Articles | Volume 25, issue 1
https://doi.org/10.5194/acp-25-263-2025
© 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-25-263-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Maximum ozone concentrations in the southwestern US and Texas: implications of the growing predominance of the background contribution
David D. Parrish
CORRESPONDING AUTHOR
David.D.Parrish, LLC, 4630 MacArthur Ln, Boulder, Colorado, USA
Ian C. Faloona
Air Quality Research Center, University of California, Davis, Davis, CA, USA
Department of Land, Air, and Water Resources, University of California, Davis, Davis, CA, USA
Richard G. Derwent
rdscientific, Newbury, Berkshire, UK
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Yugo Kanaya, Roberto Sommariva, Alfonso Saiz-Lopez, Andrea Mazzeo, Theodore K. Koenig, Kaori Kawana, James E. Johnson, Aurélie Colomb, Pierre Tulet, Suzie Molloy, Ian E. Galbally, Rainer Volkamer, Anoop Mahajan, John W. Halfacre, Paul B. Shepson, Julia Schmale, Hélène Angot, Byron Blomquist, Matthew D. Shupe, Detlev Helmig, Junsu Gil, Meehye Lee, Sean C. Coburn, Ivan Ortega, Gao Chen, James Lee, Kenneth C. Aikin, David D. Parrish, John S. Holloway, Thomas B. Ryerson, Ilana B. Pollack, Eric J. Williams, Brian M. Lerner, Andrew J. Weinheimer, Teresa Campos, Frank M. Flocke, J. Ryan Spackman, Ilann Bourgeois, Jeff Peischl, Chelsea R. Thompson, Ralf M. Staebler, Amir A. Aliabadi, Wanmin Gong, Roeland Van Malderen, Anne M. Thompson, Ryan M. Stauffer, Debra E. Kollonige, Juan Carlos Gómez Martin, Masatomo Fujiwara, Katie Read, Matthew Rowlinson, Keiichi Sato, Junichi Kurokawa, Yoko Iwamoto, Fumikazu Taketani, Hisahiro Takashima, Monica Navarro Comas, Marios Panagi, and Martin G. Schultz
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2024-566, https://doi.org/10.5194/essd-2024-566, 2025
Preprint under review for ESSD
Short summary
Short summary
The first comprehensive dataset of tropospheric ozone over oceans/polar regions is presented, including 77 ship/buoy and 48 aircraft campaign observations (1977–2022, 0–5000 m altitude), supplemented by ozonesonde and surface data. Air masses isolated from land for 72+ hours are systematically selected as essentially oceanic. Among the 11 global regions, they show daytime decreases of 10–16% in the tropics, while near-zero depletions are rare, unlike in the Arctic, implying different mechanisms.
Richard G. Derwent, David D. Parrish, and Ian C. Faloona
Atmos. Chem. Phys., 23, 13613–13623, https://doi.org/10.5194/acp-23-13613-2023, https://doi.org/10.5194/acp-23-13613-2023, 2023
Short summary
Short summary
Elevated tropospheric ozone concentrations driven by anthropogenic precursor emissions are a world-wide health and environmental concern; however, this issue lacks a generally accepted understanding of the scientific issues. Here, we briefly outline the elements required to conduct an international assessment process to establish a conceptual model of the underpinning science and motivate international policy forums for regulating ozone production over hemispheric and global scales.
David D. Parrish, Richard G. Derwent, Ian C. Faloona, and Charles A. Mims
Atmos. Chem. Phys., 22, 13423–13430, https://doi.org/10.5194/acp-22-13423-2022, https://doi.org/10.5194/acp-22-13423-2022, 2022
Short summary
Short summary
Accounting for the continuing long-term decrease of pollution ozone and the large 2020 Arctic stratospheric ozone depletion event improves estimates of background ozone changes caused by COVID-19-related emission reductions; they are smaller than reported earlier. Cooperative, international emission control efforts aimed at maximizing the ongoing decrease in hemisphere-wide background ozone may be the most effective approach to improving ozone pollution in northern midlatitude countries.
Wenjie Wang, David D. Parrish, Siwen Wang, Fengxia Bao, Ruijing Ni, Xin Li, Suding Yang, Hongli Wang, Yafang Cheng, and Hang Su
Atmos. Chem. Phys., 22, 8935–8949, https://doi.org/10.5194/acp-22-8935-2022, https://doi.org/10.5194/acp-22-8935-2022, 2022
Short summary
Short summary
Tropospheric ozone is an air pollutant that is detrimental to human health, vegetation and ecosystem productivity. A comprehensive characterisation of the spatial and temporal distribution of tropospheric ozone is critical to our understanding of these issues. Here we summarise this distribution over China from the available observational records to the extent possible. This study provides insights into efficient future ozone control strategies in China.
Suxia Yang, Bin Yuan, Yuwen Peng, Shan Huang, Wei Chen, Weiwei Hu, Chenglei Pei, Jun Zhou, David D. Parrish, Wenjie Wang, Xianjun He, Chunlei Cheng, Xiao-Bing Li, Xiaoyun Yang, Yu Song, Haichao Wang, Jipeng Qi, Baolin Wang, Chen Wang, Chaomin Wang, Zelong Wang, Tiange Li, E Zheng, Sihang Wang, Caihong Wu, Mingfu Cai, Chenshuo Ye, Wei Song, Peng Cheng, Duohong Chen, Xinming Wang, Zhanyi Zhang, Xuemei Wang, Junyu Zheng, and Min Shao
Atmos. Chem. Phys., 22, 4539–4556, https://doi.org/10.5194/acp-22-4539-2022, https://doi.org/10.5194/acp-22-4539-2022, 2022
Short summary
Short summary
We use a model constrained using observations to study the formation of nitrate aerosol in and downwind of a representative megacity. We found different contributions of various chemical reactions to ground-level nitrate concentrations between urban and suburban regions. We also show that controlling VOC emissions are effective for decreasing nitrate formation in both urban and regional environments, although VOCs are not direct precursors of nitrate aerosol.
Henry Bowman, Steven Turnock, Susanne E. Bauer, Kostas Tsigaridis, Makoto Deushi, Naga Oshima, Fiona M. O'Connor, Larry Horowitz, Tongwen Wu, Jie Zhang, Dagmar Kubistin, and David D. Parrish
Atmos. Chem. Phys., 22, 3507–3524, https://doi.org/10.5194/acp-22-3507-2022, https://doi.org/10.5194/acp-22-3507-2022, 2022
Short summary
Short summary
A full understanding of ozone in the troposphere requires investigation of its temporal variability over all timescales. Model simulations show that the northern midlatitude ozone seasonal cycle shifted with industrial development (1850–2014), with an increasing magnitude and a later summer peak. That shift reached a maximum in the mid-1980s, followed by a reversal toward the preindustrial cycle. The few available observations, beginning in the 1970s, are consistent with the model simulations.
David D. Parrish, Richard G. Derwent, Steven T. Turnock, Fiona M. O'Connor, Johannes Staehelin, Susanne E. Bauer, Makoto Deushi, Naga Oshima, Kostas Tsigaridis, Tongwen Wu, and Jie Zhang
Atmos. Chem. Phys., 21, 9669–9679, https://doi.org/10.5194/acp-21-9669-2021, https://doi.org/10.5194/acp-21-9669-2021, 2021
Short summary
Short summary
The few ozone measurements made before the 1980s indicate that industrial development increased ozone concentrations by a factor of ~ 2 at northern midlatitudes, which are now larger than at southern midlatitudes. This difference was much smaller, and likely reversed, in the pre-industrial atmosphere. Earth system models find similar increases, but not higher pre-industrial ozone in the south. This disagreement may indicate that modeled natural ozone sources and/or deposition loss are inadequate.
