Articles | Volume 23, issue 2
https://doi.org/10.5194/acp-23-843-2023
© Author(s) 2023. 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-23-843-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
18 Jan 2023
Research article |
| 18 Jan 2023
| 18 Jan 2023
Observed changes in stratospheric circulation: decreasing lifetime of N2O, 2005–2021
Earth System Science Department, University of California Irvine,
Irvine, CA 92697-3100, USA
Lucien Froidevaux
Jet Propulsion Laboratory, California Institute of Technology,
Pasadena, CA 91011, USA
Nathaniel J. Livesey
Jet Propulsion Laboratory, California Institute of Technology,
Pasadena, CA 91011, USA
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Li Xu, Qi Tang, Qing Zhu, William J. Riley, Guido R. van der Werf, Yang Chen, Michael J. Prather, and James T. Randerson
EGUsphere, https://doi.org/10.5194/egusphere-2026-4288, https://doi.org/10.5194/egusphere-2026-4288, 2026
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
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Using the E3SM version 3 model with interactive chemistry, this study shows that wildfires substantially perturb global and regional tropospheric chemistry and modify radiative effects through aerosol and ozone interactions, with particularly strong impacts in tropical fire regions. By connecting wildfire emissions with changes in atmospheric composition, radiation, and climate, this study provides important insights on how the atmosphere responds to changing fire activities.
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This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
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We model the change in greenhouse gas (ozone and methane) levels in the atmosphere caused by South Korean air pollution. We compare results obtained using a global chemistry-transport model with simplified chemistry, and a specialised hybrid model with detailed chemistry but simplified transport. Air pollution in the chemistry-transport model produces less ozone, and destroys much less methane, than the hybrid model. This leads to net global warming in the former model and cooling in the latter.
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Short summary
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Hydrogen (H2) is an indirect greenhouse gas that can affect climate through chemical reactions in the atmosphere. To better understand this impact, it is important to constrain the sources and sinks of hydrogen. Using a suite of three-dimensional and one-dimensional models, we find that atmospheric production of hydrogen is 37–60 Tg/yr and that the geological source of H2 is much smaller than suggested. More field and isotopic measurements are needed to improve these estimates.
Gunnar Myhre, Øivind Hodnebrog, Srinath Krishnan, Maria Sand, Marit Sandstad, Ragnhild B. Skeie, Lieven Clarisse, Bruno Franco, Dylan B. Millet, Kelley C. Wells, Alexander Archibald, Hannah N. Bryant, Alex T. Chaudhri, David S. Stevenson, Didier Hauglustaine, Michael Prather, J. Christopher Kaiser, Dirk J. L. Olivie, Michael Schulz, Oliver Wild, Ye Wang, Thérèse Salameh, Jason E. Williams, Philippe Le Sager, Fabien Paulot, Kostas Tsigaridis, and Haley E. Plaas
Geosci. Model Dev., 19, 2577–2591, https://doi.org/10.5194/gmd-19-2577-2026, https://doi.org/10.5194/gmd-19-2577-2026, 2026
Short summary
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Volatile organic compounds (VOCs) affect air quality and climate, but their behavior in the atmosphere is still uncertain. We launched a global research effort to compare how different models represent these compounds and to improve their accuracy. By analyzing model results alongside observations and satellite data, we aim to better understand the atmospheric composition of these compounds.
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Atmos. Chem. Phys., 26, 3995–4017, https://doi.org/10.5194/acp-26-3995-2026, https://doi.org/10.5194/acp-26-3995-2026, 2026
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Air pollution impacts global warming by changing atmospheric chemistry, effectively producing ozone and destroying methane (greenhouse gases). We quantify these greenhouse gas changes with a specialized model that tracks the chemical impact of air pollutants over their lifetime. Our summertime Korean results, scaled to all air pollution, estimate that up to 30 % of tropospheric ozone production and 10 % of methane loss is caused by air pollutants, but this scaling overrates wintertime pollution.
