratosphere with IAGOS measurements
Source contribution to ozone pollution during June 2021 fire events in Arizona: insights from WRF-Chem-tagged O3 and CO
High-resolution mapping of on-road vehicle emissions with real-time traffic datasets based on big data
Sensitivity of climate–chemistry model simulated atmospheric composition to the application of an inverse relationship between NOx emission and lightning flash frequency
Regional and sectoral contributions of NOx and reactive carbon emission sources to global trends in tropospheric ozone during the 2000–2018 period
Underappreciated contributions of biogenic volatile organic compounds from urban green spaces to ozone pollution
Chemistry–climate feedback of atmospheric methane in a methane-emission-flux-driven chemistry–climate model
Surface ozone trend variability across the United States and the impact of heat waves (1990–2023)
Influence of Various Criteria on Identifying the Springtime Tropospheric Ozone Depletion Events (ODEs) at Utqiagvik, Arctic
Sensitivity of climate effects of hydrogen to leakage size, location, and chemical background
Evaluating tropospheric nitrogen dioxide in UKCA using OMI satellite retrievals over south and east Asia
A technology-based global non-methane volatile organic compounds (NMVOC) emission inventory under the MEIC framework
The role of the tropical carbon balance in determining the large atmospheric CO2 growth rate in 2023
Shifts in global atmospheric oxidant chemistry from land cover change
Technical note: A comparative study of chemistry schemes for volcanic sulfur dioxide in Lagrangian transport simulations – a case study of the 2019 Raikoke eruption
Revisiting the high tropospheric ozone over southern Africa: role of biomass burning and anthropogenic emissions
Monoterpene oxidation pathways initiated by acyl peroxy radical addition
Local and transboundary contributions to NOy loadings across East Asia using CMAQ-ISAM and a GEMS-informed emission inventory during the winter–spring transition
Estimating the variability in NOx emissions from Wuhan with TROPOMI NO2 data during 2018 to 2023
Effects of enhancing nitrogen use efficiency in cropland and livestock systems on agricultural ammonia emissions and particulate matter air quality in China
Enhanced understanding of atmospheric blocking modulation on ozone dynamics within a high-resolution Earth system model
Tropospheric ozone responses to the El Niño-Southern Oscillation (ENSO): quantification of individual processes and future projections from multiple chemical models
Natural emissions of VOC and NOx over Africa constrained by TROPOMI HCHO and NO2 data using the MAGRITTEv1.1 model
Contributions of lightning to long-term trends and inter-annual variability in global atmospheric chemistry constrained by Schumann Resonance observations
Simulated photochemical response to observational constraints on aerosol vertical distribution over North China
Impacts of wildfire smoke aerosols on near-surface ozone photochemistry
Anthropogenic emission controls reduce summertime ozone–temperature sensitivity in the United States
Effectiveness of Emission Controls on Atmospheric Oxidation and Air Pollutant Concentrations: Uncertainties due to Chemical Mechanisms and Inventories
Investigating the response of China's surface ozone concentration to the future changes of multiple factors
The 21st-century wetting inhibits growing surface ozone in Northwestern China
Effects of different emission inventories on tropospheric ozone and methane lifetime
Assessing the relative impacts of satellite ozone and its precursor observations to improve global tropospheric ozone analysis using multiple chemical reanalysis systems
Evaluating present-day and future impacts of agricultural ammonia emissions on atmospheric chemistry and climate
Global atmospheric inversion of the NH3 emissions over 2019–2022 using the LMDZ-INCA chemistry-transport model and the IASI NH3 observations
Air-pollution-satellite-based CO2 emission inversion: system evaluation, sensitivity analysis, and future research direction
The impact of sea spray aerosol on photochemical ozone formation over eastern China: heterogeneous reaction of chlorine particles and radiative effect
Insights into ozone pollution control in urban areas by decoupling meteorological factors based on machine learning
Wanmin Gong, Stephen R. Beagley, Kenjiro Toyota, Henrik Skov, Jesper Heile Christensen, Alex Lupu, Diane Pendlebury, Junhua Zhang, Ulas Im, Yugo Kanaya, Alfonso Saiz-Lopez, Roberto Sommariva, Peter Effertz, John W. Halfacre, Nis Jepsen, Rigel Kivi, Theodore K. Koenig, Katrin Müller, Claus Nordstrøm, Irina Petropavlovskikh, Paul B. Shepson, William R. Simpson, Sverre Solberg, Ralf M. Staebler, David W. Tarasick, Roeland Van Malderen, and Mika Vestenius
Atmos. Chem. Phys., 25, 8355–8405, https://doi.org/10.5194/acp-25-8355-2025, https://doi.org/10.5194/acp-25-8355-2025, 2025
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This study showed that the springtime O3 depletion plays a critical role in driving the surface O3 seasonal cycle in the central Arctic. The O3 depletion events, while occurring most notably within the lowest few hundred metres above the Arctic Ocean, can induce a 5–7 % loss in the pan-Arctic tropospheric O3 burden during springtime. The study also found enhancements in O3 and NOy (mostly peroxyacetyl nitrate) concentrations in the Arctic due to northern boreal wildfires, particularly at higher altitudes.
