Articles | Volume 20, issue 3
https://doi.org/10.5194/acp-20-1341-2020
© Author(s) 2020. 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-20-1341-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
05 Feb 2020
Research article |
| 05 Feb 2020
| 05 Feb 2020
A machine learning examination of hydroxyl radical differences among model simulations for CCMI-1
Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, USA
NASA Goddard Space Flight Center, Greenbelt, MD, USA
Bryan N. Duncan
NASA Goddard Space Flight Center, Greenbelt, MD, USA
Thomas F. Hanisco
NASA Goddard Space Flight Center, Greenbelt, MD, USA
Glenn M. Wolfe
NASA Goddard Space Flight Center, Greenbelt, MD, USA
Joint Center for Earth Systems Technology, University of Maryland
Baltimore County, Baltimore, MD, USA
Ross J. Salawitch
Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, USA
Department of Atmospheric and Oceanic Science, University of Maryland, College Park, MD, USA
Department of Chemistry and Biochemistry, University of Maryland,
College Park, MD, USA
Makoto Deushi
Meteorological Research Institute (MRI), Tsukuba, Japan
Amund S. Haslerud
Center for International Climate and Environmental Research-Oslo
(CICERO), Oslo, Norway
Patrick Jöckel
Institut für Physik der Atmosphäre, Deutsches Zentrum für Luft- und Raumfahrt (DLR), Oberpfaffenhofen, Germany
Béatrice Josse
CNRM UMR 3589, Météo-France/CNRS, Toulouse, France
Douglas E. Kinnison
National Center for Atmospheric Research, Boulder, CO, USA
Andrew Klekociuk
Antarctica and the Global System Program, Australian Antarctic
Division, Kingston, Australia
Antarctic Climate and Ecosystems Cooperative Research Centre, Hobart, Australia
Michael E. Manyin
NASA Goddard Space Flight Center, Greenbelt, MD, USA
Science Systems and Applications, Inc., Lanham, MD, USA
Virginie Marécal
CNRM UMR 3589, Météo-France/CNRS, Toulouse, France
Olaf Morgenstern
National Institute of Water and Atmospheric Research (NIWA),
Wellington, New Zealand
Lee T. Murray
Department of Earth and Environmental Sciences, University of
Rochester, Rochester, NY, USA
Gunnar Myhre
Center for International Climate and Environmental Research-Oslo
(CICERO), Oslo, Norway
Luke D. Oman
NASA Goddard Space Flight Center, Greenbelt, MD, USA
Giovanni Pitari
Department of Physical and Chemical Sciences, Universitá
dell'Aquila, L'Aquila, Italy
Andrea Pozzer
Max-Planck-Institute for Chemistry, Air Chemistry Department, Mainz, Germany
Ilaria Quaglia
Department of Physical and Chemical Sciences, Universitá
dell'Aquila, L'Aquila, Italy
Laura E. Revell
School of Physical and Chemical Sciences, University of Canterbury, Christchurch, New Zealand
Eugene Rozanov
Institute for Atmospheric and Climate Science, ETH Zürich (ETHZ), Zürich, Switzerland
Physikalisch-Meteorologisches Observatorium Davos – World Radiation Center (PMOD/WRC), Davos, Switzerland
Andrea Stenke
Institute for Atmospheric and Climate Science, ETH Zürich (ETHZ), Zürich, Switzerland
Kane Stone
School of Earth Sciences, University of Melbourne, Melbourne,
Australia
Department of Earth, Atmospheric, and Planetary Science, Massachusetts Institute of Technology, Cambridge, MA, USA
Susan Strahan
NASA Goddard Space Flight Center, Greenbelt, MD, USA
Universities Space Research Association, Columbia, MD, USA
Simone Tilmes
National Center for Atmospheric Research, Boulder, CO, USA
Holger Tost
Institute for Atmospheric Physics, Johannes Gutenberg University,
Mainz, Germany
Daniel M. Westervelt
Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA
NASA Goddard Institute for Space Studies, New York, NY, USA
Guang Zeng
National Institute of Water and Atmospheric Research (NIWA),
Wellington, New Zealand
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Jianzhong Ma, Bin Chen, Qianshan He, Xiaolu Yan, Gaili Wang, Siyang Cheng, Benedikt Steil, Christoph Brühl, Holger Tost, Michael Höpfner, Andrea Pozzer, and Jos Lelieveld
Atmos. Chem. Phys., 26, 8125–8144, https://doi.org/10.5194/acp-26-8125-2026, https://doi.org/10.5194/acp-26-8125-2026, 2026
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Julianna A. Christopoulos, Pablo E. Saide, Manas R. Mohanty, Nattamon Maneenoi, Jhoon Kim, Laura Judd, Katherine R. Travis, Savitri Garivait, Agapol Junpen, Kazuyuki Miyazaki, Jinkyul Choi, Takashi Sekiya, David Peterson, Theodore M. McHardy, Nicholas Gapp, Jason M. St. Clair, Erin Delaria, Glenn M. Wolfe, Abby Sebol, Alessandro Franchin, Changmin Cho, Morgan L. Silverman, and James H. Crawford
Atmos. Chem. Phys., 26, 8021–8050, https://doi.org/10.5194/acp-26-8021-2026, https://doi.org/10.5194/acp-26-8021-2026, 2026
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Air quality in rapidly growing cities is difficult to model because emissions vary during the day and are often poorly constrained. We demonstrate a methodology for constraining urban emissions using hourly satellite observations combined with high-resolution air quality modeling in Bangkok. We find that emissions inventories likely overestimate nitrogen dioxide emissions, and that updated emissions improve agreement between the model and independent aircraft and ground-based observations.
Paul D. Hamer, Miha Markelj, Oscar Rojas-Munoz, Bertrand Bonan, Jean-Christophe Calvet, Virginie Marécal, Alex Guenther, Heidi Trimmel, Islen Vallejo, Sabine Eckhardt, Gabriela Sousa Santos, Katerina Sindelarova, David Simpson, Norbert Schmidbauer, Heidi Hellén, Pascal Rubli, Stefan Reimann, Anja Claude, Dagmar Kubistin, Julie Cozic, James Dernie, and Leonor Tarrasón
Earth Syst. Sci. Data, 18, 3635–3669, https://doi.org/10.5194/essd-18-3635-2026, https://doi.org/10.5194/essd-18-3635-2026, 2026
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Plants release gases like isoprene that can form ozone and affect air quality. Using models and satellite data, we mapped the emissions of isoprene from plants across Europe and found that droughts can reduce leaf growth, leading to lower emissions. This shows that to understand and predict air quality, we must also understand how drought impacts vegetation. Our findings highlight the value of linking extreme weather, plant health, and pollution in models of the Earth system as a whole.
Ilaria Quaglia, Daniele Visioni, Ewa M. Bednarz, Yunqian Zhu, Georgiy Stenchikov, Valentina Aquila, Cheng-Cheng Liu, Graham W. Mann, Yifeng Peng, Takashi Sekiya, Simone Tilmes, Xinyue Wang, Shingo Watanabe, Pengfei Yu, Jun Zhang, Wandi Yu, and Zhihong Zhuo
Atmos. Chem. Phys., 26, 7677–7704, https://doi.org/10.5194/acp-26-7677-2026, https://doi.org/10.5194/acp-26-7677-2026, 2026
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On January 15, 2022, the Hunga volcano eruption released unprecedented amounts of water vapor into the atmosphere alongside a modest amount of SO2. In this work we analyse results from multiple Earth system models. The models agree that the eruption led to small negative radiative forcing from sulfate aerosols and that the contribution from water vapor was minimal. Therefore, the Hunga eruption cannot explain the exceptional surface warming observed in 2023.
Benjamin Weyland, Simon Rosanka, Domenico Taraborrelli, Birger Bohn, Andreas Zahn, Florian Obersteiner, Eric Förster, Mariano Mertens, Patrick Jöckel, Helmut Ziereis, Katharina Kaiser, Horst Fischer, John N. Crowley, Nijing Wang, Achim Edtbauer, Jonathan Williams, Maria Dolores Andrés Hernández, John P. Burrows, Flora Kluge, Meike K. Rotermund, Andre Butz, and Klaus Pfeilsticker
Atmos. Chem. Phys., 26, 6825–6856, https://doi.org/10.5194/acp-26-6825-2026, https://doi.org/10.5194/acp-26-6825-2026, 2026
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The destruction by sunlight of nitrous acid (HONO) produces the so-called detergent of the atmosphere. HONO has been measured in concentrations which exceed predictions based on known chemistry for decades. Several reactions have been proposed which may explain this excess HONO. This study reports on airborne measurements of HONO; the observations exceed predictions and form a C-shaped profile in the troposphere. Together with a host of other measurements, various reactions are investigated.
Bosi Sheng, Massimo A. Bollasina, Alexandre S. Gagnon, Laura J. Wilcox, Thomas P. S. Reynolds, Christopher T. S. Beckett, Haolin Wang, Qingxiang Li, Pierre Nabat, Robert J. Allen, Bjørn H. Samset, Joonas Merikanto, Geeta G. Persad, Toshihiko Takemura, Kostas Tsigaridis, Sharar Ahmadi, Maxwell T. Elling, Knut von Salzen, Daniel M. Westervelt, Naga Oshima, and Tsuyoshi Koshiro
EGUsphere, https://doi.org/10.5194/egusphere-2026-2198, https://doi.org/10.5194/egusphere-2026-2198, 2026
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Observational records indicate that austral summer rainfall over southern Africa experienced substantial wetting during the late 20th century, followed by pronounced drying over the past two decades. We show that East Asian sulphate aerosol emissions played a key role in shaping these rainfall trends. These findings have important implications for reducing uncertainties in regional rainfall projections and for understanding their links to ecosystem changes.
Daniele Visioni, Alan Robock, Alistair Duffey, Matthew Henry, Haruki Hirasawa, Walker R. Lee, Cindy Wang, Kelsey Roberts, Shingo Watanabe, Michelle S. Reboita, Masahiro Sugiyama, Ben Kravitz, Jim Haywood, Simone Tilmes, Frederic Bonou, Jack Chen, Timofei Sukodolov, Sandro Vattioni, Andrin Jörimann, Diego Villanueva, Ryan Vella, Paul Farron, Ewa M. Bednarz, Ulrike Niemeier, Colleen Golja, and Juan A. Anel
EGUsphere, https://doi.org/10.5194/egusphere-2026-2417, https://doi.org/10.5194/egusphere-2026-2417, 2026
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The Geoengineering Model Intercomparison Project is a coordinated international model intercomparison effort aiming to provide robust experimental protocols for simulations of various Solar Radiation Modification (SRM) methods. In this manuscript, we describe a list of novel experiments decided by the community, to be run by climate models to better understand sources of uncertainty in SRM. We also show and discuss some preliminary results from a few climate models.
Jinkyul Choi, Kazuyuki Miyazaki, Takashi Sekiya, Jinhyeok Yu, Shin-Ya Ogino, Henk Eskes, Pieter Rijdijk, Ryan Bennett, Anke Roiger, Leon Knez, Glenn S. Diskin, Jason A. Miech, Joshua P. DiGangi, Yonghoon Choi, Alessandro Franchin, Changmin Cho, Eric C. Apel, Louisa K. Emmons, Nattamon Maneenoi, Jason M. St. Clair, Reem A. Hannun, Glenn M. Wolfe, Erin Delaria, Abby Sebol, Donald R. Blake, Monica Crippa, Rachel M. Hoesly, Steven J. Smith, Jung-Hun Woo, Le Kuai, and Ronald Macatangay
EGUsphere, https://doi.org/10.5194/egusphere-2026-2380, https://doi.org/10.5194/egusphere-2026-2380, 2026
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Asia produces half of the world's air pollution, yet emission estimates from different sources disagree widely. We assimilated satellite observations of six pollutant species to correct both concentrations and emissions. Aircraft measurements from a 2024 NASA campaign across four Asian countries confirmed the improvements. Our results reveal underreported emissions in some countries, overestimated vegetation emissions, unresolved fire estimates, and weather control on cross-border pollution.
Xiaoyi Zhao, Vitali Fioletov, Irina Petropavlovskikh, Voltaire Velazco, Alberto Redondas, Anna Solomatnikova, Corinne Vigouroux, Kimberly Strong, Michel Van Roozendael, Andrea Pazmino, Thomas F. Hanisco, Alexander Cede, Martin Tiefengraber, Gordon Labow, Masatomo Fujiwara, Ronald van der A, Debora Griffin, Chris McLinden, Tom Kralidis, Wolfgang Steinbrecht, and Sum Chi Lee
EGUsphere, https://doi.org/10.5194/egusphere-2026-2009, https://doi.org/10.5194/egusphere-2026-2009, 2026
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Total column ozone (TCO) records from six ground-based networks are compiled and evaluated using multiple satellites and reanalysis data. Station performance (1940–2024) is assessed using harmonized metrics. Ground-based annual means agree within ±2 %, while pre-satellite reanalyses show larger biases (up to −5 %). The resulting quality-assessed dataset supports trend analysis and satellite validation.
Changmin Cho, Alessandro Franchin, Frank Flocke, Kirk Lesko, Courtney Owen, Samuel R. Hall, Kirk Ullmann, Eric C. Apel, Alan J. Hills, Rebecca S. Hornbrook, Behrooz Roozitalab, Daun Jeong, Glenn S. Diskin, Yonghoon Choi, Joshua P. DiGangi, Jason Miech, Glenn M. Wolfe, Thomas F. Hanisco, Jason M. St. Clair, Jin Liao, Erin R. Delaria, Abby Sebol, Reem A. Hannun, Paul O. Wennberg, Katherine Ball, Young Ro Lee, L. Gregory Huey, David J. Tanner, Linda Arterburn, Donald R. Blake, Nicola J. Blake, Barbara Barletta, Simone Meinardi, Kyung-Eun Min, Heejoo Kang, Woohui Nam, Armin Wisthaler, Felix Piel, Wojciech Wojnowski, Jack Dibb, and James Crawford
Atmos. Chem. Phys., 26, 6097–6116, https://doi.org/10.5194/acp-26-6097-2026, https://doi.org/10.5194/acp-26-6097-2026, 2026
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Ozone pollution is a challenge in Asian cities due to its nonlinear response to precursor controls. Using aircraft measurements, we examined how ozone production depends on nitrogen oxides and volatile organic compounds using a new isopleth-based approach. Ozone production is limited by nitrogen oxides in Metro Manila and Tainan–Kaohsiung, mixed in Bangkok, and limited by volatile organic compounds in Seoul. These results inform city-specific control strategies to reduce ozone in urban areas.
Endre Z. Farago, Laura A. McBride, Brian F. Bennett, Austin P. Hope, Timothy P. Canty, and Ross J. Salawitch
Earth Syst. Dynam., 17, 451–474, https://doi.org/10.5194/esd-17-451-2026, https://doi.org/10.5194/esd-17-451-2026, 2026
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Global mean surface temperature anomalies in 2023 and 2024 were the highest on the modern record. We quantify contributions to these anomalies from human activity, including the steep reduction in sulfur emissions from ships that began in 2020, and numerous natural factors. We attribute about 92% of the observed anomalies to a combination of various human-induced and natural factors, including important contributions from the reduction in marine sulfur emissions and the Indian Ocean Dipole.
Daun Jeong, Rebecca S. Hornbrook, Alan J. Hills, Glenn Diskin, Hannah S. Halliday, Joshua P. DiGangi, Alan Fried, Dirk Richter, James Walega, Petter Weibring, Thomas F. Hanisco, Glenn M. Wolfe, Jason St. Clair, Jeff Peischl, Armin Wisthaler, Tomas Mikoviny, John B. Nowak, Felix Piel, Laura Tomsche, Christopher D. Holmes, Amber Soja, Emily Gargulinski, James H. Crawford, Jack Dibb, Carsten Warneke, Joshua Schwarz, and Eric C. Apel
Atmos. Meas. Tech., 19, 2985–3000, https://doi.org/10.5194/amt-19-2985-2026, https://doi.org/10.5194/amt-19-2985-2026, 2026
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Formaldehyde is an important atmospheric species that is present at all times throughout the troposphere. Accurately measuring formaldehyde is necessary for understanding key atmospheric chemical cycles. We describe here the first wide-scale demonstration of the gas chromatographic mass spectrometric (GC/MS) technique (NSF NCAR TOGA-TOF (National Science Foundation - National Center for Atmospheric Research - Trace Organic Gas Analyzer with Time-of-Flight mass spectrometer)) for quantifying formaldehyde in the atmosphere and we show this technique to be highly sensitive and selective.
Christine Frömming, Volker Grewe, Sigrun Matthes, Simone Dietmüller, Patrick Peter, Katrin Dahlmann, and Patrick Jöckel
J. Env. Com. Air Transp. Sys. Discuss., https://doi.org/10.5194/jecats-2026-7, https://doi.org/10.5194/jecats-2026-7, 2026
Preprint under review for JECATS
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Aviation non-CO2 climate effects could be reduced through rerouting using Climate Change Functions (CCFs) and its surrogate aCCFs. This study expands CCFs regionally and seasonally and enables a comparison with aCCFs. ACCFs simplify complex processes but reproduce magnitudes and most gradients, though they underestimate variability compared to detailed CCF simulations and limitations to certain altitudes were revealed. The present study promotes future development of refined and extended aCCFs.
Lucien Froidevaux, Michael J. Schwartz, Douglas E. Kinnison, Nathaniel J. Livesey, Gloria L. Manney, Michelle L. Santee, William G. Read, and Ryan A. Fuller
EGUsphere, https://doi.org/10.5194/egusphere-2026-2273, https://doi.org/10.5194/egusphere-2026-2273, 2026
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We examine 20 years (2004–2023) of vertical profiles of winter/spring lower stratospheric ozone inside the Antarctic vortex, based on satellite observations and a chemistry climate model. The observations show increases in the smallest ozone values, as well as trends consistent with a slow recovery from the long-term impact of ozone-depleting substances. The model also shows some reductions in lower stratospheric seasonal Antarctic ozone losses, in broad agreement with the observations.
Stephanie Fiedler, Fiona M. O'Connor, Duncan Watson-Parris, Robert J. Allen, William J. Collins, Paul T. Griffiths, Matthew Kasoar, Jarmo Kikstra, Jasper F. Kok, Lee T. Murray, Fabien Paulot, Maria Sand, Steven T. Turnock, James Weber, Laura J. Wilcox, and Vaishali Naik
Geosci. Model Dev., 19, 3477–3508, https://doi.org/10.5194/gmd-19-3477-2026, https://doi.org/10.5194/gmd-19-3477-2026, 2026
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The Aerosol and Chemistry Model Intercomparison Project phase two (AerChemMIP2) allows the community to compare results from contemporary Earth system models. AerChemMIP2 is asking modelling centres to perform experiments following the same protocol. It includes experiments for enabling new science and for tracking progress. Model output will be used for addressing research and policy questions about anthropogenic and natural drivers of climate change, and the impacts on air quality.
Isobel M. Parry, Paul D. L. Ritchie, Olivier Boucher, Peter M. Cox, James M. Haywood, Ulrike Niemeier, Roland Séférian, Simone Tilmes, and Daniele Visioni
Earth Syst. Dynam., 17, 387–414, https://doi.org/10.5194/esd-17-387-2026, https://doi.org/10.5194/esd-17-387-2026, 2026
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Contrary to some expectations, results from the latest Earth System Models suggest that Solar Radiation Geoengineering could protect the Amazon rainforest from climate-driven dieback. Under Stratospheric Aerosol Injection, carbon storage in Amazonia was projected to increase by a mean of 10.8 % relative to a high CO2 emissions scenario, and even by 8.6% compared to a more conventional medium CO2 emissions scenario.
Pasquale Sellitto, Mona Kosary, Michael Höpfner, Bernd Funke, Alex Hoffmann, Jörn Ungermann, Quentin Errera, Simone Tilmes, and Björn-Martin Sinnhuber
EGUsphere, https://doi.org/10.5194/egusphere-2026-919, https://doi.org/10.5194/egusphere-2026-919, 2026
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To counterbalance human-caused global warming, highly controversial geoengineering techniques, based on stratospheric aerosol injection (SAI), have been proposed as a complement to climate change mitigation. Unilateral or illegal SAI deployments or tests are a risk. We show that existing satellite instruments do not have the capability to detect possible illegal SAI experiments and we propose a future satellite technique, infrared limb emission sounding, that can provide this missing capability.
Marta Abalos, Thomas Birner, Andreas Chrysanthou, Sean Davis, Alvaro de la Cámara, Sandip Dhomse, Hella Garny, Michaela I. Hegglin, Daan Hubert, Oksana Ivaniha, James Keeble, Marianna Linz, Daniele Minganti, Jessica Neu, David Plummer, Laura Saunders, Kasturi Shah, Gabriele Stiller, Kleareti Tourpali, Darryn Waugh, Nathan Luke Abraham, Hideharu Akiyoshi, Martyn P. Chipperfield, Patrick Jöckel, Béatrice Josse, Marion Marchand, Patrick Martineau, Olaf Morgenstern, Timofei Sukhodolov, Shingo Watanabe, and Yousuke Yamashita
Atmos. Chem. Phys., 26, 5249–5291, https://doi.org/10.5194/acp-26-5249-2026, https://doi.org/10.5194/acp-26-5249-2026, 2026
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Accurate representation of stratospheric transport in Chemistry-Climate Models is essential for reliable climate projections. This study evaluates three generations of models using observational data and reanalyses, identifying persistent biases and their potential causes. Some biases persist or even worsen in newer models. These findings highlight key limitations and inform efforts to improve models and advance understanding through process-based studies and enhanced observations.
Jianing Guo, Xiaoning Xie, Gunnar Myhre, Drew Shindell, Alf Kirkevåg, Trond Iversen, Apostolos Voulgarakis, Toshihiko Takemura, Ke Shang, Xinzhou Li, Zhengguo Shi, Yangang Liu, Xiaodong Liu, and Hong Yan
Atmos. Chem. Phys., 26, 5169–5184, https://doi.org/10.5194/acp-26-5169-2026, https://doi.org/10.5194/acp-26-5169-2026, 2026
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Central Asia has grown wetter in recent decades, but the drivers differ by season. We analyzed observations and climate model experiments to understand these changes and their future. Our analysis reveals that greenhouse gases from human activities drive winter wetting, whereas aerosol from Asia urbanization and industrialization enhances summer precipitation. As future reductions in air pollution, the region may experience drier summers and create new risks for regional water resources.
David D. Parrish, Charles A. Mims, Richard G. Derwent, Ian C. Faloona, Henry Bowman, Tongwen Wu, Jie Zhang, Makoto Deushi, and Naga Oshima
EGUsphere, https://doi.org/10.5194/egusphere-2026-1939, https://doi.org/10.5194/egusphere-2026-1939, 2026
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Nearly a century of ozone concentration measurements (the last half continuous) is now available in the northern mid-latitude troposphere. Atmospheric models cannot yet accurately simulate that record. We compare measured and simulated long-term changes and seasonal cycles of background ozone to quantify some model shortcomings, and suggest that their important causes may be inadequate model treatments of ozone precursor evolution and vertical transport out of the planetary boundary layer.
Jin Maruhashi, Mattia Righi, Monica Sharma, Johannes Hendricks, Patrick Jöckel, Volker Grewe, and Irene C. Dedoussi
Geosci. Model Dev., 19, 2747–2784, https://doi.org/10.5194/gmd-19-2747-2026, https://doi.org/10.5194/gmd-19-2747-2026, 2026
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Aerosol-cloud interactions remain a major source of uncertainty in assessing aviation's net climate impact. We develop and evaluate a new Lagrangian tagging model that tracks aviation-emitted SO2 and H2SO4 as they are chemically transformed into SO4 aerosols and transported throughout the atmosphere. This development allows the identification of atmospheric regions with elevated potential for aerosol–cloud interactions driven by SO4 from aircraft.
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
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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.
Jize Jiang, Lenny H. E. Winkel, Chloé Wüst-Galley, Daniel Bretscher, Magdalena Necpalova, Andrea Stenke, and Johan Six
EGUsphere, https://doi.org/10.5194/egusphere-2026-1287, https://doi.org/10.5194/egusphere-2026-1287, 2026
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We studied nitrogen use in Swiss agriculture for four decades using detailed data and modelling. We found that nitrogen use efficiency improved, while nitrogen losses decreased. Yet, modelling results suggested that cropland soils may lose nitrogen. The results show that policies implementation benefited productivity and reduced pollution. On the other hand, soil nitrogen balance should also be monitored, underscoring the need for integrated nitrogen management.
Yunqian Zhu, Cheng-Cheng Liu, Charles Bardeen, Lu Wang, Simone Tilmes, Ilaria Quaglia, Christopher M. Maloney, Francis Vitt, and Owen Brian Toon
EGUsphere, https://doi.org/10.22541/essoar.177135577.71771059/v1, https://doi.org/10.22541/essoar.177135577.71771059/v1, 2026
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The Community Aerosol and Radiation Model for Atmospheres (CARMA) is a sectional microphysical model widely used to study the formation of aerosols and clouds. This paper presents an update to the CARMA model algorithms since Toon et al. 1988, with a focus on the newly developed CARMA Cloud model.
Chun Hang Chau, Peter Hoor, Katharina Kaiser, and Holger Tost
Atmos. Chem. Phys., 26, 3637–3652, https://doi.org/10.5194/acp-26-3637-2026, https://doi.org/10.5194/acp-26-3637-2026, 2026
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This study examines the potential impact of different greenhouse gases to vertical mixing by clear air turbulence in the upper troposphere and lower stratosphere . We found that ozone is most sensitive to vertical mixing and could lead to cooling at the top of the atmosphere by -0.2 W/m2. We also found that the vertical mixing by clear air turbulence could lead to changes in atmospheric chemistry including changing the methane lifetime and the ozone sensitivity.
Caterina Mogno, Peter R. Colarco, Allison B. Collow, Sampa Das, Sarah A. Strode, Vanessa Valenti, Michael E. Manyin, Qing Liang, Luke Oman, Stephen D. Steenrod, and K. Emma Knowland
Atmos. Chem. Phys., 26, 3025–3047, https://doi.org/10.5194/acp-26-3025-2026, https://doi.org/10.5194/acp-26-3025-2026, 2026
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We investigated a climate model's ability to simulate atmospheric aerosols focusing on the relationship between mass and optical properties, by comparing predictions with observations. Our analysis revealed that model errors in aerosol scattering primarily stem from inaccurate particle mass concentrations and relative humidity, rather than flawed optical property assumptions in the model. These findings point out improvements for enhancing the accuracy for aerosols representation in our model.