Clara Orbe, Alison Ming, Gabriel Chiodo, Michael Prather, Mohamadou Diallo, Qi Tang, Andreas Chrysanthou, Hiroaki Naoe, Xin Zhou, Irina Thaler, Dillon Elsbury, Ewa Bednarz, Jonathon S. Wright, Aaron Match, Shingo Watanabe, James Anstey, Tobias Kerzenmacher, Stefan Versick, Marion Marchand, Feng Li, and James Keeble
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Geosci. Model Dev., 18, 7891–7905, https://doi.org/10.5194/gmd-18-7891-2025, https://doi.org/10.5194/gmd-18-7891-2025, 2025
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Our study aims to present a new method for incorporating top-down solar forcing into stratospheric ozone relying on linearized ozone scheme. The addition of geomagnetic forcing led to significant ozone losses in the polar upper stratosphere of both hemispheres due to the catalytic cycles involving NOy. In addition to the particle precipitation effect, accounting for solar UV variability in the ICON-ART model leads to the changes in ozone in the tropical stratosphere.
Jinbo Xie, Qi Tang, Michael Prather, Jadwiga Richter, and Shixuan Zhang
Atmos. Chem. Phys., 25, 9315–9333, https://doi.org/10.5194/acp-25-9315-2025, https://doi.org/10.5194/acp-25-9315-2025, 2025
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Analysis of the interaction between the climate and ozone in the stratosphere is complicated by the inability of climate models to simulate the quasi-biennial oscillation (QBO) – an important climate mode in the stratosphere. We use a set of model simulations that realistically simulate QBO and a novel ozone diagnostic tool to separate temperature- and circulation-driven QBO impacts. These are important for diagnosing model–model differences in QBO–ozone responses for climate projections.
Paul T. Griffiths, Laura J. Wilcox, Robert J. Allen, Vaishali Naik, Fiona M. O'Connor, Michael Prather, Alex Archibald, Florence Brown, Makoto Deushi, William Collins, Stephanie Fiedler, Naga Oshima, Lee T. Murray, Bjørn H. Samset, Chris Smith, Steven Turnock, Duncan Watson-Parris, and Paul J. Young
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The Aerosol Chemistry Model Intercomparison Project (AerChemMIP) aimed to quantify the climate and air quality impacts of aerosols and chemically reactive gases. We review its contribution to AR6 (Sixth Assessment Report of the Intergovernmental Panel on Climate Change) and the wider understanding of the role of these species in climate and climate change. We identify challenges and provide recommendations to improve the utility and uptake of climate model data, detailed summary tables of CMIP6 models, experiments, and emergent diagnostics.
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Atmos. Meas. Tech., 18, 1757–1769, https://doi.org/10.5194/amt-18-1757-2025, https://doi.org/10.5194/amt-18-1757-2025, 2025
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Hanqin Tian, Naiqing Pan, Rona L. Thompson, Josep G. Canadell, Parvadha Suntharalingam, Pierre Regnier, Eric A. Davidson, Michael Prather, Philippe Ciais, Marilena Muntean, Shufen Pan, Wilfried Winiwarter, Sönke Zaehle, Feng Zhou, Robert B. Jackson, Hermann W. Bange, Sarah Berthet, Zihao Bian, Daniele Bianchi, Alexander F. Bouwman, Erik T. Buitenhuis, Geoffrey Dutton, Minpeng Hu, Akihiko Ito, Atul K. Jain, Aurich Jeltsch-Thömmes, Fortunat Joos, Sian Kou-Giesbrecht, Paul B. Krummel, Xin Lan, Angela Landolfi, Ronny Lauerwald, Ya Li, Chaoqun Lu, Taylor Maavara, Manfredi Manizza, Dylan B. Millet, Jens Mühle, Prabir K. Patra, Glen P. Peters, Xiaoyu Qin, Peter Raymond, Laure Resplandy, Judith A. Rosentreter, Hao Shi, Qing Sun, Daniele Tonina, Francesco N. Tubiello, Guido R. van der Werf, Nicolas Vuichard, Junjie Wang, Kelley C. Wells, Luke M. Western, Chris Wilson, Jia Yang, Yuanzhi Yao, Yongfa You, and Qing Zhu
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Revised manuscript not accepted
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Earth Syst. Sci. Data, 15, 3299–3349, https://doi.org/10.5194/essd-15-3299-2023, https://doi.org/10.5194/essd-15-3299-2023, 2023
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The Atmospheric Tomography Mission (ATom) measured the chemical composition in air parcels from 0–12 km altitude on 2 km horizontal by 80 m vertical scales for four seasons, resolving most scales of chemical heterogeneity. ATom is one of the first missions designed to calculate the chemical evolution of each parcel, providing semi-global diurnal budgets for ozone and methane. Observations covered the remote troposphere: Pacific and Atlantic Ocean basins, Southern Ocean, Arctic basin, Antarctica.