Wenjie Wang, David D. Parrish, Xin Li, Min Shao, Ying Liu, Ziwei Mo, Sihua Lu, Min Hu, Xin Fang, Yusheng Wu, Limin Zeng, and Yuanhang Zhang
Atmos. Chem. Phys., 20, 15617–15633, https://doi.org/10.5194/acp-20-15617-2020, https://doi.org/10.5194/acp-20-15617-2020, 2020
Short summary
Short summary
During the past decade, China has devoted very substantial resources to improving the environment. These efforts have improved atmospheric particulate matter loading, but ambient ozone levels have continued to increase. In this paper we investigate the causes of the increasing ozone concentrations through analysis of a data set that is, to our knowledge, unique: a 12-year data set including ground-level O3, NOx, and VOC precursors collected at an urban site in Beijing.
David D. Parrish, Richard G. Derwent, Simon O'Doherty, and Peter G. Simmonds
Atmos. Meas. Tech., 12, 3383–3394, https://doi.org/10.5194/amt-12-3383-2019, https://doi.org/10.5194/amt-12-3383-2019, 2019
Short summary
Short summary
We present a flexible method that employs a power series expansion and Fourier series analysis to characterize the average long-term change and seasonal cycle, respectively, from a time series of observations of a trace atmospheric species. This approach maximizes the statistically significant information derived, including non-linear aspects of the long-term trends, without over fitting the data. Generally, a small set of parameter values (e.g., 7 or 8) provides this characterization.
Yugo Kanaya, Roberto Sommariva, Alfonso Saiz-Lopez, Andrea Mazzeo, Theodore K. Koenig, Kaori Kawana, James E. Johnson, Aurélie Colomb, Pierre Tulet, Suzie Molloy, Ian E. Galbally, Rainer Volkamer, Anoop Mahajan, John W. Halfacre, Paul B. Shepson, Julia Schmale, Hélène Angot, Byron Blomquist, Matthew D. Shupe, Detlev Helmig, Junsu Gil, Meehye Lee, Sean C. Coburn, Ivan Ortega, Gao Chen, James Lee, Kenneth C. Aikin, David D. Parrish, John S. Holloway, Thomas B. Ryerson, Ilana B. Pollack, Eric J. Williams, Brian M. Lerner, Andrew J. Weinheimer, Teresa Campos, Frank M. Flocke, J. Ryan Spackman, Ilann Bourgeois, Jeff Peischl, Chelsea R. Thompson, Ralf M. Staebler, Amir A. Aliabadi, Wanmin Gong, Roeland Van Malderen, Anne M. Thompson, Ryan M. Stauffer, Debra E. Kollonige, Juan Carlos Gómez Martin, Masatomo Fujiwara, Katie Read, Matthew Rowlinson, Keiichi Sato, Junichi Kurokawa, Yoko Iwamoto, Fumikazu Taketani, Hisahiro Takashima, Monica Navarro Comas, Marios Panagi, and Martin G. Schultz
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2024-566, https://doi.org/10.5194/essd-2024-566, 2025
Preprint under review for ESSD
Short summary
Short summary
The first comprehensive dataset of tropospheric ozone over oceans/polar regions is presented, including 77 ship/buoy and 48 aircraft campaign observations (1977–2022, 0–5000 m altitude), supplemented by ozonesonde and surface data. Air masses isolated from land for 72+ hours are systematically selected as essentially oceanic. Among the 11 global regions, they show daytime decreases of 10–16% in the tropics, while near-zero depletions are rare, unlike in the Arctic, implying different mechanisms.
Richard G. Derwent, David D. Parrish, and Ian C. Faloona
Atmos. Chem. Phys., 23, 13613–13623, https://doi.org/10.5194/acp-23-13613-2023, https://doi.org/10.5194/acp-23-13613-2023, 2023
Short summary
Short summary
Elevated tropospheric ozone concentrations driven by anthropogenic precursor emissions are a world-wide health and environmental concern; however, this issue lacks a generally accepted understanding of the scientific issues. Here, we briefly outline the elements required to conduct an international assessment process to establish a conceptual model of the underpinning science and motivate international policy forums for regulating ozone production over hemispheric and global scales.
David S. Stevenson, Richard G. Derwent, Oliver Wild, and William J. Collins
Atmos. Chem. Phys., 22, 14243–14252, https://doi.org/10.5194/acp-22-14243-2022, https://doi.org/10.5194/acp-22-14243-2022, 2022
Short summary
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Atmospheric methane’s growth rate rose by 50 % in 2020 relative to 2019. Lower nitrogen oxide (NOx) emissions tend to increase methane’s atmospheric residence time; lower carbon monoxide (CO) and non-methane volatile organic compound (NMVOC) emissions decrease its lifetime. Combining model sensitivities with emission changes, we find that COVID-19 lockdown emission reductions can explain over half the observed increases in methane in 2020.
David D. Parrish, Richard G. Derwent, Ian C. Faloona, and Charles A. Mims
Atmos. Chem. Phys., 22, 13423–13430, https://doi.org/10.5194/acp-22-13423-2022, https://doi.org/10.5194/acp-22-13423-2022, 2022
Short summary
Short summary
Accounting for the continuing long-term decrease of pollution ozone and the large 2020 Arctic stratospheric ozone depletion event improves estimates of background ozone changes caused by COVID-19-related emission reductions; they are smaller than reported earlier. Cooperative, international emission control efforts aimed at maximizing the ongoing decrease in hemisphere-wide background ozone may be the most effective approach to improving ozone pollution in northern midlatitude countries.
Keming Pan and Ian C. Faloona
Atmos. Chem. Phys., 22, 9681–9702, https://doi.org/10.5194/acp-22-9681-2022, https://doi.org/10.5194/acp-22-9681-2022, 2022
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This work represents a unique analysis of 10 existing air quality network sites and meteorological sites, two AmeriFlux sites, and a radio acoustic sounding system in the Central Valley of California during five consecutive fire seasons, June through September, from 2016 to 2020. We find that the ozone production rate increases by ~ 50 % during wildfire influenced periods. Wildfire smoke also decreases the heat flux by 30 % and results in 12 % lower mixed-layer height.
Wenjie Wang, David D. Parrish, Siwen Wang, Fengxia Bao, Ruijing Ni, Xin Li, Suding Yang, Hongli Wang, Yafang Cheng, and Hang Su
Atmos. Chem. Phys., 22, 8935–8949, https://doi.org/10.5194/acp-22-8935-2022, https://doi.org/10.5194/acp-22-8935-2022, 2022
Short summary
Short summary
Tropospheric ozone is an air pollutant that is detrimental to human health, vegetation and ecosystem productivity. A comprehensive characterisation of the spatial and temporal distribution of tropospheric ozone is critical to our understanding of these issues. Here we summarise this distribution over China from the available observational records to the extent possible. This study provides insights into efficient future ozone control strategies in China.
Suxia Yang, Bin Yuan, Yuwen Peng, Shan Huang, Wei Chen, Weiwei Hu, Chenglei Pei, Jun Zhou, David D. Parrish, Wenjie Wang, Xianjun He, Chunlei Cheng, Xiao-Bing Li, Xiaoyun Yang, Yu Song, Haichao Wang, Jipeng Qi, Baolin Wang, Chen Wang, Chaomin Wang, Zelong Wang, Tiange Li, E Zheng, Sihang Wang, Caihong Wu, Mingfu Cai, Chenshuo Ye, Wei Song, Peng Cheng, Duohong Chen, Xinming Wang, Zhanyi Zhang, Xuemei Wang, Junyu Zheng, and Min Shao
Atmos. Chem. Phys., 22, 4539–4556, https://doi.org/10.5194/acp-22-4539-2022, https://doi.org/10.5194/acp-22-4539-2022, 2022
Short summary
Short summary
We use a model constrained using observations to study the formation of nitrate aerosol in and downwind of a representative megacity. We found different contributions of various chemical reactions to ground-level nitrate concentrations between urban and suburban regions. We also show that controlling VOC emissions are effective for decreasing nitrate formation in both urban and regional environments, although VOCs are not direct precursors of nitrate aerosol.