Sean Davis, William Ball, Yue Jia, Gabriel Chiodo, Justin Alsing, James Keeble, Hideharu Akiyoshi, Carlo Arosio, Ewa Bednarz, Andreas Chrysanthou, Melanie Coldewey-Egbers, Robert Damadeo, Sandip Dhomse, Mohamadou Diallo, Simone Dietmuller, Roland Eichinger, Stacey Frith, Birgit Hassler, Michaela Hegglin, Daan Hubert, Patrick Jöckel, Béatrice Josse, Natalya Kramarova, Diego Loyola, Eliane Maillard Barras, Marion Marchand, Olaf Morgenstern, David Plummer, Robert Portmann, Karen Rosenlof, Alexei Rozanov, Viktoria Sofieva, Johannes Staehelin, Timofei Sukhodolov, Kleareti Tourpali, Ronald Van der A, H. J. Ray Wang, Krzysztof Wargan, Shingo Watanabe, Mark Weber, Jeannette Wild, Yousuke Yamashita, and Jerry Ziemke
EGUsphere, https://doi.org/10.5194/egusphere-2026-532, https://doi.org/10.5194/egusphere-2026-532, 2026
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This study investigates how tropical ozone levels have changed since 2000 in chemistry climate models and satellite observations to determine how well they agree with one another, and to see if current trends can help predict future levels. At some, satellite records disagree significantly on the magnitude of ozone changes. The study shows a connection between recent ozone trends and future ozone levels, suggesting that satellite measurements could help constrain future ozone changes.
Simone Tilmes, Daniele Visioni, Ilaria Quaglia, Yunqian Zhu, Charles G. Bardeen, Francis Vitt, and Pengfei Yu
Atmos. Chem. Phys., 26, 2649–2666, https://doi.org/10.5194/acp-26-2649-2026, https://doi.org/10.5194/acp-26-2649-2026, 2026
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This study compares two sets of stratospheric aerosol injection (SAI) experiments using the same modeling framework, differing only in their aerosol microphysical schemes. Results show that these two schemes can yield substantially different aerosol burdens, radiative changes, and impacts when simulating the same injection scenarios. These findings suggest that more sophisticated aerosol models may be necessary to accurately assess the efficacy, side effects, and climate impacts of SAI.
Benjamin W. Clouser, Carly C. KleinStern, Adrien Desmoulin, Clare E. Singer, Jason M. St. Clair, Thomas F. Hanisco, David S. Sayres, and Elisabeth J. Moyer
Atmos. Meas. Tech., 19, 1147–1163, https://doi.org/10.5194/amt-19-1147-2026, https://doi.org/10.5194/amt-19-1147-2026, 2026
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Water molecules comes in several varieties, of which H216O is the most common. These varieties behave differently enough under freezing to create strong changes in the ratio of heavy to light water molecules. Here we compare observations of these ratios from satellites and high-altitude airborne instruments. These observations provide information about how air reaches the upper parts of the atmosphere, so it is important to reconcile difference between different modes of observations.
Ales Kuchar, Matthias Stocker, Alistair Bell, Bruno Lehner, Jessica Kult-Herdin, Gabriel Chiodo, Timofei Sukhodolov, Eugene Rozanov, Gunter Stober, and Harald E. Rieder
EGUsphere, https://doi.org/10.5194/egusphere-2026-406, https://doi.org/10.5194/egusphere-2026-406, 2026
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We investigated why the Northern Hemisphere winter polar vortex became unusually strong in the winter of 2024/2025. Using satellite and reanalysis datasets, and model simulations, we found that extra water erupted high in the atmosphere by the 2022 Hunga Tonga eruption led to cooling of polar latitudes of the upper atmosphere, helping the winds aloft intensify. This link suggests such volcanic eruptions can shape winters in the upper atmosphere for several years.
Birthe Marie Steensen, Gunnar Myhre, Rachael Byrom, Ada Gjermundsen, Caroline Jouan, and Camilla Weum Stjern
Atmos. Chem. Phys., 26, 2041–2054, https://doi.org/10.5194/acp-26-2041-2026, https://doi.org/10.5194/acp-26-2041-2026, 2026
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In this study we analyze summer precipitation within a regional atmospheric budget framework over Europe. We identify the terms with the largest uncertainties for current change and future projections that cause the large spread in precipitation change, as sensible heat and dry static energy flux divergence in Earth System models. However, the Earth System models show consistent agreement that there will be an increase in drying over continental Europe with global warming.
Anna Martin, Klaus Klingmüller, Benedikt Steil, Sergey Gromov, Yu-Ri Lee, Dong Yeong Chang, Nic Surawski, Jos Lelieveld, Sujong Jeong, and Andrea Pozzer
EGUsphere, https://doi.org/10.5194/egusphere-2026-371, https://doi.org/10.5194/egusphere-2026-371, 2026
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We evaluate a new model simulating soil uptake of methane and hydrogen from the atmosphere. Coupled to an atmospheric chemistry and land surface model, it accounts for weather and soil conditions. Our results match observations, showing accurate removal depending on soil properties, temperature, moisture, and atmospheric conditions. This work improves the model’s ability to represent natural cycles of methane and hydrogen.
Gopalakrishna Pillai Gopikrishnan, Daniel M. Westervelt, and Jayanarayanan Kuttippurath
Atmos. Chem. Phys., 26, 1907–1929, https://doi.org/10.5194/acp-26-1907-2026, https://doi.org/10.5194/acp-26-1907-2026, 2026
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This study examines the inverse effect of aerosol surface area and particulate matter (PM) reduction on air quality and atmospheric chemistry, particularly on surface ozone levels. Aerosols act as surfaces for the uptake of hydroxyl radicals (HO2), which are essential for controlling ozone formation. Reducing aerosols and PM may enhance surface ozone formation, thus worsening air quality. However, further efforts to decrease NOx emissions could mitigate this rise in surface ozone levels.
Nic Surawski, Benedikt Steil, Christoph Brühl, Sergey Gromov, Klaus Klingmüller, Anna Martin, Andrea Pozzer, and Jos Lelieveld
Geosci. Model Dev., 19, 911–931, https://doi.org/10.5194/gmd-19-911-2026, https://doi.org/10.5194/gmd-19-911-2026, 2026
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Hydrogen usage will likely increase to achieve net zero emission targets. We undertook calculations with an Earth system model using a high-performance computer to explore hydrogen atmospheric dynamics. Simulations with our model yielded highly accurate results at global scale. Correctly representing hydroxyl radicals in the model is a critical requirement for predicting hydrogen concentrations well. Our hydrogen budget is also in very good agreement with bottom-up literature estimates.
Amir H. Souri, Gonzalo González Abad, Bryan N. Duncan, and Luke D. Oman
Atmos. Chem. Phys., 26, 809–837, https://doi.org/10.5194/acp-26-809-2026, https://doi.org/10.5194/acp-26-809-2026, 2026
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We create long-term maps of PO3 magnitudes along with their corresponding sensitivity maps. This is achieved using a deep learning parameterization method that relies on satellite data, atmospheric models, and ground-based remote sensing. Our approach provides more quantitative information than commonly used methods that depend on ratio-based indicators (such as HCHO/NO2). Additionally, our method considers light and water vapor, making it suitable for applications with GEO satellites.
Ismail Makroum, Patrick Jöckel, Martin Dameris, Nicolas Theys, and Johannes De Leeuw
Geosci. Model Dev., 19, 447–476, https://doi.org/10.5194/gmd-19-447-2026, https://doi.org/10.5194/gmd-19-447-2026, 2026
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We use a state-of-the-art numerical chemistry-climate model to study the atmospheric sulfur dioxide budget. We simulate the atmospheric concentration of sulfur dioxide (SO2) and corresponding sulfur deposition fluxes and compare the results with observational data from a satellite instrument and with ground-based in-situ measurements. For the evaluation of the simulated atmospheric lifetime of SO2, we also simulate the fate of SO2 emitted by two volcanic eruptions that happened in 2019.
William J. Collins, John S. Daniel, Martyn P. Chipperfield, Martin Cussac, Makoto Deushi, Gregory Faluvegi, Paul Griffiths, Øivind Hodnebrog, Larry W. Horowitz, James Keeble, Douglas Kinnison, Vaishali Naik, Fiona M. O'Connor, Drew Shindell, Simone Tilmes, Kostas Tsigaridis, Zihao Wang, and James Weber
EGUsphere, https://doi.org/10.5194/egusphere-2025-6033, https://doi.org/10.5194/egusphere-2025-6033, 2026
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Ozone depleting substances (ODSs) are also greenhouse gases that cause global warming. However, their destruction of ozone contributes a global cooling. We have used results from climate models that include atmospheric chemistry and found that the cooling effect of the ozone depletion diagnosed in the models was larger than that calculated using a standard method. We find that some ODSs have a net cooling effect whereas for others the warming effect is significantly reduced.
Lianet Hernández Pardo, Joachim Curtius, Patrick Jöckel, Moritz Menken, and Anna Possner
EGUsphere, https://doi.org/10.5194/egusphere-2025-4338, https://doi.org/10.5194/egusphere-2025-4338, 2026
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Many tiny particles are formed high in the tropical atmosphere, but their impact lower down is unclear. We studied how these particles move downward using long-term computer simulations. We found that particles can reach middle levels of the atmosphere within a week, carried by winds. These results help us understand how pollution and clouds might change as particles spread around the world.
Pengfei Yu, Yifeng Peng, Karen H. Rosenlof, Ru-Shan Gao, Robert W. Portmann, Martin Ross, Eric Ray, Jianchun Bian, Simone Tilmes, and Owen B. Toon
Atmos. Chem. Phys., 25, 18449–18460, https://doi.org/10.5194/acp-25-18449-2025, https://doi.org/10.5194/acp-25-18449-2025, 2025
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Injecting sulfur dioxide at 50 km – near the stratopause – offers a far safer and more effective climate intervention than conventional 25 km injection. Rapid downward–poleward transport distributes aerosols across 20–30 km, halving tropical stratospheric warming, reducing ozone recovery delays from decades to about 5 years, and enhancing global and polar cooling by over 20 %, while better preserving Arctic sea ice.
Linda Smoydzin, Vera Bense, Heiko Bozem, Philipp Joppe, Daniel Kunkel, Hans-Christoph Lachnitt, Holger Tost, Andreas Zahn, Helmut Ziereis, Martin Riese, and Peter Hoor
EGUsphere, https://doi.org/10.5194/egusphere-2025-5372, https://doi.org/10.5194/egusphere-2025-5372, 2025
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During a research flight in early October elevated upper tropospheric mixing ratios of CO, NO, NOy and O3 were observed over a distance of more than 1000 km east of the Brasilian coast. Ozone mixing ratios are 20–40 ppbv higher than during a flight in early September. By combining aircraft observations with model simulations we find that ozone production from biomass burning over Amazonia caused predominantly the ozone enhancements which have a local effect on the radiative forcing of 50 mWm−2.
Luis Valero, Konrad Kandler, Sina Jost, Holger Tost, Luca Katarina Eichhorn, Christian von Glahn, Harald Rott, Marilena Flory, Alexandre Baron, Kathie Smith, Troy Thornberry, and Ralf Weigel
EGUsphere, https://doi.org/10.5194/egusphere-2025-5568, https://doi.org/10.5194/egusphere-2025-5568, 2025
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We developed a low-cost, balloon-lifted platform with lightweight instruments to measure particles and collect samples. We tested this platform during two field campaigns in Germany. A case study showed its ability to observe the vertical distribution of particles and how they form cloud droplets. Electronic microscope analysis of the samples identified their chemical composition. This work shows the platform is a capable tool for studying atmospheric processes.
Cameron McErlich, Felix Goddard, Alex Aves, Catherine Hardacre, Nikolaos Evangeliou, Alan J. Hewitt, and Laura E. Revell
Geosci. Model Dev., 18, 8827–8854, https://doi.org/10.5194/gmd-18-8827-2025, https://doi.org/10.5194/gmd-18-8827-2025, 2025
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Airborne microplastics are a new air pollutant but are not yet included in most global models. We add them to the UK Earth System Model to show how they move, change, and are removed from air. Smaller microplastics persist for longer and can travel further, even to Antarctica. While their current role in air pollution is small, their presence is expected to grow in future. This work offers a framework to assess future impacts of microplastics on air quality and climate.
Johannes Degen, Bianca C. Baier, Patrick Jöckel, J. Moritz Menken, Tanja J. Schuck, Colm Sweeney, and Andreas Engel
Atmos. Chem. Phys., 25, 15741–15763, https://doi.org/10.5194/acp-25-15741-2025, https://doi.org/10.5194/acp-25-15741-2025, 2025
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We investigate the distribution of CO2 in the upper troposphere and lower stratosphere using both, observations and an atmospheric model. Simulating an artificial tracer, we separate CO2 seasonality from long-term trend and transport variability. We found that patterns in the seasonal signal are attributable to large-scale transport features like the subtropical jet or the Brewer-Dobson circulation. Being a powerful diagnostic tool we recommend to use this tracer for model intercomparisons.
Yasuto Watanabe, Makoto Deushi, and Kohei Yoshida
Clim. Past, 21, 2243–2261, https://doi.org/10.5194/cp-21-2243-2025, https://doi.org/10.5194/cp-21-2243-2025, 2025
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This study uses an Earth System Model, MRI-ESM2.0, to demonstrate that the atmospheric ozone distribution during warm interglacial periods is modified by the changes in the Earth's orbital parameters. We further show that the change in atmospheric ozone works to cool the surface at the high-latitude regions of the northern hemisphere in the past warm interglacial periods (6 and 127 thousand years ago), while its impact is small around Antarctica.
Abby Sebol, Glenn Wolfe, Timothy Canty, Jason St. Clair, Erin Delaria, Jennifer Kaiser, Nidhi Desai, Andrew Rollins, Eleanor Waxman, Kristen Zuraski, Bryan Place, Apoorva Pandey, Akanksha Singh, Allison Ring, Charles Gatebe, and Jonathan Dean-Day
EGUsphere, https://doi.org/10.5194/egusphere-2025-5261, https://doi.org/10.5194/egusphere-2025-5261, 2025
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Ground-based spectrometers measuring HCHO and NO2 were compared to airborne in situ observations in the Summer 2023. Total column HCHO is within uncertainty, but with high biases near the surface. NO2 results are highly sensitive to the viewing angle of the ground monitor which must be considered during validation studies. Spectrometers in NYC show good agreement with a geostationary satellite on clear-sky days. Further quantified uncertainty for the monitors is necessary.
Linda Ort, Andrea Pozzer, Peter Hoor, Florian Obersteiner, Andreas Zahn, Thomas B. Ryerson, Chelsea R. Thompson, Jeff Peischl, Róisín Commane, Bruce Daube, Ilann Bourgeois, Jos Lelieveld, and Horst Fischer
Atmos. Chem. Phys., 25, 14987–15007, https://doi.org/10.5194/acp-25-14987-2025, https://doi.org/10.5194/acp-25-14987-2025, 2025
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This study investigates the role of lightning emissions on the O3–CO ratio in the northern subtropics. We used in situ observations and a global circulation model to show an effect of up to 40 % onto the subtropical O3–CO ratio by tropical air masses transported via the Hadley cell. This influence of lightning emissions and its photochemistry has a global effect on trace and greenhouse gases and needs to be considered for global chemical distributions.
Miriam Sinnhuber, Christina Arras, Stefan Bender, Bernd Funke, Hanli Liu, Daniel R. Marsh, Thomas Reddmann, Eugene Rozanov, Timofei Sukhodolov, Monika E. Szelag, and Jan Maik Wissing
Atmos. Chem. Phys., 25, 14719–14734, https://doi.org/10.5194/acp-25-14719-2025, https://doi.org/10.5194/acp-25-14719-2025, 2025
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Nitric oxide in the upper atmosphere varies with solar activity. Observations show that this starts a chain of processes affecting the ozone layer and climate system. This is often underestimated in models. We compare five models which show large differences in simulated NO. Analysis of these discrepancies identify two processes which interact with each other: the balance between atomic and molecular oxygen in the thermosphere, and a poleward - downward transport in the winter thermosphere.
Sergey Khaykin, Slimane Bekki, Sophie Godin-Beekmann, Michael D. Fromm, Philippe Goloub, Qiaoyun Hu, Béatrice Josse, Alexandra Laeng, Mehdi Meziane, David A. Peterson, Sophie Pelletier, and Valérie Thouret
Atmos. Chem. Phys., 25, 14551–14571, https://doi.org/10.5194/acp-25-14551-2025, https://doi.org/10.5194/acp-25-14551-2025, 2025
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In 2023, massive wildfires in Canada injected huge amounts of smoke into the atmosphere. Surprisingly, despite their intensity, the smoke did not rise very high but lingered at flight cruising altitudes, causing widespread pollution. This study shows how two different pathways lifted smoke into the lower stratosphere and reveals new insights into how wildfires affect air quality and climate, challenging what we thought we knew about fire and atmospheric impacts.
Adrienne Jeske and Holger Tost
Atmos. Chem. Phys., 25, 14435–14448, https://doi.org/10.5194/acp-25-14435-2025, https://doi.org/10.5194/acp-25-14435-2025, 2025
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Thunderstorms lead to a vertical redistribution of tracers throughout the troposphere. We applied a new tool, the convective exchange matrix, in historical simulations with a chemistry–climate model to investigate the trends in convective transport. This reveals that convection reaches higher but that deep convection occurs less often in the time period from 2011 to 2020 than in the 1980s. Thus, convective transport towards the upper troposphere has declined as an adaptation to climate change.
Catherine Acquah, Laura Stecher, Mariano Mertens, and Patrick Jöckel
Atmos. Chem. Phys., 25, 13665–13686, https://doi.org/10.5194/acp-25-13665-2025, https://doi.org/10.5194/acp-25-13665-2025, 2025
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Short-lived ozone precursor species influence the formation of ozone and also the atmospheric lifetime of methane. Our study assesses the effect of two widely used emission inventories of these species on ozone and the methane lifetime. Our results indicate tropospheric ozone and methane lifetime differences of around 4 % even though both emission inventories aim at representing present-day conditions. We further attribute the differences to emissions of individual sectors, e.g. land traffic.
Chun Hang Chau, Peter Hoor, and Holger Tost
Atmos. Chem. Phys., 25, 13123–13140, https://doi.org/10.5194/acp-25-13123-2025, https://doi.org/10.5194/acp-25-13123-2025, 2025
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This study examines how the turbulence in the upper troposphere/lower stratosphere (UTLS) could modify the tracer distribution under different situations. Using a multi-scale chemistry model with a novel diagnostic, we found that both the pre-existing tracer gradient and the dynamical and thermodynamical forcing play a role in modifying the tracer distribution. These results allow further research on the UTLS turbulent mixing and its implications for the climate system.
Zhihong Zhuo, Xinyue Wang, Yunqian Zhu, Wandi Yu, Ewa M. Bednarz, Eric Fleming, Peter R. Colarco, Shingo Watanabe, David Plummer, Georgiy Stenchikov, William Randel, Adam Bourassa, Valentina Aquila, Takashi Sekiya, Mark R. Schoeberl, Simone Tilmes, Jun Zhang, Paul J. Kushner, and Francesco S. R. Pausata
Atmos. Chem. Phys., 25, 13161–13176, https://doi.org/10.5194/acp-25-13161-2025, https://doi.org/10.5194/acp-25-13161-2025, 2025
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The 2022 Hunga eruption caused unprecedented stratospheric water injection, triggering unique atmospheric impacts. This study combines observations and model simulations, projecting a stratospheric water vapor anomaly lasting 4–7 years, with significant temperature variations and ozone depletion in the upper atmosphere lasting 7–10 years. These findings offer critical insights into the role of stratospheric water vapor in shaping climate and atmospheric chemistry.
Endre Z. Farago, Laura A. McBride, Austin P. Hope, Timothy P. Canty, Brian F. Bennett, and Ross J. Salawitch
Earth Syst. Dynam., 16, 1739–1758, https://doi.org/10.5194/esd-16-1739-2025, https://doi.org/10.5194/esd-16-1739-2025, 2025
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We show that recent assessed updates to the future abundance and radiative forcing (RF) of greenhouse gases (GHGs) and tropospheric aerosols result in a 0.2 to 0.4 ⁰C rise in global mean surface temperature by the end of the century, relative to prior projections. For society to have confidence in achieving the 2 ⁰C warming limit of the Paris Agreement, the RF due to GHGs and aerosols must be placed close to the primary 2.6 W m−2 Shared Socioeconomic Pathway scenario (SSP1−2.6) over the coming decades.
Samuel Bartusek, Yutian Wu, Mingfang Ting, Arlene Fiore, and Daniel M. Westervelt
EGUsphere, https://doi.org/10.5194/egusphere-2025-4874, https://doi.org/10.5194/egusphere-2025-4874, 2025
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Air pollution and extreme humid heat are both significant hazards, but their co-occurrence remains unstudied on a global scale. Using chemical and meteorological reanalyses, we find that in many areas, accounting for much of the global population, more humid heat tends to correspond with worse pollution than drier heat. We identify hotspots and study the mechanisms of this co-occurrence; our results imply it may be driven by more urban background chemistry and air stagnation during humid heat.
Rafael Pedro Fernandez, Carlos Alberto Cuevas, Julián Villamayor, Aryeh Feinberg, Douglas E. Kinnison, Francis Vitt, Adriana Bossolasco, Javier A. Barrera, Amelia Reynoso, Orlando G. Tomazzeli, Qinyi Li, and Alfonso Saiz-Lopez
EGUsphere, https://doi.org/10.5194/egusphere-2025-3250, https://doi.org/10.5194/egusphere-2025-3250, 2025
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In this work we summarize 15 years of research and developments of short-lived halogens (SLH) using the Community Earth System Model (CESM) and present a complete description of the implementation and capabilities achieved with the new released version CESM2-SLH, including specific namelist options, input files and technical notes detailing the most important SLH updates that must be considered for the different model configurations and resolutions.
Joe Adabouk Amooli, Marianne T. Lund, Sourangsu Chowdhury, Gunnar Myhre, Ane N. Johansen, Bjørn H. Samset, and Daniel M. Westervelt
Atmos. Chem. Phys., 25, 11611–11632, https://doi.org/10.5194/acp-25-11611-2025, https://doi.org/10.5194/acp-25-11611-2025, 2025
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We analyze various projections of African aerosol emissions and their potential impacts on climate and public health. We find that future emissions vary widely across emission projections, with differences in sectoral emission distributions. Using the Oslo chemical transport model, we show that air pollution exposure in some regions of Africa could increase significantly by 2050, increasing pollution-related deaths, with most scenarios projecting aerosol-induced warming over sub-Saharan Africa.
Paul A. Nicknish, Kane Stone, Susan Solomon, and Simon A. Carn
Atmos. Chem. Phys., 25, 11535–11555, https://doi.org/10.5194/acp-25-11535-2025, https://doi.org/10.5194/acp-25-11535-2025, 2025
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Large volcanic eruptions can inject teragrams of sulfur dioxide (SO2) into the stratosphere, influencing stratospheric chemistry and Earth's climate. This work calculates decay timescales of volcanic gas-phase SO2 in the stratosphere using data from three satellite products. SO2 decay timescales vary significantly between the different products, and this uncertainty limits our ability to attribute an observed SO2 decay following an eruption to a specific chemical process.
Sarah Brüning and Holger Tost
Atmos. Chem. Phys., 25, 10797–10822, https://doi.org/10.5194/acp-25-10797-2025, https://doi.org/10.5194/acp-25-10797-2025, 2025
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The connection between convective clouds and severe weather demands a robust characterisation of convective organisation. This study investigates spatio-temporal patterns of convective organisation and their relationship to machine-learning-based 3D cloud properties through a combination of different indices. We analyse how organisation affects cloud and core properties in a tropical domain, revealing overlapping effects of strong and weak organisation that may frequently blur statistics.
Sarah Brüning and Holger Tost
Atmos. Chem. Phys., 25, 10773–10795, https://doi.org/10.5194/acp-25-10773-2025, https://doi.org/10.5194/acp-25-10773-2025, 2025
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This study analyses the temporal variability and life cycle of 3D convective clouds characteristics in the tropics. We derive the data from a machine-learning-based 3D extrapolation of high-resolution 2D satellite data and an object-based detection algorithm. Cloud properties are not only affected by the surface type. Instead, our findings highlight the impact of convective cores on horizontal and vertical cloud and core properties and a potential prolonging of the cloud life cycle.
Alexandra M. Catena, Mackenzie L. Smith, Lee T. Murray, Eric M. Leibensperger, Jie Zhang, Margaret J. Schwab, and James J. Schwab
Earth Syst. Sci. Data, 17, 4555–4568, https://doi.org/10.5194/essd-17-4555-2025, https://doi.org/10.5194/essd-17-4555-2025, 2025
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Methane and carbon dioxide emission rates were calculated for facilities across several sectors in New York State using aerial observations. Of the sampled facilities, landfills dominated the methane emission rates, while combustion facilities had the highest carbon dioxide emission rates, followed by landfills. The self-reported Environmental Protection Agency (EPA) inventory mostly underestimates landfill methane emissions, apart from a few facilities with comparable numbers.
Xurong Wang, Alexandra P. Tsimpidi, Zhenqi Luo, Benedikt Steil, Andrea Pozzer, Jos Lelieveld, and Vlassis A. Karydis
Atmos. Chem. Phys., 25, 10559–10586, https://doi.org/10.5194/acp-25-10559-2025, https://doi.org/10.5194/acp-25-10559-2025, 2025
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Ammonia (NH3) is an abundant alkaline gas and key precursor in particulate matter formation. While SO2 and NOx emissions have decreased, global NH3 emissions are stable or rising. This study investigates NH3 emission impacts on size-resolved aerosol composition and acidity using the EMAC (ECHAM5/MESSy Atmospheric Chemistry) model, analyzing three emission schemes. Sulfate–nitrate–ammonium aerosols in fine-mode sizes are most sensitive to NH3 changes. Regional responses vary. NH3 buffers aerosol acidity, mitigating pH shifts.
Catherine A. Toolan, Joe Adabouk Amooli, Laura J. Wilcox, Bjørn H. Samset, Andrew G. Turner, and Daniel M. Westervelt
Atmos. Chem. Phys., 25, 10523–10557, https://doi.org/10.5194/acp-25-10523-2025, https://doi.org/10.5194/acp-25-10523-2025, 2025
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Our research explores how well air pollution and rainfall patterns in Africa are represented in current climate models by comparing model data to observations from 1981 to 2023. While most models capture seasonal air quality changes well, they struggle to replicate the distribution of non-dust pollutants and certain rainfall patterns, especially over east Africa. Improving these models is crucial for better climate predictions and preparing for future risks.