Hao Guo, Clare M. Flynn, Michael J. Prather, Sarah A. Strode, Stephen D. Steenrod, Louisa Emmons, Forrest Lacey, Jean-Francois Lamarque, Arlene M. Fiore, Gus Correa, Lee T. Murray, Glenn M. Wolfe, Jason M. St. Clair, Michelle Kim, John Crounse, Glenn Diskin, Joshua DiGangi, Bruce C. Daube, Roisin Commane, Kathryn McKain, Jeff Peischl, Thomas B. Ryerson, Chelsea Thompson, Thomas F. Hanisco, Donald Blake, Nicola J. Blake, Eric C. Apel, Rebecca S. Hornbrook, James W. Elkins, Eric J. Hintsa, Fred L. Moore, and Steven C. Wofsy
Atmos. Chem. Phys., 23, 99–117, https://doi.org/10.5194/acp-23-99-2023, https://doi.org/10.5194/acp-23-99-2023, 2023
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We have prepared a unique and unusual result from the recent ATom aircraft mission: a measurement-based derivation of the production and loss rates of ozone and methane over the ocean basins. These are the key products of chemistry models used in assessments but have thus far lacked observational metrics. It also shows the scales of variability of atmospheric chemical rates and provides a major challenge to the atmospheric models.
Michael J. Prather
Earth Syst. Dynam., 13, 703–709, https://doi.org/10.5194/esd-13-703-2022, https://doi.org/10.5194/esd-13-703-2022, 2022
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Atmospheric CO2 fluctuations point to changes in fossil fuel emissions plus natural and perturbed variations in the natural carbon cycle. One unstudied source of variability is the stratosphere, where the influx of aged CO2-depleted air can cause surface fluctuations. Using modeling and, separately, scaling the observed N2O variability, I find that stratosphere-driven surface variability in CO2 is not a significant uncertainty (at most 10 % of the observed interannual variability).
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Atmos. Chem. Phys., 22, 2079–2093, https://doi.org/10.5194/acp-22-2079-2022, https://doi.org/10.5194/acp-22-2079-2022, 2022
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The stratosphere is an important source of tropospheric ozone, which affects climate, chemistry, and air quality, but is extremely difficult to quantify given the large production and loss terms in the troposphere. Here, we use other gases that are well observed and quantified as a reference to test our simulations of ozone transport in the atmosphere. This allows us to better constrain the stratospheric source of ozone and also offers guidance to improve future simulations of ozone transport.
Li Xu, Qi Tang, Qing Zhu, William J. Riley, Guido R. van der Werf, Yang Chen, Michael J. Prather, and James T. Randerson
EGUsphere, https://doi.org/10.5194/egusphere-2026-4288, https://doi.org/10.5194/egusphere-2026-4288, 2026
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
Short summary
Using the E3SM version 3 model with interactive chemistry, this study shows that wildfires substantially perturb global and regional tropospheric chemistry and modify radiative effects through aerosol and ozone interactions, with particularly strong impacts in tropical fire regions. By connecting wildfire emissions with changes in atmospheric composition, radiation, and climate, this study provides important insights on how the atmosphere responds to changing fire activities.
Calum Patrick Wilson and Michael John Prather
EGUsphere, https://doi.org/10.5194/egusphere-2026-4590, https://doi.org/10.5194/egusphere-2026-4590, 2026
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
Short summary
We model the change in greenhouse gas (ozone and methane) levels in the atmosphere caused by South Korean air pollution. We compare results obtained using a global chemistry-transport model with simplified chemistry, and a specialised hybrid model with detailed chemistry but simplified transport. Air pollution in the chemistry-transport model produces less ozone, and destroys much less methane, than the hybrid model. This leads to net global warming in the former model and cooling in the latter.
Srinath Krishnan, Ragnhild Bieltvedt Skeie, Øivind Hodnebrog, Gunnar Myhre, Maria Sand, Marit Sandstad, Hannah Bryant, Didier A. Hauglustaine, Fabien Paulot, Michael Prather, and David Stevenson
Atmos. Chem. Phys., 26, 9509–9539, https://doi.org/10.5194/acp-26-9509-2026, https://doi.org/10.5194/acp-26-9509-2026, 2026
Short summary
Short summary
Hydrogen (H2) is an indirect greenhouse gas that can affect climate through chemical reactions in the atmosphere. To better understand this impact, it is important to constrain the sources and sinks of hydrogen. Using a suite of three-dimensional and one-dimensional models, we find that atmospheric production of hydrogen is 37–60 Tg/yr and that the geological source of H2 is much smaller than suggested. More field and isotopic measurements are needed to improve these estimates.