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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Satellites and model simulations show enhancement in tropospheric ozone, which is highly impacted by human-produced nitrous oxides compared to volatile organic compounds. The increased amount of ozone enhances ozone radiative forcing. The ozone enhancement and associated radiative forcing are the highest over South and East Asia. The emissions of nitrous oxides show a higher influence on shifting ozone photochemical regimes than volatile organic compounds.
Xiao Lu, Yiming Liu, Jiayin Su, Xiang Weng, Tabish Ansari, Yuqiang Zhang, Guowen He, Yuqi Zhu, Haolin Wang, Ganquan Zeng, Jingyu Li, Cheng He, Shuai Li, Teerachai Amnuaylojaroen, Tim Butler, Qi Fan, Shaojia Fan, Grant L. Forster, Meng Gao, Jianlin Hu, Yugo Kanaya, Mohd Talib Latif, Keding Lu, Philippe Nédélec, Peer Nowack, Bastien Sauvage, Xiaobin Xu, Lin Zhang, Ke Li, Ja-Ho Koo, and Tatsuya Nagashima
Atmos. Chem. Phys., 25, 7991–8028, https://doi.org/10.5194/acp-25-7991-2025, https://doi.org/10.5194/acp-25-7991-2025, 2025
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This study analyzes summertime ozone trends in East and Southeast Asia derived from a comprehensive observational database spanning from 1995 to 2019, incorporating aircraft observations, ozonesonde data, and measurements from 2500 surface sites. Multiple models are applied to attribute to changes in anthropogenic emissions and climate. The results highlight that increases in anthropogenic emissions are the primary driver of ozone increases both in the free troposphere and at the surface.
Nana Wei, Eloise A. Marais, Gongda Lu, Robert G. Ryan, and Bastien Sauvage
Atmos. Chem. Phys., 25, 7925–7940, https://doi.org/10.5194/acp-25-7925-2025, https://doi.org/10.5194/acp-25-7925-2025, 2025
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This study uses reactive nitrogen observations from NASA DC-8 research aircraft and the In-service Aircraft for a Global Observing System (IAGOS) campaigns to characterize reactive nitrogen seasonality and composition in the global upper troposphere and to diagnose the greatest knowledge gaps from comparison to a state-of-the-science model, GEOS-Chem, that need to be resolved for climate, nitrogen cycle, and air pollution assessments.
Alexander K. Tardito Chaudhri and David S. Stevenson
Atmos. Chem. Phys., 25, 7369–7385, https://doi.org/10.5194/acp-25-7369-2025, https://doi.org/10.5194/acp-25-7369-2025, 2025
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There remains a large uncertainty in the global warming potential of atmospheric hydrogen due to poor constraints on its soil deposition and, therefore, its lifetime. A new analysis of the latitudinal variation in the observed seasonality of hydrogen is used to constrain its surface fluxes. This is complemented with a simple latitude–height model where surface fluxes are adjusted from a prototype deposition scheme.
María Cazorla, Melissa Trujillo, Rodrigo Seguel, and Laura Gallardo
Atmos. Chem. Phys., 25, 7087–7109, https://doi.org/10.5194/acp-25-7087-2025, https://doi.org/10.5194/acp-25-7087-2025, 2025
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The current climate and environmental crises impose the need to take actions in cities to curb ozone as a pollutant and a climate forcer. This endeavor is challenging in understudied regions. In this work we analyze how reducing levels of precursor chemicals would affect ozone formation in Quito, Ecuador, and Santiago, Chile.
Ji Xia, Yi Zhou, Li Fang, Yingfei Qi, Dehao Li, Hong Liao, and Jianbing Jin
Atmos. Chem. Phys., 25, 7071–7086, https://doi.org/10.5194/acp-25-7071-2025, https://doi.org/10.5194/acp-25-7071-2025, 2025
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This study established an ammonia emission inventory for South Asia via an assimilation-based inversion system. The posterior emissions, calculated by integrating the anthropogenic inventory and satellite observations, showed significant improvement over the prior. Validation against various measurements supports our results. The study offers a deep understanding of ammonia emissions for policymakers and researchers aiming to develop air quality management and mitigation strategies for South Asia.
Yuwen Peng, Bin Yuan, Sihang Wang, Xin Song, Zhe Peng, Wenjie Wang, Suxia Yang, Jipeng Qi, Xianjun He, Yibo Huangfu, Xiao-Bing Li, and Min Shao
Atmos. Chem. Phys., 25, 7037–7052, https://doi.org/10.5194/acp-25-7037-2025, https://doi.org/10.5194/acp-25-7037-2025, 2025
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A structural-based parameterization for the photolysis rates of oxygenated volatile organic compounds (OVOCs) was integrated into an updated chemical mechanism. This method links photolysis rates to species' structure, bypassing limitations of insufficient quantum yield data. Box model results show that non-HCHO OVOCs, particularly multifunctional carbonyl compounds, significantly contribute to radical production, with alkene and aromatic oxidation products playing key roles.