Sina Jost, Ralf Weigel, Konrad Kandler, Luis Valero, Jessica Girdwood, Chris Stopford, Warren Stanley, Luca K. Eichhorn, Christian von Glahn, and Holger Tost
Atmos. Meas. Tech., 18, 4397–4412, https://doi.org/10.5194/amt-18-4397-2025, https://doi.org/10.5194/amt-18-4397-2025, 2025
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For the balloon-borne detection of particles (diameter 0.4 < Dp < 40 µm), the Universal Cloud and Aerosol Sounding System (UCASS) was used, whose sample flow is determined by GPS-measured ascent rates. In flights, actual UCASS sample flows rarely match the ascent rates. Errors are minimised by real-time detection of the UCASS flows, e.g. by implementing a thermal flow sensor (TFS) within the UCASS. The TFSs were tested in flight and calibrated at up to 10 m s−1 and at variable angles of attack.
Mingxuan Wu, Hailong Wang, Zheng Lu, Xiaohong Liu, Huisheng Bian, David D. Cohen, Yan Feng, Mian Chin, Didier A. Hauglustaine, Vlassis A. Karydis, Marianne T. Lund, Gunnar Myhre, Andrea Pozzer, Michael Schulz, Ragnhild B. Skeie, Alexandra P. Tsimpidi, Svetlana G. Tsyro, and Shaocheng Xie
Atmos. Chem. Phys., 25, 10049–10074, https://doi.org/10.5194/acp-25-10049-2025, https://doi.org/10.5194/acp-25-10049-2025, 2025
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A key challenge in simulating the life cycle of nitrate aerosol in global models is accurately representing the mass size distribution of nitrate aerosol, which lacks sufficient observational constraints. We found that most global models underestimate the mass fraction of fine-mode nitrate at the surface in all regions. Our study highlights the importance of gas–aerosol partitioning parameterization and the simulation of dust and sea salt in correctly simulating the mass size distribution of nitrate.
Ryan Vella, Sergey Gromov, Clara M. Nussbaumer, Laura Stecher, Matthias Kohl, Samuel Ruhl, Holger Tost, Jos Lelieveld, and Andrea Pozzer
Atmos. Chem. Phys., 25, 9885–9904, https://doi.org/10.5194/acp-25-9885-2025, https://doi.org/10.5194/acp-25-9885-2025, 2025
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This work examines the impact of replacing forests with farmland and grazing areas on atmospheric composition. Using a global climate–chemistry model, we found that deforestation reduces biogenic volatile organic compounds (BVOCs), increases farming emissions, and shifts ozone chemistry. These changes result in a slight cooling effect on the climate. Restoring natural vegetation could reverse some of these effects.
Yunqian Zhu, Hideharu Akiyoshi, Valentina Aquila, Elizabeth Asher, Ewa M. Bednarz, Slimane Bekki, Christoph Brühl, Amy H. Butler, Parker Case, Simon Chabrillat, Gabriel Chiodo, Margot Clyne, Peter R. Colarco, Sandip Dhomse, Lola Falletti, Eric Fleming, Ben Johnson, Andrin Jörimann, Mahesh Kovilakam, Gerbrand Koren, Ales Kuchar, Nicolas Lebas, Qing Liang, Cheng-Cheng Liu, Graham Mann, Michael Manyin, Marion Marchand, Olaf Morgenstern, Paul Newman, Luke D. Oman, Freja F. Østerstrøm, Yifeng Peng, David Plummer, Ilaria Quaglia, William Randel, Samuel Rémy, Takashi Sekiya, Stephen Steenrod, Timofei Sukhodolov, Simone Tilmes, Kostas Tsigaridis, Rei Ueyama, Daniele Visioni, Xinyue Wang, Shingo Watanabe, Yousuke Yamashita, Pengfei Yu, Wandi Yu, Jun Zhang, and Zhihong Zhuo
Geosci. Model Dev., 18, 5487–5512, https://doi.org/10.5194/gmd-18-5487-2025, https://doi.org/10.5194/gmd-18-5487-2025, 2025
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To understand the climate impact of the 2022 Hunga volcanic eruption, we developed a climate model–observation comparison project. The paper describes the protocols and models that participate in the experiments. We designed several experiments to achieve our goals of this activity: (1) to evaluate the climate model performance and (2) to understand the Earth system responses to this eruption.
William J. Collins, Fiona M. O'Connor, Rachael E. Byrom, Øivind Hodnebrog, Patrick Jöckel, Mariano Mertens, Gunnar Myhre, Matthias Nützel, Dirk Olivié, Ragnhild Bieltvedt Skeie, Laura Stecher, Larry W. Horowitz, Vaishali Naik, Gregory Faluvegi, Ulas Im, Lee T. Murray, Drew Shindell, Kostas Tsigaridis, Nathan Luke Abraham, and James Keeble
Atmos. Chem. Phys., 25, 9031–9060, https://doi.org/10.5194/acp-25-9031-2025, https://doi.org/10.5194/acp-25-9031-2025, 2025
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We used 7 climate models that include atmospheric chemistry and find that in a scenario with weak controls on air quality, the warming effects (over 2015 to 2050) of decreases in ozone-depleting substances and increases in air quality pollutants are approximately equal and would make ozone the second highest contributor to warming over this period. We find that for stratospheric ozone recovery, the standard measure of climate effects underestimates a more comprehensive measure.
Jiaqi Shen, Ronald C. Cohen, Glenn M. Wolfe, and Xiaomeng Jin
Atmos. Chem. Phys., 25, 8701–8718, https://doi.org/10.5194/acp-25-8701-2025, https://doi.org/10.5194/acp-25-8701-2025, 2025
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This study shows large chemical and radiative effects of smoke aerosols from fires on near-surface ozone production. Aerosol loading and NOx levels are identified as the primary factors influencing these effects. Furthermore, we show that the ratio of surface PM2.5 to NO2 tropospheric column can be used as an indicator for identifying aerosol-dominated regimes, facilitating the assessment of aerosol impacts on ozone formation through satellite observations.
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
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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.
Kane Stone, Susan Solomon, Pengfei Yu, Daniel M. Murphy, Douglas Kinnison, and Jian Guan
Atmos. Chem. Phys., 25, 7683–7697, https://doi.org/10.5194/acp-25-7683-2025, https://doi.org/10.5194/acp-25-7683-2025, 2025
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The Australian 2019–2020 wildfires injected a substantial amount of smoke into the upper atmosphere, causing unusual chemical reactions that altered the chemical makeup of the upper atmosphere. This led to ozone depletion in the Southern Hemisphere midlatitudes that likely did not fully recover until 2 years after the initial event due to the persistent chemical effects of the smoke.
Raphael Dreger, Timo Kirfel, Andrea Pozzer, Simon Rosanka, Rolf Sander, and Domenico Taraborrelli
Geosci. Model Dev., 18, 4273–4291, https://doi.org/10.5194/gmd-18-4273-2025, https://doi.org/10.5194/gmd-18-4273-2025, 2025
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Model simulations are essential for understanding the interactions between atmospheric composition and weather. However, models including chemistry are very slow. Hence, any computation speedup of such models is important for understanding the role of atmospheric chemistry within the Earth system. In this study we analyzed and optimized the time step for chemistry calculations. Our results show that atmospheric models could be run notably faster without any loss in accuracy.
Steven T. Turnock, Dimitris Akritidis, Larry Horowitz, Mariano Mertens, Andrea Pozzer, Carly L. Reddington, Hantao Wang, Putian Zhou, and Fiona O'Connor
Atmos. Chem. Phys., 25, 7111–7136, https://doi.org/10.5194/acp-25-7111-2025, https://doi.org/10.5194/acp-25-7111-2025, 2025
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We assess the drivers behind changes in peak-season surface ozone concentrations and risks to human health between 1850 and 2014. Substantial increases in surface ozone have occurred over this period, resulting in an increased risk to human health, driven mainly by increases in anthropogenic NOx emissions and global CH4 concentrations. Fixing anthropogenic NOx emissions at 1850 values in the near-present-day period can eliminate the risk to human health associated with exposure to surface ozone.
Prajjwal Rawat, James H. Crawford, Katherine R. Travis, Laura M. Judd, Mary Angelique G. Demetillo, Lukas C. Valin, James J. Szykman, Andrew Whitehill, Eric Baumann, and Thomas F. Hanisco
Atmos. Meas. Tech., 18, 2899–2917, https://doi.org/10.5194/amt-18-2899-2025, https://doi.org/10.5194/amt-18-2899-2025, 2025
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The Pandonia Global Network (PGN) consists of Pandora spectrometers that observe trace gases at a high time resolution to validate satellite observations and understand local air quality. To aid users, PGN assigns quality flags that assure scientifically valid data but eliminate large amounts of data appropriate for scientific applications. A new method based on contemporaneous data in two independent observation modes is proven using complementary ground-based and airborne observations.
Matthias Kohl, Christoph Brühl, Jennifer Schallock, Holger Tost, Patrick Jöckel, Adrian Jost, Steffen Beirle, Michael Höpfner, and Andrea Pozzer
Geosci. Model Dev., 18, 3985–4007, https://doi.org/10.5194/gmd-18-3985-2025, https://doi.org/10.5194/gmd-18-3985-2025, 2025
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SO2 from explosive volcanic eruptions reaching the stratosphere can oxidize and form sulfur aerosols, potentially persisting for several years. We developed a new submodel, Explosive Volcanic ERuptions (EVER), that seamlessly includes stratospheric volcanic SO2 emissions in global numerical simulations based on a novel standard historical model setup, successfully evaluated with satellite observations. Sensitivity studies on the Nabro eruption in 2011 evaluate different emission methods.
Simone Tilmes, Ewa M. Bednarz, Andrin Jörimann, Daniele Visioni, Douglas E. Kinnison, Gabriel Chiodo, and David Plummer
Atmos. Chem. Phys., 25, 6001–6023, https://doi.org/10.5194/acp-25-6001-2025, https://doi.org/10.5194/acp-25-6001-2025, 2025
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In this paper, we describe the details of a new multi-model intercomparison experiment to assess the effects of Stratospheric Aerosol Intervention (SAI) on stratospheric chemistry and dynamics and, therefore, ozone. Second, we discuss the advantages and differences of the more constrained experiment compared to fully interactive model experiments. This way, we advance the process-level understanding of the drivers of SAI-induced atmospheric responses.
Patrick Peter, Sigrun Matthes, Christine Frömming, Patrick Jöckel, Luca Bugliaro, Andreas Giez, Martina Krämer, and Volker Grewe
Atmos. Chem. Phys., 25, 5911–5934, https://doi.org/10.5194/acp-25-5911-2025, https://doi.org/10.5194/acp-25-5911-2025, 2025
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Our study examines how well the global climate model EMAC (ECHAM/MESSy Atmospheric Chemistry) predicts contrail formation by analysing temperature and humidity – two key factors for contrail development and persistence. The model underestimates temperature, leading to an overprediction of contrail formation and larger ice-supersaturated regions. Adjusting the model improves temperature accuracy but adds uncertainties. Better predictions of contrail formation areas can help optimise flight tracks to reduce aviation's climate effect.
Rachael E. Byrom, Gunnar Myhre, Øivind Hodnebrog, Dirk Olivié, and Michael Schulz
Atmos. Chem. Phys., 25, 5683–5693, https://doi.org/10.5194/acp-25-5683-2025, https://doi.org/10.5194/acp-25-5683-2025, 2025
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Addressing the cause of model spread in CO2 effective radiative forcing (ERF) is important for reducing uncertainty in climate change. We investigate stratospheric O3 as a driver of this spread by altering its concentration by 50 % and analysing the impact on CO2 forcing. Our experiments show a significant effect on stratospheric temperature that impacts instantaneous radiative forcing, primarily due to the influence on longwave emission. However, the impact on ERF is minimal.
Martin Cussac, Martine Michou, Pierre Nabat, Béatrice Josse, and Sophie Pelletier
EGUsphere, https://doi.org/10.5194/egusphere-2025-1933, https://doi.org/10.5194/egusphere-2025-1933, 2025
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This study evaluates three chemistry schemes of varying complexity, one mainly stratospheric and two tropospheric-stratospheric, in the latest version of the climate model ARPEGE-Climat. Stratospheric ozone and water vapour are better represented. Despite issues with carbon monoxide in one scheme and with winter nitrogen species in the other, tropospheric ozone is overall realistically simulated. These modelling evolutions strengthen future research on chemistry-climate interactions.
Francisco J. Pérez-Invernón, Francisco J. Gordillo-Vázquez, Heidi Huntrieser, Patrick Jöckel, and Eric J. Bucsela
Atmos. Chem. Phys., 25, 5557–5575, https://doi.org/10.5194/acp-25-5557-2025, https://doi.org/10.5194/acp-25-5557-2025, 2025
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Lightning plays a significant role in tropospheric chemistry by producing substantial amounts of nitrogen oxides. According to recent estimates, thunderstorms that produce a higher lightning frequency rate also produce less nitrogen oxide per flash. We implemented the dependency of nitrogen oxide production per flash on lightning flash frequency in a chemical atmospheric model.
Genevieve Rose Lorenzo, Luke D. Ziemba, Avelino F. Arellano, Mary C. Barth, Ewan C. Crosbie, Joshua P. DiGangi, Glenn S. Diskin, Richard Ferrare, Miguel Ricardo A. Hilario, Michael A. Shook, Simone Tilmes, Jian Wang, Qian Xiao, Jun Zhang, and Armin Sorooshian
Atmos. Chem. Phys., 25, 5469–5495, https://doi.org/10.5194/acp-25-5469-2025, https://doi.org/10.5194/acp-25-5469-2025, 2025
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Novel aerosol hygroscopicity analyses of CAMP2Ex (Cloud, Aerosol, and Monsoon Processes Philippines Experiment) field campaign data show low aerosol hygroscopicity values in Southeast Asia. Organic carbon from smoke decreases hygroscopicity to levels more like those in continental than in polluted marine regions. Hygroscopicity changes at cloud level demonstrate how surface particles impact clouds in the region, affecting model representation of aerosol and cloud interactions in similar polluted marine regions with high organic carbon emissions.
Laura Stecher, Franziska Winterstein, Patrick Jöckel, Michael Ponater, Mariano Mertens, and Martin Dameris
Atmos. Chem. Phys., 25, 5133–5158, https://doi.org/10.5194/acp-25-5133-2025, https://doi.org/10.5194/acp-25-5133-2025, 2025
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Methane, the second most important anthropogenic greenhouse gas, is chemically decomposed in the atmosphere. The chemical sink of atmospheric methane is not constant but depends on the temperature and on the abundance of its reaction partners. In this study, we use a global chemistry–climate model to assess the feedback of atmospheric methane induced by changes in the chemical sink in a warming climate and its implications for the chemical composition and the surface air temperature change.
Ragnhild Bieltvedt Skeie, Marit Sandstad, Srinath Krishnan, Gunnar Myhre, and Maria Sand
Atmos. Chem. Phys., 25, 4929–4942, https://doi.org/10.5194/acp-25-4929-2025, https://doi.org/10.5194/acp-25-4929-2025, 2025
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Hydrogen leakages can alter the amount of climate gases in the atmosphere and hence have a climate impact. In this study we investigate, using an atmospheric chemistry model, how this indirect climate effect differs with different amounts of leakages and with where the hydrogen leaks and if this effect changes in the future. The effect is largest for emissions far from areas where hydrogen is removed from the atmosphere by the soil, but these are not relevant locations for a future hydrogen economy.
Duncan Watson-Parris, Laura J. Wilcox, Camilla W. Stjern, Robert J. Allen, Geeta Persad, Massimo A. Bollasina, Annica M. L. Ekman, Carley E. Iles, Manoj Joshi, Marianne T. Lund, Daniel McCoy, Daniel M. Westervelt, Andrew I. L. Williams, and Bjørn H. Samset
Atmos. Chem. Phys., 25, 4443–4454, https://doi.org/10.5194/acp-25-4443-2025, https://doi.org/10.5194/acp-25-4443-2025, 2025
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In 2020, regulations by the International Maritime Organization aimed to reduce aerosol emissions from ships. These aerosols previously had a cooling effect, which the regulations might reduce, revealing more greenhouse gas warming. Here we find that, while there is regional warming, the global 2020–2040 temperature rise is only +0.03 °C. This small change is difficult to distinguish from natural climate variability, indicating the regulations have had a limited effect on observed warming to date.
Ales Kuchar, Timofei Sukhodolov, Gabriel Chiodo, Andrin Jörimann, Jessica Kult-Herdin, Eugene Rozanov, and Harald H. Rieder
Atmos. Chem. Phys., 25, 3623–3634, https://doi.org/10.5194/acp-25-3623-2025, https://doi.org/10.5194/acp-25-3623-2025, 2025
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In January 2022, the Hunga Tonga–Hunga Ha'apai (HTHH) volcano erupted, sending massive amounts of water vapour into the atmosphere. This event had a significant impact on stratospheric and lower-mesospheric chemical composition. Two years later, stratospheric conditions were disturbed during so-called sudden stratospheric warmings. Here we simulate a novel pathway by which this water-rich eruption may have contributed to conditions during these events and consequently impacted the surface climate.
Hector Navarro-Barboza, Jordi Rovira, Vincenzo Obiso, Andrea Pozzer, Marta Via, Andres Alastuey, Xavier Querol, Noemi Perez, Marjan Savadkoohi, Gang Chen, Jesus Yus-Díez, Matic Ivancic, Martin Rigler, Konstantinos Eleftheriadis, Stergios Vratolis, Olga Zografou, Maria Gini, Benjamin Chazeau, Nicolas Marchand, Andre S. H. Prevot, Kaspar Dallenbach, Mikael Ehn, Krista Luoma, Tuukka Petäjä, Anna Tobler, Jaroslaw Necki, Minna Aurela, Hilkka Timonen, Jarkko Niemi, Olivier Favez, Jean-Eudes Petit, Jean-Philippe Putaud, Christoph Hueglin, Nicolas Pascal, Aurélien Chauvigné, Sébastien Conil, Marco Pandolfi, and Oriol Jorba
Atmos. Chem. Phys., 25, 2667–2694, https://doi.org/10.5194/acp-25-2667-2025, https://doi.org/10.5194/acp-25-2667-2025, 2025
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Brown carbon (BrC) absorbs ultraviolet (UV) and visible light, influencing climate. This study explores BrC's imaginary refractive index (k) using data from 12 European sites. Residential emissions are a major organic aerosol (OA) source in winter, while secondary organic aerosol (SOA) dominates in summer. Source-specific k values were derived, improving model accuracy. The findings highlight BrC's climate impact and emphasize source-specific constraints in atmospheric models.
Astrid Kerkweg, Timo Kirfel, Duong H. Do, Sabine Griessbach, Patrick Jöckel, and Domenico Taraborrelli
Geosci. Model Dev., 18, 1265–1286, https://doi.org/10.5194/gmd-18-1265-2025, https://doi.org/10.5194/gmd-18-1265-2025, 2025
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Normally, the Modular Earth Submodel System (MESSy) is linked to complete dynamic models to create chemical climate models. However, the modular concept of MESSy and the newly developed DWARF component presented here make it possible to create simplified models that contain only one or a few process descriptions. This is very useful for technical optimisation, such as porting to GPUs, and can be used to create less complex models, such as a chemical box model.
Axel Lauer, Lisa Bock, Birgit Hassler, Patrick Jöckel, Lukas Ruhe, and Manuel Schlund
Geosci. Model Dev., 18, 1169–1188, https://doi.org/10.5194/gmd-18-1169-2025, https://doi.org/10.5194/gmd-18-1169-2025, 2025
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Earth system models are important tools to improve our understanding of current climate and to project climate change. Thus, it is crucial to understand possible shortcomings in the models. New features of the ESMValTool software package allow one to compare and visualize a model's performance with respect to reproducing observations in the context of other climate models in an easy and user-friendly way. We aim to help model developers assess and monitor climate simulations more efficiently.
Kerstin Hartung, Bastian Kern, Nils-Arne Dreier, Jörn Geisbüsch, Mahnoosh Haghighatnasab, Patrick Jöckel, Astrid Kerkweg, Wilton Jaciel Loch, Florian Prill, and Daniel Rieger
Geosci. Model Dev., 18, 1001–1015, https://doi.org/10.5194/gmd-18-1001-2025, https://doi.org/10.5194/gmd-18-1001-2025, 2025
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The ICOsahedral Non-hydrostatic (ICON) model system Community Interface (ComIn) library supports connecting third-party modules to the ICON model. Third-party modules can range from simple diagnostic Python scripts to full chemistry models. ComIn offers a low barrier for code extensions to ICON, provides multi-language support (Fortran, C/C++, and Python), and reduces the migration effort in response to new ICON releases. This paper presents the ComIn design principles and a range of use cases.
Danny M. Leung, Jasper F. Kok, Longlei Li, David M. Lawrence, Natalie M. Mahowald, Simone Tilmes, and Erik Kluzek
Atmos. Chem. Phys., 25, 2311–2331, https://doi.org/10.5194/acp-25-2311-2025, https://doi.org/10.5194/acp-25-2311-2025, 2025
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This study derives a gridded dust emission dataset for 1841–2000 by employing a combination of observed dust from core records and reanalyzed global dust cycle constraints. We evaluate the ability of global models to replicate the observed historical dust variability by using the emission dataset to force a historical simulation in an Earth system model. We show that prescribing our emissions forces the model to better match observations than other mechanistic models.
Amir H. Souri, Gonzalo González Abad, Glenn M. Wolfe, Tijl Verhoelst, Corinne Vigouroux, Gaia Pinardi, Steven Compernolle, Bavo Langerock, Bryan N. Duncan, and Matthew S. Johnson
Atmos. Chem. Phys., 25, 2061–2086, https://doi.org/10.5194/acp-25-2061-2025, https://doi.org/10.5194/acp-25-2061-2025, 2025
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We establish a simple yet robust relationship between ozone production rates and geophysical parameters obtained from several intensive atmospheric composition campaigns. We show that satellite remote sensing data can effectively constrain these parameters, enabling us to produce the first global maps of ozone production rates with unprecedented resolution.
Hossein Maazallahi, Foteini Stavropoulou, Samuel Jonson Sutanto, Michael Steiner, Dominik Brunner, Mariano Mertens, Patrick Jöckel, Antoon Visschedijk, Hugo Denier van der Gon, Stijn Dellaert, Nataly Velandia Salinas, Stefan Schwietzke, Daniel Zavala-Araiza, Sorin Ghemulet, Alexandru Pana, Magdalena Ardelean, Marius Corbu, Andreea Calcan, Stephen A. Conley, Mackenzie L. Smith, and Thomas Röckmann
Atmos. Chem. Phys., 25, 1497–1511, https://doi.org/10.5194/acp-25-1497-2025, https://doi.org/10.5194/acp-25-1497-2025, 2025
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This article presents insights from airborne in situ measurements collected during the ROmanian Methane Emissions from Oil and gas (ROMEO) campaign supported by two models. Results reveal Romania's oil and gas methane emissions were significantly under-reported to the United Nations Framework Convention on Climate Change (UNFCCC) in 2019. A large underestimation was also found in the Emissions Database for Global Atmospheric Research (EDGAR) v7.0 for the study domain in the same year.
Prashant Chavan, Suvarna Fadnavis, Anton Laakso, Jean-Paul Vernier, Simone Tilmes, and Rolf Müller
EGUsphere, https://doi.org/10.5194/egusphere-2024-3825, https://doi.org/10.5194/egusphere-2024-3825, 2025
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Our simulations with volcanoes, when compared without volcanoes, show that volcanic aerosol precursors enter the tropical stratosphere, propagating upward and enhancing sulphate aerosol and heating. This stratospheric heating caused by the volcanoes reduces the amplitude of the QBO and disrupts its phases. Since QBO also modulates tropical convection and weather, we suggest including volcanic emissions and the QBO in the weather prediction model for a better forecast.
Mariya Petrenko, Ralph Kahn, Mian Chin, Susanne E. Bauer, Tommi Bergman, Huisheng Bian, Gabriele Curci, Ben Johnson, Johannes W. Kaiser, Zak Kipling, Harri Kokkola, Xiaohong Liu, Keren Mezuman, Tero Mielonen, Gunnar Myhre, Xiaohua Pan, Anna Protonotariou, Samuel Remy, Ragnhild Bieltvedt Skeie, Philip Stier, Toshihiko Takemura, Kostas Tsigaridis, Hailong Wang, Duncan Watson-Parris, and Kai Zhang
Atmos. Chem. Phys., 25, 1545–1567, https://doi.org/10.5194/acp-25-1545-2025, https://doi.org/10.5194/acp-25-1545-2025, 2025
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We compared smoke plume simulations from 11 global models to each other and to satellite smoke amount observations aimed at constraining smoke source strength. In regions where plumes are thick and background aerosol is low, models and satellites compare well. However, the input emission inventory tends to underestimate in many places, and particle property and loss rate assumptions vary enormously among models, causing uncertainties that require systematic in situ measurements to resolve.
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.
Lucien Froidevaux, Douglas E. Kinnison, Benjamin Gaubert, Michael J. Schwartz, Nathaniel J. Livesey, William G. Read, Charles G. Bardeen, Jerry R. Ziemke, and Ryan A. Fuller
Atmos. Chem. Phys., 25, 597–624, https://doi.org/10.5194/acp-25-597-2025, https://doi.org/10.5194/acp-25-597-2025, 2025
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We compare observed changes in ozone (O3) and carbon monoxide (CO) in the tropical upper troposphere (10–15 km altitude) for 2005–2020 to predictions from model simulations that track the evolution of natural and industrial emissions transported to this region. An increasing trend in measured upper-tropospheric O3 is well matched by model trends. We find that changes in modeled industrial CO surface emissions lead to better model agreement with observed slight decreases in upper-tropospheric CO.
Ryan Vella, Matthew Forrest, Andrea Pozzer, Alexandra P. Tsimpidi, Thomas Hickler, Jos Lelieveld, and Holger Tost
Atmos. Chem. Phys., 25, 243–262, https://doi.org/10.5194/acp-25-243-2025, https://doi.org/10.5194/acp-25-243-2025, 2025
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This study examines how land cover changes influence biogenic volatile organic compound (BVOC) emissions and atmospheric states. Using a coupled chemistry–climate–vegetation model, we compare present-day land cover (deforested for crops and grazing) with natural vegetation and an extreme reforestation scenario. We find that vegetation changes significantly impact global BVOC emissions and organic aerosols but have a relatively small effect on total aerosols, clouds, and radiative effects.