Quentin Errera, Marc Op de beeck, Stefan Bender, Johannes Flemming, Bernd Funke, Alex Hoffmann, Michael Höpfner, Nathaniel Livesey, Gabriele Poli, Didier Pieroux, Piera Raspollini, and Björn-Martin Sinnhuber
Atmos. Meas. Tech., 19, 2601–2620, https://doi.org/10.5194/amt-19-2601-2026, https://doi.org/10.5194/amt-19-2601-2026, 2026
Short summary
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The Changing Atmosphere Infra-Red Tomography Explorer (CAIRT) is a satellite mission concept developed to observe, among other, the gradient of ozone and water vapour in the upper troposphere and lower stratosphere where these species have their largest radiative impact. By simulating CAIRT observations and measuring their constrain on an atmospheric model using data assimilation, this study shows that CAIRT specifications are adequate to fulfil this objective.
Gunnar Myhre, Øivind Hodnebrog, Srinath Krishnan, Maria Sand, Marit Sandstad, Ragnhild B. Skeie, Lieven Clarisse, Bruno Franco, Dylan B. Millet, Kelley C. Wells, Alexander Archibald, Hannah N. Bryant, Alex T. Chaudhri, David S. Stevenson, Didier Hauglustaine, Michael Prather, J. Christopher Kaiser, Dirk J. L. Olivie, Michael Schulz, Oliver Wild, Ye Wang, Thérèse Salameh, Jason E. Williams, Philippe Le Sager, Fabien Paulot, Kostas Tsigaridis, and Haley E. Plaas
Geosci. Model Dev., 19, 2577–2591, https://doi.org/10.5194/gmd-19-2577-2026, https://doi.org/10.5194/gmd-19-2577-2026, 2026
Short summary
Short summary
Volatile organic compounds (VOCs) affect air quality and climate, but their behavior in the atmosphere is still uncertain. We launched a global research effort to compare how different models represent these compounds and to improve their accuracy. By analyzing model results alongside observations and satellite data, we aim to better understand the atmospheric composition of these compounds.
Calum Patrick Wilson and Michael John Prather
Atmos. Chem. Phys., 26, 3995–4017, https://doi.org/10.5194/acp-26-3995-2026, https://doi.org/10.5194/acp-26-3995-2026, 2026
Short summary
Short summary
Air pollution impacts global warming by changing atmospheric chemistry, effectively producing ozone and destroying methane (greenhouse gases). We quantify these greenhouse gas changes with a specialized model that tracks the chemical impact of air pollutants over their lifetime. Our summertime Korean results, scaled to all air pollution, estimate that up to 30 % of tropospheric ozone production and 10 % of methane loss is caused by air pollutants, but this scaling overrates wintertime pollution.
Viktoria F. Sofieva, Alexandra Laeng, Thomas von Clarmann, Gabriele Stiller, Michael Kiefer, Johanna Tamminen, Alexey Rozanov, Carlo Arosio, Nathaniel Livesey, Robert Damadeo, Patrick Sheese, Kaley A. Walker, Doug Degenstein, Daniel Zawada, Natalya A. Kramarova, and Arno Keppens
Atmos. Meas. Tech., 19, 1837–1852, https://doi.org/10.5194/amt-19-1837-2026, https://doi.org/10.5194/amt-19-1837-2026, 2026
Short summary
Short summary
For satellite measurements of atmospheric composition, the random uncertainty estimates provided by retrieval algorithms might be imperfect due to various approximations used in the retrievals or presence of unknown error sources. This paper presents an overview of the methods used for validation of random uncertainty estimates. All methods discussed in this study are categorized, and assumptions and limitations of each method are discussed.
Clara Orbe, Alison Ming, Gabriel Chiodo, Michael Prather, Mohamadou Diallo, Qi Tang, Andreas Chrysanthou, Hiroaki Naoe, Xin Zhou, Irina Thaler, Dillon Elsbury, Ewa Bednarz, Jonathon S. Wright, Aaron Match, Shingo Watanabe, James Anstey, Tobias Kerzenmacher, Stefan Versick, Marion Marchand, Feng Li, and James Keeble
Geosci. Model Dev., 19, 773–794, https://doi.org/10.5194/gmd-19-773-2026, https://doi.org/10.5194/gmd-19-773-2026, 2026
Short summary
Short summary
The quasi-biennial oscillation (QBO) is the main source of wind fluctuations in the tropical stratosphere, which can couple to surface climate. However, models do a poor job of simulating the QBO in the lower stratosphere, for reasons that remain unclear. One possibility is that models do not completely represent how ozone influences the QBO-associated wind variations. Here we propose a multi-model framework for assessing how ozone influences the QBO in recent past and future climates.
