Articles | Volume 25, issue 24
https://doi.org/10.5194/acp-25-18475-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-25-18475-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
19 Dec 2025
Research article |
| 19 Dec 2025
| 19 Dec 2025
Tropical tropospheric ozone trends (1998 to 2023): new perspectives from SHADOZ, IAGOS and OMI/MLS observations
Anne M. Thompson
CORRESPONDING AUTHOR
NASA/Goddard Space Flight Center (GSFC), Greenbelt, MD, USA
University of Maryland-Baltimore County, Baltimore, MD 21228, USA
Ryan M. Stauffer
NASA/Goddard Space Flight Center (GSFC), Greenbelt, MD, USA
Debra E. Kollonige
NASA/Goddard Space Flight Center (GSFC), Greenbelt, MD, USA
Science Systems and Applications, Inc., Lanham, MD, USA
Jerald R. Ziemke
NASA/Goddard Space Flight Center (GSFC), Greenbelt, MD, USA
Morgan State Univ., Baltimore, MD, USA
Bryan J. Johnson
NOAA/Global Monitoring Lab, Boulder, CO, USA
Gary A. Morris
NOAA/Global Monitoring Lab, Boulder, CO, USA
Patrick Cullis
NOAA/Global Monitoring Lab, Boulder, CO, USA
María Cazorla
Universidad San Francisco de Quito USFQ, Colegio de Ciencias e Ingenierías, Instituto de Investigaciones Atmosféricas, Quito, Ecuador
Jorge Andres Diaz
Universidad de Costa Rica, San Jose, Costa Rica
Ankie Piters
Royal Netherlands Meteorological Institute (KNMI), De Bilt, the Netherlands
Igor Nedeljkovic
Royal Netherlands Meteorological Institute (KNMI), De Bilt, the Netherlands
Truus Warsodikromo
Meteorological Service of Suriname, Paramaribo, Suriname
Francisco Raimundo Silva
Brazilian National Institute of Space Research (INPE), Natal, Brazil
E. Thomas Northam
Science Systems and Applications, Inc., Lanham, MD, USA
Science Systems and Applications, Inc., Wallops Island, VA, USA
Patrick Benjamin
US Space Force Base, Patrick, FSB, FL, Yang Enterprises, Inc., USA
Thumeka Mkololo
South African Weather Service (SAWS), Pretoria, South Africa
Tshidi Machinini
South African Weather Service (SAWS), Pretoria, South Africa
Christian Félix
MeteoSwiss, Payerne, Switzerland
Gonzague Romanens
MeteoSwiss, Payerne, Switzerland
Syprose Nyadida
Kenya Meteorological Department, Nairobi, Kenya
Jérôme Brioude
Université de La Réunion, Laboratoire de l'Atmosphère et des Cyclones (LACy), La Réunion, France
Stéphanie Evan
Université de La Réunion, Laboratoire de l'Atmosphère et des Cyclones (LACy), La Réunion, France
Jean-Marc Metzger
Université de La Réunion, Laboratoire de l'Atmosphère et des Cyclones (LACy), La Réunion, France
Ambun Dindang
Malaysian Meteorological Department, Petaling Jaya, Malaysia
Yuzaimi B. Mahat
Malaysian Meteorological Department, Petaling Jaya, Malaysia
Mohan Kumar Sammathuria
Malaysian Meteorological Department, Petaling Jaya, Malaysia
Norazura Binti Zakaria
Malaysian Meteorological Department, Petaling Jaya, Malaysia
Ninong Komala
National Research and Innovation Agency (BRIN), Bandung, Indonesia
Shin-Ya Ogino
Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Research Institute for Global Change, Yokosuka, Japan
Nguyen Thi Quyen
Aero-Meteorological Observatory (AMO), Viet Nam Meteorological and Hydrological Administration, Hanoi, Vietnam
Francis S. Mani
The University of the South Pacific (USP), Suva, Fiji
Miriama Vuiyasawa
The University of the South Pacific (USP), Suva, Fiji
David Nardini
CIMAR, University of Hawaii at Manoa, Honolulu, HI, USA
Matthew Martinsen