Jin Liao, Glenn M. Wolfe, Alexander E. Kotsakis, Julie M. Nicely, Jason M. St. Clair, Thomas F. Hanisco, Gonzalo González Abad, Caroline R. Nowlan, Zolal Ayazpour, Isabelle De Smedt, Eric C. Apel, and Rebecca S. Hornbrook
Atmos. Meas. Tech., 18, 1–16, https://doi.org/10.5194/amt-18-1-2025, https://doi.org/10.5194/amt-18-1-2025, 2025
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Validation of satellite HCHO over the remote marine regions is relatively low, and modeled HCHO in these regions is usually added as a global satellite HCHO background. This paper intercompares three satellite HCHO retrievals and validates them against in situ observations from the NASA ATom mission. All retrievals are correlated with ATom-integrated columns over remote oceans, with OMI SAO (v004) showing the best agreement. A persistent low bias is found in all retrievals at high latitudes.
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.
Fang Li, Xiang Song, Sandy P. Harrison, Jennifer R. Marlon, Zhongda Lin, L. Ruby Leung, Jörg Schwinger, Virginie Marécal, Shiyu Wang, Daniel S. Ward, Xiao Dong, Hanna Lee, Lars Nieradzik, Sam S. Rabin, and Roland Séférian
Geosci. Model Dev., 17, 8751–8771, https://doi.org/10.5194/gmd-17-8751-2024, https://doi.org/10.5194/gmd-17-8751-2024, 2024
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This study provides the first comprehensive assessment of historical fire simulations from 19 Earth system models in phase 6 of the Coupled Model Intercomparison Project (CMIP6). Most models reproduce global totals, spatial patterns, seasonality, and regional historical changes well but fail to simulate the recent decline in global burned area and underestimate the fire response to climate variability. CMIP6 simulations address three critical issues of phase-5 models.
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.
Ragnhild Bieltvedt Skeie, Rachael Byrom, Øivind Hodnebrog, Caroline Jouan, and Gunnar Myhre
Atmos. Chem. Phys., 24, 13361–13370, https://doi.org/10.5194/acp-24-13361-2024, https://doi.org/10.5194/acp-24-13361-2024, 2024
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In 2020, new regulations by the International Maritime Organization regarding sulfur emissions came into force, reducing emissions of SO2 from the shipping sector by approximately 80 %. In this study, we use multiple models to calculate how much the Earth energy balance changed due to the emission reduction or the so-called effective radiative forcing. The calculated effective radiative forcing is weak, comparable to the effect of the increase in CO2 over the last 2 to 3 years.
Megan J. Lickley, John S. Daniel, Laura A. McBride, Ross J. Salawitch, and Guus J. M. Velders
Atmos. Chem. Phys., 24, 13081–13099, https://doi.org/10.5194/acp-24-13081-2024, https://doi.org/10.5194/acp-24-13081-2024, 2024
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The expected ozone recovery date was delayed by 17 years between the 2006 and 2022 international scientific assessments of ozone depletion. We quantify the primary drivers of this delay. Changes in the metric used to estimate ozone recovery explain ca. 5 years of this delay. Of the remaining 12 years, changes in estimated banks, atmospheric lifetimes, and emission projections explain 4, 3.5, and 3 years of this delay, respectively.
Bryan N. Duncan, Daniel C. Anderson, Arlene M. Fiore, Joanna Joiner, Nickolay A. Krotkov, Can Li, Dylan B. Millet, Julie M. Nicely, Luke D. Oman, Jason M. St. Clair, Joshua D. Shutter, Amir H. Souri, Sarah A. Strode, Brad Weir, Glenn M. Wolfe, Helen M. Worden, and Qindan Zhu
Atmos. Chem. Phys., 24, 13001–13023, https://doi.org/10.5194/acp-24-13001-2024, https://doi.org/10.5194/acp-24-13001-2024, 2024
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Trace gases emitted to or formed within the atmosphere may be chemically or physically removed from the atmosphere. One trace gas, the hydroxyl radical (OH), is responsible for initiating the chemical removal of many trace gases, including some greenhouse gases. Despite its importance, scientists have not been able to adequately measure OH. In this opinion piece, we discuss promising new methods to indirectly constrain OH using satellite data of trace gases that control the abundance of OH.
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.
Leon Kuhn, Steffen Beirle, Sergey Osipov, Andrea Pozzer, and Thomas Wagner
Atmos. Meas. Tech., 17, 6485–6516, https://doi.org/10.5194/amt-17-6485-2024, https://doi.org/10.5194/amt-17-6485-2024, 2024
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This paper presents a new machine learning model that allows us to compute NO2 concentration profiles from satellite observations. A neural network was trained on synthetic data from the regional chemistry and transport model WRF-Chem. This is the first model of its kind. We present a thorough model validation study, covering various seasons and regions of the world.
Ragnhild Bieltvedt Skeie, Magne Aldrin, Terje K. Berntsen, Marit Holden, Ragnar Bang Huseby, Gunnar Myhre, and Trude Storelvmo
Earth Syst. Dynam., 15, 1435–1458, https://doi.org/10.5194/esd-15-1435-2024, https://doi.org/10.5194/esd-15-1435-2024, 2024
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Climate sensitivity and aerosol forcing are central quantities in climate science that are uncertain and contribute to the spread in climate projections. To constrain them, we use observations of temperature and ocean heat content as well as prior knowledge of radiative forcings over the industrialized period. The estimates are sensitive to how aerosol cooling evolved over the latter part of the 20th century, and a strong aerosol forcing trend in the 1960s–1970s is not supported by our analysis.
Sandro Vattioni, Rahel Weber, Aryeh Feinberg, Andrea Stenke, John A. Dykema, Beiping Luo, Georgios A. Kelesidis, Christian A. Bruun, Timofei Sukhodolov, Frank N. Keutsch, Thomas Peter, and Gabriel Chiodo
Geosci. Model Dev., 17, 7767–7793, https://doi.org/10.5194/gmd-17-7767-2024, https://doi.org/10.5194/gmd-17-7767-2024, 2024
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We quantified impacts and efficiency of stratospheric solar climate intervention via solid particle injection. Microphysical interactions of solid particles with the sulfur cycle were interactively coupled to the heterogeneous chemistry scheme and the radiative transfer code of an aerosol–chemistry–climate model. Compared to injection of SO2 we only find a stronger cooling efficiency for solid particles when normalizing to the aerosol load but not when normalizing to the injection rate.
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.
Theodore K. Koenig, François Hendrick, Douglas Kinnison, Christopher F. Lee, Michel Van Roozendael, and Rainer Volkamer
Atmos. Meas. Tech., 17, 5911–5934, https://doi.org/10.5194/amt-17-5911-2024, https://doi.org/10.5194/amt-17-5911-2024, 2024
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Atmospheric bromine destroys ozone, impacts oxidation capacity, and oxidizes mercury into its toxic form. We constrain bromine by remote sensing of BrO from a mountaintop. Previous measurements retrieved two to three pieces of information vertically; we apply new methods to get five and a half vertically and two more in time. We compare with aircraft measurements to validate the methods and look at variations in BrO over the Pacific.
Steven A. Bailey, Reem A. Hannun, Andrew K. Swanson, and Thomas F. Hanisco
Atmos. Meas. Tech., 17, 5903–5910, https://doi.org/10.5194/amt-17-5903-2024, https://doi.org/10.5194/amt-17-5903-2024, 2024
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We have developed a portable, optically based instrument that measures NO2. It consumes less than 6 W of power, so it can easily run off a small battery. This instrument has made both balloon and UAV flights. NO2 measurement results compare favorably with other known NO2 instruments. We find this instrument to be stable with repeatable results compared with calibration sources. Material cost to build a single instrument is around USD 4000. This could be lowered with economies of scale.
Sergio Soler, Francisco J. Gordillo-Vázquez, Francisco J. Pérez-Invernón, Patrick Jöckel, Torsten Neubert, Olivier Chanrion, Victor Reglero, and Nikolai Østgaard
Atmos. Chem. Phys., 24, 10225–10243, https://doi.org/10.5194/acp-24-10225-2024, https://doi.org/10.5194/acp-24-10225-2024, 2024
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Sudden local ozone (O3) enhancements have been reported in different regions of the world since the 1970s. While the hot channel of lightning strokes directly produce significant amounts of nitrogen oxide, no direct emission of O3 is expected. Corona discharges in convective active regions could explain local O3 increases, which remains unexplained. We present the first mathematical functions that relate the global annual frequency of in-cloud coronas with four sets of meteorological variables.
Pantelis Georgiades, Matthias Kohl, Mihalis A. Nicolaou, Theodoros Christoudias, Andrea Pozzer, Constantine Dovrolis, and Jos Lelieveld
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2024-314, https://doi.org/10.5194/essd-2024-314, 2024
Manuscript not accepted for further review
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This study maps global ultrafine particle (UFP) concentrations, pollutants known to affect health, using machine learning. By combining environmental and urban data, we predicted UFP levels at a fine 1 km resolution, highlighting areas of high exposure. Our results provide data for public health policies aimed at reducing air pollution impacts. This research bridges data gaps, offering a valuable tool for understanding and mitigating the health effects of UFP exposure.
Amir H. Souri, Bryan N. Duncan, Sarah A. Strode, Daniel C. Anderson, Michael E. Manyin, Junhua Liu, Luke D. Oman, Zhen Zhang, and Brad Weir
Atmos. Chem. Phys., 24, 8677–8701, https://doi.org/10.5194/acp-24-8677-2024, https://doi.org/10.5194/acp-24-8677-2024, 2024
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We explore a new method of using the wealth of information obtained from satellite observations of Aura OMI NO2, HCHO, and MERRA-2 reanalysis in NASA’s GEOS model equipped with an efficient tropospheric OH (TOH) estimator to enhance the representation of TOH spatial distribution and its long-term trends. This new framework helps us pinpoint regional inaccuracies in TOH and differentiate between established prior knowledge and newly acquired information from satellites on TOH trends.
Matthias Nützel, Laura Stecher, Patrick Jöckel, Franziska Winterstein, Martin Dameris, Michael Ponater, Phoebe Graf, and Markus Kunze
Geosci. Model Dev., 17, 5821–5849, https://doi.org/10.5194/gmd-17-5821-2024, https://doi.org/10.5194/gmd-17-5821-2024, 2024
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We extended the infrastructure of our modelling system to enable the use of an additional radiation scheme. After calibrating the model setups to the old and the new radiation scheme, we find that the simulation with the new scheme shows considerable improvements, e.g. concerning the cold-point temperature and stratospheric water vapour. Furthermore, perturbations of radiative fluxes associated with greenhouse gas changes, e.g. of methane, tend to be improved when the new scheme is employed.
Anna Martin, Veronika Gayler, Benedikt Steil, Klaus Klingmüller, Patrick Jöckel, Holger Tost, Jos Lelieveld, and Andrea Pozzer
Geosci. Model Dev., 17, 5705–5732, https://doi.org/10.5194/gmd-17-5705-2024, https://doi.org/10.5194/gmd-17-5705-2024, 2024
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The study evaluates the land surface and vegetation model JSBACHv4 as a replacement for the simplified submodel SURFACE in EMAC. JSBACH mitigates earlier problems of soil dryness, which are critical for vegetation modelling. When analysed using different datasets, the coupled model shows strong correlations of key variables, such as land surface temperature, surface albedo and radiation flux. The versatility of the model increases significantly, while the overall performance does not degrade.
Benjamin Hmiel, Vasilii V. Petrenko, Christo Buizert, Andrew M. Smith, Michael N. Dyonisius, Philip Place, Bin Yang, Quan Hua, Ross Beaudette, Jeffrey P. Severinghaus, Christina Harth, Ray F. Weiss, Lindsey Davidge, Melisa Diaz, Matthew Pacicco, James A. Menking, Michael Kalk, Xavier Faïn, Alden Adolph, Isaac Vimont, and Lee T. Murray
The Cryosphere, 18, 3363–3382, https://doi.org/10.5194/tc-18-3363-2024, https://doi.org/10.5194/tc-18-3363-2024, 2024
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The main aim of this research is to improve understanding of carbon-14 that is produced by cosmic rays in ice sheets. Measurements of carbon-14 in ice cores can provide a range of useful information (age of ice, past atmospheric chemistry, past cosmic ray intensity). Our results show that almost all (>99 %) of carbon-14 that is produced in the upper layer of ice sheets is rapidly lost to the atmosphere. Our results also provide better estimates of carbon-14 production rates in deeper ice.
Olaf Morgenstern
Atmos. Chem. Phys., 24, 8105–8123, https://doi.org/10.5194/acp-24-8105-2024, https://doi.org/10.5194/acp-24-8105-2024, 2024
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I use errors in climate model simulations to derive correction factors for the impacts of greenhouse gases and particles that bring these simulated temperature fields into agreement with an observational reconstruction of the Earth's temperature. On average across eight models, a reduction by about one-half of the particle-induced cooling would be required, causing only 0.24 K of cooling since 1850–1899. The greenhouse gas warming simulated by several highly sensitive models would also reduce.
Andrea E. Gordon, Cameron R. Homeyer, Jessica B. Smith, Rei Ueyama, Jonathan M. Dean-Day, Elliot L. Atlas, Kate Smith, Jasna V. Pittman, David S. Sayres, David M. Wilmouth, Apoorva Pandey, Jason M. St. Clair, Thomas F. Hanisco, Jennifer Hare, Reem A. Hannun, Steven Wofsy, Bruce C. Daube, and Stephen Donnelly
Atmos. Chem. Phys., 24, 7591–7608, https://doi.org/10.5194/acp-24-7591-2024, https://doi.org/10.5194/acp-24-7591-2024, 2024
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In situ airborne observations of ongoing tropopause-overshooting convection and an above-anvil cirrus plume from the 31 May 2022 flight of the Dynamics and Chemistry of the Summer Stratosphere (DCOTSS) field campaign are examined. Upper troposphere and lower stratosphere composition changes are evaluated along with possible contributing dynamical and physical processes. Measurements reveal multiple changes in air mass composition and stratospheric hydration throughout the flight.
Piers M. Forster, Chris Smith, Tristram Walsh, William F. Lamb, Robin Lamboll, Bradley Hall, Mathias Hauser, Aurélien Ribes, Debbie Rosen, Nathan P. Gillett, Matthew D. Palmer, Joeri Rogelj, Karina von Schuckmann, Blair Trewin, Myles Allen, Robbie Andrew, Richard A. Betts, Alex Borger, Tim Boyer, Jiddu A. Broersma, Carlo Buontempo, Samantha Burgess, Chiara Cagnazzo, Lijing Cheng, Pierre Friedlingstein, Andrew Gettelman, Johannes Gütschow, Masayoshi Ishii, Stuart Jenkins, Xin Lan, Colin Morice, Jens Mühle, Christopher Kadow, John Kennedy, Rachel E. Killick, Paul B. Krummel, Jan C. Minx, Gunnar Myhre, Vaishali Naik, Glen P. Peters, Anna Pirani, Julia Pongratz, Carl-Friedrich Schleussner, Sonia I. Seneviratne, Sophie Szopa, Peter Thorne, Mahesh V. M. Kovilakam, Elisa Majamäki, Jukka-Pekka Jalkanen, Margreet van Marle, Rachel M. Hoesly, Robert Rohde, Dominik Schumacher, Guido van der Werf, Russell Vose, Kirsten Zickfeld, Xuebin Zhang, Valérie Masson-Delmotte, and Panmao Zhai
Earth Syst. Sci. Data, 16, 2625–2658, https://doi.org/10.5194/essd-16-2625-2024, https://doi.org/10.5194/essd-16-2625-2024, 2024
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This paper tracks some key indicators of global warming through time, from 1850 through to the end of 2023. It is designed to give an authoritative estimate of global warming to date and its causes. We find that in 2023, global warming reached 1.3 °C and is increasing at over 0.2 °C per decade. This is caused by all-time-high greenhouse gas emissions.
Edward Groot, Patrick Kuntze, Annette Miltenberger, and Holger Tost
Weather Clim. Dynam., 5, 779–803, https://doi.org/10.5194/wcd-5-779-2024, https://doi.org/10.5194/wcd-5-779-2024, 2024
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Deep convective clouds (thunderstorms), which may cause severe weather, tend to coherently organise into structured cloud systems. Accurate representation of these systems in models is difficult due to their complex dynamics and, in numerical simulations, the dependence of their dynamics on resolution. Here, the effect of convective organisation and geometry on their outflow winds (altitudes of 7–14 km) is investigated. Representation of their dynamics and outflows improves at higher resolution.
Guang Zeng, Richard Querel, Hisako Shiona, Deniz Poyraz, Roeland Van Malderen, Alex Geddes, Penny Smale, Dan Smale, John Robinson, and Olaf Morgenstern
Atmos. Chem. Phys., 24, 6413–6432, https://doi.org/10.5194/acp-24-6413-2024, https://doi.org/10.5194/acp-24-6413-2024, 2024
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We present a homogenised ozonesonde record (1987–2020) for Lauder, a Southern Hemisphere mid-latitude site; identify factors driving ozone trends; and attribute them to anthropogenic forcings using statistical analysis and model simulations. We find that significant negative lower-stratospheric ozone trends identified at Lauder are associated with an increase in tropopause height and that CO2-driven dynamical changes have played an increasingly important role in driving ozone trends.
Sandro Vattioni, Andrea Stenke, Beiping Luo, Gabriel Chiodo, Timofei Sukhodolov, Elia Wunderlin, and Thomas Peter
Geosci. Model Dev., 17, 4181–4197, https://doi.org/10.5194/gmd-17-4181-2024, https://doi.org/10.5194/gmd-17-4181-2024, 2024
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We investigate the sensitivity of aerosol size distributions in the presence of strong SO2 injections for climate interventions or after volcanic eruptions to the call sequence and frequency of the routines for nucleation and condensation in sectional aerosol models with operator splitting. Using the aerosol–chemistry–climate model SOCOL-AERv2, we show that the radiative and chemical outputs are sensitive to these settings at high H2SO4 supersaturations and how to obtain reliable results.
Christina V. Brodowsky, Timofei Sukhodolov, Gabriel Chiodo, Valentina Aquila, Slimane Bekki, Sandip S. Dhomse, Michael Höpfner, Anton Laakso, Graham W. Mann, Ulrike Niemeier, Giovanni Pitari, Ilaria Quaglia, Eugene Rozanov, Anja Schmidt, Takashi Sekiya, Simone Tilmes, Claudia Timmreck, Sandro Vattioni, Daniele Visioni, Pengfei Yu, Yunqian Zhu, and Thomas Peter
Atmos. Chem. Phys., 24, 5513–5548, https://doi.org/10.5194/acp-24-5513-2024, https://doi.org/10.5194/acp-24-5513-2024, 2024
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The aerosol layer is an essential part of the climate system. We characterize the sulfur budget in a volcanically quiescent (background) setting, with a special focus on the sulfate aerosol layer using, for the first time, a multi-model approach. The aim is to identify weak points in the representation of the atmospheric sulfur budget in an intercomparison of nine state-of-the-art coupled global circulation models.
Anton Laakso, Daniele Visioni, Ulrike Niemeier, Simone Tilmes, and Harri Kokkola
Earth Syst. Dynam., 15, 405–427, https://doi.org/10.5194/esd-15-405-2024, https://doi.org/10.5194/esd-15-405-2024, 2024
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This study is the second in a two-part series in which we explore the dependency of the impacts of stratospheric sulfur injections on both the model employed and the strategy of injection utilized. The study uncovers uncertainties associated with these techniques to cool climate, highlighting how the simulated climate impacts are dependent on both the selected model and the magnitude of the injections. We also show that estimating precipitation impacts of aerosol injection is a complex task.
Simon Rosanka, Holger Tost, Rolf Sander, Patrick Jöckel, Astrid Kerkweg, and Domenico Taraborrelli
Geosci. Model Dev., 17, 2597–2615, https://doi.org/10.5194/gmd-17-2597-2024, https://doi.org/10.5194/gmd-17-2597-2024, 2024
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The capabilities of the Modular Earth Submodel System (MESSy) are extended to account for non-equilibrium aqueous-phase chemistry in the representation of deliquescent aerosols. When applying the new development in a global simulation, we find that MESSy's bias in modelling routinely observed reduced inorganic aerosol mass concentrations, especially in the United States. Furthermore, the representation of fine-aerosol pH is particularly improved in the marine boundary layer.
Daniele Visioni, Alan Robock, Jim Haywood, Matthew Henry, Simone Tilmes, Douglas G. MacMartin, Ben Kravitz, Sarah J. Doherty, John Moore, Chris Lennard, Shingo Watanabe, Helene Muri, Ulrike Niemeier, Olivier Boucher, Abu Syed, Temitope S. Egbebiyi, Roland Séférian, and Ilaria Quaglia
Geosci. Model Dev., 17, 2583–2596, https://doi.org/10.5194/gmd-17-2583-2024, https://doi.org/10.5194/gmd-17-2583-2024, 2024
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This paper describes a new experimental protocol for the Geoengineering Model Intercomparison Project (GeoMIP). In it, we describe the details of a new simulation of sunlight reflection using the stratospheric aerosols that climate models are supposed to run, and we explain the reasons behind each choice we made when defining the protocol.
Francisco J. Pérez-Invernón, Francisco J. Gordillo-Vázquez, Alejandro Malagón-Romero, and Patrick Jöckel
Atmos. Chem. Phys., 24, 3577–3592, https://doi.org/10.5194/acp-24-3577-2024, https://doi.org/10.5194/acp-24-3577-2024, 2024
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Sprites are electrical discharges that occur in the upper atmosphere. Recent modelling and observational data suggest that they may have a measurable impact on atmospheric chemistry. We incorporate both the occurrence rate of sprites and their production of chemical species into a chemistry–climate model. While our results indicate that sprites have a minimal global influence on atmospheric chemistry, they underscore their noteworthy importance at a regional scale.
Stephanie Fiedler, Vaishali Naik, Fiona M. O'Connor, Christopher J. Smith, Paul Griffiths, Ryan J. Kramer, Toshihiko Takemura, Robert J. Allen, Ulas Im, Matthew Kasoar, Angshuman Modak, Steven Turnock, Apostolos Voulgarakis, Duncan Watson-Parris, Daniel M. Westervelt, Laura J. Wilcox, Alcide Zhao, William J. Collins, Michael Schulz, Gunnar Myhre, and Piers M. Forster
Geosci. Model Dev., 17, 2387–2417, https://doi.org/10.5194/gmd-17-2387-2024, https://doi.org/10.5194/gmd-17-2387-2024, 2024
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Climate scientists want to better understand modern climate change. Thus, climate model experiments are performed and compared. The results of climate model experiments differ, as assessed in the latest Intergovernmental Panel on Climate Change (IPCC) assessment report. This article gives insights into the challenges and outlines opportunities for further improving the understanding of climate change. It is based on views of a group of experts in atmospheric composition–climate interactions.
Adriana Rocha-Lima, Peter R. Colarco, Anton S. Darmenov, Edward P. Nowottnick, Arlindo M. da Silva, and Luke D. Oman
Atmos. Chem. Phys., 24, 2443–2464, https://doi.org/10.5194/acp-24-2443-2024, https://doi.org/10.5194/acp-24-2443-2024, 2024
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Observations show an increasing aerosol optical depth trend in the Middle East between 2003–2012. We evaluate the NASA Goddard Earth Observing System (GEOS) model's ability to capture these trends and examine the meteorological and surface parameters driving dust emissions. Our results highlight the importance of data assimilation for long-term trends of atmospheric aerosols and support the hypothesis that vegetation cover loss may have contributed to increasing dust emissions in the period.
Danny M. Leung, Jasper F. Kok, Longlei Li, Natalie M. Mahowald, David M. Lawrence, Simone Tilmes, Erik Kluzek, Martina Klose, and Carlos Pérez García-Pando
Atmos. Chem. Phys., 24, 2287–2318, https://doi.org/10.5194/acp-24-2287-2024, https://doi.org/10.5194/acp-24-2287-2024, 2024
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This study uses a premier Earth system model to evaluate a new desert dust emission scheme proposed in our companion paper. We show that our scheme accounts for more dust emission physics, hence matching better against observations than other existing dust emission schemes do. Our scheme's dust emissions also couple tightly with meteorology, hence likely improving the modeled dust sensitivity to climate change. We believe this work is vital for improving dust representation in climate models.
Simone Rodrigues, Glauber Cirino, Demerval Moreira, Andrea Pozzer, Rafael Palácios, Sung-Ching Lee, Breno Imbiriba, José Nogueira, Maria Isabel Vitorino, and George Vourlitis
Biogeosciences, 21, 843–868, https://doi.org/10.5194/bg-21-843-2024, https://doi.org/10.5194/bg-21-843-2024, 2024
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The radiative effects of atmospheric particles are still unknown for a wide variety of species and types of vegetation present in Amazonian biomes. We examined the effects of aerosols on solar radiation and their impacts on photosynthesis in an area of semideciduous forest in the southern Amazon Basin. Under highly smoky-sky conditions, our results show substantial photosynthetic interruption (20–70 %), attributed specifically to the decrease in solar radiation and leaf canopy temperature.
Imran A. Girach, Narendra Ojha, Prabha R. Nair, Kandula V. Subrahmanyam, Neelakantan Koushik, Mohammed M. Nazeer, Nadimpally Kiran Kumar, Surendran Nair Suresh Babu, Jos Lelieveld, and Andrea Pozzer
Atmos. Chem. Phys., 24, 1979–1995, https://doi.org/10.5194/acp-24-1979-2024, https://doi.org/10.5194/acp-24-1979-2024, 2024
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We investigate surface ozone variability in East Antarctica based on measurements and EMAC global model simulations during austral summer. Nearly half of the surface ozone is found to be of stratospheric origin. The east coast of Antarctica acts as a stronger sink of ozone than surrounding regions. Photochemical loss of ozone is counterbalanced by downward transport of ozone. The study highlights the intertwined role of chemistry and dynamics in governing ozone variations over East Antarctica.
Bernd Funke, Thierry Dudok de Wit, Ilaria Ermolli, Margit Haberreiter, Doug Kinnison, Daniel Marsh, Hilde Nesse, Annika Seppälä, Miriam Sinnhuber, and Ilya Usoskin
Geosci. Model Dev., 17, 1217–1227, https://doi.org/10.5194/gmd-17-1217-2024, https://doi.org/10.5194/gmd-17-1217-2024, 2024
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We outline a road map for the preparation of a solar forcing dataset for the upcoming Phase 7 of the Coupled Model Intercomparison Project (CMIP7), considering the latest scientific advances made in the reconstruction of solar forcing and in the understanding of climate response while also addressing the issues that were raised during CMIP6.