Maryam Ramezani Ziarani, Miriam Sinnhuber, Thomas Reddmann, Bernd Funke, Stefan Bender, and Michael Prather
Geosci. Model Dev., 18, 7891–7905, https://doi.org/10.5194/gmd-18-7891-2025, https://doi.org/10.5194/gmd-18-7891-2025, 2025
Short summary
Short summary
Our study aims to present a new method for incorporating top-down solar forcing into stratospheric ozone relying on linearized ozone scheme. The addition of geomagnetic forcing led to significant ozone losses in the polar upper stratosphere of both hemispheres due to the catalytic cycles involving NOy. In addition to the particle precipitation effect, accounting for solar UV variability in the ICON-ART model leads to the changes in ozone in the tropical stratosphere.
Jinbo Xie, Qi Tang, Michael Prather, Jadwiga Richter, and Shixuan Zhang
Atmos. Chem. Phys., 25, 9315–9333, https://doi.org/10.5194/acp-25-9315-2025, https://doi.org/10.5194/acp-25-9315-2025, 2025
Short summary
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Analysis of the interaction between the climate and ozone in the stratosphere is complicated by the inability of climate models to simulate the quasi-biennial oscillation (QBO) – an important climate mode in the stratosphere. We use a set of model simulations that realistically simulate QBO and a novel ozone diagnostic tool to separate temperature- and circulation-driven QBO impacts. These are important for diagnosing model–model differences in QBO–ozone responses for climate projections.
Paul T. Griffiths, Laura J. Wilcox, Robert J. Allen, Vaishali Naik, Fiona M. O'Connor, Michael Prather, Alex Archibald, Florence Brown, Makoto Deushi, William Collins, Stephanie Fiedler, Naga Oshima, Lee T. Murray, Bjørn H. Samset, Chris Smith, Steven Turnock, Duncan Watson-Parris, and Paul J. Young
Atmos. Chem. Phys., 25, 8289–8328, https://doi.org/10.5194/acp-25-8289-2025, https://doi.org/10.5194/acp-25-8289-2025, 2025
Short summary
Short summary
The Aerosol Chemistry Model Intercomparison Project (AerChemMIP) aimed to quantify the climate and air quality impacts of aerosols and chemically reactive gases. We review its contribution to AR6 (Sixth Assessment Report of the Intergovernmental Panel on Climate Change) and the wider understanding of the role of these species in climate and climate change. We identify challenges and provide recommendations to improve the utility and uptake of climate model data, detailed summary tables of CMIP6 models, experiments, and emergent diagnostics.
Calum P. Wilson and Michael J. Prather
Atmos. Meas. Tech., 18, 1757–1769, https://doi.org/10.5194/amt-18-1757-2025, https://doi.org/10.5194/amt-18-1757-2025, 2025
Short summary
Short summary
We evaluated how well we can infer air pollutant levels (ozone, carbon monoxide, and nitrogen oxides) between air quality stations throughout South Korea, finding good representation in most densely measured cities in spite of intense small-scale emission hotspots. Comparing observed air quality with gridded model output is desirable, and so we created gridded datasets over South Korea using air quality station measurements, which agreed with airborne measurements around Seoul.
Lucien Froidevaux, Douglas E. Kinnison, Benjamin Gaubert, Michael J. Schwartz, Nathaniel J. Livesey, William G. Read, Charles G. Bardeen, Jerry R. Ziemke, and Ryan A. Fuller
Atmos. Chem. Phys., 25, 597–624, https://doi.org/10.5194/acp-25-597-2025, https://doi.org/10.5194/acp-25-597-2025, 2025
Short summary
Short summary
We compare observed changes in ozone (O3) and carbon monoxide (CO) in the tropical upper troposphere (10–15 km altitude) for 2005–2020 to predictions from model simulations that track the evolution of natural and industrial emissions transported to this region. An increasing trend in measured upper-tropospheric O3 is well matched by model trends. We find that changes in modeled industrial CO surface emissions lead to better model agreement with observed slight decreases in upper-tropospheric CO.