Henry Bowman, Steven Turnock, Susanne E. Bauer, Kostas Tsigaridis, Makoto Deushi, Naga Oshima, Fiona M. O'Connor, Larry Horowitz, Tongwen Wu, Jie Zhang, Dagmar Kubistin, and David D. Parrish
Atmos. Chem. Phys., 22, 3507–3524, https://doi.org/10.5194/acp-22-3507-2022, https://doi.org/10.5194/acp-22-3507-2022, 2022
Short summary
Short summary
A full understanding of ozone in the troposphere requires investigation of its temporal variability over all timescales. Model simulations show that the northern midlatitude ozone seasonal cycle shifted with industrial development (1850–2014), with an increasing magnitude and a later summer peak. That shift reached a maximum in the mid-1980s, followed by a reversal toward the preindustrial cycle. The few available observations, beginning in the 1970s, are consistent with the model simulations.
David D. Parrish, Richard G. Derwent, Steven T. Turnock, Fiona M. O'Connor, Johannes Staehelin, Susanne E. Bauer, Makoto Deushi, Naga Oshima, Kostas Tsigaridis, Tongwen Wu, and Jie Zhang
Atmos. Chem. Phys., 21, 9669–9679, https://doi.org/10.5194/acp-21-9669-2021, https://doi.org/10.5194/acp-21-9669-2021, 2021
Short summary
Short summary
The few ozone measurements made before the 1980s indicate that industrial development increased ozone concentrations by a factor of ~ 2 at northern midlatitudes, which are now larger than at southern midlatitudes. This difference was much smaller, and likely reversed, in the pre-industrial atmosphere. Earth system models find similar increases, but not higher pre-industrial ozone in the south. This disagreement may indicate that modeled natural ozone sources and/or deposition loss are inadequate.
Wenjie Wang, David D. Parrish, Xin Li, Min Shao, Ying Liu, Ziwei Mo, Sihua Lu, Min Hu, Xin Fang, Yusheng Wu, Limin Zeng, and Yuanhang Zhang
Atmos. Chem. Phys., 20, 15617–15633, https://doi.org/10.5194/acp-20-15617-2020, https://doi.org/10.5194/acp-20-15617-2020, 2020
Short summary
Short summary
During the past decade, China has devoted very substantial resources to improving the environment. These efforts have improved atmospheric particulate matter loading, but ambient ozone levels have continued to increase. In this paper we investigate the causes of the increasing ozone concentrations through analysis of a data set that is, to our knowledge, unique: a 12-year data set including ground-level O3, NOx, and VOC precursors collected at an urban site in Beijing.
Justin F. Trousdell, Dani Caputi, Jeanelle Smoot, Stephen A. Conley, and Ian C. Faloona
Atmos. Chem. Phys., 19, 10697–10716, https://doi.org/10.5194/acp-19-10697-2019, https://doi.org/10.5194/acp-19-10697-2019, 2019
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We flew a small single-engine instrumented aircraft in a large valley of California to study the factors that determine air pollutant levels in a region of the US that faces serious air quality challenges. After carefully accounting for atmospheric mixing, we found that agriculture is likely a significant and currently underestimated source of nitrogen oxide, a precursor to both ozone and particulate matter pollution and methane, a potent greenhouse gas.
David D. Parrish, Richard G. Derwent, Simon O'Doherty, and Peter G. Simmonds
Atmos. Meas. Tech., 12, 3383–3394, https://doi.org/10.5194/amt-12-3383-2019, https://doi.org/10.5194/amt-12-3383-2019, 2019
Short summary
Short summary
We present a flexible method that employs a power series expansion and Fourier series analysis to characterize the average long-term change and seasonal cycle, respectively, from a time series of observations of a trace atmospheric species. This approach maximizes the statistically significant information derived, including non-linear aspects of the long-term trends, without over fitting the data. Generally, a small set of parameter values (e.g., 7 or 8) provides this characterization.
Dani J. Caputi, Ian Faloona, Justin Trousdell, Jeanelle Smoot, Nicholas Falk, and Stephen Conley
Atmos. Chem. Phys., 19, 4721–4740, https://doi.org/10.5194/acp-19-4721-2019, https://doi.org/10.5194/acp-19-4721-2019, 2019
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This paper covers the importance of understanding ozone pollution in California’s southern San Joaquin Valley from the perspective of meteorological conditions that occur overnight. Our main finding is that stronger winds aloft allow ozone to be depleted overnight, leading to less ozone the following day. This finding has the potential to greatly improve ozone forecasts in the San Joaquin Valley. This study is primarily conducted with aircraft observations.
Conner Daube, Stephen Conley, Ian C. Faloona, Claudia Arndt, Tara I. Yacovitch, Joseph R. Roscioli, and Scott C. Herndon
Atmos. Meas. Tech., 12, 2085–2095, https://doi.org/10.5194/amt-12-2085-2019, https://doi.org/10.5194/amt-12-2085-2019, 2019
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This study describes aircraft measurements of methane from dairy farms in central California. A small deliberate release of a tracer gas is done on the ground and measured from the air and the ratio of methane to tracer used to quantify emissions. Farm-scale methane emissions are determined as well as the fraction of those emissions coming from animal activity versus liquid manure management. These findings were within the uncertainty of two established methods.
Andrew O. Langford, Raul J. Alvarez II, Guillaume Kirgis, Christoph J. Senff, Dani Caputi, Stephen A. Conley, Ian C. Faloona, Laura T. Iraci, Josette E. Marrero, Mimi E. McNamara, Ju-Mee Ryoo, and Emma L. Yates
Atmos. Meas. Tech., 12, 1889–1904, https://doi.org/10.5194/amt-12-1889-2019, https://doi.org/10.5194/amt-12-1889-2019, 2019
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Lidar, aircraft, and surface measurements of ozone made during the 2016 California Baseline Ozone Transport Study (CABOTS) are compared to assess their validity and verify their suitability for investigations into the contributions of stratosphere-to-troposphere transport, Asian pollution, and wildfires to summertime surface ozone concentrations in the San Joaquin Valley of California. Our analysis shows that the lidar and aircraft measurements agree, on average, to within ±5 ppbv.
Gouri Prabhakar, Caroline L. Parworth, Xiaolu Zhang, Hwajin Kim, Dominique E. Young, Andreas J. Beyersdorf, Luke D. Ziemba, John B. Nowak, Timothy H. Bertram, Ian C. Faloona, Qi Zhang, and Christopher D. Cappa
Atmos. Chem. Phys., 17, 14747–14770, https://doi.org/10.5194/acp-17-14747-2017, https://doi.org/10.5194/acp-17-14747-2017, 2017
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This work assesses the processes that control the ambient concentrations of particulate nitrate in the the wintertime San Joaquin Valley of California through a combination of aircraft and surface measurements made during the DISCOVER-AQ study. We provide an observational demonstration of how nocturnal production and advection in aloft layers combines with daytime production and loss from entrainment and deposition to give rise to a distinct diurnal profile in surface nitrate concentrations.
Stephen Conley, Ian Faloona, Shobhit Mehrotra, Maxime Suard, Donald H. Lenschow, Colm Sweeney, Scott Herndon, Stefan Schwietzke, Gabrielle Pétron, Justin Pifer, Eric A. Kort, and Russell Schnell
Atmos. Meas. Tech., 10, 3345–3358, https://doi.org/10.5194/amt-10-3345-2017, https://doi.org/10.5194/amt-10-3345-2017, 2017
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This paper describes a new method of quantifying surface trace gas emissions (e.g. methane) from small aircraft (e.g. Mooney, Cessna) in about 30 min. This technique greatly enhances our ability to rapidly respond in the event of catastrophic failures such as Aliso Canyon and Deep Water Horizon.