George Jordan, Florent Malavelle, Ying Chen, Amy Peace, Eliza Duncan, Daniel G. Partridge, Paul Kim, Duncan Watson-Parris, Toshihiko Takemura, David Neubauer, Gunnar Myhre, Ragnhild Skeie, Anton Laakso, and James Haywood
Atmos. Chem. Phys., 24, 1939–1960, https://doi.org/10.5194/acp-24-1939-2024, https://doi.org/10.5194/acp-24-1939-2024, 2024
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The 2014–15 Holuhraun eruption caused a huge aerosol plume in an otherwise unpolluted region, providing a chance to study how aerosol alters cloud properties. This two-part study uses observations and models to quantify this relationship’s impact on the Earth’s energy budget. Part 1 suggests the models capture the observed spatial and chemical evolution of the plume, yet no model plume is exact. Understanding these differences is key for Part 2, where changes to cloud properties are explored.
Sarah Brüning, Stefan Niebler, and Holger Tost
Atmos. Meas. Tech., 17, 961–978, https://doi.org/10.5194/amt-17-961-2024, https://doi.org/10.5194/amt-17-961-2024, 2024
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We apply the Res-UNet to derive a comprehensive 3D cloud tomography from 2D satellite data over heterogeneous landscapes. We combine observational data from passive and active remote sensing sensors by an automated matching algorithm. These data are fed into a neural network to predict cloud reflectivities on the whole satellite domain between 2.4 and 24 km height. With an average RMSE of 2.99 dBZ, we contribute to closing data gaps in the representation of clouds in observational data.
Dongqi Lin, Jiawei Zhang, Basit Khan, Marwan Katurji, and Laura E. Revell
Geosci. Model Dev., 17, 815–845, https://doi.org/10.5194/gmd-17-815-2024, https://doi.org/10.5194/gmd-17-815-2024, 2024
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GEO4PALM is an open-source tool to generate static input for the Parallelized Large-Eddy Simulation (PALM) model system. Geospatial static input is essential for realistic PALM simulations. However, existing tools fail to generate PALM's geospatial static input for most regions. GEO4PALM is compatible with diverse geospatial data sources and provides access to free data sets. In addition, this paper presents two application examples, which show successful PALM simulations using GEO4PALM.
Ryan S. Williams, Michaela I. Hegglin, Patrick Jöckel, Hella Garny, and Keith P. Shine
Atmos. Chem. Phys., 24, 1389–1413, https://doi.org/10.5194/acp-24-1389-2024, https://doi.org/10.5194/acp-24-1389-2024, 2024
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During winter, a brief but abrupt reversal of the mean stratospheric westerly flow (~30 km high) around the Arctic occurs ~6 times a decade. Using a chemistry–climate model, about half of these events are shown to induce large anomalies in Arctic ozone (>25 %) and water vapour (>±25 %) around ~8–12 km altitude for up to 2–3 months, important for weather forecasting. We also calculate a doubling to trebling of the risk in breaches of mid-latitude surface air quality (ozone) standards (~60 ppbv).
Abolfazl Rezaei, Khalil Karami, Simone Tilmes, and John C. Moore
Earth Syst. Dynam., 15, 91–108, https://doi.org/10.5194/esd-15-91-2024, https://doi.org/10.5194/esd-15-91-2024, 2024
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Water storage (WS) plays a profound role in the lives of people in the Middle East and North Africa as well as Mediterranean climate "hot spots". WS change by greenhouse gas (GHG) warming is simulated with and without stratospheric aerosol intervention (SAI). WS significantly increases in the Arabian Peninsula and decreases around the Mediterranean under GHG. While SAI partially ameliorates GHG impacts, projected WS increases in dry regions and decreases in wet areas relative to present climate.
Victoria A. Flood, Kimberly Strong, Cynthia H. Whaley, Kaley A. Walker, Thomas Blumenstock, James W. Hannigan, Johan Mellqvist, Justus Notholt, Mathias Palm, Amelie N. Röhling, Stephen Arnold, Stephen Beagley, Rong-You Chien, Jesper Christensen, Makoto Deushi, Srdjan Dobricic, Xinyi Dong, Joshua S. Fu, Michael Gauss, Wanmin Gong, Joakim Langner, Kathy S. Law, Louis Marelle, Tatsuo Onishi, Naga Oshima, David A. Plummer, Luca Pozzoli, Jean-Christophe Raut, Manu A. Thomas, Svetlana Tsyro, and Steven Turnock
Atmos. Chem. Phys., 24, 1079–1118, https://doi.org/10.5194/acp-24-1079-2024, https://doi.org/10.5194/acp-24-1079-2024, 2024
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It is important to understand the composition of the Arctic atmosphere and how it is changing. Atmospheric models provide simulations that can inform policy. This study examines simulations of CH4, CO, and O3 by 11 models. Model performance is assessed by comparing results matched in space and time to measurements from five high-latitude ground-based infrared spectrometers. This work finds that models generally underpredict the concentrations of these gases in the Arctic troposphere.
Georgios I. Gkatzelis, Matthew M. Coggon, Chelsea E. Stockwell, Rebecca S. Hornbrook, Hannah Allen, Eric C. Apel, Megan M. Bela, Donald R. Blake, Ilann Bourgeois, Steven S. Brown, Pedro Campuzano-Jost, Jason M. St. Clair, James H. Crawford, John D. Crounse, Douglas A. Day, Joshua P. DiGangi, Glenn S. Diskin, Alan Fried, Jessica B. Gilman, Hongyu Guo, Johnathan W. Hair, Hannah S. Halliday, Thomas F. Hanisco, Reem Hannun, Alan Hills, L. Gregory Huey, Jose L. Jimenez, Joseph M. Katich, Aaron Lamplugh, Young Ro Lee, Jin Liao, Jakob Lindaas, Stuart A. McKeen, Tomas Mikoviny, Benjamin A. Nault, J. Andrew Neuman, John B. Nowak, Demetrios Pagonis, Jeff Peischl, Anne E. Perring, Felix Piel, Pamela S. Rickly, Michael A. Robinson, Andrew W. Rollins, Thomas B. Ryerson, Melinda K. Schueneman, Rebecca H. Schwantes, Joshua P. Schwarz, Kanako Sekimoto, Vanessa Selimovic, Taylor Shingler, David J. Tanner, Laura Tomsche, Krystal T. Vasquez, Patrick R. Veres, Rebecca Washenfelder, Petter Weibring, Paul O. Wennberg, Armin Wisthaler, Glenn M. Wolfe, Caroline C. Womack, Lu Xu, Katherine Ball, Robert J. Yokelson, and Carsten Warneke
Atmos. Chem. Phys., 24, 929–956, https://doi.org/10.5194/acp-24-929-2024, https://doi.org/10.5194/acp-24-929-2024, 2024
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This study reports emissions of gases and particles from wildfires. These emissions are related to chemical proxies that can be measured by satellite and incorporated into models to improve predictions of wildfire impacts on air quality and climate.
Leon Kuhn, Steffen Beirle, Vinod Kumar, Sergey Osipov, Andrea Pozzer, Tim Bösch, Rajesh Kumar, and Thomas Wagner
Atmos. Chem. Phys., 24, 185–217, https://doi.org/10.5194/acp-24-185-2024, https://doi.org/10.5194/acp-24-185-2024, 2024
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NO₂ is an important air pollutant. It was observed that the WRF-Chem model shows significant deviations in NO₂ abundance when compared to measurements. We use a 1-month simulation over central Europe to show that these deviations can be mostly resolved by reparameterization of the vertical mixing routine. In order to validate our results, they are compared to in situ, satellite, and MAX-DOAS measurements.
Yaowei Li, Corey Pedersen, John Dykema, Jean-Paul Vernier, Sandro Vattioni, Amit Kumar Pandit, Andrea Stenke, Elizabeth Asher, Troy Thornberry, Michael A. Todt, Thao Paul Bui, Jonathan Dean-Day, and Frank N. Keutsch
Atmos. Chem. Phys., 23, 15351–15364, https://doi.org/10.5194/acp-23-15351-2023, https://doi.org/10.5194/acp-23-15351-2023, 2023
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In 2021, the eruption of La Soufrière released sulfur dioxide into the stratosphere, resulting in a spread of volcanic aerosol over the Northern Hemisphere. We conducted extensive aircraft and balloon-borne measurements after that, revealing enhanced particle concentration and altered size distribution due to the eruption. The eruption's impact on ozone depletion was minimal, contributing ~0.6 %, and its global radiative forcing effect was modest, mainly affecting tropical and midlatitude areas.
Yusuf A. Bhatti, Laura E. Revell, Alex J. Schuddeboom, Adrian J. McDonald, Alex T. Archibald, Jonny Williams, Abhijith U. Venugopal, Catherine Hardacre, and Erik Behrens
Atmos. Chem. Phys., 23, 15181–15196, https://doi.org/10.5194/acp-23-15181-2023, https://doi.org/10.5194/acp-23-15181-2023, 2023
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Aerosols are a large source of uncertainty over the Southern Ocean. A dominant source of sulfate aerosol in this region is dimethyl sulfide (DMS), which is poorly simulated by climate models. We show the sensitivity of simulated atmospheric DMS to the choice of oceanic DMS data set and emission scheme. We show that oceanic DMS has twice the influence on atmospheric DMS than the emission scheme. Simulating DMS more accurately in climate models will help to constrain aerosol uncertainty.
Meghna Soni, Rolf Sander, Lokesh K. Sahu, Domenico Taraborrelli, Pengfei Liu, Ankit Patel, Imran A. Girach, Andrea Pozzer, Sachin S. Gunthe, and Narendra Ojha
Atmos. Chem. Phys., 23, 15165–15180, https://doi.org/10.5194/acp-23-15165-2023, https://doi.org/10.5194/acp-23-15165-2023, 2023
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The study presents the implementation of comprehensive multiphase chlorine chemistry in the box model CAABA/MECCA. Simulations for contrasting urban environments of Asia and Europe highlight the significant impacts of chlorine on atmospheric oxidation capacity and composition. Chemical processes governing the production and loss of chlorine-containing species has been discussed. The updated chemical mechanism will be useful to interpret field measurements and for future air quality studies.
Hamza Ahsan, Hailong Wang, Jingbo Wu, Mingxuan Wu, Steven J. Smith, Susanne Bauer, Harrison Suchyta, Dirk Olivié, Gunnar Myhre, Hitoshi Matsui, Huisheng Bian, Jean-François Lamarque, Ken Carslaw, Larry Horowitz, Leighton Regayre, Mian Chin, Michael Schulz, Ragnhild Bieltvedt Skeie, Toshihiko Takemura, and Vaishali Naik
Atmos. Chem. Phys., 23, 14779–14799, https://doi.org/10.5194/acp-23-14779-2023, https://doi.org/10.5194/acp-23-14779-2023, 2023
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We examine the impact of the assumed effective height of SO2 injection, SO2 and BC emission seasonality, and the assumed fraction of SO2 emissions injected as SO4 on climate and chemistry model results. We find that the SO2 injection height has a large impact on surface SO2 concentrations and, in some models, radiative flux. These assumptions are a
hiddensource of inter-model variability and may be leading to bias in some climate model results.
Ben A. Cala, Scott Archer-Nicholls, James Weber, N. Luke Abraham, Paul T. Griffiths, Lorrie Jacob, Y. Matthew Shin, Laura E. Revell, Matthew Woodhouse, and Alexander T. Archibald
Atmos. Chem. Phys., 23, 14735–14760, https://doi.org/10.5194/acp-23-14735-2023, https://doi.org/10.5194/acp-23-14735-2023, 2023
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Dimethyl sulfide (DMS) is an important trace gas emitted from the ocean recognised as setting the sulfate aerosol background, but its oxidation is complex. As a result representation in chemistry-climate models is greatly simplified. We develop and compare a new mechanism to existing mechanisms via a series of global and box model experiments. Our studies show our updated DMS scheme is a significant improvement but significant variance exists between mechanisms.
Dongqi Lin, Marwan Katurji, Laura E. Revell, Basit Khan, and Andrew Sturman
Atmos. Chem. Phys., 23, 14451–14479, https://doi.org/10.5194/acp-23-14451-2023, https://doi.org/10.5194/acp-23-14451-2023, 2023
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Accurate fog forecasting is difficult in a complex environment. Spatial variations in soil moisture could impact fog. Here, we carried out fog simulations with spatially different soil moisture in complex topography. The soil moisture was calculated using satellite observations. The results show that the spatial variations in soil moisture do not have a significant impact on where fog occurs but do impact how long fog lasts. This finding could improve fog forecasts in the future.
Simone Tilmes, Michael J. Mills, Yunqian Zhu, Charles G. Bardeen, Francis Vitt, Pengfei Yu, David Fillmore, Xiaohong Liu, Brian Toon, and Terry Deshler
Geosci. Model Dev., 16, 6087–6125, https://doi.org/10.5194/gmd-16-6087-2023, https://doi.org/10.5194/gmd-16-6087-2023, 2023
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We implemented an alternative aerosol scheme in the high- and low-top model versions of the Community Earth System Model Version 2 (CESM2) with a more detailed description of tropospheric and stratospheric aerosol size distributions than the existing aerosol model. This development enables the comparison of different aerosol schemes with different complexity in the same model framework. It identifies improvements compared to a range of observations in both the troposphere and stratosphere.
Ryan Vella, Andrea Pozzer, Matthew Forrest, Jos Lelieveld, Thomas Hickler, and Holger Tost
Biogeosciences, 20, 4391–4412, https://doi.org/10.5194/bg-20-4391-2023, https://doi.org/10.5194/bg-20-4391-2023, 2023
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We investigated the effect of the El Niño–Southern Oscillation (ENSO) on biogenic volatile organic compound (BVOC) emissions from plants. ENSO events can cause a significant increase in these emissions, which have a long-term impact on the Earth's atmosphere. Persistent ENSO conditions can cause long-term changes in vegetation, resulting in even higher BVOC emissions. We link ENSO-induced emission anomalies with driving atmospheric and vegetational variables.
Wenfu Tang, Louisa K. Emmons, Helen M. Worden, Rajesh Kumar, Cenlin He, Benjamin Gaubert, Zhonghua Zheng, Simone Tilmes, Rebecca R. Buchholz, Sara-Eva Martinez-Alonso, Claire Granier, Antonin Soulie, Kathryn McKain, Bruce C. Daube, Jeff Peischl, Chelsea Thompson, and Pieternel Levelt
Geosci. Model Dev., 16, 6001–6028, https://doi.org/10.5194/gmd-16-6001-2023, https://doi.org/10.5194/gmd-16-6001-2023, 2023
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The new MUSICAv0 model enables the study of atmospheric chemistry across all relevant scales. We develop a MUSICAv0 grid for Africa. We evaluate MUSICAv0 with observations and compare it with a previously used model – WRF-Chem. Overall, the performance of MUSICAv0 is comparable to WRF-Chem. Based on model–satellite discrepancies, we find that future field campaigns in an eastern African region (30°E–45°E, 5°S–5°N) could substantially improve the predictive skill of air quality models.
Franziska Zilker, Timofei Sukhodolov, Gabriel Chiodo, Marina Friedel, Tatiana Egorova, Eugene Rozanov, Jan Sedlacek, Svenja Seeber, and Thomas Peter
Atmos. Chem. Phys., 23, 13387–13411, https://doi.org/10.5194/acp-23-13387-2023, https://doi.org/10.5194/acp-23-13387-2023, 2023
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The Montreal Protocol (MP) has successfully reduced the Antarctic ozone hole by banning chlorofluorocarbons (CFCs) that destroy the ozone layer. Moreover, CFCs are strong greenhouse gases (GHGs) that would have strengthened global warming. In this study, we investigate the surface weather and climate in a world without the MP at the end of the 21st century, disentangling ozone-mediated and GHG impacts of CFCs. Overall, we avoided 1.7 K global surface warming and a poleward shift in storm tracks.
Yunqian Zhu, Robert W. Portmann, Douglas Kinnison, Owen Brian Toon, Luis Millán, Jun Zhang, Holger Vömel, Simone Tilmes, Charles G. Bardeen, Xinyue Wang, Stephanie Evan, William J. Randel, and Karen H. Rosenlof
Atmos. Chem. Phys., 23, 13355–13367, https://doi.org/10.5194/acp-23-13355-2023, https://doi.org/10.5194/acp-23-13355-2023, 2023
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The 2022 Hunga Tonga eruption injected a large amount of water into the stratosphere. Ozone depletion was observed inside the volcanic plume. Chlorine and water vapor injected by this eruption exceeded the normal range, which made the ozone chemistry during this event occur at a higher temperature than polar ozone depletion. Unlike polar ozone chemistry where chlorine nitrate is more important, hypochlorous acid plays a large role in the in-plume chlorine balance and heterogeneous processes.
Susanna Strada, Andrea Pozzer, Graziano Giuliani, Erika Coppola, Fabien Solmon, Xiaoyan Jiang, Alex Guenther, Efstratios Bourtsoukidis, Dominique Serça, Jonathan Williams, and Filippo Giorgi
Atmos. Chem. Phys., 23, 13301–13327, https://doi.org/10.5194/acp-23-13301-2023, https://doi.org/10.5194/acp-23-13301-2023, 2023
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Water deficit modifies emissions of isoprene, an aromatic compound released by plants that influences the production of an air pollutant such as ozone. Numerical modelling shows that, during the warmest and driest summers, isoprene decreases between −20 and −60 % over the Euro-Mediterranean region, while near-surface ozone only diminishes by a few percent. Decreases in isoprene emissions not only happen under dry conditions, but also could occur after prolonged or repeated water deficits.
Matthias Kohl, Jos Lelieveld, Sourangsu Chowdhury, Sebastian Ehrhart, Disha Sharma, Yafang Cheng, Sachchida Nand Tripathi, Mathew Sebastian, Govindan Pandithurai, Hongli Wang, and Andrea Pozzer
Atmos. Chem. Phys., 23, 13191–13215, https://doi.org/10.5194/acp-23-13191-2023, https://doi.org/10.5194/acp-23-13191-2023, 2023
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Knowledge on atmospheric ultrafine particles (UFPs) with a diameter smaller than 100 nm is crucial for public health and the hydrological cycle. We present a new global dataset of UFP concentrations at the Earth's surface derived with a comprehensive chemistry–climate model and evaluated with ground-based observations. The evaluation results are combined with high-resolution primary emissions to downscale UFP concentrations to an unprecedented horizontal resolution of 0.1° × 0.1°.
Clara M. Nussbaumer, Horst Fischer, Jos Lelieveld, and Andrea Pozzer
Atmos. Chem. Phys., 23, 12651–12669, https://doi.org/10.5194/acp-23-12651-2023, https://doi.org/10.5194/acp-23-12651-2023, 2023
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Ozone is a greenhouse gas and contributes to the earth’s radiative energy budget and therefore to global warming. This effect is the largest in the upper troposphere. In this study, we investigate the processes controlling ozone formation and the sensitivity to its precursors in the upper tropical troposphere based on model simulations by the ECHAM5/MESSy2 Atmospheric Chemistry (EMAC) model. We find that NO𝑥 emissions from lightning most importantly affect ozone chemistry at these altitudes.
Roland Eichinger, Sebastian Rhode, Hella Garny, Peter Preusse, Petr Pisoft, Aleš Kuchař, Patrick Jöckel, Astrid Kerkweg, and Bastian Kern
Geosci. Model Dev., 16, 5561–5583, https://doi.org/10.5194/gmd-16-5561-2023, https://doi.org/10.5194/gmd-16-5561-2023, 2023
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The columnar approach of gravity wave (GW) schemes results in dynamical model biases, but parallel decomposition makes horizontal GW propagation computationally unfeasible. In the global model EMAC, we approximate it by GW redistribution at one altitude using tailor-made redistribution maps generated with a ray tracer. More spread-out GW drag helps reconcile the model with observations and close the 60°S GW gap. Polar vortex dynamics are improved, enhancing climate model credibility.
Seyed Vahid Mousavi, Khalil Karami, Simone Tilmes, Helene Muri, Lili Xia, and Abolfazl Rezaei
Atmos. Chem. Phys., 23, 10677–10695, https://doi.org/10.5194/acp-23-10677-2023, https://doi.org/10.5194/acp-23-10677-2023, 2023
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Understanding atmospheric dust changes in the Middle East and North Africa (MENA) region under future climate scenarios is essential. By injecting sulfate aerosols into the stratosphere, stratospheric aerosol injection (SAI) geoengineering reflects some of the incoming sunlight back to space. This study shows that the MENA region would experience lower dust concentration under both SAI and RCP8.5 scenarios compared to the current climate (CTL) by the end of the century.
Herizo Narivelo, Paul David Hamer, Virginie Marécal, Luke Surl, Tjarda Roberts, Sophie Pelletier, Béatrice Josse, Jonathan Guth, Mickaël Bacles, Simon Warnach, Thomas Wagner, Stefano Corradini, Giuseppe Salerno, and Lorenzo Guerrieri
Atmos. Chem. Phys., 23, 10533–10561, https://doi.org/10.5194/acp-23-10533-2023, https://doi.org/10.5194/acp-23-10533-2023, 2023
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Volcanic emissions emit large quantities of gases and primary aerosols that can play an important role in atmospheric chemistry. We present a study of the fate of volcanic bromine emissions from the eruption of Mount Etna around Christmas 2018. Using a numerical model and satellite observations, we analyse the impact of the volcanic plume and how it modifies the composition of the air over the whole Mediterranean basin, in particular on tropospheric ozone through the bromine-explosion cycle.
Gabriel Chiodo, Marina Friedel, Svenja Seeber, Daniela Domeisen, Andrea Stenke, Timofei Sukhodolov, and Franziska Zilker
Atmos. Chem. Phys., 23, 10451–10472, https://doi.org/10.5194/acp-23-10451-2023, https://doi.org/10.5194/acp-23-10451-2023, 2023
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Stratospheric ozone protects the biosphere from harmful UV radiation. Anthropogenic activity has led to a reduction in the ozone layer in the recent past, but thanks to the implementation of the Montreal Protocol, the ozone layer is projected to recover. In this study, we show that projected future changes in Arctic ozone abundances during springtime will influence stratospheric climate and thereby actively modulate large-scale circulation changes in the Northern Hemisphere.
Jian Guan, Susan Solomon, Sasha Madronich, and Douglas Kinnison
Atmos. Chem. Phys., 23, 10413–10422, https://doi.org/10.5194/acp-23-10413-2023, https://doi.org/10.5194/acp-23-10413-2023, 2023
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This paper provides a novel method to obtain a global and accurate photodissociation coefficient for NO2 (J(NO2)) based on satellite data, and the results are shown to be consistent with model results. The J(NO2) value decreases as the solar zenith angle increases and has a weak altitude dependence. A key finding is that the satellite-derived J(NO2) increases in the polar regions, in good agreement with model predictions, due to the effects of ice and snow on surface albedo.
Marina Friedel, Gabriel Chiodo, Timofei Sukhodolov, James Keeble, Thomas Peter, Svenja Seeber, Andrea Stenke, Hideharu Akiyoshi, Eugene Rozanov, David Plummer, Patrick Jöckel, Guang Zeng, Olaf Morgenstern, and Béatrice Josse
Atmos. Chem. Phys., 23, 10235–10254, https://doi.org/10.5194/acp-23-10235-2023, https://doi.org/10.5194/acp-23-10235-2023, 2023
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Previously, it has been suggested that springtime Arctic ozone depletion might worsen in the coming decades due to climate change, which might counteract the effect of reduced ozone-depleting substances. Here, we show with different chemistry–climate models that springtime Arctic ozone depletion will likely decrease in the future. Further, we explain why models show a large spread in the projected development of Arctic ozone depletion and use the model spread to constrain future projections.
Serin Kim, Daewon Kim, Hyunkee Hong, Lim-Seok Chang, Hanlim Lee, Deok-Rae Kim, Donghee Kim, Jeong-Ah Yu, Dongwon Lee, Ukkyo Jeong, Chang-Kuen Song, Sang-Woo Kim, Sang Seo Park, Jhoon Kim, Thomas F. Hanisco, Junsung Park, Wonei Choi, and Kwangyul Lee
Atmos. Meas. Tech., 16, 3959–3972, https://doi.org/10.5194/amt-16-3959-2023, https://doi.org/10.5194/amt-16-3959-2023, 2023
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A first evaluation of the Geostationary Environmental Monitoring Spectrometer (GEMS) NO2 was carried out via comparison with the NO2 data obtained from the ground-based Pandora direct-sun measurements at four sites in Seosan, Republic of Korea. Comparisons between GEMS NO2 and Pandora NO2 were performed according to GEMS cloud fraction. GEMS NO2 showed good agreement with that of Pandora NO2 under less cloudy conditions.
Laura J. Wilcox, Robert J. Allen, Bjørn H. Samset, Massimo A. Bollasina, Paul T. Griffiths, James Keeble, Marianne T. Lund, Risto Makkonen, Joonas Merikanto, Declan O'Donnell, David J. Paynter, Geeta G. Persad, Steven T. Rumbold, Toshihiko Takemura, Kostas Tsigaridis, Sabine Undorf, and Daniel M. Westervelt
Geosci. Model Dev., 16, 4451–4479, https://doi.org/10.5194/gmd-16-4451-2023, https://doi.org/10.5194/gmd-16-4451-2023, 2023
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Changes in anthropogenic aerosol emissions have strongly contributed to global and regional climate change. However, the size of these regional impacts and the way they arise are still uncertain. With large changes in aerosol emissions a possibility over the next few decades, it is important to better quantify the potential role of aerosol in future regional climate change. The Regional Aerosol Model Intercomparison Project will deliver experiments designed to facilitate this.
Jonny Williams, Erik Behrens, Olaf Morgenstern, Peter Gibson, and Joao Teixeira
EGUsphere, https://doi.org/10.5194/egusphere-2023-1694, https://doi.org/10.5194/egusphere-2023-1694, 2023
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We use open-source cyclone tracking software and state-of-the-art climate models to characterise present-day tropical cyclones – TCs – in the South Pacific before moving on to estimate how they may change in the future. A robust result of this work is the projection of future intensification of TCs. However, the question of their future occurrence frequency is less clear. Under extreme future warming scenarios, we postulate a possible increase in power dissipation per TC of up to 25 %.
Marie Dumont, Simon Gascoin, Marion Réveillet, Didier Voisin, François Tuzet, Laurent Arnaud, Mylène Bonnefoy, Montse Bacardit Peñarroya, Carlo Carmagnola, Alexandre Deguine, Aurélie Diacre, Lukas Dürr, Olivier Evrard, Firmin Fontaine, Amaury Frankl, Mathieu Fructus, Laure Gandois, Isabelle Gouttevin, Abdelfateh Gherab, Pascal Hagenmuller, Sophia Hansson, Hervé Herbin, Béatrice Josse, Bruno Jourdain, Irene Lefevre, Gaël Le Roux, Quentin Libois, Lucie Liger, Samuel Morin, Denis Petitprez, Alvaro Robledano, Martin Schneebeli, Pascal Salze, Delphine Six, Emmanuel Thibert, Jürg Trachsel, Matthieu Vernay, Léo Viallon-Galinier, and Céline Voiron
Earth Syst. Sci. Data, 15, 3075–3094, https://doi.org/10.5194/essd-15-3075-2023, https://doi.org/10.5194/essd-15-3075-2023, 2023
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Saharan dust outbreaks have profound effects on ecosystems, climate, health, and the cryosphere, but the spatial deposition pattern of Saharan dust is poorly known. Following the extreme dust deposition event of February 2021 across Europe, a citizen science campaign was launched to sample dust on snow over the Pyrenees and the European Alps. This campaign triggered wide interest and over 100 samples. The samples revealed the high variability of the dust properties within a single event.