Catalina Poraicu, Jean-François Müller, Trissevgeni Stavrakou, Crist Amelynck, Bert W. D. Verreyken, Niels Schoon, Corinne Vigouroux, Nicolas Kumps, Jérôme Brioude, Pierre Tulet, and Camille Mouchel-Vallon
Atmos. Chem. Phys., 25, 6903–6941, https://doi.org/10.5194/acp-25-6903-2025, https://doi.org/10.5194/acp-25-6903-2025, 2025
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We investigated the sources and impacts of nitrogen oxides and organic compounds over a remote tropical island. Simulations of the high-resolution Weather Research and Forecasting model coupled with chemistry (WRF-Chem) were evaluated using in situ Fourier transform infrared spectroscopy (FTIR) and satellite measurements. This work highlights gaps in current models, like missing sources of key organic compounds and inaccuracies in emission inventories, emphasizing the importance of improving chemical and dynamical processes in atmospheric modelling for budget estimates in tropical regions.
Yosuke Niwa, Yasunori Tohjima, Yukio Terao, Tazu Saeki, Akihiko Ito, Taku Umezawa, Kyohei Yamada, Motoki Sasakawa, Toshinobu Machida, Shin-Ichiro Nakaoka, Hideki Nara, Hiroshi Tanimoto, Hitoshi Mukai, Yukio Yoshida, Shinji Morimoto, Shinya Takatsuji, Kazuhiro Tsuboi, Yousuke Sawa, Hidekazu Matsueda, Kentaro Ishijima, Ryo Fujita, Daisuke Goto, Xin Lan, Kenneth Schuldt, Michal Heliasz, Tobias Biermann, Lukasz Chmura, Jarsolaw Necki, Irène Xueref-Remy, and Damiano Sferlazzo
Atmos. Chem. Phys., 25, 6757–6785, https://doi.org/10.5194/acp-25-6757-2025, https://doi.org/10.5194/acp-25-6757-2025, 2025
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This study estimated regional and sectoral emission contributions to the unprecedented surge of atmospheric methane for 2020–2022. The methane is the second most important greenhouse gas, and its emissions reduction is urgently required to mitigate global warming. Numerical modeling-based estimates with three different sets of atmospheric observations consistently suggested large contributions of biogenic emissions from South Asia and Southeast Asia to the surge of atmospheric methane.
Sanhita Ghosh, Arineh Cholakian, Sylvain Mailler, and Laurent Menut
Atmos. Chem. Phys., 25, 6273–6297, https://doi.org/10.5194/acp-25-6273-2025, https://doi.org/10.5194/acp-25-6273-2025, 2025
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In this study, we evaluate the present state of modelling lightning flashes over the Northern Hemisphere, using the classical CTH (cloud-top height) scheme and the ICEFLUX scheme with the CHIMERE model. Our study provides a comprehensive 3D comparison of model outputs to assess the robustness and applicability of these schemes. An improvement in O3 distribution in the tropical free troposphere is observed due to inclusion of LNOx (nitrogen oxide emissions from lightning) in the model. Inclusion of LNOx also reduces the lifetime of trace gas CH4.
Audrey Fortems-Cheiney, Grégoire Broquet, Elise Potier, Antoine Berchet, Isabelle Pison, Adrien Martinez, Robin Plauchu, Rimal Abeed, Aurélien Sicsik-Paré, Gaelle Dufour, Adriana Coman, Dilek Savas, Guillaume Siour, Henk Eskes, Hugo A. C. Denier van der Gon, and Stijn N. C. Dellaert
Atmos. Chem. Phys., 25, 6047–6068, https://doi.org/10.5194/acp-25-6047-2025, https://doi.org/10.5194/acp-25-6047-2025, 2025
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This study assesses the potential of the Ozone Monitoring Instrument (OMI) and the TROPOspheric Monitoring Instrument (TROPOMI) satellite observations to inform about the decrease in anthropogenic emissions of nitrogen oxides (NOx) in 2019 compared with 2005 at regional to national scales in Europe. Both the OMI and TROPOMI inversions show decreases in European NOx anthropogenic emission budgets in 2019 compared to 2005 but with different magnitudes.
Yawen Kong, Bo Zheng, and Yuxi Liu
Atmos. Chem. Phys., 25, 5959–5976, https://doi.org/10.5194/acp-25-5959-2025, https://doi.org/10.5194/acp-25-5959-2025, 2025
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Current high-resolution satellite remote sensing technologies provide a unique opportunity to derive timely high-resolution emission data. We developed an emission inversion system to assimilate satellite NO2 data to obtain daily kilometer-scale NOx emission inventories. Our results enhance inventory accuracy, allowing us to capture the effects of pollution control policies on daily emissions (e.g., during COVID-19 lockdowns) and improve fine-scale air quality modeling.
Yann Cohen, Didier Hauglustaine, Nicolas Bellouin, Marianne Tronstad Lund, Sigrun Matthes, Agnieszka Skowron, Robin Thor, Ulrich Bundke, Andreas Petzold, Susanne Rohs, Valérie Thouret, Andreas Zahn, and Helmut Ziereis
Atmos. Chem. Phys., 25, 5793–5836, https://doi.org/10.5194/acp-25-5793-2025, https://doi.org/10.5194/acp-25-5793-2025, 2025
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The chemical composition of the atmosphere near the tropopause is a key parameter for evaluating the climate impact of subsonic aviation pollutants. This study uses in situ data collected aboard passenger aircraft to assess the ability of four chemistry–climate models to reproduce (bi-)decadal climatologies of ozone, carbon monoxide, water vapour, and reactive nitrogen in this region. The models reproduce the very distinct ozone seasonality in the upper troposphere and in the lower stratosphere well.