Kimberlee Dubé, Susann Tegtmeier, Adam Bourassa, Daniel Zawada, Douglas Degenstein, William Randel, Sean Davis, Michael Schwartz, Nathaniel Livesey, and Anne Smith
Atmos. Chem. Phys., 24, 12925–12941, https://doi.org/10.5194/acp-24-12925-2024, https://doi.org/10.5194/acp-24-12925-2024, 2024
Short summary
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Greenhouse gas emissions that warm the troposphere also result in stratospheric cooling. The cooling rate is difficult to quantify above 35 km due to a deficit of long-term observational data with high vertical resolution in this region. We use satellite observations from several instruments, including a new temperature product from OSIRIS, to show that the upper stratosphere, from 35–60 km, cooled by 0.5 to 1 K per decade over 2005–2021 and by 0.6 K per decade over 1979–2021.
Hanqin Tian, Naiqing Pan, Rona L. Thompson, Josep G. Canadell, Parvadha Suntharalingam, Pierre Regnier, Eric A. Davidson, Michael Prather, Philippe Ciais, Marilena Muntean, Shufen Pan, Wilfried Winiwarter, Sönke Zaehle, Feng Zhou, Robert B. Jackson, Hermann W. Bange, Sarah Berthet, Zihao Bian, Daniele Bianchi, Alexander F. Bouwman, Erik T. Buitenhuis, Geoffrey Dutton, Minpeng Hu, Akihiko Ito, Atul K. Jain, Aurich Jeltsch-Thömmes, Fortunat Joos, Sian Kou-Giesbrecht, Paul B. Krummel, Xin Lan, Angela Landolfi, Ronny Lauerwald, Ya Li, Chaoqun Lu, Taylor Maavara, Manfredi Manizza, Dylan B. Millet, Jens Mühle, Prabir K. Patra, Glen P. Peters, Xiaoyu Qin, Peter Raymond, Laure Resplandy, Judith A. Rosentreter, Hao Shi, Qing Sun, Daniele Tonina, Francesco N. Tubiello, Guido R. van der Werf, Nicolas Vuichard, Junjie Wang, Kelley C. Wells, Luke M. Western, Chris Wilson, Jia Yang, Yuanzhi Yao, Yongfa You, and Qing Zhu
Earth Syst. Sci. Data, 16, 2543–2604, https://doi.org/10.5194/essd-16-2543-2024, https://doi.org/10.5194/essd-16-2543-2024, 2024
Short summary
Short summary
Atmospheric concentrations of nitrous oxide (N2O), a greenhouse gas 273 times more potent than carbon dioxide, have increased by 25 % since the preindustrial period, with the highest observed growth rate in 2020 and 2021. This rapid growth rate has primarily been due to a 40 % increase in anthropogenic emissions since 1980. Observed atmospheric N2O concentrations in recent years have exceeded the worst-case climate scenario, underscoring the importance of reducing anthropogenic N2O emissions.
Hsiang-He Lee, Qi Tang, and Michael Prather
Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2023-203, https://doi.org/10.5194/gmd-2023-203, 2024
Revised manuscript not accepted
Short summary
Short summary
The E3SM Chemistry diagnostics package (ChemDyg) is a software tool, which is designed for the global climate model (E3SM) chemistry development. ChemDyg generates several diagnostic plots and tables for model-to-model and model-to-observation comparison, including 2-dimentional contour mapping plots, diurnal and annual cycle, time-series plots, and comprehensive processing tables. This paper is to introduce the details of each diagnostics set and its required input data formats in ChemDyg.
Michael J. Prather, Hao Guo, and Xin Zhu
Earth Syst. Sci. Data, 15, 3299–3349, https://doi.org/10.5194/essd-15-3299-2023, https://doi.org/10.5194/essd-15-3299-2023, 2023
Short summary
Short summary
The Atmospheric Tomography Mission (ATom) measured the chemical composition in air parcels from 0–12 km altitude on 2 km horizontal by 80 m vertical scales for four seasons, resolving most scales of chemical heterogeneity. ATom is one of the first missions designed to calculate the chemical evolution of each parcel, providing semi-global diurnal budgets for ozone and methane. Observations covered the remote troposphere: Pacific and Atlantic Ocean basins, Southern Ocean, Arctic basin, Antarctica.