Duseong S. Jo, Simone Tilmes, Louisa K. Emmons, Siyuan Wang, and Francis Vitt
Geosci. Model Dev., 16, 3893–3906, https://doi.org/10.5194/gmd-16-3893-2023, https://doi.org/10.5194/gmd-16-3893-2023, 2023
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A new simple secondary organic aerosol (SOA) scheme has been developed for the Community Atmosphere Model (CAM) based on the complex SOA scheme in CAM with detailed chemistry (CAM-chem). The CAM with the new SOA scheme shows better agreements with CAM-chem in terms of aerosol concentrations and radiative fluxes, which ensures more consistent results between different compsets in the Community Earth System Model. The new SOA scheme also has technical advantages for future developments.
Michael Weimer, Douglas E. Kinnison, Catherine Wilka, and Susan Solomon
Atmos. Chem. Phys., 23, 6849–6861, https://doi.org/10.5194/acp-23-6849-2023, https://doi.org/10.5194/acp-23-6849-2023, 2023
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We investigate the influence of the number density of nitric acid trihydrate (NAT) particles on associated trace gases in the lower stratosphere using data from a satellite, ozonesondes and simulations by a community chemistry climate model. By comparing probability density functions between observations and the model, we find that the standard NAT number density should be reduced for future simulations with the model.
Marianne Tronstad Lund, Gunnar Myhre, Ragnhild Bieltvedt Skeie, Bjørn Hallvard Samset, and Zbigniew Klimont
Atmos. Chem. Phys., 23, 6647–6662, https://doi.org/10.5194/acp-23-6647-2023, https://doi.org/10.5194/acp-23-6647-2023, 2023
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Here we show that differences, in magnitude and trend, between recent global anthropogenic emission inventories have a notable influence on simulated regional abundances of anthropogenic aerosol over the 1990–2019 period. This, in turn, affects estimates of radiative forcing. Our findings form a basis for comparing existing and upcoming studies on anthropogenic aerosols using different emission inventories.
Daniel C. Anderson, Bryan N. Duncan, Julie M. Nicely, Junhua Liu, Sarah A. Strode, and Melanie B. Follette-Cook
Atmos. Chem. Phys., 23, 6319–6338, https://doi.org/10.5194/acp-23-6319-2023, https://doi.org/10.5194/acp-23-6319-2023, 2023
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We describe a methodology that combines machine learning, satellite observations, and 3D chemical model output to infer the abundance of the hydroxyl radical (OH), a chemical that removes many trace gases from the atmosphere. The methodology successfully captures the variability of observed OH, although further observations are needed to evaluate absolute accuracy. Current satellite observations are of sufficient quality to infer OH, but retrieval validation in the remote tropics is needed.
Emma L. Yates, Laura T. Iraci, Susan S. Kulawik, Ju-Mee Ryoo, Josette E. Marrero, Caroline L. Parworth, Jason M. St. Clair, Thomas F. Hanisco, Thao Paul V. Bui, Cecilia S. Chang, and Jonathan M. Dean-Day
Earth Syst. Sci. Data, 15, 2375–2389, https://doi.org/10.5194/essd-15-2375-2023, https://doi.org/10.5194/essd-15-2375-2023, 2023
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The Alpha Jet Atmospheric eXperiment (AJAX) flew scientific flights between 2011 and 2018 providing measurements of carbon dioxide, methane, ozone, formaldehyde, water vapor and meteorological parameters over California and Nevada, USA. AJAX was a multi-year, multi-objective, multi-instrument program with a variety of sampling strategies resulting in an extensive dataset of interest to a wide variety of users. AJAX measurements have been published at https://asdc.larc.nasa.gov/project/AJAX.
Edward Groot and Holger Tost
Atmos. Chem. Phys., 23, 6065–6081, https://doi.org/10.5194/acp-23-6065-2023, https://doi.org/10.5194/acp-23-6065-2023, 2023
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It is shown that the outflow from cumulonimbus clouds or thunderstorms in the upper troposphere and lower stratosphere in idealized high-resolution simulations (LESs) depends linearly on the net amount of latent heat released by the cloud for fixed geometry of the clouds. However, it is shown that, in more realistic situations, convective organization and aggregation (collecting mechanisms of cumulonimbus clouds) affect the amount of outflow non-linearly through non-idealized geometry.
Zaneta Hamryszczak, Dirk Dienhart, Bettina Brendel, Roland Rohloff, Daniel Marno, Monica Martinez, Hartwig Harder, Andrea Pozzer, Birger Bohn, Martin Zöger, Jos Lelieveld, and Horst Fischer
Atmos. Chem. Phys., 23, 5929–5943, https://doi.org/10.5194/acp-23-5929-2023, https://doi.org/10.5194/acp-23-5929-2023, 2023
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Hydrogen peroxide is a key contributor to the oxidative chemistry of the atmosphere through its link to the most prominent oxidants controlling its self-cleansing capacity, HOx. During the CAFE-Africa campaign, H2O2 was measured over the Atlantic Ocean and western Africa in August/September 2018. The study gives an overview of the distribution of H2O2 in the upper tropical troposphere and investigates the impact of convective processes in the Intertropical Convergence Zone on the budget of H2O2.
Virginie Marécal, Ronan Voisin-Plessis, Tjarda Jane Roberts, Alessandro Aiuppa, Herizo Narivelo, Paul David Hamer, Béatrice Josse, Jonathan Guth, Luke Surl, and Lisa Grellier
Geosci. Model Dev., 16, 2873–2898, https://doi.org/10.5194/gmd-16-2873-2023, https://doi.org/10.5194/gmd-16-2873-2023, 2023
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We implemented a halogen volcanic chemistry scheme in a one-dimensional modelling framework preparing for further use in a three-dimensional global chemistry-transport model. The results of the simulations for an eruption of Mt Etna in 2008, including various sensitivity tests, show a good consistency with previous modelling studies.
Abolfazl Rezaei, Khalil Karami, Simone Tilmes, and John C. Moore
Atmos. Chem. Phys., 23, 5835–5850, https://doi.org/10.5194/acp-23-5835-2023, https://doi.org/10.5194/acp-23-5835-2023, 2023
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Teleconnection patterns are important characteristics of the climate system; well-known examples include the El Niño and La Niña events driven from the tropical Pacific. We examined how spatiotemporal patterns that arise in the Pacific and Atlantic oceans behave under stratospheric aerosol geoengineering and greenhouse gas (GHG)-induced warming. In general, geoengineering reverses trends; however, the changes in decadal oscillation for the AMO, NAO, and PDO imposed by GHG are not suppressed.
Wenfu Tang, Simone Tilmes, David M. Lawrence, Fang Li, Cenlin He, Louisa K. Emmons, Rebecca R. Buchholz, and Lili Xia
Atmos. Chem. Phys., 23, 5467–5486, https://doi.org/10.5194/acp-23-5467-2023, https://doi.org/10.5194/acp-23-5467-2023, 2023
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Globally, total wildfire burned area is projected to increase over the 21st century under scenarios without geoengineering and decrease under the two geoengineering scenarios. Geoengineering reduces fire by decreasing surface temperature and wind speed and increasing relative humidity and soil water. However, geoengineering also yields reductions in precipitation, which offset some of the fire reduction.
Daniele Visioni, Ben Kravitz, Alan Robock, Simone Tilmes, Jim Haywood, Olivier Boucher, Mark Lawrence, Peter Irvine, Ulrike Niemeier, Lili Xia, Gabriel Chiodo, Chris Lennard, Shingo Watanabe, John C. Moore, and Helene Muri
Atmos. Chem. Phys., 23, 5149–5176, https://doi.org/10.5194/acp-23-5149-2023, https://doi.org/10.5194/acp-23-5149-2023, 2023
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Geoengineering indicates methods aiming to reduce the temperature of the planet by means of reflecting back a part of the incoming radiation before it reaches the surface or allowing more of the planetary radiation to escape into space. It aims to produce modelling experiments that are easy to reproduce and compare with different climate models, in order to understand the potential impacts of these techniques. Here we assess its past successes and failures and talk about its future.
Tatiana Egorova, Jan Sedlacek, Timofei Sukhodolov, Arseniy Karagodin-Doyennel, Franziska Zilker, and Eugene Rozanov
Atmos. Chem. Phys., 23, 5135–5147, https://doi.org/10.5194/acp-23-5135-2023, https://doi.org/10.5194/acp-23-5135-2023, 2023
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This paper describes the climate and atmosphere benefits of the Montreal Protocol, simulated with the state-of-the-art Earth system model SOCOLv4.0. We have added to and confirmed the previous studies by showing that without the Montreal Protocol by the end of the 21st century there would be a dramatic reduction in the ozone layer as well as substantial perturbation of the essential climate variables in the troposphere caused by the warming from increasing ozone-depleting substances.
Arseniy Karagodin-Doyennel, Eugene Rozanov, Timofei Sukhodolov, Tatiana Egorova, Jan Sedlacek, and Thomas Peter
Atmos. Chem. Phys., 23, 4801–4817, https://doi.org/10.5194/acp-23-4801-2023, https://doi.org/10.5194/acp-23-4801-2023, 2023
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The future ozone evolution in SOCOLv4 simulations under SSP2-4.5 and SSP5-8.5 scenarios has been assessed for the period 2015–2099 and subperiods using the DLM approach. The SOCOLv4 projects a decline in tropospheric ozone in the 2030s in SSP2-4.5 and in the 2060s in SSP5-8.5. The stratospheric ozone increase is ~3 times higher in SSP5-8.5, confirming the important role of GHGs in ozone evolution. We also showed that tropospheric ozone strongly impacts the total column in the tropics.
Claire Bekker, Wendell W. Walters, Lee T. Murray, and Meredith G. Hastings
Atmos. Chem. Phys., 23, 4185–4201, https://doi.org/10.5194/acp-23-4185-2023, https://doi.org/10.5194/acp-23-4185-2023, 2023
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Nitrate is a critical component of the atmosphere that degrades air quality and ecosystem health. We have investigated the nitrogen isotope compositions of nitrate from deposition samples collected across the northeastern United States. Spatiotemporal variability in the nitrogen isotope compositions was found to track with nitrate formation chemistry. Our results highlight that nitrogen isotope compositions may be a robust tool for improving model representation of nitrate chemistry.
Heejeong Kim, Wendell W. Walters, Claire Bekker, Lee T. Murray, and Meredith G. Hastings
Atmos. Chem. Phys., 23, 4203–4219, https://doi.org/10.5194/acp-23-4203-2023, https://doi.org/10.5194/acp-23-4203-2023, 2023
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Atmospheric nitrate has an important impact on human and ecosystem health. We evaluated atmospheric nitrate formation pathways in the northeastern US utilizing oxygen isotope compositions, which indicated a significant difference between the phases of nitrate (i.e., gas vs. particle). Comparing the observations with model simulations indicated that N2O5 hydrolysis chemistry was overpredicted. Our study has important implications for improving atmospheric chemistry model representation.
Andrey V. Koval, Olga N. Toptunova, Maxim A. Motsakov, Ksenia A. Didenko, Tatiana S. Ermakova, Nikolai M. Gavrilov, and Eugene V. Rozanov
Atmos. Chem. Phys., 23, 4105–4114, https://doi.org/10.5194/acp-23-4105-2023, https://doi.org/10.5194/acp-23-4105-2023, 2023
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Periodic changes in all hydrodynamic parameters are constantly observed in the atmosphere. The amplitude of these fluctuations increases with height due to a decrease in the atmospheric density. In the upper layers of the atmosphere, waves are the dominant form of motion. We use a model of the general circulation of the atmosphere to study the contribution to the formation of the dynamic and temperature regimes of the middle and upper atmosphere made by different global-scale atmospheric waves.
Khalil Karami, Rolando Garcia, Christoph Jacobi, Jadwiga H. Richter, and Simone Tilmes
Atmos. Chem. Phys., 23, 3799–3818, https://doi.org/10.5194/acp-23-3799-2023, https://doi.org/10.5194/acp-23-3799-2023, 2023
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Alongside mitigation and adaptation efforts, stratospheric aerosol intervention (SAI) is increasingly considered a third pillar to combat dangerous climate change. We investigate the teleconnection between the quasi-biennial oscillation in the equatorial stratosphere and the Arctic stratospheric polar vortex under a warmer climate and an SAI scenario. We show that the Holton–Tan relationship weakens under both scenarios and discuss the physical mechanisms responsible for such changes.
Forwood Wiser, Bryan K. Place, Siddhartha Sen, Havala O. T. Pye, Benjamin Yang, Daniel M. Westervelt, Daven K. Henze, Arlene M. Fiore, and V. Faye McNeill
Geosci. Model Dev., 16, 1801–1821, https://doi.org/10.5194/gmd-16-1801-2023, https://doi.org/10.5194/gmd-16-1801-2023, 2023
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We developed a reduced model of atmospheric isoprene oxidation, AMORE-Isoprene 1.0. It was created using a new Automated Model Reduction (AMORE) method designed to simplify complex chemical mechanisms with minimal manual adjustments to the output. AMORE-Isoprene 1.0 has improved accuracy and similar size to other reduced isoprene mechanisms. When included in the CRACMM mechanism, it improved the accuracy of EPA’s CMAQ model predictions for the northeastern USA compared to observations.
Ruhi S. Humphries, Melita D. Keywood, Jason P. Ward, James Harnwell, Simon P. Alexander, Andrew R. Klekociuk, Keiichiro Hara, Ian M. McRobert, Alain Protat, Joel Alroe, Luke T. Cravigan, Branka Miljevic, Zoran D. Ristovski, Robyn Schofield, Stephen R. Wilson, Connor J. Flynn, Gourihar R. Kulkarni, Gerald G. Mace, Greg M. McFarquhar, Scott D. Chambers, Alastair G. Williams, and Alan D. Griffiths
Atmos. Chem. Phys., 23, 3749–3777, https://doi.org/10.5194/acp-23-3749-2023, https://doi.org/10.5194/acp-23-3749-2023, 2023
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Observations of aerosols in pristine regions are rare but are vital to constraining the natural baseline from which climate simulations are calculated. Here we present recent seasonal observations of aerosols from the Southern Ocean and contrast them with measurements from Antarctica, Australia and regionally relevant voyages. Strong seasonal cycles persist, but striking differences occur at different latitudes. This study highlights the need for more long-term observations in remote regions.
Róisín Commane, Andrew Hallward-Driemeier, and Lee T. Murray
Atmos. Meas. Tech., 16, 1431–1441, https://doi.org/10.5194/amt-16-1431-2023, https://doi.org/10.5194/amt-16-1431-2023, 2023
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Methane / ethane ratios can be used to identify and partition the different sources of methane, especially in areas with natural gas mixed with biogenic methane emissions, such as cities. We tested three commercially available laser-based analyzers for sensitivity, precision, size, power requirement, ease of use on mobile platforms, and expertise needed to operate the instrument, and we make recommendations for use in various situations.
Robin N. Thor, Mariano Mertens, Sigrun Matthes, Mattia Righi, Johannes Hendricks, Sabine Brinkop, Phoebe Graf, Volker Grewe, Patrick Jöckel, and Steven Smith
Geosci. Model Dev., 16, 1459–1466, https://doi.org/10.5194/gmd-16-1459-2023, https://doi.org/10.5194/gmd-16-1459-2023, 2023
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We report on an inconsistency in the latitudinal distribution of aviation emissions between two versions of a data product which is widely used by researchers. From the available documentation, we do not expect such an inconsistency. We run a chemistry–climate model to compute the effect of the inconsistency in emissions on atmospheric chemistry and radiation and find that the radiative forcing associated with aviation ozone is 7.6 % higher when using the less recent version of the data.
Dominik Brunner, Gerrit Kuhlmann, Stephan Henne, Erik Koene, Bastian Kern, Sebastian Wolff, Christiane Voigt, Patrick Jöckel, Christoph Kiemle, Anke Roiger, Alina Fiehn, Sven Krautwurst, Konstantin Gerilowski, Heinrich Bovensmann, Jakob Borchardt, Michal Galkowski, Christoph Gerbig, Julia Marshall, Andrzej Klonecki, Pascal Prunet, Robert Hanfland, Margit Pattantyús-Ábrahám, Andrzej Wyszogrodzki, and Andreas Fix
Atmos. Chem. Phys., 23, 2699–2728, https://doi.org/10.5194/acp-23-2699-2023, https://doi.org/10.5194/acp-23-2699-2023, 2023
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We evaluated six atmospheric transport models for their capability to simulate the CO2 plumes from two of the largest power plants in Europe by comparing the models against aircraft observations collected during the CoMet (Carbon Dioxide and Methane Mission) campaign in 2018. The study analyzed how realistically such plumes can be simulated at different model resolutions and how well the planned European satellite mission CO2M will be able to quantify emissions from power plants.
Amir H. Souri, Matthew S. Johnson, Glenn M. Wolfe, James H. Crawford, Alan Fried, Armin Wisthaler, William H. Brune, Donald R. Blake, Andrew J. Weinheimer, Tijl Verhoelst, Steven Compernolle, Gaia Pinardi, Corinne Vigouroux, Bavo Langerock, Sungyeon Choi, Lok Lamsal, Lei Zhu, Shuai Sun, Ronald C. Cohen, Kyung-Eun Min, Changmin Cho, Sajeev Philip, Xiong Liu, and Kelly Chance
Atmos. Chem. Phys., 23, 1963–1986, https://doi.org/10.5194/acp-23-1963-2023, https://doi.org/10.5194/acp-23-1963-2023, 2023
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We have rigorously characterized different sources of error in satellite-based HCHO / NO2 tropospheric columns, a widely used metric for diagnosing near-surface ozone sensitivity. Specifically, the errors were categorized/quantified into (i) an inherent chemistry error, (ii) the decoupled relationship between columns and the near-surface concentration, (iii) the spatial representativeness error of ground satellite pixels, and (iv) the satellite retrieval errors.
Ryan Vella, Matthew Forrest, Jos Lelieveld, and Holger Tost
Geosci. Model Dev., 16, 885–906, https://doi.org/10.5194/gmd-16-885-2023, https://doi.org/10.5194/gmd-16-885-2023, 2023
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Biogenic volatile organic compounds (BVOCs) are released by vegetation and have a major impact on atmospheric chemistry and aerosol formation. Non-interacting vegetation constrains the majority of numerical models used to estimate global BVOC emissions, and thus, the effects of changing vegetation on emissions are not addressed. In this work, we replace the offline vegetation with dynamic vegetation states by linking a chemistry–climate model with a global dynamic vegetation model.
Yangxin Chen, Duoying Ji, Qian Zhang, John C. Moore, Olivier Boucher, Andy Jones, Thibaut Lurton, Michael J. Mills, Ulrike Niemeier, Roland Séférian, and Simone Tilmes
Earth Syst. Dynam., 14, 55–79, https://doi.org/10.5194/esd-14-55-2023, https://doi.org/10.5194/esd-14-55-2023, 2023
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Solar geoengineering has been proposed as a way of counteracting the warming effects of increasing greenhouse gases by reflecting solar radiation. This work shows that solar geoengineering can slow down the northern-high-latitude permafrost degradation but cannot preserve the permafrost ecosystem as that under a climate of the same warming level without solar geoengineering.
Ilaria Quaglia, Claudia Timmreck, Ulrike Niemeier, Daniele Visioni, Giovanni Pitari, Christina Brodowsky, Christoph Brühl, Sandip S. Dhomse, Henning Franke, Anton Laakso, Graham W. Mann, Eugene Rozanov, and Timofei Sukhodolov
Atmos. Chem. Phys., 23, 921–948, https://doi.org/10.5194/acp-23-921-2023, https://doi.org/10.5194/acp-23-921-2023, 2023
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The last very large explosive volcanic eruption we have measurements for is the eruption of Mt. Pinatubo in 1991. It is therefore often used as a benchmark for climate models' ability to reproduce these kinds of events. Here, we compare available measurements with the results from multiple experiments conducted with climate models interactively simulating the aerosol cloud formation.
Cynthia H. Whaley, Kathy S. Law, Jens Liengaard Hjorth, Henrik Skov, Stephen R. Arnold, Joakim Langner, Jakob Boyd Pernov, Garance Bergeron, Ilann Bourgeois, Jesper H. Christensen, Rong-You Chien, Makoto Deushi, Xinyi Dong, Peter Effertz, Gregory Faluvegi, Mark Flanner, Joshua S. Fu, Michael Gauss, Greg Huey, Ulas Im, Rigel Kivi, Louis Marelle, Tatsuo Onishi, Naga Oshima, Irina Petropavlovskikh, Jeff Peischl, David A. Plummer, Luca Pozzoli, Jean-Christophe Raut, Tom Ryerson, Ragnhild Skeie, Sverre Solberg, Manu A. Thomas, Chelsea Thompson, Kostas Tsigaridis, Svetlana Tsyro, Steven T. Turnock, Knut von Salzen, and David W. Tarasick
Atmos. Chem. Phys., 23, 637–661, https://doi.org/10.5194/acp-23-637-2023, https://doi.org/10.5194/acp-23-637-2023, 2023
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This study summarizes recent research on ozone in the Arctic, a sensitive and rapidly warming region. We find that the seasonal cycles of near-surface atmospheric ozone are variable depending on whether they are near the coast, inland, or at high altitude. Several global model simulations were evaluated, and we found that because models lack some of the ozone chemistry that is important for the coastal Arctic locations, they do not accurately simulate ozone there.
Edward Groot and Holger Tost
Atmos. Chem. Phys., 23, 565–585, https://doi.org/10.5194/acp-23-565-2023, https://doi.org/10.5194/acp-23-565-2023, 2023
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Thunderstorm systems play an important role in the dynamics of the Earth’s atmosphere, and some of them form a well-organised line: squall lines. Simulations of such squall lines with very small initial perturbations are compared to a reference simulation. The evolution of perturbations and processes amplifying them are analysed. It is shown that the formation of new secondary thunderstorm cells (after the initial primary cells) directly ahead of the line affects the spread strongly.
Mohamed Abdelkader, Georgiy Stenchikov, Andrea Pozzer, Holger Tost, and Jos Lelieveld
Atmos. Chem. Phys., 23, 471–500, https://doi.org/10.5194/acp-23-471-2023, https://doi.org/10.5194/acp-23-471-2023, 2023
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We study the effect of injected volcanic ash, water vapor, and SO2 on the development of the volcanic cloud and the stratospheric aerosol optical depth (AOD). Both are sensitive to the initial injection height and to the aging of the volcanic ash shaped by heterogeneous chemistry coupled with the ozone cycle. The paper explains the large differences in AOD for different injection scenarios, which could improve the estimate of the radiative forcing of volcanic eruptions.
Manuel Schlund, Birgit Hassler, Axel Lauer, Bouwe Andela, Patrick Jöckel, Rémi Kazeroni, Saskia Loosveldt Tomas, Brian Medeiros, Valeriu Predoi, Stéphane Sénési, Jérôme Servonnat, Tobias Stacke, Javier Vegas-Regidor, Klaus Zimmermann, and Veronika Eyring
Geosci. Model Dev., 16, 315–333, https://doi.org/10.5194/gmd-16-315-2023, https://doi.org/10.5194/gmd-16-315-2023, 2023
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The Earth System Model Evaluation Tool (ESMValTool) is a community diagnostics and performance metrics tool for routine evaluation of Earth system models. Originally, ESMValTool was designed to process reformatted output provided by large model intercomparison projects like the Coupled Model Intercomparison Project (CMIP). Here, we describe a new extension of ESMValTool that allows for reading and processing native climate model output, i.e., data that have not been reformatted before.
Dirk Dienhart, Bettina Brendel, John N. Crowley, Philipp G. Eger, Hartwig Harder, Monica Martinez, Andrea Pozzer, Roland Rohloff, Jan Schuladen, Sebastian Tauer, David Walter, Jos Lelieveld, and Horst Fischer
Atmos. Chem. Phys., 23, 119–142, https://doi.org/10.5194/acp-23-119-2023, https://doi.org/10.5194/acp-23-119-2023, 2023
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Formaldehyde and hydroperoxide measurements were performed in the marine boundary layer around the Arabian Peninsula and highlight the Suez Canal and Arabian (Persian) Gulf as a hotspot of photochemical air pollution. A comparison with the EMAC model shows that the formaldehyde results match within a factor of 2, while hydrogen peroxide was overestimated by more than a factor of 5, which revealed enhanced HOx (OH+HO2) radicals in the simulation and an underestimation of dry deposition velocites.
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.
Matthias Nützel, Sabine Brinkop, Martin Dameris, Hella Garny, Patrick Jöckel, Laura L. Pan, and Mijeong Park
Atmos. Chem. Phys., 22, 15659–15683, https://doi.org/10.5194/acp-22-15659-2022, https://doi.org/10.5194/acp-22-15659-2022, 2022
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During the Asian summer monsoon season, a large high-pressure system is present at levels close to the tropopause above Asia. We analyse how air masses are transported from surface levels to this high-pressure system, which shows distinct features from the surrounding air masses. To this end, we employ multiannual data from two complementary models that allow us to analyse the climatology as well as the interannual and intraseasonal variability of these transport pathways.
Pamela S. Rickly, Hongyu Guo, Pedro Campuzano-Jost, Jose L. Jimenez, Glenn M. Wolfe, Ryan Bennett, Ilann Bourgeois, John D. Crounse, Jack E. Dibb, Joshua P. DiGangi, Glenn S. Diskin, Maximilian Dollner, Emily M. Gargulinski, Samuel R. Hall, Hannah S. Halliday, Thomas F. Hanisco, Reem A. Hannun, Jin Liao, Richard Moore, Benjamin A. Nault, John B. Nowak, Jeff Peischl, Claire E. Robinson, Thomas Ryerson, Kevin J. Sanchez, Manuel Schöberl, Amber J. Soja, Jason M. St. Clair, Kenneth L. Thornhill, Kirk Ullmann, Paul O. Wennberg, Bernadett Weinzierl, Elizabeth B. Wiggins, Edward L. Winstead, and Andrew W. Rollins
Atmos. Chem. Phys., 22, 15603–15620, https://doi.org/10.5194/acp-22-15603-2022, https://doi.org/10.5194/acp-22-15603-2022, 2022
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Biomass burning sulfur dioxide (SO2) emission factors range from 0.27–1.1 g kg-1 C. Biomass burning SO2 can quickly form sulfate and organosulfur, but these pathways are dependent on liquid water content and pH. Hydroxymethanesulfonate (HMS) appears to be directly emitted from some fire sources but is not the sole contributor to the organosulfur signal. It is shown that HMS and organosulfur chemistry may be an important S(IV) reservoir with the fate dependent on the surrounding conditions.