CIRES, Univ. Colorado, Boulder, CO, USA
Darryl T. Kuniyuki
NOAA/Global Monitoring Lab, Boulder, CO, USA
Katrin Müller
Alfred-Wegener-Institut, Helmholtz Centre for Polar and Marine Research, Potsdam, Germany
Pawel Wolff
SEDOO, Univ. Paul Sabatier III, Toulouse, France
now at: ECMWF, Bonn, Germany
Bastien Sauvage
Laboratoire d'Aérologie Observatoire Midi-Pyrénées, 14 av. E. Belin, 31400 Toulouse, France
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Short summary
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EGUsphere, https://doi.org/10.5194/egusphere-2025-6557, https://doi.org/10.5194/egusphere-2025-6557, 2026
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This introduction to the special issue "Achievements and perspectives of the Network for the Detection of Atmospheric Composition Change after 35 years of operation” provides an overview of important research findings achieved under the NDACC objectives. The future of NDACC is discussed in the light of the evolution of the scientific questions, evolving collaborations with partners and Cooperating Networks, and the current landscape of gaps in satellite and ground-based observations.
Igo Paulino, Francisco Raimundo da Silva, Ana Roberta Paulino, and Gilvan Borba
EGUsphere, https://doi.org/10.5194/egusphere-2025-6194, https://doi.org/10.5194/egusphere-2025-6194, 2026
This preprint is open for discussion and under review for Annales Geophysicae (ANGEO).
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The study utilized a stratospheric balloon over Natal, Brazil, to investigate the atmospheric response to the 14 October 2023 annular solar eclipse near sunset. Measurements included temperature, pressure, relative humidity, and ozone. Significant changes in these parameters were found at different altitudes. These complex changes confirm the annular eclipse's importance as a driver of localized atmospheric dynamics.
Felipe Cifuentes, Henk Eskes, Ankie Piters, Julian Gomez, John Douros, Gaia Pinardi, Martina M. Friedrich, Enrico Dammers, Manuel Gebetsberger, and K. Folkert Boersma
EGUsphere, https://doi.org/10.5194/egusphere-2025-6175, https://doi.org/10.5194/egusphere-2025-6175, 2026
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Satellite NO2 data are essential for monitoring air pollution, but they are affected by several sources of uncertainty. This study evaluates the major error contributors in TROPOMI NO2 retrievals by analyzing each retrieval step and comparing with ground-based observations. Key findings include biases in the separation of stratospheric and tropospheric NO2, representation and smoothing errors, and substantial variability among the ground-based instruments used for validation.
Xiaoyu Sun, Mathias Palm, Katrin Müller, Denghui Ji, and Justus Notholt
EGUsphere, https://doi.org/10.5194/egusphere-2025-5394, https://doi.org/10.5194/egusphere-2025-5394, 2025
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Near-surface ozone over the tropical Pacific is among the lowest on Earth, and this study provides rare observations from this key region. Using sunlight measurements with an infrared spectrometer in Palau, we found that ozone rises in the morning and falls after noon. This daily rhythm and very low levels show how clean ocean air and weak thunderstorms shape atmospheric chemistry and affect Earth’s climate.