Justin F. Trousdell, Stephen A. Conley, Andy Post, and Ian C. Faloona
Atmos. Chem. Phys., 16, 15433–15450, https://doi.org/10.5194/acp-16-15433-2016, https://doi.org/10.5194/acp-16-15433-2016, 2016
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In situ data from two flight campaigns in California’s San Joaquin Valley, an area characterized by complex terrain and patchy sources, is used to estimate important aspects of air pollution meteorology including rates of: vertical mixing, photochemical production of ozone, and the surface emission of non-reactive gases. Shown is the utility of airborne studies to help constrain crucial elements of air pollution modeling including vertical mixing, horizontal advection, and emission inventories.
M. Lothon, F. Lohou, D. Pino, F. Couvreux, E. R. Pardyjak, J. Reuder, J. Vilà-Guerau de Arellano, P Durand, O. Hartogensis, D. Legain, P. Augustin, B. Gioli, D. H. Lenschow, I. Faloona, C. Yagüe, D. C. Alexander, W. M. Angevine, E Bargain, J. Barrié, E. Bazile, Y. Bezombes, E. Blay-Carreras, A. van de Boer, J. L. Boichard, A. Bourdon, A. Butet, B. Campistron, O. de Coster, J. Cuxart, A. Dabas, C. Darbieu, K. Deboudt, H. Delbarre, S. Derrien, P. Flament, M. Fourmentin, A. Garai, F. Gibert, A. Graf, J. Groebner, F. Guichard, M. A. Jiménez, M. Jonassen, A. van den Kroonenberg, V. Magliulo, S. Martin, D. Martinez, L. Mastrorillo, A. F. Moene, F. Molinos, E. Moulin, H. P. Pietersen, B. Piguet, E. Pique, C. Román-Cascón, C. Rufin-Soler, F. Saïd, M. Sastre-Marugán, Y. Seity, G. J. Steeneveld, P. Toscano, O. Traullé, D. Tzanos, S. Wacker, N. Wildmann, and A. Zaldei
Atmos. Chem. Phys., 14, 10931–10960, https://doi.org/10.5194/acp-14-10931-2014, https://doi.org/10.5194/acp-14-10931-2014, 2014
H. Ikawa, I. Faloona, J. Kochendorfer, K. T. Paw U, and W. C. Oechel
Biogeosciences, 10, 4419–4432, https://doi.org/10.5194/bg-10-4419-2013, https://doi.org/10.5194/bg-10-4419-2013, 2013
Related subject area
Subject: Gases | Research Activity: Atmospheric Modelling and Data Analysis | Altitude Range: Troposphere | Science Focus: Chemistry (chemical composition and reactions)
Estimating the variability in NOx emissions from Wuhan with TROPOMI NO2 data during 2018 to 2023
Enhanced understanding of atmospheric blocking modulation on ozone dynamics within a high-resolution Earth system model
Natural emissions of VOC and NOx over Africa constrained by TROPOMI HCHO and NO2 data using the MAGRITTEv1.1 model
Anthropogenic emission controls reduce summertime ozone–temperature sensitivity in the United States
Investigating the response of China's surface ozone concentration to the future changes of multiple factors
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
Air-pollution-satellite-based CO2 emission inversion: system evaluation, sensitivity analysis, and future research direction
Insights into ozone pollution control in urban areas by decoupling meteorological factors based on machine learning
Quantification of regional net CO2 flux errors in the Orbiting Carbon Observatory-2 (OCO-2) v10 model intercomparison project (MIP) ensemble using airborne measurements
Reactive nitrogen in and around the northeastern and mid-Atlantic US: sources, sinks, and connections with ozone
Preindustrial-to-present-day changes in atmospheric carbon monoxide: agreement and gaps between ice archives and global model reconstructions
Investigating processes influencing simulation of local Arctic wintertime anthropogenic pollution in Fairbanks, Alaska, during ALPACA-2022
Urban ozone formation and sensitivities to volatile chemical products, cooking emissions, and NOx upwind of and within two Los Angeles Basin cities
Causes of growing middle-to-upper tropospheric ozone over the northwest Pacific region
Impact of introducing electric vehicles on ground-level O3 and PM2.5 in the Greater Tokyo Area: yearly trends and the importance of changes in the urban heat island effect
Constraining the budget of NOx and VOCs at a remote Tropical island using multi-platform observations and WRF-Chem model simulations
A CO2–Δ14CO2 inversion setup for estimating European fossil CO2 emissions
Derivation of atmospheric reaction mechanisms for volatile organic compounds by the SAPRC mechanism generation system (MechGen)
Seasonal, regional, and vertical characteristics of high-carbon-monoxide plumes along with their associated ozone anomalies, as seen by IAGOS between 2002 and 2019
The potential of drone observations to improve air quality predictions by 4D-Var
Process analysis of elevated concentrations of organic acids at Whiteface Mountain, New York
Sensitivity of climate-chemistry model simulated atmospheric composition to lightning-produced NOx parameterizations based on lightning frequency
Ozone source attribution in polluted European areas during summer 2017 as simulated with MECO(n)
Surface ozone trend variability across the United States and the impact of heatwaves (1990–2023)
Opinion: Challenges and needs of tropospheric chemical mechanism development
Decrease of the European NOx anthropogenic emissions between 2005 and 2019 as seen from the OMI and TROPOMI NO2 satellite observations
Tracking daily NOx emissions from an urban agglomeration based on TROPOMI NO2 and a local ensemble transform Kalman filter
The atmospheric oxidizing capacity in China – Part 2: Sensitivity to emissions of primary pollutants
Role of chemical production and depositional losses on formaldehyde in the Community Regional Atmospheric Chemistry Multiphase Mechanism (CRACMM)
Review of source analyses of ambient volatile organic compounds considering reactive losses: methods of reducing loss effects, impacts of losses, and sources
Interpreting summertime hourly variation of NO2 columns with implications for geostationary satellite applications
An investigation into atmospheric nitrous acid (HONO) processes in South Korea
Performance evaluation of UKESM1 for surface ozone across the pan-tropics
Constraining light dependency in modeled emissions through comparison to observed biogenic volatile organic compound (BVOC) concentrations in a southeastern US forest
A global re-analysis of regionally resolved emissions and atmospheric mole fractions of SF6 for the period 2005–2021
Monoterpene oxidation pathways initiated by acyl peroxy radical addition
Tropospheric ozone precursors: global and regional distributions, trends, and variability
Representing improved tropospheric ozone distribution by including lightning NOx emissions in CHIMERE
Sensitivity of climate effects of hydrogen to leakage size, location, and chemical background
The contribution of transport emissions to ozone mixing ratios and methane lifetime in 2015 and 2050 in the Shared Socioeconomic Pathways (SSPs)
Local and transboundary contributions to nitrogen loadings across East Asia using CMAQ-ISAM and GEMS-informed emissions inventory during the winter-spring transition
Ether and ester formation from peroxy radical recombination: a qualitative reaction channel analysis
ACEIC: a comprehensive anthropogenic chlorine emission inventory for China
Impact of methane and other precursor emission reductions on surface ozone in Europe: scenario analysis using the European Monitoring and Evaluation Programme (EMEP) Meteorological Synthesizing Centre – West (MSC-W) model
High-resolution mapping of on-road vehicle emissions with real-time traffic datasets based on big data
Chemistry-climate feedback of atmospheric methane in a methane emission flux driven chemistry-climate model
Verifying national inventory-based combustion emissions of CO2 across the UK and mainland Europe using satellite observations of atmospheric CO and CO2
Revisiting the high tropospheric ozone over Southern Africa: overestimated biomass burning and underestimated anthropogenic emissions
Source contribution to ozone pollution during June 2021 in Arizona: Insights from WRF-Chem tagged O3 and CO
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.