Arseniy Karagodin-Doyennel, Eugene Rozanov, Timofei Sukhodolov, Tatiana Egorova, Jan Sedlacek, William Ball, and Thomas Peter
Atmos. Chem. Phys., 22, 15333–15350, https://doi.org/10.5194/acp-22-15333-2022, https://doi.org/10.5194/acp-22-15333-2022, 2022
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Applying the dynamic linear model, we confirm near-global ozone recovery (55°N–55°S) in the mesosphere, upper and middle stratosphere, and a steady increase in the troposphere. We also show that modern chemistry–climate models (CCMs) like SOCOLv4 may reproduce the observed trend distribution of lower stratospheric ozone, despite exhibiting a lower magnitude and statistical significance. The obtained ozone trend pattern in SOCOLv4 is generally consistent with observations and reanalysis datasets.
Amy Christiansen, Loretta J. Mickley, Junhua Liu, Luke D. Oman, and Lu Hu
Atmos. Chem. Phys., 22, 14751–14782, https://doi.org/10.5194/acp-22-14751-2022, https://doi.org/10.5194/acp-22-14751-2022, 2022
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Understanding tropospheric ozone trends is crucial for accurate predictions of future air quality and climate, but drivers of trends are not well understood. We analyze global tropospheric ozone trends since 1980 using ozonesonde and surface measurements, and we evaluate two models for their ability to reproduce trends. We find observational evidence of increasing tropospheric ozone, but models underestimate these increases. This hinders our ability to estimate ozone radiative forcing.
Jin Maruhashi, Volker Grewe, Christine Frömming, Patrick Jöckel, and Irene C. Dedoussi
Atmos. Chem. Phys., 22, 14253–14282, https://doi.org/10.5194/acp-22-14253-2022, https://doi.org/10.5194/acp-22-14253-2022, 2022
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Aviation NOx emissions lead to the formation of ozone in the atmosphere in the short term, which has a climate warming effect. This study uses global-scale simulations to characterize the transport patterns between NOx emissions at an altitude of ~ 10.4 km and the resulting ozone. Results show a strong spatial and temporal dependence of NOx in disturbing atmospheric O3 concentrations, with the location that is most impacted in terms of warming not necessarily coinciding with the emission region.
Johannes Pletzer, Didier Hauglustaine, Yann Cohen, Patrick Jöckel, and Volker Grewe
Atmos. Chem. Phys., 22, 14323–14354, https://doi.org/10.5194/acp-22-14323-2022, https://doi.org/10.5194/acp-22-14323-2022, 2022
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Very fast aircraft can travel long distances in extremely short times and can fly at high altitudes (15 to 35 km). These aircraft emit water vapour, nitrogen oxides, and hydrogen. Water vapour emissions remain for months to several years at these altitudes and have an important impact on temperature. We investigate two aircraft fleets flying at 26 and 35 km. Ozone is depleted more, and the water vapour perturbation and temperature change are larger for the aircraft flying at 35 km.
Marina Friedel, Gabriel Chiodo, Andrea Stenke, Daniela I. V. Domeisen, and Thomas Peter
Atmos. Chem. Phys., 22, 13997–14017, https://doi.org/10.5194/acp-22-13997-2022, https://doi.org/10.5194/acp-22-13997-2022, 2022
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In spring, winds the Arctic stratosphere change direction – an event called final stratospheric warming (FSW). Here, we examine whether the interannual variability in Arctic stratospheric ozone impacts the timing of the FSW. We find that Arctic ozone shifts the FSW to earlier and later dates in years with high and low ozone via the absorption of UV light. The modulation of the FSW by ozone has consequences for surface climate in ozone-rich years, which may result in better seasonal predictions.
Sarah A. Strode, Ghassan Taha, Luke D. Oman, Robert Damadeo, David Flittner, Mark Schoeberl, Christopher E. Sioris, and Ryan Stauffer
Atmos. Meas. Tech., 15, 6145–6161, https://doi.org/10.5194/amt-15-6145-2022, https://doi.org/10.5194/amt-15-6145-2022, 2022
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We use a global atmospheric chemistry model simulation to generate scaling factors that account for the daily cycle of NO2 and ozone. These factors facilitate comparisons between sunrise and sunset observations from SAGE III/ISS and observations from other instruments. We provide the scaling factors as monthly zonal means for different latitudes and altitudes. We find that applying these factors yields more consistent comparisons between observations from SAGE III/ISS and other instruments.
Kostas Eleftheratos, John Kapsomenakis, Ilias Fountoulakis, Christos S. Zerefos, Patrick Jöckel, Martin Dameris, Alkiviadis F. Bais, Germar Bernhard, Dimitra Kouklaki, Kleareti Tourpali, Scott Stierle, J. Ben Liley, Colette Brogniez, Frédérique Auriol, Henri Diémoz, Stana Simic, Irina Petropavlovskikh, Kaisa Lakkala, and Kostas Douvis
Atmos. Chem. Phys., 22, 12827–12855, https://doi.org/10.5194/acp-22-12827-2022, https://doi.org/10.5194/acp-22-12827-2022, 2022
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We present the future evolution of DNA-active ultraviolet (UV) radiation in view of increasing greenhouse gases (GHGs) and decreasing ozone depleting substances (ODSs). It is shown that DNA-active UV radiation might increase after 2050 between 50° N–50° S due to GHG-induced reductions in clouds and ozone, something that is likely not to happen at high latitudes, where DNA-active UV radiation will continue its downward trend mainly due to stratospheric ozone recovery from the reduction in ODSs.
Mengze Li, Andrea Pozzer, Jos Lelieveld, and Jonathan Williams
Earth Syst. Sci. Data, 14, 4351–4364, https://doi.org/10.5194/essd-14-4351-2022, https://doi.org/10.5194/essd-14-4351-2022, 2022
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We present a northern hemispheric airborne measurement dataset of atmospheric ethane, propane and methane and temporal trends for the time period 2006–2016 in the upper troposphere and lower stratosphere. The growth rates of ethane, methane, and propane in the upper troposphere are -2.24, 0.33, and -0.78 % yr-1, respectively, and in the lower stratosphere they are -3.27, 0.26, and -4.91 % yr-1, respectively, in 2006–2016.
Flossie Brown, Gerd A. Folberth, Stephen Sitch, Susanne Bauer, Marijn Bauters, Pascal Boeckx, Alexander W. Cheesman, Makoto Deushi, Inês Dos Santos Vieira, Corinne Galy-Lacaux, James Haywood, James Keeble, Lina M. Mercado, Fiona M. O'Connor, Naga Oshima, Kostas Tsigaridis, and Hans Verbeeck
Atmos. Chem. Phys., 22, 12331–12352, https://doi.org/10.5194/acp-22-12331-2022, https://doi.org/10.5194/acp-22-12331-2022, 2022
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Surface ozone can decrease plant productivity and impair human health. In this study, we evaluate the change in surface ozone due to climate change over South America and Africa using Earth system models. We find that if the climate were to change according to the worst-case scenario used here, models predict that forested areas in biomass burning locations and urban populations will be at increasing risk of ozone exposure, but other areas will experience a climate benefit.
Johannes Quaas, Hailing Jia, Chris Smith, Anna Lea Albright, Wenche Aas, Nicolas Bellouin, Olivier Boucher, Marie Doutriaux-Boucher, Piers M. Forster, Daniel Grosvenor, Stuart Jenkins, Zbigniew Klimont, Norman G. Loeb, Xiaoyan Ma, Vaishali Naik, Fabien Paulot, Philip Stier, Martin Wild, Gunnar Myhre, and Michael Schulz
Atmos. Chem. Phys., 22, 12221–12239, https://doi.org/10.5194/acp-22-12221-2022, https://doi.org/10.5194/acp-22-12221-2022, 2022
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Pollution particles cool climate and offset part of the global warming. However, they are washed out by rain and thus their effect responds quickly to changes in emissions. We show multiple datasets to demonstrate that aerosol emissions and their concentrations declined in many regions influenced by human emissions, as did the effects on clouds. Consequently, the cooling impact on the Earth energy budget became smaller. This change in trend implies a relative warming.
Qirui Zhong, Nick Schutgens, Guido van der Werf, Twan van Noije, Kostas Tsigaridis, Susanne E. Bauer, Tero Mielonen, Alf Kirkevåg, Øyvind Seland, Harri Kokkola, Ramiro Checa-Garcia, David Neubauer, Zak Kipling, Hitoshi Matsui, Paul Ginoux, Toshihiko Takemura, Philippe Le Sager, Samuel Rémy, Huisheng Bian, Mian Chin, Kai Zhang, Jialei Zhu, Svetlana G. Tsyro, Gabriele Curci, Anna Protonotariou, Ben Johnson, Joyce E. Penner, Nicolas Bellouin, Ragnhild B. Skeie, and Gunnar Myhre
Atmos. Chem. Phys., 22, 11009–11032, https://doi.org/10.5194/acp-22-11009-2022, https://doi.org/10.5194/acp-22-11009-2022, 2022
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Aerosol optical depth (AOD) errors for biomass burning aerosol (BBA) are evaluated in 18 global models against satellite datasets. Notwithstanding biases in satellite products, they allow model evaluations. We observe large and diverse model biases due to errors in BBA. Further interpretations of AOD diversities suggest large biases exist in key processes for BBA which require better constraining. These results can contribute to further model improvement and development.
Ilann Bourgeois, Jeff Peischl, J. Andrew Neuman, Steven S. Brown, Hannah M. Allen, Pedro Campuzano-Jost, Matthew M. Coggon, Joshua P. DiGangi, Glenn S. Diskin, Jessica B. Gilman, Georgios I. Gkatzelis, Hongyu Guo, Hannah A. Halliday, Thomas F. Hanisco, Christopher D. Holmes, L. Gregory Huey, Jose L. Jimenez, Aaron D. Lamplugh, Young Ro Lee, Jakob Lindaas, Richard H. Moore, Benjamin A. Nault, John B. Nowak, Demetrios Pagonis, Pamela S. Rickly, Michael A. Robinson, Andrew W. Rollins, Vanessa Selimovic, Jason M. St. Clair, David Tanner, Krystal T. Vasquez, Patrick R. Veres, Carsten Warneke, Paul O. Wennberg, Rebecca A. Washenfelder, Elizabeth B. Wiggins, Caroline C. Womack, Lu Xu, Kyle J. Zarzana, and Thomas B. Ryerson
Atmos. Meas. Tech., 15, 4901–4930, https://doi.org/10.5194/amt-15-4901-2022, https://doi.org/10.5194/amt-15-4901-2022, 2022
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Understanding fire emission impacts on the atmosphere is key to effective air quality management and requires accurate measurements. We present a comparison of airborne measurements of key atmospheric species in ambient air and in fire smoke. We show that most instruments performed within instrument uncertainties. In some cases, further work is needed to fully characterize instrument performance. Comparing independent measurements using different techniques is important to assess their accuracy.
Mari R. Tye, Katherine Dagon, Maria J. Molina, Jadwiga H. Richter, Daniele Visioni, Ben Kravitz, and Simone Tilmes
Earth Syst. Dynam., 13, 1233–1257, https://doi.org/10.5194/esd-13-1233-2022, https://doi.org/10.5194/esd-13-1233-2022, 2022
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We examined the potential effect of stratospheric aerosol injection (SAI) on extreme temperature and precipitation. SAI may cause daytime temperatures to cool but nighttime to warm. Daytime cooling may occur in all seasons across the globe, with the largest decreases in summer. In contrast, nighttime warming may be greatest at high latitudes in winter. SAI may reduce the frequency and intensity of extreme rainfall. The combined changes may exacerbate drying over parts of the global south.
Simon F. Reifenberg, Anna Martin, Matthias Kohl, Sara Bacer, Zaneta Hamryszczak, Ivan Tadic, Lenard Röder, Daniel J. Crowley, Horst Fischer, Katharina Kaiser, Johannes Schneider, Raphael Dörich, John N. Crowley, Laura Tomsche, Andreas Marsing, Christiane Voigt, Andreas Zahn, Christopher Pöhlker, Bruna A. Holanda, Ovid Krüger, Ulrich Pöschl, Mira Pöhlker, Patrick Jöckel, Marcel Dorf, Ulrich Schumann, Jonathan Williams, Birger Bohn, Joachim Curtius, Hardwig Harder, Hans Schlager, Jos Lelieveld, and Andrea Pozzer
Atmos. Chem. Phys., 22, 10901–10917, https://doi.org/10.5194/acp-22-10901-2022, https://doi.org/10.5194/acp-22-10901-2022, 2022
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In this work we use a combination of observational data from an aircraft campaign and model results to investigate the effect of the European lockdown due to COVID-19 in spring 2020. Using model results, we show that the largest relative changes to the atmospheric composition caused by the reduced emissions are located in the upper troposphere around aircraft cruise altitude, while the largest absolute changes are present at the surface.
Daniel C. Anderson, Melanie B. Follette-Cook, Sarah A. Strode, Julie M. Nicely, Junhua Liu, Peter D. Ivatt, and Bryan N. Duncan
Geosci. Model Dev., 15, 6341–6358, https://doi.org/10.5194/gmd-15-6341-2022, https://doi.org/10.5194/gmd-15-6341-2022, 2022
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The hydroxyl radical (OH) is the most important chemical in the atmosphere for removing certain pollutants, including methane, the second-most-important greenhouse gas. We present a methodology to create an easily modifiable parameterization that can calculate OH concentrations in a computationally efficient way. The parameterization, which predicts OH within 5 %, can be integrated into larger climate models to allow for calculation of the interactions between OH, methane, and other chemicals.
Zaneta T. Hamryszczak, Andrea Pozzer, Florian Obersteiner, Birger Bohn, Benedikt Steil, Jos Lelieveld, and Horst Fischer
Atmos. Chem. Phys., 22, 9483–9497, https://doi.org/10.5194/acp-22-9483-2022, https://doi.org/10.5194/acp-22-9483-2022, 2022
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Hydrogen peroxide plays a pivotal role in the chemistry of the atmosphere. Together with organic hydroperoxides, it forms a reservoir for peroxy radicals, which are known to be the key contributors to the self-cleaning processes of the atmosphere. Hydroperoxides were measured over Europe during the BLUESKY campaign in May–June 2020. The paper gives an overview of the distribution of the species in the troposphere and investigates the impact of wet scavenging and deposition on the budget of H2O2.
Ovid O. Krüger, Bruna A. Holanda, Sourangsu Chowdhury, Andrea Pozzer, David Walter, Christopher Pöhlker, Maria Dolores Andrés Hernández, John P. Burrows, Christiane Voigt, Jos Lelieveld, Johannes Quaas, Ulrich Pöschl, and Mira L. Pöhlker
Atmos. Chem. Phys., 22, 8683–8699, https://doi.org/10.5194/acp-22-8683-2022, https://doi.org/10.5194/acp-22-8683-2022, 2022
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The abrupt reduction in human activities during the first COVID-19 lockdown created unprecedented atmospheric conditions. We took the opportunity to quantify changes in black carbon (BC) as a major anthropogenic air pollutant. Therefore, we measured BC on board a research aircraft over Europe during the lockdown and compared the results to measurements from 2017. With model simulations we account for different weather conditions and find a lockdown-related decrease in BC of 41 %.
Adrien Guyot, Alain Protat, Simon P. Alexander, Andrew R. Klekociuk, Peter Kuma, and Adrian McDonald
Atmos. Meas. Tech., 15, 3663–3681, https://doi.org/10.5194/amt-15-3663-2022, https://doi.org/10.5194/amt-15-3663-2022, 2022
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Ceilometers are instruments that are widely deployed as part of operational networks. They are usually not able to detect cloud phase. Here, we propose an evaluation of various methods to detect supercooled liquid water with ceilometer observations, using an extensive dataset from Davis, Antarctica. Our results highlight the possibility for ceilometers to detect supercooled liquid water in clouds.
Jason E. Williams, Vincent Huijnen, Idir Bouarar, Mehdi Meziane, Timo Schreurs, Sophie Pelletier, Virginie Marécal, Beatrice Josse, and Johannes Flemming
Geosci. Model Dev., 15, 4657–4687, https://doi.org/10.5194/gmd-15-4657-2022, https://doi.org/10.5194/gmd-15-4657-2022, 2022
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The global CAMS air quality model is used for providing tropospheric ozone information to end users. This paper updates the chemical mechanism employed (CBA) and compares it against two other mechanisms (MOCAGE, MOZART) and a multi-decadal dataset based on a previous version of CBA. We perform extensive validation for the US using multiple surface and aircraft datasets, providing an assessment of biases and the extent of correlation across different seasons during 2014.
Francisco J. Pérez-Invernón, Heidi Huntrieser, Thilo Erbertseder, Diego Loyola, Pieter Valks, Song Liu, Dale J. Allen, Kenneth E. Pickering, Eric J. Bucsela, Patrick Jöckel, Jos van Geffen, Henk Eskes, Sergio Soler, Francisco J. Gordillo-Vázquez, and Jeff Lapierre
Atmos. Meas. Tech., 15, 3329–3351, https://doi.org/10.5194/amt-15-3329-2022, https://doi.org/10.5194/amt-15-3329-2022, 2022
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Lightning, one of the major sources of nitrogen oxides in the atmosphere, contributes to the tropospheric concentration of ozone and to the oxidizing capacity of the atmosphere. In this work, we contribute to improving the estimation of lightning-produced nitrogen oxides in the Ebro Valley and the Pyrenees by using two different TROPOMI products and comparing the results.
Alex R. Aves, Laura E. Revell, Sally Gaw, Helena Ruffell, Alex Schuddeboom, Ngaire E. Wotherspoon, Michelle LaRue, and Adrian J. McDonald
The Cryosphere, 16, 2127–2145, https://doi.org/10.5194/tc-16-2127-2022, https://doi.org/10.5194/tc-16-2127-2022, 2022
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This study confirms the presence of microplastics in Antarctic snow, highlighting the extent of plastic pollution globally. Fresh snow was collected from Ross Island, Antarctica, and subsequent analysis identified an average of 29 microplastic particles per litre of melted snow. The most likely source of these airborne microplastics is local scientific research stations; however, modelling shows their origin could have been up to 6000 km away.
Tianlang Zhao, Jingqiu Mao, William R. Simpson, Isabelle De Smedt, Lei Zhu, Thomas F. Hanisco, Glenn M. Wolfe, Jason M. St. Clair, Gonzalo González Abad, Caroline R. Nowlan, Barbara Barletta, Simone Meinardi, Donald R. Blake, Eric C. Apel, and Rebecca S. Hornbrook
Atmos. Chem. Phys., 22, 7163–7178, https://doi.org/10.5194/acp-22-7163-2022, https://doi.org/10.5194/acp-22-7163-2022, 2022
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Monitoring formaldehyde (HCHO) can help us understand Arctic vegetation change. Here, we compare satellite data and model and show that Alaska summertime HCHO is largely dominated by a background from methane oxidation during mild wildfire years and is dominated by wildfire (largely from direct emission of fire) during strong fire years. Consequently, it is challenging to use satellite HCHO to study vegetation change in the Arctic region.
Irina Mironova, Miriam Sinnhuber, Galina Bazilevskaya, Mark Clilverd, Bernd Funke, Vladimir Makhmutov, Eugene Rozanov, Michelle L. Santee, Timofei Sukhodolov, and Thomas Ulich
Atmos. Chem. Phys., 22, 6703–6716, https://doi.org/10.5194/acp-22-6703-2022, https://doi.org/10.5194/acp-22-6703-2022, 2022
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From balloon measurements, we detected unprecedented, extremely powerful, electron precipitation over the middle latitudes. The robustness of this event is confirmed by satellite observations of electron fluxes and chemical composition, as well as by ground-based observations of the radio signal propagation. The applied chemistry–climate model shows the almost complete destruction of ozone in the mesosphere over the region where high-energy electrons were observed.
Dimitris Akritidis, Andrea Pozzer, Johannes Flemming, Antje Inness, Philippe Nédélec, and Prodromos Zanis
Atmos. Chem. Phys., 22, 6275–6289, https://doi.org/10.5194/acp-22-6275-2022, https://doi.org/10.5194/acp-22-6275-2022, 2022
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We perform a process-oriented evaluation of Copernicus Atmosphere Monitoring Service (CAMS) reanalysis (CAMSRA) O3 over Europe using WOUDC (World Ozone and Ultraviolet Radiation Data Centre) ozonesondes and IAGOS (In-service Aircraft for a Global Observing System) aircraft measurements. Chemical data assimilation assists CAMSRA to reproduce the observed O3 increases in the troposphere during the examined folding events, but it mostly results in O3 overestimation in the upper troposphere.
Clara M. Nussbaumer, Andrea Pozzer, Ivan Tadic, Lenard Röder, Florian Obersteiner, Hartwig Harder, Jos Lelieveld, and Horst Fischer
Atmos. Chem. Phys., 22, 6151–6165, https://doi.org/10.5194/acp-22-6151-2022, https://doi.org/10.5194/acp-22-6151-2022, 2022
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The European COVID-19 lockdowns have significantly reduced the emission of primary pollutants such as NOx, which impacts the tropospheric photochemical processes and the abundance of O3. In this study, we present how the lockdowns have affected tropospheric trace gases and ozone production based on in situ observations and modeling simulations. We additionally show that the chemical regime shifted from a transition point to a NOx limitation in the upper troposphere.
M. Dolores Andrés Hernández, Andreas Hilboll, Helmut Ziereis, Eric Förster, Ovid O. Krüger, Katharina Kaiser, Johannes Schneider, Francesca Barnaba, Mihalis Vrekoussis, Jörg Schmidt, Heidi Huntrieser, Anne-Marlene Blechschmidt, Midhun George, Vladyslav Nenakhov, Theresa Harlass, Bruna A. Holanda, Jennifer Wolf, Lisa Eirenschmalz, Marc Krebsbach, Mira L. Pöhlker, Anna B. Kalisz Hedegaard, Linlu Mei, Klaus Pfeilsticker, Yangzhuoran Liu, Ralf Koppmann, Hans Schlager, Birger Bohn, Ulrich Schumann, Andreas Richter, Benjamin Schreiner, Daniel Sauer, Robert Baumann, Mariano Mertens, Patrick Jöckel, Markus Kilian, Greta Stratmann, Christopher Pöhlker, Monica Campanelli, Marco Pandolfi, Michael Sicard, José L. Gómez-Amo, Manuel Pujadas, Katja Bigge, Flora Kluge, Anja Schwarz, Nikos Daskalakis, David Walter, Andreas Zahn, Ulrich Pöschl, Harald Bönisch, Stephan Borrmann, Ulrich Platt, and John P. Burrows
Atmos. Chem. Phys., 22, 5877–5924, https://doi.org/10.5194/acp-22-5877-2022, https://doi.org/10.5194/acp-22-5877-2022, 2022
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EMeRGe provides a unique set of in situ and remote sensing airborne measurements of trace gases and aerosol particles along selected flight routes in the lower troposphere over Europe. The interpretation uses also complementary collocated ground-based and satellite measurements. The collected data help to improve the current understanding of the complex spatial distribution of trace gases and aerosol particles resulting from mixing, transport, and transformation of pollution plumes over Europe.
Ilaria Quaglia, Daniele Visioni, Giovanni Pitari, and Ben Kravitz
Atmos. Chem. Phys., 22, 5757–5773, https://doi.org/10.5194/acp-22-5757-2022, https://doi.org/10.5194/acp-22-5757-2022, 2022
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Carbonyl sulfide is a gas that mixes very well in the atmosphere and can reach the stratosphere, where it reacts with sunlight and produces aerosol. Here we propose that, by increasing surface fluxes by an order of magnitude, the number of stratospheric aerosols produced may be enough to partially offset the warming produced by greenhouse gases. We explore what effect this would have on the atmospheric composition.
Wenyu Sun, Matias Berasategui, Andrea Pozzer, Jos Lelieveld, and John N. Crowley
Atmos. Chem. Phys., 22, 4969–4984, https://doi.org/10.5194/acp-22-4969-2022, https://doi.org/10.5194/acp-22-4969-2022, 2022
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The reaction between OH and SO2 is a termolecular process that in the atmosphere results in the formation of H2SO4 and thus aerosols. We present the first temperature- and pressure-dependent measurements of the rate coefficients in N2. This is also the first study to examine the effects of water vapour on the kinetics of this reaction. Our results indicate the rate coefficient is larger than that recommended by evaluation panels, with deviations of up to 30 % in some parts of the atmosphere.
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.
Simone Tilmes, Daniele Visioni, Andy Jones, James Haywood, Roland Séférian, Pierre Nabat, Olivier Boucher, Ewa Monica Bednarz, and Ulrike Niemeier
Atmos. Chem. Phys., 22, 4557–4579, https://doi.org/10.5194/acp-22-4557-2022, https://doi.org/10.5194/acp-22-4557-2022, 2022
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This study assesses the impacts of climate interventions, using stratospheric sulfate aerosol and solar dimming on stratospheric ozone, based on three Earth system models with interactive stratospheric chemistry. The climate interventions have been applied to a high emission (baseline) scenario in order to reach global surface temperatures of a medium emission scenario. We find significant increases and decreases in total column ozone, depending on regions and seasons.
Mathew Sebastian, Sobhan Kumar Kompalli, Vasudevan Anil Kumar, Sandhya Jose, S. Suresh Babu, Govindan Pandithurai, Sachchidanand Singh, Rakesh K. Hooda, Vijay K. Soni, Jeffrey R. Pierce, Ville Vakkari, Eija Asmi, Daniel M. Westervelt, Antti-Pekka Hyvärinen, and Vijay P. Kanawade
Atmos. Chem. Phys., 22, 4491–4508, https://doi.org/10.5194/acp-22-4491-2022, https://doi.org/10.5194/acp-22-4491-2022, 2022
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Characteristics of particle number size distributions and new particle formation in six locations in India were analyzed. New particle formation occurred frequently during the pre-monsoon (spring) season and it significantly modulates the shape of the particle number size distributions. The contribution of newly formed particles to cloud condensation nuclei concentrations was ~3 times higher in urban locations than in mountain background locations.