Arno Keppens, Daan Hubert, José Granville, Oindrila Nath, Jean-Christopher Lambert, Catherine Wespes, Pierre-François Coheur, Cathy Clerbaux, Anne Boynard, Richard Siddans, Barry Latter, Brian Kerridge, Serena Di Pede, Pepijn Veefkind, Juan Cuesta, Gaelle Dufour, Klaus-Peter Heue, Melanie Coldewey-Egbers, Diego Loyola, Andrea Orfanoz-Cheuquelaf, Swathi Maratt Satheesan, Kai-Uwe Eichmann, Alexei Rozanov, Viktoria F. Sofieva, Jerald R. Ziemke, Antje Inness, Roeland Van Malderen, and Lars Hoffmann
Atmos. Meas. Tech., 18, 6893–6916, https://doi.org/10.5194/amt-18-6893-2025, https://doi.org/10.5194/amt-18-6893-2025, 2025
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The first Tropospheric Ozone Assessment Report (TOAR) encountered discrepancies between several satellite sensors’ estimates of the distribution and change of ozone in the free troposphere. Therefore, contributing to the second TOAR, we harmonise as much as possible the observational perspective of sixteen tropospheric ozone products from satellites. This only partially accounts for the observed discrepancies, with a reduction of 10–40 % of the inter-product dispersion upon harmonisation.
Pasquale Sellitto, Audrey Gaudel, and Bastien Sauvage
Atmos. Chem. Phys., 25, 13299–13309, https://doi.org/10.5194/acp-25-13299-2025, https://doi.org/10.5194/acp-25-13299-2025, 2025
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Tropospheric ozone is a potent greenhouse gas: its anthropogenic levels rise contributes to climate change. We evaluate tropospheric ozone trends and climate impacts with aircraft data and a radiative model, comparing a baseline period (1994–2004) to different recent time periods (2011–2016 to 2020-2023). Tropospheric ozone levels increasing trends progressively stopped and even decreased in the upper troposphere. Correspondingly, the decadal ozone radiative forcing is progressively decreasing.
Eric Martial Yao, Fabien Solmon, Marcellin Adon, Claire Delon, Corinne Galy-Lacaux, Graziano Giuliani, Bastien Sauvage, and Véronique Yoboue
Atmos. Chem. Phys., 25, 12101–12136, https://doi.org/10.5194/acp-25-12101-2025, https://doi.org/10.5194/acp-25-12101-2025, 2025
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As climate change and human activities intensify in Africa, understanding how air pollution, climate, and natural cycles interact is crucial. This study explores how nitrogen oxide emissions from African soils, especially in dry regions, contribute to atmospheric pollution. By using a climate-chemistry model, we show that considering these emissions improves predictions of nitrogen dioxide, nitric acid and ozone, although some discrepancies remain compared to observations.
Yugo Kanaya, Roberto Sommariva, Alfonso Saiz-Lopez, Andrea Mazzeo, Theodore K. Koenig, Kaori Kawana, James E. Johnson, Aurélie Colomb, Pierre Tulet, Suzie Molloy, Ian E. Galbally, Rainer Volkamer, Anoop Mahajan, John W. Halfacre, Paul B. Shepson, Julia Schmale, Hélène Angot, Byron Blomquist, Matthew D. Shupe, Detlev Helmig, Junsu Gil, Meehye Lee, Sean C. Coburn, Ivan Ortega, Gao Chen, James Lee, Kenneth C. Aikin, David D. Parrish, John S. Holloway, Thomas B. Ryerson, Ilana B. Pollack, Eric J. Williams, Brian M. Lerner, Andrew J. Weinheimer, Teresa Campos, Frank M. Flocke, J. Ryan Spackman, Ilann Bourgeois, Jeff Peischl, Chelsea R. Thompson, Ralf M. Staebler, Amir A. Aliabadi, Wanmin Gong, Roeland Van Malderen, Anne M. Thompson, Ryan M. Stauffer, Debra E. Kollonige, Juan Carlos Gómez Martin, Masatomo Fujiwara, Katie Read, Matthew Rowlinson, Keiichi Sato, Junichi Kurokawa, Yoko Iwamoto, Fumikazu Taketani, Hisahiro Takashima, Mónica Navarro-Comas, Marios Panagi, and Martin G. Schultz
Earth Syst. Sci. Data, 17, 4901–4932, https://doi.org/10.5194/essd-17-4901-2025, https://doi.org/10.5194/essd-17-4901-2025, 2025
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The first comprehensive dataset of tropospheric ozone over oceans/polar regions is presented, including 77 ship/buoy and 48 aircraft campaign observations (1977–2022, 0–5000 m altitude), supplemented by ozonesonde and surface data. Air masses isolated from land for 72+ hours are systematically selected as essentially oceanic. Among the 11 global regions, they show daytime decreases of 11–16 % in the tropics, while near-zero depletions are rare, unlike in the Arctic, implying different mechanisms.