Yafang Guo, Mohammad Amin Mirrezaei, Armin Sorooshian, and Avelino F. Arellano
Atmos. Chem. Phys., 25, 5591–5616, https://doi.org/10.5194/acp-25-5591-2025, https://doi.org/10.5194/acp-25-5591-2025, 2025
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We assess the contributions of fire and anthropogenic emissions to O3 levels in Phoenix, Arizona, during a period of intense heat and drought conditions. We find that fire exacerbates O3 pollution and that interactions between weather, climate, and air chemistry are important to consider. This has implications for activities related to formulating emission reduction strategies in areas that are currently understudied yet becoming relevant due to reports of increasing global aridity.
Yujia Wang, Hongbin Wang, Bo Zhang, Peng Liu, Xinfeng Wang, Shuchun Si, Likun Xue, Qingzhu Zhang, and Qiao Wang
Atmos. Chem. Phys., 25, 5537–5555, https://doi.org/10.5194/acp-25-5537-2025, https://doi.org/10.5194/acp-25-5537-2025, 2025
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This study established a bottom-up approach that employs real-time traffic flows and interpolation to obtain a spatially continuous on-road vehicle emission mapping for the main urban area of Jinan. The diurnal variation, spatial distribution, and emission hotspots were analyzed with clustering and hotspot analysis, showing unique fine-scale variation characteristics of on-road vehicle emissions. Future scenario analysis demonstrates remarkable benefits of electrification on emission reduction.
Francisco J. Pérez-Invernón, Francisco J. Gordillo-Vázquez, Heidi Huntrieser, Patrick Jöckel, and Eric J. Bucsela
Atmos. Chem. Phys., 25, 5557–5575, https://doi.org/10.5194/acp-25-5557-2025, https://doi.org/10.5194/acp-25-5557-2025, 2025
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Lightning plays a significant role in tropospheric chemistry by producing substantial amounts of nitrogen oxides. According to recent estimates, thunderstorms that produce a higher lightning frequency rate also produce less nitrogen oxide per flash. We implemented the dependency of nitrogen oxide production per flash on lightning flash frequency in a chemical atmospheric model.
Aditya Nalam, Aura Lupaşcu, Tabish Ansari, and Tim Butler
Atmos. Chem. Phys., 25, 5287–5311, https://doi.org/10.5194/acp-25-5287-2025, https://doi.org/10.5194/acp-25-5287-2025, 2025
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Tropospheric O3 molecules are labeled with the identity of their precursor source to simulate contributions from various emission sources to the global tropospheric O3 burden (TOB) and its trends. With an equatorward shift, anthropogenic NOx emissions become significantly more efficient at producing O3 and play a major role in driving TOB trends, mainly due to larger convection at the tropics effectively lifting O3 and its precursors to the free troposphere, where O3 lifetime is longer.
Haofan Wang, Yuejin Li, Yiming Liu, Xiao Lu, Yang Zhang, Qi Fan, Chong Shen, Senchao Lai, Yan Zhou, Tao Zhang, and Dingli Yue
Atmos. Chem. Phys., 25, 5233–5250, https://doi.org/10.5194/acp-25-5233-2025, https://doi.org/10.5194/acp-25-5233-2025, 2025
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This study explores how urban green spaces (UGSs) in Guangzhou influence ozone levels. By using advanced models, we found that natural emissions from these areas can significantly affect air quality. Our results suggest that the design and planning of UGSs should not only consider aesthetics and social factors but also their environmental impacts on air quality.
Laura Stecher, Franziska Winterstein, Patrick Jöckel, Michael Ponater, Mariano Mertens, and Martin Dameris
Atmos. Chem. Phys., 25, 5133–5158, https://doi.org/10.5194/acp-25-5133-2025, https://doi.org/10.5194/acp-25-5133-2025, 2025
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Methane, the second most important anthropogenic greenhouse gas, is chemically decomposed in the atmosphere. The chemical sink of atmospheric methane is not constant but depends on the temperature and on the abundance of its reaction partners. In this study, we use a global chemistry–climate model to assess the feedback of atmospheric methane induced by changes in the chemical sink in a warming climate and its implications for the chemical composition and the surface air temperature change.
Kai-Lan Chang, Brian C. McDonald, Colin Harkins, and Owen R. Cooper
Atmos. Chem. Phys., 25, 5101–5132, https://doi.org/10.5194/acp-25-5101-2025, https://doi.org/10.5194/acp-25-5101-2025, 2025
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Exposure to high levels of ozone can be harmful to human health. This study shows consistent and robust evidence of decreasing ozone extremes across much of the United States over the period from 1990 to 2023, previously attributed to ozone precursor emission controls. Nevertheless, we also show that the increasing heat wave frequencies are likely to contribute to additional ozone exceedances, slowing the progress of decreasing the frequency of ozone exceedances.