Glenn M. Wolfe, Thomas F. Hanisco, Heather L. Arkinson, Donald R. Blake, Armin Wisthaler, Tomas Mikoviny, Thomas B. Ryerson, Ilana Pollack, Jeff Peischl, Paul O. Wennberg, John D. Crounse, Jason M. St. Clair, Alex Teng, L. Gregory Huey, Xiaoxi Liu, Alan Fried, Petter Weibring, Dirk Richter, James Walega, Samuel R. Hall, Kirk Ullmann, Jose L. Jimenez, Pedro Campuzano-Jost, T. Paul Bui, Glenn Diskin, James R. Podolske, Glen Sachse, and Ronald C. Cohen
Atmos. Chem. Phys., 22, 4253–4275, https://doi.org/10.5194/acp-22-4253-2022, https://doi.org/10.5194/acp-22-4253-2022, 2022
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Smoke plumes are chemically complex. This work combines airborne observations of smoke plume composition with a photochemical model to probe the production of ozone and the fate of reactive gases in the outflow of a large wildfire. Model–measurement comparisons illustrate how uncertain emissions and chemical processes propagate into simulated chemical evolution. Results provide insight into how this system responds to perturbations, which can help guide future observation and modeling efforts.
Andrea Pozzer, Simon F. Reifenberg, Vinod Kumar, Bruno Franco, Matthias Kohl, Domenico Taraborrelli, Sergey Gromov, Sebastian Ehrhart, Patrick Jöckel, Rolf Sander, Veronica Fall, Simon Rosanka, Vlassis Karydis, Dimitris Akritidis, Tamara Emmerichs, Monica Crippa, Diego Guizzardi, Johannes W. Kaiser, Lieven Clarisse, Astrid Kiendler-Scharr, Holger Tost, and Alexandra Tsimpidi
Geosci. Model Dev., 15, 2673–2710, https://doi.org/10.5194/gmd-15-2673-2022, https://doi.org/10.5194/gmd-15-2673-2022, 2022
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A newly developed setup of the chemistry general circulation model EMAC (ECHAM5/MESSy for Atmospheric Chemistry) is evaluated here. A comprehensive organic degradation mechanism is used and coupled with a volatility base model.
The results show that the model reproduces most of the tracers and aerosols satisfactorily but shows discrepancies for oxygenated organic gases. It is also shown that this model configuration can be used for further research in atmospheric chemistry.
Irina Petropavlovskikh, Koji Miyagawa, Audra McClure-Beegle, Bryan Johnson, Jeannette Wild, Susan Strahan, Krzysztof Wargan, Richard Querel, Lawrence Flynn, Eric Beach, Gerard Ancellet, and Sophie Godin-Beekmann
Atmos. Meas. Tech., 15, 1849–1870, https://doi.org/10.5194/amt-15-1849-2022, https://doi.org/10.5194/amt-15-1849-2022, 2022
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The Montreal Protocol and its amendments assure the recovery of the stratospheric ozone layer that protects the Earth from harmful ultraviolet radiation. To monitor ozone recovery, multiple satellites and ground-based observational platforms collect ozone data. The changes in instruments can influence the continuation of the ozone data. We discuss a method to remove instrumental artifacts from ozone records to improve the internal consistency among multiple observational records.
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
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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.
Andy Jones, Jim M. Haywood, Adam A. Scaife, Olivier Boucher, Matthew Henry, Ben Kravitz, Thibaut Lurton, Pierre Nabat, Ulrike Niemeier, Roland Séférian, Simone Tilmes, and Daniele Visioni
Atmos. Chem. Phys., 22, 2999–3016, https://doi.org/10.5194/acp-22-2999-2022, https://doi.org/10.5194/acp-22-2999-2022, 2022
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Simulations by six Earth-system models of geoengineering by introducing sulfuric acid aerosols into the tropical stratosphere are compared. A robust impact on the northern wintertime North Atlantic Oscillation is found, exacerbating precipitation reduction over parts of southern Europe. In contrast, the models show no consistency with regard to impacts on the Quasi-Biennial Oscillation, although results do indicate a risk that the oscillation could become locked into a permanent westerly phase.
Francisco J. Pérez-Invernón, Heidi Huntrieser, Patrick Jöckel, and Francisco J. Gordillo-Vázquez
Geosci. Model Dev., 15, 1545–1565, https://doi.org/10.5194/gmd-15-1545-2022, https://doi.org/10.5194/gmd-15-1545-2022, 2022
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This study reports the first parameterization of long-continuing-current lightning in a climate model. Long-continuing-current lightning is proposed to be the main precursor of lightning-ignited wildfires and sprites, a type of transient luminous event taking place in the mesosphere. This parameterization can significantly contribute to improving the implementation of wildfires in climate models.
Matthias Schneider, Benjamin Ertl, Christopher J. Diekmann, Farahnaz Khosrawi, Andreas Weber, Frank Hase, Michael Höpfner, Omaira E. García, Eliezer Sepúlveda, and Douglas Kinnison
Earth Syst. Sci. Data, 14, 709–742, https://doi.org/10.5194/essd-14-709-2022, https://doi.org/10.5194/essd-14-709-2022, 2022
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We present atmospheric H2O, HDO / H2O ratio, N2O, CH4, and HNO3 data generated by the MUSICA IASI processor using thermal nadir spectra measured by the IASI satellite instrument. The data have global daily coverage and are available for the period between October 2014 and June 2021. Multiple possibilities of data reuse are offered by providing each individual data product together with information about retrieval settings and the products' uncertainty and vertical representativeness.
Daniele Visioni, Simone Tilmes, Charles Bardeen, Michael Mills, Douglas G. MacMartin, Ben Kravitz, and Jadwiga H. Richter
Atmos. Chem. Phys., 22, 1739–1756, https://doi.org/10.5194/acp-22-1739-2022, https://doi.org/10.5194/acp-22-1739-2022, 2022
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Aerosols are simulated in a simplified way in climate models: in the model analyzed here, they are represented in every grid as described by three simple logarithmic distributions, mixing all different species together. The size can evolve when new particles are formed, particles merge together to create a larger one or particles are deposited to the surface. This approximation normally works fairly well. Here we show however that when large amounts of sulfate are simulated, there are problems.
Abhinna K. Behera, Emmanuel D. Rivière, Sergey M. Khaykin, Virginie Marécal, Mélanie Ghysels, Jérémie Burgalat, and Gerhard Held
Atmos. Chem. Phys., 22, 881–901, https://doi.org/10.5194/acp-22-881-2022, https://doi.org/10.5194/acp-22-881-2022, 2022
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Deep convection overshooting the stratosphere's contribution to the global stratospheric water budget is still being quantified. We ran three different cloud-resolving simulations of an observed case of overshoots in Bauru during the TRO-Pico balloon campaign in the context of upscaling the impact of overshoots at a large scale. These simulations, which have been validated with balloon-borne and S-band radar measurements, shed light on the local-scale variability and composition of overshoots.
Nicholas A. Davis, Patrick Callaghan, Isla R. Simpson, and Simone Tilmes
Atmos. Chem. Phys., 22, 197–214, https://doi.org/10.5194/acp-22-197-2022, https://doi.org/10.5194/acp-22-197-2022, 2022
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Specified dynamics schemes attempt to constrain the atmospheric circulation in a climate model to isolate the role of transport in chemical variability, evaluate model physics, and interpret field campaign observations. We show that the specified dynamics scheme in CESM2 erroneously suppresses convection and induces circulation errors that project onto errors in tracers, even using the most optimal settings. Development of a more sophisticated scheme is necessary for future progress.
Anton Laakso, Ulrike Niemeier, Daniele Visioni, Simone Tilmes, and Harri Kokkola
Atmos. Chem. Phys., 22, 93–118, https://doi.org/10.5194/acp-22-93-2022, https://doi.org/10.5194/acp-22-93-2022, 2022
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The use of different spatio-temporal sulfur injection strategies with different magnitudes to create an artificial reflective aerosol layer to cool the climate is studied using sectional and modal aerosol schemes in a climate model. There are significant differences in the results depending on the aerosol microphysical module used. Different spatio-temporal injection strategies have a significant impact on the magnitude and zonal distribution of radiative forcing and atmospheric dynamics.
Guangjie Zheng, Hang Su, Siwen Wang, Andrea Pozzer, and Yafang Cheng
Atmos. Chem. Phys., 22, 47–63, https://doi.org/10.5194/acp-22-47-2022, https://doi.org/10.5194/acp-22-47-2022, 2022
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The recently proposed multiphase buffer theory provides a framework to reconstruct long-term trends and spatial variations in aerosol pH, while non-ideality is a major limitation for its broad applications. Here we proposed a parameterization method to estimate the impact of non-ideality and validated it against long-term observations and global simulations. With this method, the multiphase buffer theory can reproduce well aerosol pH variations estimated by comprehensive thermodynamic models.
Jin Liao, Glenn M. Wolfe, Reem A. Hannun, Jason M. St. Clair, Thomas F. Hanisco, Jessica B. Gilman, Aaron Lamplugh, Vanessa Selimovic, Glenn S. Diskin, John B. Nowak, Hannah S. Halliday, Joshua P. DiGangi, Samuel R. Hall, Kirk Ullmann, Christopher D. Holmes, Charles H. Fite, Anxhelo Agastra, Thomas B. Ryerson, Jeff Peischl, Ilann Bourgeois, Carsten Warneke, Matthew M. Coggon, Georgios I. Gkatzelis, Kanako Sekimoto, Alan Fried, Dirk Richter, Petter Weibring, Eric C. Apel, Rebecca S. Hornbrook, Steven S. Brown, Caroline C. Womack, Michael A. Robinson, Rebecca A. Washenfelder, Patrick R. Veres, and J. Andrew Neuman
Atmos. Chem. Phys., 21, 18319–18331, https://doi.org/10.5194/acp-21-18319-2021, https://doi.org/10.5194/acp-21-18319-2021, 2021
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Formaldehyde (HCHO) is an important oxidant precursor and affects the formation of O3 and other secondary pollutants in wildfire plumes. We disentangle the processes controlling HCHO evolution from wildfire plumes sampled by NASA DC-8 during FIREX-AQ. We find that OH abundance rather than normalized OH reactivity is the main driver of fire-to-fire variability in HCHO secondary production and estimate an effective HCHO yield per volatile organic compound molecule oxidized in wildfire plumes.
Kseniia Golubenko, Eugene Rozanov, Gennady Kovaltsov, Ari-Pekka Leppänen, Timofei Sukhodolov, and Ilya Usoskin
Geosci. Model Dev., 14, 7605–7620, https://doi.org/10.5194/gmd-14-7605-2021, https://doi.org/10.5194/gmd-14-7605-2021, 2021
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A new full 3-D time-dependent model, based on SOCOL-AERv2, of beryllium atmospheric production, transport, and deposition has been developed and validated using directly measured data. The model is recommended to be used in studies related to, e.g., atmospheric dynamical patterns, extreme solar particle storms, long-term solar activity reconstruction from cosmogenic proxy data, and solar–terrestrial relations.
Matthieu Plu, Guillaume Bigeard, Bojan Sič, Emanuele Emili, Luca Bugliaro, Laaziz El Amraoui, Jonathan Guth, Beatrice Josse, Lucia Mona, and Dennis Piontek
Nat. Hazards Earth Syst. Sci., 21, 3731–3747, https://doi.org/10.5194/nhess-21-3731-2021, https://doi.org/10.5194/nhess-21-3731-2021, 2021
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Volcanic eruptions that spread out ash over large areas, like Eyjafjallajökull in 2010, may have huge economic consequences due to flight cancellations. In this article, we demonstrate the benefits of source term improvement and of data assimilation for quantifying volcanic ash concentrations. The work, which was supported by the EUNADICS-AV project, is the first one, to our knowledge, that demonstrates the benefit of the assimilation of ground-based lidar data over Europe during an eruption.
Paul D. Hamer, Virginie Marécal, Ryan Hossaini, Michel Pirre, Gisèle Krysztofiak, Franziska Ziska, Andreas Engel, Stephan Sala, Timo Keber, Harald Bönisch, Elliot Atlas, Kirstin Krüger, Martyn Chipperfield, Valery Catoire, Azizan A. Samah, Marcel Dorf, Phang Siew Moi, Hans Schlager, and Klaus Pfeilsticker
Atmos. Chem. Phys., 21, 16955–16984, https://doi.org/10.5194/acp-21-16955-2021, https://doi.org/10.5194/acp-21-16955-2021, 2021
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Bromoform is a stratospheric ozone-depleting gas released by seaweed and plankton transported to the stratosphere via convection in the tropics. We study the chemical interactions of bromoform and its derivatives within convective clouds using a cloud-scale model and observations. Our findings are that soluble bromine gases are efficiently washed out and removed within the convective clouds and that most bromine is transported vertically to the upper troposphere in the form of bromoform.
Alexander D. Fraser, Robert A. Massom, Mark S. Handcock, Phillip Reid, Kay I. Ohshima, Marilyn N. Raphael, Jessica Cartwright, Andrew R. Klekociuk, Zhaohui Wang, and Richard Porter-Smith
The Cryosphere, 15, 5061–5077, https://doi.org/10.5194/tc-15-5061-2021, https://doi.org/10.5194/tc-15-5061-2021, 2021
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Landfast ice is sea ice that remains stationary by attaching to Antarctica's coastline and grounded icebergs. Although a variable feature, landfast ice exerts influence on key coastal processes involving pack ice, the ice sheet, ocean, and atmosphere and is of ecological importance. We present a first analysis of change in landfast ice over an 18-year period and quantify trends (−0.19 ± 0.18 % yr−1). This analysis forms a reference of landfast-ice extent and variability for use in other studies.
Arseniy Karagodin-Doyennel, Eugene Rozanov, Timofei Sukhodolov, Tatiana Egorova, Alfonso Saiz-Lopez, Carlos A. Cuevas, Rafael P. Fernandez, Tomás Sherwen, Rainer Volkamer, Theodore K. Koenig, Tanguy Giroud, and Thomas Peter
Geosci. Model Dev., 14, 6623–6645, https://doi.org/10.5194/gmd-14-6623-2021, https://doi.org/10.5194/gmd-14-6623-2021, 2021
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Here, we present the iodine chemistry module in the SOCOL-AERv2 model. The obtained iodine distribution demonstrated a good agreement when validated against other simulations and available observations. We also estimated the iodine influence on ozone in the case of present-day iodine emissions, the sensitivity of ozone to doubled iodine emissions, and when considering only organic or inorganic iodine sources. The new model can be used as a tool for further studies of iodine effects on ozone.
Maria Sand, Bjørn H. Samset, Gunnar Myhre, Jonas Gliß, Susanne E. Bauer, Huisheng Bian, Mian Chin, Ramiro Checa-Garcia, Paul Ginoux, Zak Kipling, Alf Kirkevåg, Harri Kokkola, Philippe Le Sager, Marianne T. Lund, Hitoshi Matsui, Twan van Noije, Dirk J. L. Olivié, Samuel Remy, Michael Schulz, Philip Stier, Camilla W. Stjern, Toshihiko Takemura, Kostas Tsigaridis, Svetlana G. Tsyro, and Duncan Watson-Parris
Atmos. Chem. Phys., 21, 15929–15947, https://doi.org/10.5194/acp-21-15929-2021, https://doi.org/10.5194/acp-21-15929-2021, 2021
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Absorption of shortwave radiation by aerosols can modify precipitation and clouds but is poorly constrained in models. A total of 15 different aerosol models from AeroCom phase III have reported total aerosol absorption, and for the first time, 11 of these models have reported in a consistent experiment the contributions to absorption from black carbon, dust, and organic aerosol. Here, we document the model diversity in aerosol absorption.
Catherine Wilka, Susan Solomon, Doug Kinnison, and David Tarasick
Atmos. Chem. Phys., 21, 15771–15781, https://doi.org/10.5194/acp-21-15771-2021, https://doi.org/10.5194/acp-21-15771-2021, 2021
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We use satellite and balloon measurements to evaluate modeled ozone loss seen in the unusually cold Arctic of 2020 in the real world and compare it to simulations of a world avoided. We show that extensive denitrification in 2020 provides an important test case for stratospheric model process representations. If the Montreal Protocol had not banned ozone-depleting substances, an Arctic ozone hole would have emerged for the first time in spring 2020 that is comparable to those in the Antarctic.
Vlassis A. Karydis, Alexandra P. Tsimpidi, Andrea Pozzer, and Jos Lelieveld
Atmos. Chem. Phys., 21, 14983–15001, https://doi.org/10.5194/acp-21-14983-2021, https://doi.org/10.5194/acp-21-14983-2021, 2021
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Aerosol particle pH is well-buffered by alkaline compounds, notably NH3 and crustal elements. NH3 is found to supply remarkable buffering capacity on a global scale, from the polluted continents to the remote oceans. Potential future changes in agricultural NH3 must be accompanied by strong reductions of SO2 and NOx to avoid particles becoming highly acidic, with implications for human health (aerosol toxicity), ecosystems (acid deposition), clouds, and climate (aerosol hygroscopicity).
Liam Bindle, Randall V. Martin, Matthew J. Cooper, Elizabeth W. Lundgren, Sebastian D. Eastham, Benjamin M. Auer, Thomas L. Clune, Hongjian Weng, Jintai Lin, Lee T. Murray, Jun Meng, Christoph A. Keller, William M. Putman, Steven Pawson, and Daniel J. Jacob
Geosci. Model Dev., 14, 5977–5997, https://doi.org/10.5194/gmd-14-5977-2021, https://doi.org/10.5194/gmd-14-5977-2021, 2021
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Atmospheric chemistry models like GEOS-Chem are versatile tools widely used in air pollution and climate studies. The simulations used in such studies can be very computationally demanding, and thus it is useful if the model can simulate a specific geographic region at a higher resolution than the rest of the globe. Here, we implement, test, and demonstrate a new variable-resolution capability in GEOS-Chem that is suitable for simulations conducted on supercomputers.
Jerald R. Ziemke, Gordon J. Labow, Natalya A. Kramarova, Richard D. McPeters, Pawan K. Bhartia, Luke D. Oman, Stacey M. Frith, and David P. Haffner
Atmos. Meas. Tech., 14, 6407–6418, https://doi.org/10.5194/amt-14-6407-2021, https://doi.org/10.5194/amt-14-6407-2021, 2021
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Seasonal and interannual ozone profile climatologies are produced from combined MLS and MERRA-2 GMI ozone for the general public. Both climatologies extend from pole to pole at altitudes of 0–80 km (1 km spacing) for the time record from 1970 to 2018. These climatologies are important for use as a priori information in satellite ozone retrieval algorithms, as validation of other measured and model-simulated ozone, and in radiative transfer studies of the atmosphere.
Andrea Pozzer
Geosci. Commun., 4, 453–460, https://doi.org/10.5194/gc-4-453-2021, https://doi.org/10.5194/gc-4-453-2021, 2021
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In this paper we investigate the numbers of pages, references and references per page in open-access EGU journals. We showed that, while the number of references and number of pages have been constantly increasing in the period 2010–2020, the number of references per page did not change in the same period. Furthermore, all the journals showed a similar number of references per page, i.e. ~ 3.8 references per page.
Philipp G. Eger, Luc Vereecken, Rolf Sander, Jan Schuladen, Nicolas Sobanski, Horst Fischer, Einar Karu, Jonathan Williams, Ville Vakkari, Tuukka Petäjä, Jos Lelieveld, Andrea Pozzer, and John N. Crowley
Atmos. Chem. Phys., 21, 14333–14349, https://doi.org/10.5194/acp-21-14333-2021, https://doi.org/10.5194/acp-21-14333-2021, 2021
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We determine the impact of pyruvic acid photolysis on the formation of acetaldehyde and peroxy radicals during summer and autumn in the Finnish boreal forest using a data-constrained box model. Our results are dependent on the chosen scenario in which the overall quantum yield and the photolysis products are varied. We highlight that pyruvic acid photolysis can be an important contributor to acetaldehyde and peroxy radical formation in remote, forested regions.
Huisheng Bian, Eunjee Lee, Randal D. Koster, Donifan Barahona, Mian Chin, Peter R. Colarco, Anton Darmenov, Sarith Mahanama, Michael Manyin, Peter Norris, John Shilling, Hongbin Yu, and Fanwei Zeng
Atmos. Chem. Phys., 21, 14177–14197, https://doi.org/10.5194/acp-21-14177-2021, https://doi.org/10.5194/acp-21-14177-2021, 2021
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The study using the NASA Earth system model shows ~2.6 % increase in burning season gross primary production and ~1.5 % increase in annual net primary production across the Amazon Basin during 2010–2016 due to the change in surface downward direct and diffuse photosynthetically active radiation by biomass burning aerosols. Such an aerosol effect is strongly dependent on the presence of clouds. The cloud fraction at which aerosols switch from stimulating to inhibiting plant growth occurs at ~0.8.
Lee T. Murray, Eric M. Leibensperger, Clara Orbe, Loretta J. Mickley, and Melissa Sulprizio
Geosci. Model Dev., 14, 5789–5823, https://doi.org/10.5194/gmd-14-5789-2021, https://doi.org/10.5194/gmd-14-5789-2021, 2021
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Chemical-transport models are tools used to study air pollution and inform public policy. However, they are limited by the availability of archived meteorology. Here, we describe how the GEOS-Chem chemical-transport model may now be driven by meteorology archived from a state-of-the-art general circulation model for past and future climates, allowing it to be used to explore the impact of climate change on air pollution and atmospheric composition.
Tao Tang, Drew Shindell, Yuqiang Zhang, Apostolos Voulgarakis, Jean-Francois Lamarque, Gunnar Myhre, Gregory Faluvegi, Bjørn H. Samset, Timothy Andrews, Dirk Olivié, Toshihiko Takemura, and Xuhui Lee
Atmos. Chem. Phys., 21, 13797–13809, https://doi.org/10.5194/acp-21-13797-2021, https://doi.org/10.5194/acp-21-13797-2021, 2021
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Previous studies showed that black carbon (BC) could warm the surface with decreased incoming radiation. With climate models, we found that the surface energy redistribution plays a more crucial role in surface temperature compared with other forcing agents. Though BC could reduce the surface heating, the energy dissipates less efficiently, which is manifested by reduced convective and evaporative cooling, thereby warming the surface.
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 Wofsy
Atmos. Chem. Phys., 21, 13729–13746, https://doi.org/10.5194/acp-21-13729-2021, https://doi.org/10.5194/acp-21-13729-2021, 2021
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The NASA Atmospheric Tomography (ATom) mission built a climatology of the chemical composition of tropospheric air parcels throughout the middle of the Pacific and Atlantic oceans. The level of detail allows us to reconstruct the photochemical budgets of O3 and CH4 over these vast, remote regions. We find that most of the chemical heterogeneity is captured at the resolution used in current global chemistry models and that the majority of reactivity occurs in the
hottest20 % of parcels.
Ralf Weigel, Christoph Mahnke, Manuel Baumgartner, Martina Krämer, Peter Spichtinger, Nicole Spelten, Armin Afchine, Christian Rolf, Silvia Viciani, Francesco D'Amato, Holger Tost, and Stephan Borrmann
Atmos. Chem. Phys., 21, 13455–13481, https://doi.org/10.5194/acp-21-13455-2021, https://doi.org/10.5194/acp-21-13455-2021, 2021
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In July and August 2017, the StratoClim mission took place in Nepal with eight flights of the M-55 Geophysica at up to 20 km in the Asian monsoon anticyclone. New particle formation (NPF) next to cloud ice was detected in situ by abundant nucleation-mode aerosols (> 6 nm) along with ice particles (> 3 µm). NPF was observed mainly below the tropopause, down to 15 % being non-volatile residues. Observed intra-cloud NPF indicates its importance for the composition in the tropical tropopause layer.
Camilla K. Crockart, Tessa R. Vance, Alexander D. Fraser, Nerilie J. Abram, Alison S. Criscitiello, Mark A. J. Curran, Vincent Favier, Ailie J. E. Gallant, Christoph Kittel, Helle A. Kjær, Andrew R. Klekociuk, Lenneke M. Jong, Andrew D. Moy, Christopher T. Plummer, Paul T. Vallelonga, Jonathan Wille, and Lingwei Zhang
Clim. Past, 17, 1795–1818, https://doi.org/10.5194/cp-17-1795-2021, https://doi.org/10.5194/cp-17-1795-2021, 2021
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We present preliminary analyses of the annual sea salt concentrations and snowfall accumulation in a new East Antarctic ice core, Mount Brown South. We compare this record with an updated Law Dome (Dome Summit South site) ice core record over the period 1975–2016. The Mount Brown South record preserves a stronger and inverse signal for the El Niño–Southern Oscillation (in austral winter and spring) compared to the Law Dome record (in summer).
Timofei Sukhodolov, Tatiana Egorova, Andrea Stenke, William T. Ball, Christina Brodowsky, Gabriel Chiodo, Aryeh Feinberg, Marina Friedel, Arseniy Karagodin-Doyennel, Thomas Peter, Jan Sedlacek, Sandro Vattioni, and Eugene Rozanov
Geosci. Model Dev., 14, 5525–5560, https://doi.org/10.5194/gmd-14-5525-2021, https://doi.org/10.5194/gmd-14-5525-2021, 2021
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This paper features the new atmosphere–ocean–aerosol–chemistry–climate model SOCOLv4.0 and its validation. The model performance is evaluated against reanalysis products and observations of atmospheric circulation and trace gas distribution, with a focus on stratospheric processes. Although we identified some problems to be addressed in further model upgrades, we demonstrated that SOCOLv4.0 is already well suited for studies related to chemistry–climate–aerosol interactions.
Thierno Doumbia, Claire Granier, Nellie Elguindi, Idir Bouarar, Sabine Darras, Guy Brasseur, Benjamin Gaubert, Yiming Liu, Xiaoqin Shi, Trissevgeni Stavrakou, Simone Tilmes, Forrest Lacey, Adrien Deroubaix, and Tao Wang
Earth Syst. Sci. Data, 13, 4191–4206, https://doi.org/10.5194/essd-13-4191-2021, https://doi.org/10.5194/essd-13-4191-2021, 2021
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Most countries around the world have implemented control measures to combat the spread of the COVID-19 pandemic, resulting in significant changes in economic and personal activities. We developed the CONFORM (COvid-19 adjustmeNt Factors fOR eMissions) dataset to account for changes in emissions during lockdowns. This dataset was created with the intention of being directly applicable to existing global and regional inventories used in chemical transport models.
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Short summary
Differences in methane lifetime among global models are large and poorly understood. We use a neural network method and simulations from the Chemistry Climate Model Initiative to quantify the factors influencing methane lifetime spread among models and variations over time. UV photolysis, tropospheric ozone, and nitrogen oxides drive large model differences, while the same factors plus specific humidity contribute to a decreasing trend in methane lifetime between 1980 and 2015.
Differences in methane lifetime among global models are large and poorly understood. We use a...
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