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.
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.
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.
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.
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.
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.
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.
Jeongmin Yun, Junjie Liu, Brendan Byrne, Brad Weir, Lesley E. Ott, Kathryn McKain, Bianca C. Baier, Luciana V. Gatti, and Sebastien C. Biraud
Atmos. Chem. Phys., 25, 1725–1748, https://doi.org/10.5194/acp-25-1725-2025, https://doi.org/10.5194/acp-25-1725-2025, 2025
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This study quantifies errors in regional net surface–atmosphere CO2 flux estimates from an inverse model ensemble using airborne CO2 measurements. Our results show that flux error estimates based on observations significantly exceed those computed from the ensemble spread of flux estimates in regions with high fossil fuel emissions. This finding suggests the presence of systematic biases in the inversion estimates, associated with errors in the fossil fuel emissions common to all models.
Min Huang, Gregory R. Carmichael, Kevin W. Bowman, Isabelle De Smedt, Andreas Colliander, Michael H. Cosh, Sujay V. Kumar, Alex B. Guenther, Scott J. Janz, Ryan M. Stauffer, Anne M. Thompson, Niko M. Fedkin, Robert J. Swap, John D. Bolten, and Alicia T. Joseph
Atmos. Chem. Phys., 25, 1449–1476, https://doi.org/10.5194/acp-25-1449-2025, https://doi.org/10.5194/acp-25-1449-2025, 2025
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We use model simulations along with multiplatform, multidisciplinary observations and a range of analysis methods to estimate and understand the distributions, temporal changes, and impacts of reactive nitrogen and ozone over the most populous US region that has undergone significant environmental changes. Deposition, biogenic emissions, and extra-regional sources have been playing increasingly important roles in controlling pollutant budgets in this area as local anthropogenic emissions drop.
Xavier Faïn, Sophie Szopa, Vaishali Naïk, Patricia Martinerie, David M. Etheridge, Rachael H. Rhodes, Cathy M. Trudinger, Vasilii V. Petrenko, Kévin Fourteau, and Philip Place
Atmos. Chem. Phys., 25, 1105–1119, https://doi.org/10.5194/acp-25-1105-2025, https://doi.org/10.5194/acp-25-1105-2025, 2025
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Carbon monoxide (CO) plays a crucial role in the atmosphere's oxidizing capacity. In this study, we analyse how historical (1850–2014) [CO] outputs from state-of-the-art global chemistry–climate models over Greenland and Antarctica are able to capture both absolute values and trends recorded in multi-site ice archives. A disparity in [CO] growth rates emerges in the Northern Hemisphere between models and observations from 1920–1975 CE, possibly linked to uncertainties in CO emission factors.
Natalie Brett, Kathy S. Law, Steve R. Arnold, Javier G. Fochesatto, Jean-Christophe Raut, Tatsuo Onishi, Robert Gilliam, Kathleen Fahey, Deanna Huff, George Pouliot, Brice Barret, Elsa Dieudonné, Roman Pohorsky, Julia Schmale, Andrea Baccarini, Slimane Bekki, Gianluca Pappaccogli, Federico Scoto, Stefano Decesari, Antonio Donateo, Meeta Cesler-Maloney, William Simpson, Patrice Medina, Barbara D'Anna, Brice Temime-Roussel, Joel Savarino, Sarah Albertin, Jingqiu Mao, Becky Alexander, Allison Moon, Peter F. DeCarlo, Vanessa Selimovic, Robert Yokelson, and Ellis S. Robinson
Atmos. Chem. Phys., 25, 1063–1104, https://doi.org/10.5194/acp-25-1063-2025, https://doi.org/10.5194/acp-25-1063-2025, 2025
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Processes influencing dispersion of local anthropogenic pollution in Arctic wintertime are investigated with Lagrangian dispersion modelling. Simulated power plant plume rise that considers temperature inversion layers improves results compared to observations (interior Alaska). Modelled surface concentrations are improved by representation of vertical mixing and emission estimates. Large increases in diesel vehicle emissions at temperatures reaching −35°C are required to reproduce observed NOx.
Chelsea E. Stockwell, Matthew M. Coggon, Rebecca H. Schwantes, Colin Harkins, Bert Verreyken, Congmeng Lyu, Qindan Zhu, Lu Xu, Jessica B. Gilman, Aaron Lamplugh, Jeff Peischl, Michael A. Robinson, Patrick R. Veres, Meng Li, Andrew W. Rollins, Kristen Zuraski, Sunil Baidar, Shang Liu, Toshihiro Kuwayama, Steven S. Brown, Brian C. McDonald, and Carsten Warneke
Atmos. Chem. Phys., 25, 1121–1143, https://doi.org/10.5194/acp-25-1121-2025, https://doi.org/10.5194/acp-25-1121-2025, 2025
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In urban areas, emissions from everyday products like paints, cleaners, and personal care products, along with non-traditional sources such as cooking, are increasingly important and impact air quality. This study uses a box model to evaluate how these emissions impact ozone in the Los Angeles Basin and quantifies the impact of gaseous cooking emissions. Accurate representation of these and other anthropogenic sources in inventories is crucial for informing effective air quality policies.
Xiaodan Ma, Jianping Huang, Michaela I. Hegglin, Patrick Jöckel, and Tianliang Zhao
Atmos. Chem. Phys., 25, 943–958, https://doi.org/10.5194/acp-25-943-2025, https://doi.org/10.5194/acp-25-943-2025, 2025
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Our research explored changes in ozone levels in the northwest Pacific region over 30 years, revealing a significant increase in the middle-to-upper troposphere, especially during spring and summer. This rise is influenced by both stratospheric and tropospheric sources, which affect climate and air quality in East Asia. This work underscores the need for continued study to understand underlying mechanisms.
Hiroo Hata, Norifumi Mizushima, and Tomohiko Ihara
Atmos. Chem. Phys., 25, 1037–1061, https://doi.org/10.5194/acp-25-1037-2025, https://doi.org/10.5194/acp-25-1037-2025, 2025
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The introduction of battery electric vehicles (BEVs) is expected to reduce the primary air pollutants from vehicular exhaust and evaporative emissions while reducing the anthropogenic heat produced by vehicles, ultimately mitigating the urban heat island (UHI) effect. This study revealed the impact of introducing BEVs on the decrease in the UHI effect and the impact of BEVs on the formation of tropospheric ozone and fine particulate matter in the Greater Tokyo Area of Japan.
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
EGUsphere, https://doi.org/10.5194/egusphere-2024-3555, https://doi.org/10.5194/egusphere-2024-3555, 2025
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We investigated the sources and impacts of nitrogen oxides and organic compounds over a remote tropical island. High-resolution WRF-Chem simulations were evaluated using in situ, 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.
Carlos Gómez-Ortiz, Guillaume Monteil, Sourish Basu, and Marko Scholze
Atmos. Chem. Phys., 25, 397–424, https://doi.org/10.5194/acp-25-397-2025, https://doi.org/10.5194/acp-25-397-2025, 2025
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In this paper, we test new implementations of our inverse modeling tool to estimate the weekly and regional CO2 emissions from fossil fuels in Europe. We use synthetic atmospheric observations of CO2 and radiocarbon (14CO2) to trace emissions to their sources, while separating the natural and fossil CO2. Our tool accurately estimates fossil CO2 emissions in densely monitored regions like western/central Europe. This approach aids in developing strategies for reducing CO2 emissions.