Xiaochun Zhu, Le Cao, Xin Yang, Simeng Li, Jiandong Wang, and Tianliang Zhao
EGUsphere, https://doi.org/10.5194/egusphere-2024-3873, https://doi.org/10.5194/egusphere-2024-3873, 2025
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We applied various criteria to identify springtime ODEs at Utqiagvik, Arctic, and investigated the influences of using different criteria on conclusions regarding the characteristics of ODEs. We found criteria using a constant threshold and using thresholds based on the monthly averaged ozone more suitable for identifying ODEs than the others. Applying a threshold varying with the monthly average or stricter thresholds also signifies a more significant reduction in the ODE occurrences.
Ragnhild Bieltvedt Skeie, Marit Sandstad, Srinath Krishnan, Gunnar Myhre, and Maria Sand
Atmos. Chem. Phys., 25, 4929–4942, https://doi.org/10.5194/acp-25-4929-2025, https://doi.org/10.5194/acp-25-4929-2025, 2025
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Hydrogen leakages can alter the amount of climate gases in the atmosphere and hence have a climate impact. In this study we investigate, using an atmospheric chemistry model, how this indirect climate effect differs with different amounts of leakages and with where the hydrogen leaks and if this effect changes in the future. The effect is largest for emissions far from areas where hydrogen is removed from the atmosphere by the soil, but these are not relevant locations for a future hydrogen economy.
Alok K. Pandey, David S. Stevenson, Alcide Zhao, Richard J. Pope, Ryan Hossaini, Krishan Kumar, and Martyn P. Chipperfield
Atmos. Chem. Phys., 25, 4785–4802, https://doi.org/10.5194/acp-25-4785-2025, https://doi.org/10.5194/acp-25-4785-2025, 2025
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Nitrogen dioxide is an air pollutant largely controlled by human activity that affects ozone, methane, and aerosols. Satellite instruments can quantify column NO2 and, by carefully matching the time and location of measurements, enable evaluation of model simulations. NO2 over south and east Asia is assessed, showing that the model captures not only many features of the measurements, but also important differences that suggest model deficiencies in representing several aspects of the atmospheric chemistry of NO2.
Ruochong Xu, Hanchen Ma, Jingxian Li, Dan Tong, Liu Yan, Lanyuan Wang, Xinying Qin, Qingyang Xiao, Xizhe Yan, Hanwen Hu, Yujia Fu, Nana Wu, Huaxuan Wang, Yuexuanzi Wang, Xiaodong Liu, Guannan Geng, Kebin He, and Qiang Zhang
EGUsphere, https://doi.org/10.5194/egusphere-2025-1085, https://doi.org/10.5194/egusphere-2025-1085, 2025
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In this study, we developed a new global emission inventory for non-methane volatile organic compounds (NMVOC) for the period of 1970–2020, with a focus on improving the representation of NMVOC-emission-related technologies. Our analysis revealed that activity growth, technology advancements, and policy-driven emission controls were key driving forces of NMVOC emission changes, but their roles were different across sectors and regions.
Liang Feng, Paul Palmer, Luke Smallman, Jingfeng Xiao, Paulo Cristofanelli, Ove Hermansen, John Lee, Casper Labuschagne, Simonetta Montaguti, Steffen Noe, Stephen Platt, Xinrong Ren, Martin Steinbacher, and Irene Xueref-Remy
EGUsphere, https://doi.org/10.5194/egusphere-2025-1793, https://doi.org/10.5194/egusphere-2025-1793, 2025
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2023 saw an unexpectedly high global atmospheric CO2 growth. Satellite data reveal a role for increased emissions over the tropics. Larger emissions over eastern Brazil can be explained by warmer temperatures, while changes in rainfall and soil moisture play more of a role in emission increases elsewhere in the tropics.
Ryan Vella, Sergey Gromov, Clara M. Nussbaumer, Laura Stecher, Matthias Kohl, Samuel Ruhl, Holger Tost, Jos Lelieveld, and Andrea Pozzer
EGUsphere, https://doi.org/10.5194/egusphere-2025-1800, https://doi.org/10.5194/egusphere-2025-1800, 2025
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We evaluated how replacing forests with farmland and grazing areas affects atmospheric composition. Using a global climate-chemistry model, we found that deforestation reduces BVOCs, increases farming pollutants, and shifts ozone chemistry. These changes lead to a small cooling effect on the climate. Restoring natural vegetation could reverse some of these effects.
Mingzhao Liu, Lars Hoffmann, Jens-Uwe Grooß, Zhongyin Cai, Sabine Grießbach, and Yi Heng
Atmos. Chem. Phys., 25, 4403–4418, https://doi.org/10.5194/acp-25-4403-2025, https://doi.org/10.5194/acp-25-4403-2025, 2025
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We studied the transport and chemical decomposition of volcanic SO2, focusing on the 2019 Raikoke event. By comparing two different chemistry modeling schemes, we found that including complex chemical reactions leads to a more accurate prediction of how long SO2 stays in the atmosphere. This research helps improve our understanding of volcanic pollution and its impact on air quality and climate, providing better tools for scientists to track and predict the movement of these pollutants.