Meredith Dournaux, Pierre Tulet, Joris Pianezze, Jérome Brioude, Jean-Marc Metzger, Melilotus Thyssen, and Gilles Athier
Atmos. Chem. Phys., 25, 10315–10335, https://doi.org/10.5194/acp-25-10315-2025, https://doi.org/10.5194/acp-25-10315-2025, 2025
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Aerosol measurements collected during six oceanographic campaigns carried out in 2021 and 2023 in the southwestern Indian Ocean are presented and analyzed in this paper. The results highlight large variability in the aerosol concentration, size, and water vapor affinity depending on in situ conditions and air mass transport over the ocean. Marine aerosol chemical composition is highly variable over this region and should be considered to better study the impacts of aerosols on regional weather and climate.
Roeland Van Malderen, Zhou Zang, Kai-Lan Chang, Robin Björklund, Owen R. Cooper, Jane Liu, Eliane Maillard Barras, Corinne Vigouroux, Irina Petropavlovskikh, Thierry Leblanc, Valérie Thouret, Pawel Wolff, Peter Effertz, Audrey Gaudel, David W. Tarasick, Herman G. J. Smit, Anne M. Thompson, Ryan M. Stauffer, Debra E. Kollonige, Deniz Poyraz, Gérard Ancellet, Marie-Renée De Backer, Matthias M. Frey, James W. Hannigan, José L. Hernandez, Bryan J. Johnson, Nicholas Jones, Rigel Kivi, Emmanuel Mahieu, Isamu Morino, Glen McConville, Katrin Müller, Isao Murata, Justus Notholt, Ankie Piters, Maxime Prignon, Richard Querel, Vincenzo Rizi, Dan Smale, Wolfgang Steinbrecht, Kimberly Strong, and Ralf Sussmann
Atmos. Chem. Phys., 25, 9905–9935, https://doi.org/10.5194/acp-25-9905-2025, https://doi.org/10.5194/acp-25-9905-2025, 2025
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Tropospheric ozone is an important greenhouse gas and an air pollutant whose distribution and time variability are mainly governed by anthropogenic emissions and dynamics. In this paper, we assess regional trends of tropospheric ozone column amounts, based on two different approaches of merging or synthesizing ground-based observations and their trends within specific regions. Our findings clearly demonstrate regional trend differences but also consistently higher pre-COVID than post-COVID trends.
Wanmin Gong, Stephen R. Beagley, Kenjiro Toyota, Henrik Skov, Jesper Heile Christensen, Alex Lupu, Diane Pendlebury, Junhua Zhang, Ulas Im, Yugo Kanaya, Alfonso Saiz-Lopez, Roberto Sommariva, Peter Effertz, John W. Halfacre, Nis Jepsen, Rigel Kivi, Theodore K. Koenig, Katrin Müller, Claus Nordstrøm, Irina Petropavlovskikh, Paul B. Shepson, William R. Simpson, Sverre Solberg, Ralf M. Staebler, David W. Tarasick, Roeland Van Malderen, and Mika Vestenius
Atmos. Chem. Phys., 25, 8355–8405, https://doi.org/10.5194/acp-25-8355-2025, https://doi.org/10.5194/acp-25-8355-2025, 2025
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This study showed that the springtime O3 depletion plays a critical role in driving the surface O3 seasonal cycle in the central Arctic. The O3 depletion events, while occurring most notably within the lowest few hundred metres above the Arctic Ocean, can induce a 5–7 % loss in the pan-Arctic tropospheric O3 burden during springtime. The study also found enhancements in O3 and NOy (mostly peroxyacetyl nitrate) concentrations in the Arctic due to northern boreal wildfires, particularly at higher altitudes.