William P. L. Carter, Jia Jiang, John J. Orlando, and Kelley C. Barsanti
Atmos. Chem. Phys., 25, 199–242, https://doi.org/10.5194/acp-25-199-2025, https://doi.org/10.5194/acp-25-199-2025, 2025
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This paper describes the scientific basis for gas-phase atmospheric chemical mechanisms derived using the SAPRC mechanism generation system, MechGen. It can derive mechanisms for most organic compounds with C, H, O, or N atoms, including initial reactions of organics with OH, O3, NO3, and O3P or by photolysis, as well as the reactions of the various types of intermediates that are formed. The paper includes a description of areas of uncertainty where additional research and updates are needed.
Thibaut Lebourgeois, Bastien Sauvage, Pawel Wolff, Béatrice Josse, Virginie Marécal, Yasmine Bennouna, Romain Blot, Damien Boulanger, Hannah Clark, Jean-Marc Cousin, Philippe Nedelec, and Valérie Thouret
Atmos. Chem. Phys., 24, 13975–14004, https://doi.org/10.5194/acp-24-13975-2024, https://doi.org/10.5194/acp-24-13975-2024, 2024
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Our study examines intense-carbon-monoxide (CO) pollution events measured by commercial aircraft from the In-service Aircraft for a Global Observing System (IAGOS) research infrastructure. We combine these measurements with the SOFT-IO model to trace the origin of the observed CO. A comprehensive analysis of the geographical origin, source type, seasonal variation, and ozone levels of these pollution events is provided.
Hassnae Erraji, Philipp Franke, Astrid Lampert, Tobias Schuldt, Ralf Tillmann, Andreas Wahner, and Anne Caroline Lange
Atmos. Chem. Phys., 24, 13913–13934, https://doi.org/10.5194/acp-24-13913-2024, https://doi.org/10.5194/acp-24-13913-2024, 2024
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Four-dimensional variational data assimilation allows for the simultaneous optimisation of initial values and emission rates by using trace-gas profiles from drone observations in a regional air quality model. Assimilated profiles positively impact the representation of air pollutants in the model by improving their vertical distribution and ground-level concentrations. This case study highlights the potential of drone data to enhance air quality analyses including local emission evaluation.
Christopher Lawrence, Mary Barth, John Orlando, Paul Casson, Richard Brandt, Daniel Kelting, Elizabeth Yerger, and Sara Lance
Atmos. Chem. Phys., 24, 13693–13713, https://doi.org/10.5194/acp-24-13693-2024, https://doi.org/10.5194/acp-24-13693-2024, 2024
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This work uses chemical transport and box modeling to study the gas- and aqueous-phase production of organic acid concentrations measured in cloud water at the summit of Whiteface Mountain on 1 July 2018. Isoprene was the major source of formic, acetic, and oxalic acid. Gas-phase chemistry greatly underestimated formic and acetic acid, indicating missing sources, while cloud chemistry was a key source of oxalic acid. More studies of organic acids are required to better constrain their sources.
Francisco J. Pérez-Invernón, Francisco J. Gordillo-Vázquez, Heidi Huntrieser, Patrick Jöckel, and Eric J. Bucsela
EGUsphere, https://doi.org/10.5194/egusphere-2024-3348, https://doi.org/10.5194/egusphere-2024-3348, 2024
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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.
Markus Kilian, Volker Grewe, Patrick Jöckel, Astrid Kerkweg, Mariano Mertens, Andreas Zahn, and Helmut Ziereis
Atmos. Chem. Phys., 24, 13503–13523, https://doi.org/10.5194/acp-24-13503-2024, https://doi.org/10.5194/acp-24-13503-2024, 2024
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Anthropogenic emissions are a major source of precursors of tropospheric ozone. As ozone formation is highly non-linear, we apply a global–regional chemistry–climate model with a source attribution method (tagging) to quantify the contribution of anthropogenic emissions to ozone. Our analysis shows that the contribution of European anthropogenic emissions largely increases during large ozone periods, indicating that emissions from these sectors drive ozone values.
Kai-Lan Chang, Brian C. McDonald, and Owen R. Cooper
EGUsphere, https://doi.org/10.5194/egusphere-2024-3674, https://doi.org/10.5194/egusphere-2024-3674, 2024
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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 1990–2023, previously attributed to ozone precursor emission controls. Nevertheless, we also show that the increasing heatwave frequencies are likely to contribute to additional ozone exceedances, slowing the progress of decreasing the frequency of ozone exceedances.
Barbara Ervens, Andrew Rickard, Bernard Aumont, William P. L. Carter, Max McGillen, Abdelwahid Mellouki, John Orlando, Bénédicte Picquet-Varrault, Paul Seakins, William R. Stockwell, Luc Vereecken, and Timothy J. Wallington
Atmos. Chem. Phys., 24, 13317–13339, https://doi.org/10.5194/acp-24-13317-2024, https://doi.org/10.5194/acp-24-13317-2024, 2024
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Chemical mechanisms describe the chemical processes in atmospheric models that are used to describe the changes in the atmospheric composition. Therefore, accurate chemical mechanisms are necessary to predict the evolution of air pollution and climate change. The article describes all steps that are needed to build chemical mechanisms and discusses the advances and needs of experimental and theoretical research activities needed to build reliable chemical mechanisms.
Audrey Fortems-Cheiney, Grégoire Broquet, Robin Plauchu, Elise Potier, Antoine Berchet, Isabelle Pison, Adrien Martinez, Rimal Abeed, Gaelle Dufour, Adriana Coman, Dilek Savas, Guillaume Siour, Henk Eskes, Hugo A. C. Denier van der Gon, and Stijn N. C. Dellaert
EGUsphere, https://doi.org/10.5194/egusphere-2024-3679, https://doi.org/10.5194/egusphere-2024-3679, 2024
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This study assesses the potential of the OMI and TROPOMI satellite observations to inform about the evolution of NOx anthropogenic emissions between year 2005 and year 2019 at the regional to national scales in Europe. Both the OMI and TROPOMI inversions show decreases in European NOx anthropogenic emission budgets between 2005 and 2019, but with different magnitudes.
Yawen Kong, Bo Zheng, and Yuxi Liu
EGUsphere, https://doi.org/10.5194/egusphere-2024-2996, https://doi.org/10.5194/egusphere-2024-2996, 2024
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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 lockdown) and improve fine-scale air quality modeling.
Jianing Dai, Guy P. Brasseur, Mihalis Vrekoussis, Maria Kanakidou, Kun Qu, Yijuan Zhang, Hongliang Zhang, and Tao Wang
Atmos. Chem. Phys., 24, 12943–12962, https://doi.org/10.5194/acp-24-12943-2024, https://doi.org/10.5194/acp-24-12943-2024, 2024
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This paper employs a regional chemical transport model to quantify the sensitivity of air pollutants and photochemical parameters to specified emission reductions in China for representative winter and summer conditions. The study provides insights into further air quality control in China with reduced primary emissions.
T. Nash Skipper, Emma L. D'Ambro, Forwood C. Wiser, V. Faye McNeill, Rebecca H. Schwantes, Barron H. Henderson, Ivan R. Piletic, Colleen B. Baublitz, Jesse O. Bash, Andrew R. Whitehill, Lukas C. Valin, Asher P. Mouat, Jennifer Kaiser, Glenn M. Wolfe, Jason M. St. Clair, Thomas F. Hanisco, Alan Fried, Bryan K. Place, and Havala O.T. Pye
Atmos. Chem. Phys., 24, 12903–12924, https://doi.org/10.5194/acp-24-12903-2024, https://doi.org/10.5194/acp-24-12903-2024, 2024
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We develop the Community Regional Atmospheric Chemistry Multiphase Mechanism (CRACMM) version 2 to improve predictions of formaldehyde in ambient air compared to satellite-, aircraft-, and ground-based observations. With the updated chemistry, we estimate the cancer risk from inhalation exposure to ambient formaldehyde across the contiguous USA and predict that 40 % of this risk is controllable through reductions in anthropogenic emissions of nitrogen oxides and reactive organic carbon.