Yufen Wang, Ke Li, Xi Chen, Zhenjiang Yang, Minglong Tang, Pascoal M. D. Campos, Yang Yang, Xu Yue, and Hong Liao
Atmos. Chem. Phys., 25, 4455–4475, https://doi.org/10.5194/acp-25-4455-2025, https://doi.org/10.5194/acp-25-4455-2025, 2025
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The impacts of biomass burning and anthropogenic emissions on high tropospheric ozone levels are not well studied in southern Africa. We combined model simulations with recent observations at the surface and from space to quantify tropospheric ozone and its drivers in southern Africa. Our work focuses on the impact of emissions from different sources at different spatial scales, contributing to a comprehensive understanding of air pollution drivers and their uncertainties in southern Africa.
Dominika Pasik, Thomas Golin Almeida, Emelda Ahongshangbam, Siddharth Iyer, and Nanna Myllys
Atmos. Chem. Phys., 25, 4313–4331, https://doi.org/10.5194/acp-25-4313-2025, https://doi.org/10.5194/acp-25-4313-2025, 2025
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We used quantum chemistry methods to investigate the oxidation mechanisms of acyl peroxy radicals (APRs) with various monoterpenes. Our findings reveal unique oxidation pathways for different monoterpenes, leading to either chain-terminating products or highly reactive intermediates that can contribute to particle formation in the atmosphere. This research highlights APRs as potentially significant but underexplored atmospheric oxidants that may influence future approaches to modelling climate.
Jincheol Park, Yunsoo Choi, and Sagun Kayastha
Atmos. Chem. Phys., 25, 4291–4311, https://doi.org/10.5194/acp-25-4291-2025, https://doi.org/10.5194/acp-25-4291-2025, 2025
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We investigated NOx emission contributions to NOy loadings across five regions of East Asia during the 2022 winter–spring transition through chemical transport modeling informed by satellite data. As seasons progress, local contributions within each region to its NOy budget decreased from 32 %–43 % to 23 %–30 %, while transboundary contributions increased from 16 %–33 % to 27 %–37 %, driven by a shift in synoptic settings that allowed pollutants to spread more broadly across the regions.
Qianqian Zhang, K. Folkert Boersma, Chiel van der Laan, Alba Mols, Bin Zhao, Shengyue Li, and Yuepeng Pan
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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Accurate NOx emission estimates are required to better understand air pollution. This study investigates and demonstrates the ability of the superposition column model in combination with TROPOMI tropospheric NO2 column data to estimate city-scale NOx emissions and lifetimes and their variabilities. The results of this work nevertheless confirm the strength of the superposition column model in estimating urban NOx emissions with reasonable accuracy.
Biao Luo, Lei Liu, David H. Y. Yung, Tiangang Yuan, Jingwei Zhang, Leo T. H. Ng, and Amos P. K. Tai
EGUsphere, https://doi.org/10.5194/egusphere-2025-72, https://doi.org/10.5194/egusphere-2025-72, 2025
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Through a combination of emission models and air quality model, we aimed to address the pressing issue of poor nitrogen management while promoting sustainable food systems and public health in China. We discovered that improving nitrogen management of crop and livestock can substantially reduce air pollutant emissions, particularly in North China Plain. Our findings further provide the benefits of such interventions on PM2.5 reductions, offering valuable insights for policymakers.
Wenbin Kou, Yang Gao, Dan Tong, Xiaojie Guo, Xiadong An, Wenyu Liu, Mengshi Cui, Xiuwen Guo, Shaoqing Zhang, Huiwang Gao, and Lixin Wu
Atmos. Chem. Phys., 25, 3029–3048, https://doi.org/10.5194/acp-25-3029-2025, https://doi.org/10.5194/acp-25-3029-2025, 2025
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Unlike traditional numerical studies, we apply a high-resolution Earth system model, improving simulations of surface ozone and large-scale circulations such as atmospheric blocking. Besides local heat waves, we quantify the impact of atmospheric blocking on downstream ozone concentrations, which is closely associated with the blocking position. We identify three major pathways of Rossby wave propagation, stressing the critical role of large-scale circulation in regional air quality.
Jingyu Li, Haolin Wang, Qi Fan, and Xiao Lu
EGUsphere, https://doi.org/10.5194/egusphere-2025-782, https://doi.org/10.5194/egusphere-2025-782, 2025
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We use multiple global chemical models to quantify processes contributing the ozone response to ENSO. We find that changes in transport patterns are the dominant factor in the overall ozone-ENSO responses, with the opposing effects of chemical depletion and increased biomass burning on ozone largely offsetting each other. Models consistently project an increase in tropical ozone-ENSO response associated with strengthening anomalous circulation and more abundant water vapor with global warming.
Beata Opacka, Trissevgeni Stavrakou, Jean-François Müller, Isabelle De Smedt, Jos van Geffen, Eloise A. Marais, Rebekah P. Horner, Dylan B. Millet, Kelly C. Wells, and Alex B. Guenther
Atmos. Chem. Phys., 25, 2863–2894, https://doi.org/10.5194/acp-25-2863-2025, https://doi.org/10.5194/acp-25-2863-2025, 2025
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Vegetation releases biogenic volatile organic compounds, while soils and lightning contribute to the natural emissions of nitrogen oxides into the atmosphere. These gases interact in complex ways. Using satellite data and models, we developed a new method to simultaneously optimize these natural emissions over Africa in 2019. Our approach resulted in an increase in natural emissions, supported by independent data indicating that current estimates are underestimated.