Frank Werner, Nathaniel J. Livesey, Luis F. Millán, William G. Read, Michael J. Schwartz, Paul A. Wagner, William H. Daffer, Alyn Lambert, Sasha N. Tolstoff, and Michelle L. Santee
Atmos. Meas. Tech., 16, 2733–2751, https://doi.org/10.5194/amt-16-2733-2023, https://doi.org/10.5194/amt-16-2733-2023, 2023
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The algorithm that produces the near-real-time data products of the Aura Microwave Limb Sounder has been updated. The new algorithm is based on machine learning techniques and yields data products with much improved accuracy. It is shown that the new algorithm outperforms the previous versions, even when it is trained on only a few years of satellite observations. This confirms the potential of applying machine learning to the near-real-time efforts of other current and future mission concepts.
Hao Guo, Clare M. Flynn, Michael J. Prather, Sarah A. Strode, Stephen D. Steenrod, Louisa Emmons, Forrest Lacey, Jean-Francois Lamarque, Arlene M. Fiore, Gus Correa, Lee T. Murray, Glenn M. Wolfe, Jason M. St. Clair, Michelle Kim, John Crounse, Glenn Diskin, Joshua DiGangi, Bruce C. Daube, Roisin Commane, Kathryn McKain, Jeff Peischl, Thomas B. Ryerson, Chelsea Thompson, Thomas F. Hanisco, Donald Blake, Nicola J. Blake, Eric C. Apel, Rebecca S. Hornbrook, James W. Elkins, Eric J. Hintsa, Fred L. Moore, and Steven C. Wofsy
Atmos. Chem. Phys., 23, 99–117, https://doi.org/10.5194/acp-23-99-2023, https://doi.org/10.5194/acp-23-99-2023, 2023
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We have prepared a unique and unusual result from the recent ATom aircraft mission: a measurement-based derivation of the production and loss rates of ozone and methane over the ocean basins. These are the key products of chemistry models used in assessments but have thus far lacked observational metrics. It also shows the scales of variability of atmospheric chemical rates and provides a major challenge to the atmospheric models.
Eliane Maillard Barras, Alexander Haefele, René Stübi, Achille Jouberton, Herbert Schill, Irina Petropavlovskikh, Koji Miyagawa, Martin Stanek, and Lucien Froidevaux
Atmos. Chem. Phys., 22, 14283–14302, https://doi.org/10.5194/acp-22-14283-2022, https://doi.org/10.5194/acp-22-14283-2022, 2022
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Intercomparisons of three Dobson and three Brewer spectrophotometers at Arosa/Davos, Switzerland, are used for the homogenization of the longest Umkehr ozone profiles time series worldwide. Dynamic linear modeling (DLM) reveals a significant positive trend after 2004 in the upper stratosphere, a persistent negative trend between 25 and 30 km in the middle stratosphere, and a negative trend at 20 km in the lower stratosphere, with different levels of significance depending on the dataset.
Sophie Godin-Beekmann, Niramson Azouz, Viktoria F. Sofieva, Daan Hubert, Irina Petropavlovskikh, Peter Effertz, Gérard Ancellet, Doug A. Degenstein, Daniel Zawada, Lucien Froidevaux, Stacey Frith, Jeannette Wild, Sean Davis, Wolfgang Steinbrecht, Thierry Leblanc, Richard Querel, Kleareti Tourpali, Robert Damadeo, Eliane Maillard Barras, René Stübi, Corinne Vigouroux, Carlo Arosio, Gerald Nedoluha, Ian Boyd, Roeland Van Malderen, Emmanuel Mahieu, Dan Smale, and Ralf Sussmann
Atmos. Chem. Phys., 22, 11657–11673, https://doi.org/10.5194/acp-22-11657-2022, https://doi.org/10.5194/acp-22-11657-2022, 2022
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An updated evaluation up to 2020 of stratospheric ozone profile long-term trends at extrapolar latitudes based on satellite and ground-based records is presented. Ozone increase in the upper stratosphere is confirmed, with significant trends at most latitudes. In this altitude region, a very good agreement is found with trends derived from chemistry–climate model simulations. Observed and modelled trends diverge in the lower stratosphere, but the differences are non-significant.
Lucien Froidevaux, Douglas E. Kinnison, Michelle L. Santee, Luis F. Millán, Nathaniel J. Livesey, William G. Read, Charles G. Bardeen, John J. Orlando, and Ryan A. Fuller
Atmos. Chem. Phys., 22, 4779–4799, https://doi.org/10.5194/acp-22-4779-2022, https://doi.org/10.5194/acp-22-4779-2022, 2022
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We analyze satellite-derived distributions of chlorine monoxide (ClO) and hypochlorous acid (HOCl) in the upper atmosphere. For 2005–2020, from 50°S to 50°N and over ~30 to 45 km, ClO and HOCl decreased by −0.7 % and −0.4 % per year, respectively. A detailed model of chemistry and dynamics agrees with the results. These decreases confirm the effectiveness of the 1987 Montreal Protocol, which limited emissions of chlorine- and bromine-containing source gases, in order to protect the ozone layer.