Baoshuang Liu, Yao Gu, Yutong Wu, Qili Dai, Shaojie Song, Yinchang Feng, and Philip K. Hopke
Atmos. Chem. Phys., 24, 12861–12879, https://doi.org/10.5194/acp-24-12861-2024, https://doi.org/10.5194/acp-24-12861-2024, 2024
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Reactive loss of volatile organic compounds (VOCs) is a long-term issue yet to be resolved in VOC source analyses. We assess common methods of, and existing issues in, reducing losses, impacts of losses, and sources in current source analyses. We offer a potential supporting role for solving issues of VOC conversion. Source analyses of consumed VOCs that reacted to produce ozone and secondary organic aerosols can play an important role in the effective control of secondary pollution in air.
Deepangsu Chatterjee, Randall V. Martin, Chi Li, Dandan Zhang, Haihui Zhu, Daven K. Henze, James H. Crawford, Ronald C. Cohen, Lok N. Lamsal, and Alexander M. Cede
Atmos. Chem. Phys., 24, 12687–12706, https://doi.org/10.5194/acp-24-12687-2024, https://doi.org/10.5194/acp-24-12687-2024, 2024
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We investigate the hourly variation of NO2 columns and surface concentrations by applying the GEOS-Chem model to interpret aircraft and ground-based measurements over the US and Pandora sun photometer measurements over the US, Europe, and Asia. Corrections to the Pandora columns and finer model resolution improve the modeled representation of the summertime hourly variation of total NO2 columns to explain the weaker hourly variation in NO2 columns than at the surface.
Kiyeon Kim, Kyung Man Han, Chul Han Song, Hyojun Lee, Ross Beardsley, Jinhyeok Yu, Greg Yarwood, Bonyoung Koo, Jasper Madalipay, Jung-Hun Woo, and Seogju Cho
Atmos. Chem. Phys., 24, 12575–12593, https://doi.org/10.5194/acp-24-12575-2024, https://doi.org/10.5194/acp-24-12575-2024, 2024
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We incorporated each HONO process into the current CMAQ modeling framework to enhance the accuracy of HONO mixing ratio predictions. These results expand our understanding of HONO photochemistry and identify crucial sources of HONO that impact the total HONO budget in Seoul, South Korea. Through this investigation, we contribute to resolving discrepancies in understanding chemical transport models, with implications for better air quality management and environmental protection in the region.
Flossie Brown, Gerd Folberth, Stephen Sitch, Paulo Artaxo, Marijn Bauters, Pascal Boeckx, Alexander W. Cheesman, Matteo Detto, Ninong Komala, Luciana Rizzo, Nestor Rojas, Ines dos Santos Vieira, Steven Turnock, Hans Verbeeck, and Alfonso Zambrano
Atmos. Chem. Phys., 24, 12537–12555, https://doi.org/10.5194/acp-24-12537-2024, https://doi.org/10.5194/acp-24-12537-2024, 2024
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Ozone is a pollutant that is detrimental to human and plant health. Ozone monitoring sites in the tropics are limited, so models are often used to understand ozone exposure. We use measurements from the tropics to evaluate ozone from the UK Earth system model, UKESM1. UKESM1 is able to capture the pattern of ozone in the tropics, except in southeast Asia, although it systematically overestimates it at all sites. This work highlights that UKESM1 can capture seasonal and hourly variability.
Namrata Shanmukh Panji, Deborah F. McGlynn, Laura E. R. Barry, Todd M. Scanlon, Manuel T. Lerdau, Sally E. Pusede, and Gabriel Isaacman-VanWertz
Atmos. Chem. Phys., 24, 12495–12507, https://doi.org/10.5194/acp-24-12495-2024, https://doi.org/10.5194/acp-24-12495-2024, 2024
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Climate change will bring about changes in parameters that are currently used in global-scale models to calculate biogenic emissions. This study seeks to understand the factors driving these models by comparing long-term datasets of biogenic compounds to modeled emissions. We note that the light-dependent fractions currently used in models do not accurately represent regional observations. We provide evidence for the time-dependent variation in this parameter for future modifications to models.
Martin Vojta, Andreas Plach, Saurabh Annadate, Sunyoung Park, Gawon Lee, Pallav Purohit, Florian Lindl, Xin Lan, Jens Mühle, Rona L. Thompson, and Andreas Stohl
Atmos. Chem. Phys., 24, 12465–12493, https://doi.org/10.5194/acp-24-12465-2024, https://doi.org/10.5194/acp-24-12465-2024, 2024
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We constrain the global emissions of the very potent greenhouse gas sulfur hexafluoride (SF6) between 2005 and 2021. We show that SF6 emissions are decreasing in the USA and in the EU, while they are substantially growing in China, leading overall to an increasing global emission trend. The national reports for the USA, EU, and China all underestimated their SF6 emissions. However, stringent mitigation measures can successfully reduce SF6 emissions, as can be seen in the EU emission trend.
Dominika Pasik, Thomas Golin Almeida, Emelda Ahongshangbam, Siddharth Iyer, and Nanna Myllys
EGUsphere, https://doi.org/10.5194/egusphere-2024-3464, https://doi.org/10.5194/egusphere-2024-3464, 2024
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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, which may influence future approaches to modeling climate.
Yasin Elshorbany, Jerald R. Ziemke, Sarah Strode, Hervé Petetin, Kazuyuki Miyazaki, Isabelle De Smedt, Kenneth Pickering, Rodrigo J. Seguel, Helen Worden, Tamara Emmerichs, Domenico Taraborrelli, Maria Cazorla, Suvarna Fadnavis, Rebecca R. Buchholz, Benjamin Gaubert, Néstor Y. Rojas, Thiago Nogueira, Thérèse Salameh, and Min Huang
Atmos. Chem. Phys., 24, 12225–12257, https://doi.org/10.5194/acp-24-12225-2024, https://doi.org/10.5194/acp-24-12225-2024, 2024
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We investigated tropospheric ozone spatial variability and trends from 2005 to 2019 and related those to ozone precursors on global and regional scales. We also investigate the spatiotemporal characteristics of the ozone formation regime in relation to ozone chemical sources and sinks. Our analysis is based on remote sensing products of the tropospheric column of ozone and its precursors, nitrogen dioxide, formaldehyde, and total column CO, as well as ozonesonde data and model simulations.
Sanhita Ghosh, Arineh Cholakian, Sylvain Mailler, and Laurent Menut
EGUsphere, https://doi.org/10.5194/egusphere-2024-3087, https://doi.org/10.5194/egusphere-2024-3087, 2024
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In the study, we estimate the emissions of nitrogen oxides from lightning (LNOx) over the northern hemisphere and study its impact on tropospheric ozone (O3). We evaluate the present state of modelling the lightning, using a classical parametrization scheme and the model CHIMERE. The comparison of the simulated O3 to measurements shows that the inclusion of LNOx emissions remarkably improves the tropospheric O3 distribution, reducing the bias significantly, particularly in the free troposphere.
Ragnhild Bieltvedt Skeie, Marit Sandstad, Srinath Krishnan, Gunnar Myhre, and Maria Sand
EGUsphere, https://doi.org/10.5194/egusphere-2024-3079, https://doi.org/10.5194/egusphere-2024-3079, 2024
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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 for different amounts of leakages, 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.