Xiaobo Wang, Yuzhong Zhang, Tamás Bozóki, Ruosi Liang, Xinchun Xie, Shutao Zhao, Rui Wang, Yujia Zhao, and Shuai Sun
EGUsphere, https://doi.org/10.5194/egusphere-2025-370, https://doi.org/10.5194/egusphere-2025-370, 2025
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Schumann Resonance observations are used to parameterize lightning NOx emissions for better capturing global lightning trend and variability. Updated simulations reveal insignificant trend but greater variability in lightning NOx emissions, impacting tropospheric NOx, O3 and OH. Lightning generally counteracts non-lightning factors, reducing the inter-annua variability of tropospheric O3 and OH. Variations of global lightning play important role in understanding the atmospheric methane budget.
Xi Chen, Ke Li, Ting Yang, Xipeng Jin, Lei Chen, Yang Yang, Shuman Zhao, Bo Hu, Bin Zhu, Zifa Wang, and Hong Liao
EGUsphere, https://doi.org/10.5194/egusphere-2025-430, https://doi.org/10.5194/egusphere-2025-430, 2025
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Aerosol vertical distribution that plays a crucial role in aerosol-photolysis interaction (API) remains underrepresented in chemical models. We integrated lidar and radiosonde observations to constrain the simulated aerosol profiles over North China and quantified the photochemical responses. The increased photolysis rates in the lower layers led to increased ozone and accounted for a 36 %–56 % reduction in API effects, resulting in enhanced atmospheric oxidizing capacity and aerosol formation.
Jiaqi Shen, Ronald C. Cohen, Glenn M. Wolfe, and Xiaomeng Jin
EGUsphere, https://doi.org/10.5194/egusphere-2025-706, https://doi.org/10.5194/egusphere-2025-706, 2025
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This study shows large chemical and radiative effects of smoke aerosols from fires on near-surface ozone production. Aerosol loading and NOx levels are identified as the primary factors influencing these effects. Furthermore, we show that the surface PM2.5 to NO2 column ratio can be used as an indicator for identifying aerosol-dominated regimes, facilitating the assessments of aerosol impacts on ozone formation through satellite observations.
Shuai Li, Haolin Wang, and Xiao Lu
Atmos. Chem. Phys., 25, 2725–2743, https://doi.org/10.5194/acp-25-2725-2025, https://doi.org/10.5194/acp-25-2725-2025, 2025
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Summertime ozone–temperature sensitivity has decreased by 50 % from 3.0 ppbv per K in 1990 to 1.5 ppb per K in 2021 in the US. GEOS-Chem simulations show that anthropogenic nitrogen oxide emission reduction is the dominant driver of ozone–temperature sensitivity decline by influencing both temperature direct and temperature indirect processes. Reduced ozone–temperature sensitivity has decreased ozone enhancement from low to high temperatures by an average of 6.8 ppbv across the US.
Mingjie Kang, Hongliang Zhang, and Qi Ying
EGUsphere, https://doi.org/10.5194/egusphere-2025-255, https://doi.org/10.5194/egusphere-2025-255, 2025
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This study examines the impacts of reducing nitrogen oxides and volatile organic compounds on ozone (O3), secondary inorganic aerosols (SIA), and OH and NO3 radicals. The results show similar predictions for 8-h O3 but significant variability for SIA and radicals, with differences up to 30 % for SIA and 200 % for radicals across chemical mechanisms and inventories. The findings highlight that evaluating control strategies for SIA and atmospheric oxidation capacity requires an ensemble approach.
Jinya Yang, Yutong Wang, Lei Zhang, and Yu Zhao
Atmos. Chem. Phys., 25, 2649–2666, https://doi.org/10.5194/acp-25-2649-2025, https://doi.org/10.5194/acp-25-2649-2025, 2025
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We develop a modeling framework to predict future ozone concentrations (till the 2060s) in China following an IPCC scenario. We evaluate the contributions of climatic, anthropogenic, and biogenic factors by season and region. We find persistent emission controls will alter the nonlinear response of ozone to its precursors and dominate the declining ozone level. The outcomes highlight the importance of human actions, even with a climate penalty on air quality.
Xiaodong Zhang, Yu Yan, Ning Zhang, Wenpeng Wang, Huabing Suo, Xiaohu Jian, Chao Wang, Haibo Ma, Hong Gao, Zhaoli Yang, Tao Huang, and Jianmin Ma
EGUsphere, https://doi.org/10.5194/egusphere-2025-258, https://doi.org/10.5194/egusphere-2025-258, 2025
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This study performed comprehensive sensitivity model simulations to explore the surface O3 responses to historical and projected climate change in Northwestern China (NW). Our results reveal that substantial wetting trends since the 21st century have mitigated O3 growth in this region, with the influence of wetting on O3 evolution outweighing the warming effect. These findings should be taken into account in future policymaking aimed at scientifically reducing O3 pollution in NW.