Michael J. Prather
Earth Syst. Dynam., 13, 703–709, https://doi.org/10.5194/esd-13-703-2022, https://doi.org/10.5194/esd-13-703-2022, 2022
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Atmospheric CO2 fluctuations point to changes in fossil fuel emissions plus natural and perturbed variations in the natural carbon cycle. One unstudied source of variability is the stratosphere, where the influx of aged CO2-depleted air can cause surface fluctuations. Using modeling and, separately, scaling the observed N2O variability, I find that stratosphere-driven surface variability in CO2 is not a significant uncertainty (at most 10 % of the observed interannual variability).
Daniel J. Ruiz and Michael J. Prather
Atmos. Chem. Phys., 22, 2079–2093, https://doi.org/10.5194/acp-22-2079-2022, https://doi.org/10.5194/acp-22-2079-2022, 2022
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The stratosphere is an important source of tropospheric ozone, which affects climate, chemistry, and air quality, but is extremely difficult to quantify given the large production and loss terms in the troposphere. Here, we use other gases that are well observed and quantified as a reference to test our simulations of ozone transport in the atmosphere. This allows us to better constrain the stratospheric source of ozone and also offers guidance to improve future simulations of ozone transport.
Frank Werner, Nathaniel J. Livesey, Michael J. Schwartz, William G. Read, Michelle L. Santee, and Galina Wind
Atmos. Meas. Tech., 14, 7749–7773, https://doi.org/10.5194/amt-14-7749-2021, https://doi.org/10.5194/amt-14-7749-2021, 2021
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In this study we present an improved cloud detection scheme for the Microwave Limb Sounder, which is based on a feedforward artificial neural network. This new algorithm is shown not only to reliably detect high and mid-level convection containing even small amounts of cloud water but also to distinguish between high-reaching and mid-level to low convection.
Hugh C. Pumphrey, Michael J. Schwartz, Michelle L. Santee, George P. Kablick III, Michael D. Fromm, and Nathaniel J. Livesey
Atmos. Chem. Phys., 21, 16645–16659, https://doi.org/10.5194/acp-21-16645-2021, https://doi.org/10.5194/acp-21-16645-2021, 2021
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Forest fires in British Columbia in August 2017 caused an unusual phenomonon: smoke and gases from the fires rose quickly to a height of 10 km. From there, the pollution continued to rise more slowly for many weeks, travelling around the world as it did so. In this paper, we describe how we used data from a satellite instrument to observe this polluted volume of air. The satellite has now been working for 16 years but has observed only three events of this type.
Nathaniel J. Livesey, William G. Read, Lucien Froidevaux, Alyn Lambert, Michelle L. Santee, Michael J. Schwartz, Luis F. Millán, Robert F. Jarnot, Paul A. Wagner, Dale F. Hurst, Kaley A. Walker, Patrick E. Sheese, and Gerald E. Nedoluha
Atmos. Chem. Phys., 21, 15409–15430, https://doi.org/10.5194/acp-21-15409-2021, https://doi.org/10.5194/acp-21-15409-2021, 2021
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The Microwave Limb Sounder (MLS), an instrument on NASA's Aura mission launched in 2004, measures vertical profiles of the temperature and composition of Earth's "middle atmosphere" (the region from ~12 to ~100 km altitude). We describe how, among the 16 trace gases measured by MLS, the measurements of water vapor (H2O) and nitrous oxide (N2O) have started to drift since ~2010. The paper also discusses the origins of this drift and work to ameliorate it in a new version of the MLS dataset.
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Short summary
From satellite data for nitrous oxide (N2O), ozone and temperature, we calculate the monthly loss of N2O and find it is increasing faster than expected, resulting in a shorter lifetime, which reduces the impact of anthropogenic emissions. We identify the cause as enhanced vertical lofting of high-N2O air into the tropical middle stratosphere, where it is destroyed photochemically. Because global warming is due in part to N2O, this finding presents a new negative climate-chemistry feedback.
From satellite data for nitrous oxide (N2O), ozone and temperature, we calculate the monthly...
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