Mariano Mertens, Sabine Brinkop, Phoebe Graf, Volker Grewe, Johannes Hendricks, Patrick Jöckel, Anna Lanteri, Sigrun Matthes, Vanessa S. Rieger, Mattia Righi, and Robin N. Thor
Atmos. Chem. Phys., 24, 12079–12106, https://doi.org/10.5194/acp-24-12079-2024, https://doi.org/10.5194/acp-24-12079-2024, 2024
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We quantified the contributions of land transport, shipping, and aviation emissions to tropospheric ozone; its radiative forcing; and the reductions of the methane lifetime using chemistry-climate model simulations. The contributions were analysed for the conditions of 2015 and for three projections for the year 2050. The results highlight the challenges of mitigating ozone formed by emissions of the transport sector, caused by the non-linearitiy of the ozone chemistry and the long lifetime.
Jincheol Park, Yunsoo Choi, and Sagun Kayastha
EGUsphere, https://doi.org/10.5194/egusphere-2024-3312, https://doi.org/10.5194/egusphere-2024-3312, 2024
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We investigated NOx emissions’ contributions to nitrogen 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.
Lauri Franzon, Marie Camredon, Richard Valorso, Bernard Aumont, and Theo Kurtén
Atmos. Chem. Phys., 24, 11679–11699, https://doi.org/10.5194/acp-24-11679-2024, https://doi.org/10.5194/acp-24-11679-2024, 2024
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In this article we investigate the formation of large, sticky molecules from various organic compounds entering the atmosphere as primary emissions and the degree to which these processes may contribute to organic aerosol particle mass. More specifically, we qualitatively investigate a recently discovered chemical reaction channel for one of the most important short-lived radical compounds, peroxy radicals, and discover which of these reactions are most atmospherically important.
Siting Li, Yiming Liu, Yuqi Zhu, Yinbao Jin, Yingying Hong, Ao Shen, Yifei Xu, Haofan Wang, Haichao Wang, Xiao Lu, Shaojia Fan, and Qi Fan
Atmos. Chem. Phys., 24, 11521–11544, https://doi.org/10.5194/acp-24-11521-2024, https://doi.org/10.5194/acp-24-11521-2024, 2024
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This study establishes an inventory of anthropogenic chlorine emissions in China in 2019 with expanded species (HCl, Cl-, Cl2, HOCl) and sources (41 specific sources). The inventory is validated by a modeling study against the observations. This study enhances the understanding of anthropogenic chlorine emissions in the atmosphere, identifies key sources, and provides scientific support for pollution control and climate change.
Willem E. van Caspel, Zbigniew Klimont, Chris Heyes, and Hilde Fagerli
Atmos. Chem. Phys., 24, 11545–11563, https://doi.org/10.5194/acp-24-11545-2024, https://doi.org/10.5194/acp-24-11545-2024, 2024
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Methane in the atmosphere contributes to the production of ozone gas – an air pollutant and greenhouse gas. Our results highlight that simultaneous reductions in methane emissions help avoid offsetting the air pollution benefits already achieved by the already-approved precursor emission reductions by 2050 in the European Monitoring and Evaluation Programme region, while also playing an important role in bringing air pollution further down towards World Health Organization guideline limits.
Yujia Wang, Hongbin Wang, Bo Zhang, Peng Liu, Xinfeng Wang, Shuchun Si, Likun Xue, Qingzhu Zhang, and Qiao Wang
EGUsphere, https://doi.org/10.5194/egusphere-2024-2791, https://doi.org/10.5194/egusphere-2024-2791, 2024
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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.
Laura Stecher, Franziska Winterstein, Patrick Jöckel, Michael Ponater, Mariano Mertens, and Martin Dameris
EGUsphere, https://doi.org/10.5194/egusphere-2024-2938, https://doi.org/10.5194/egusphere-2024-2938, 2024
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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 of the chemical sink in a warming climate, and its implications for the chemical composition and the surface air temperature change.
Tia R. Scarpelli, Paul I. Palmer, Mark Lunt, Ingrid Super, and Arjan Droste
Atmos. Chem. Phys., 24, 10773–10791, https://doi.org/10.5194/acp-24-10773-2024, https://doi.org/10.5194/acp-24-10773-2024, 2024
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Under the Paris Agreement, countries must track their anthropogenic greenhouse gas emissions. This study describes a method to determine self-consistent estimates for combustion emissions and natural fluxes of CO2 from atmospheric data. We report consistent estimates inferred using this approach from satellite data and ground-based data over Europe, suggesting that satellite data can be used to determine national anthropogenic CO2 emissions for countries where ground-based CO2 data are absent.
Yufen Wang, Ke Li, Xi Chen, Zhenjiang Yang, Minglong Tang, Pascoal M. D. Campos, Yang Yang, Xu Yue, and Hong Liao
EGUsphere, https://doi.org/10.5194/egusphere-2024-2576, https://doi.org/10.5194/egusphere-2024-2576, 2024
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The impact of biomass burning and anthropogenic emissions on high tropospheric ozone was not well studied in Southern Africa. We combined the model simulation with recent observations at the surface and from space to quantify tropospheric ozone and its main 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.
Yafang Guo, Mohammad Amin Mirrezaei, Armin Sorooshian, and Avelino F. Arellano
EGUsphere, https://doi.org/10.5194/egusphere-2024-2617, https://doi.org/10.5194/egusphere-2024-2617, 2024
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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 to activities related to formulating emission reduction strategies in areas that are currently under-studied yet becoming relevant due to reports of increasing global aridity.
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Oltmans, S. J., Lefohn, A. S., Harris, J. M., and Shadwick, D. S.: Background ozone levels of air entering the west coast of the U.S., and assessment of longer-term changes, Atmos. Environ., 42, 6020–6038, https://doi.org/10.1016/j.atmosenv.2008.03.034, 2008.
Parrish, D. D. and Ennis, C. A.: Estimating background contributions and US anthropogenic enhancements to maximum ozone concentrations in the northern US, Atmos. Chem. Phys., 19, 12587–12605, https://doi.org/10.5194/acp-19-12587-2019, 2019.
Parrish, D. D. and Stockwell, W. R.: Urbanization and air pollution: Then and now, Eos: Earth & Space Science News, 96, 10–15, 2015.
Parrish, D. D., Millet, D. B., and Goldstein, A. H.: Increasing ozone in marine boundary layer inflow at the west coasts of North America and Europe, Atmos. Chem. Phys., 9, 1303–1323, https://doi.org/10.5194/acp-9-1303-2009, 2009.
Parrish, D. D., Aikin, K. C., Oltmans, S. J., Johnson, B. J., Ives, M., and Sweeny, C.: Impact of transported background ozone inflow on summertime air quality in a California ozone exceedance area, Atmos. Chem. Phys., 10, 10093–10109, https://doi.org/10.5194/acp-10-10093-2010, 2010.
Parrish, D. D., Law, K. S., Staehelin, J., Derwent, R., Cooper, O. R., Tanimoto, H., Volz-Thomas, A., Gilge, S., Scheel, H.-E., Steinbacher, M., and Chan, E.: Long-term changes in lower tropospheric baseline ozone concentrations at northern mid-latitudes, Atmos. Chem. Phys., 12, 11485–11504, https://doi.org/10.5194/acp-12-11485-2012, 2012.
Parrish, D. D., Xu, J,. Croes, B., and Shao, M.: Air Quality Improvement in Los Angeles - Perspectives for Developing Cities, Front. Environ. Sci. Eng., 10, 11, https://doi.org/10.1007/s11783-016-0859-5, 2016.
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Short summary
Observation-based estimates of contributions to maximum ozone (O3) concentrations show that background O3 can exceed the air quality standard of 70 ppb in the southwestern US, precluding standard attainment. Over the past 4 decades, US anthropogenic O3 has decreased by a factor of ~ 6.3, while wildfire contributions have increased, so that the background now dominates maximum concentrations, even in Los Angeles, and the occurrence of maximum O3 has shifted from the eastern to the western US.
Observation-based estimates of contributions to maximum ozone (O3) concentrations show that...
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