Catherine Acquah, Laura Stecher, Mariano Mertens, and Patrick Jöckel
EGUsphere, https://doi.org/10.5194/egusphere-2025-294, https://doi.org/10.5194/egusphere-2025-294, 2025
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Short-lived ozone precursor species influence the formation of ozone and also the atmospheric lifetime of methane. Our study assesses the effect of two widely used emission inventories of these species on ozone and the methane lifetime. Our results indicate tropospheric ozone and methane lifetime differences of around 4 % even though both emission inventories aim at representing present-day conditions. We further attribute the differences to emissions of individual sectors, e.g. land traffic.
Takashi Sekiya, Emanuele Emili, Kazuyuki Miyazaki, Antje Inness, Zhen Qu, R. Bradley Pierce, Dylan Jones, Helen Worden, William Y. Y. Cheng, Vincent Huijnen, and Gerbrand Koren
Atmos. Chem. Phys., 25, 2243–2268, https://doi.org/10.5194/acp-25-2243-2025, https://doi.org/10.5194/acp-25-2243-2025, 2025
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Five global chemical reanalysis datasets were used to assess the relative impacts of assimilating satellite ozone and its precursor measurements on tropospheric ozone analyses for 2010. The multiple reanalysis system comparison allows an evaluation of the dependency of the impacts on different reanalysis systems. The results suggested the importance of satellite ozone and its precursor measurements for improving ozone analysis in the whole troposphere, with varying magnitudes among the systems.
Maureen Beaudor, Didier Hauglustaine, Juliette Lathière, Martin Van Damme, Lieven Clarisse, and Nicolas Vuichard
Atmos. Chem. Phys., 25, 2017–2046, https://doi.org/10.5194/acp-25-2017-2025, https://doi.org/10.5194/acp-25-2017-2025, 2025
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Agriculture is the biggest ammonia (NH3) source, impacting air quality, climate, and ecosystems. Because of food demand, NH3 emissions are projected to rise by 2100. Using a global model, we analyzed the impact of present and future NH3 emissions generated from a land model. Our results show improved ammonia patterns compared to a reference inventory. Future scenarios predict up to 70 % increase in global NH3 burden, with significant changes in radiative forcing that can greatly elevate N2O.
Pramod Kumar, Grégoire Broquet, Didier Hauglustaine, Maureen Beaudor, Lieven Clarisse, Martin Van Damme, Pierre Coheur, Anne Cozic, Bo Zheng, Beatriz Revilla Romero, Antony Delavois, and Philippe Ciais
EGUsphere, https://doi.org/10.5194/egusphere-2025-162, https://doi.org/10.5194/egusphere-2025-162, 2025
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Global maps of the NH3 emissions over 2019–2022 are derived using IASI NH3 spaceborne observations, the LMDZ-INCA chemistry-transport model at 1.27°×2.5° resolution and mass balance approach. The average global NH3 emissions over the period are ~98 Tg NH3 yr-1, which is significantly higher than three reference inventories. The analysis provides confidence in the seasonal variability and regional budgets, and provides new insights into NH3 emissions at global and regional scales.
Hui Li, Jiaxin Qiu, and Bo Zheng
Atmos. Chem. Phys., 25, 1949–1963, https://doi.org/10.5194/acp-25-1949-2025, https://doi.org/10.5194/acp-25-1949-2025, 2025
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We conduct a sensitivity analysis with 31 tests on various factors including prior emissions, model resolution, satellite constraint, and other system configurations to assess the vulnerability of emission estimates across temporal, sectoral, and regional dimensions. This reveals the robustness of emissions estimated by this air-pollution-satellite-based CO2 emission inversion system, with relative change between tests and base inversion below 4.0 % for national annual NOx and CO2 emissions.
Yingying Hong, Yuqi Zhu, Yuxuan Huang, Yiming Liu, Chuqi Xiong, and Qi Fan
EGUsphere, https://doi.org/10.5194/egusphere-2024-4132, https://doi.org/10.5194/egusphere-2024-4132, 2025
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This study investigates the impact of sea spray aerosol on ozone formation across Eastern China, highlighting its complex influence through both chemical reactions and radiative effects, which vary seasonally and geographically.
Yuqing Qiu, Xin Li, Wenxuan Chai, Yi Liu, Mengdi Song, Xudong Tian, Qiaoli Zou, Wenjun Lou, Wangyao Zhang, Juan Li, and Yuanhang Zhang
Atmos. Chem. Phys., 25, 1749–1763, https://doi.org/10.5194/acp-25-1749-2025, https://doi.org/10.5194/acp-25-1749-2025, 2025
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The chemical reactions of ozone (O3) formation are related to meteorology and local emissions. Here, a random forest approach was used to eliminate the effects of meteorological factors (dispersion or transport) on O3 and its precursors. Variations in the sensitivity of O3 formation and the apportionment of emission sources were revealed after meteorological normalization. Our results suggest that meteorological variations should be considered when diagnosing O3 formation.
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Short summary
Although it is the second-most important greenhouse gas, our understanding of the atmospheric-methane budget is limited. The uncertainty highlights the need for new tools to investigate sources and sinks. Here, we use a Gaussian process emulator to efficiently approximate the response of atmospheric-methane observations to changes in the most uncertain emission or loss processes. With this new method, we rigorously quantify the sensitivity of atmospheric observations to budget uncertainties.
Although it is the second-most important greenhouse gas, our understanding of the...
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