Suvarna Fadnavis, Yasin Elshorbany, Jerald Ziemke, Brice Barret, Alexandru Rap, P. R. Satheesh Chandran, Richard J. Pope, Vijay Sagar, Domenico Taraborrelli, Eric Le Flochmoen, Juan Cuesta, Catherine Wespes, Folkert Boersma, Isolde Glissenaar, Isabelle De Smedt, Michel Van Roozendael, Hervé Petetin, and Isidora Anglou
Atmos. Chem. Phys., 25, 8229–8254, https://doi.org/10.5194/acp-25-8229-2025, https://doi.org/10.5194/acp-25-8229-2025, 2025
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Satellites and model simulations show enhancement in tropospheric ozone, which is highly impacted by human-produced nitrous oxides compared to volatile organic compounds. The increased amount of ozone enhances ozone radiative forcing. The ozone enhancement and associated radiative forcing are the highest over South and East Asia. The emissions of nitrous oxides show a higher influence on shifting ozone photochemical regimes than volatile organic compounds.
Xiao Lu, Yiming Liu, Jiayin Su, Xiang Weng, Tabish Ansari, Yuqiang Zhang, Guowen He, Yuqi Zhu, Haolin Wang, Ganquan Zeng, Jingyu Li, Cheng He, Shuai Li, Teerachai Amnuaylojaroen, Tim Butler, Qi Fan, Shaojia Fan, Grant L. Forster, Meng Gao, Jianlin Hu, Yugo Kanaya, Mohd Talib Latif, Keding Lu, Philippe Nédélec, Peer Nowack, Bastien Sauvage, Xiaobin Xu, Lin Zhang, Ke Li, Ja-Ho Koo, and Tatsuya Nagashima
Atmos. Chem. Phys., 25, 7991–8028, https://doi.org/10.5194/acp-25-7991-2025, https://doi.org/10.5194/acp-25-7991-2025, 2025
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This study analyzes summertime ozone trends in East and Southeast Asia derived from a comprehensive observational database spanning from 1995 to 2019, incorporating aircraft observations, ozonesonde data, and measurements from 2500 surface sites. Multiple models are applied to attribute to changes in anthropogenic emissions and climate. The results highlight that increases in anthropogenic emissions are the primary driver of ozone increases both in the free troposphere and at the surface.
Nana Wei, Eloise A. Marais, Gongda Lu, Robert G. Ryan, and Bastien Sauvage
Atmos. Chem. Phys., 25, 7925–7940, https://doi.org/10.5194/acp-25-7925-2025, https://doi.org/10.5194/acp-25-7925-2025, 2025
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This study uses reactive nitrogen observations from NASA DC-8 research aircraft and the In-service Aircraft for a Global Observing System (IAGOS) campaigns to characterize reactive nitrogen seasonality and composition in the global upper troposphere and to diagnose the greatest knowledge gaps from comparison to a state-of-the-science model, GEOS-Chem, that need to be resolved for climate, nitrogen cycle, and air pollution assessments.
Carlo Arosio, Viktoria Sofieva, Andrea Orfanoz-Cheuquelaf, Alexei Rozanov, Klaus-Peter Heue, Diego Loyola, Edward Malina, Ryan M. Stauffer, David Tarasick, Roeland Van Malderen, Jerry R. Ziemke, and Mark Weber
Atmos. Meas. Tech., 18, 3247–3265, https://doi.org/10.5194/amt-18-3247-2025, https://doi.org/10.5194/amt-18-3247-2025, 2025
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Tropospheric ozone affects air quality and climate, being a pollutant and a greenhouse gas. We analyze satellite data of tropospheric ozone columns obtained by combining two types of observations: one providing stratospheric and the other total ozone. We compare common climatological features and study the influence of the tropopause (troposphere to stratosphere boundary) on the results. We also examine trends over the last 20 years and compare satellite data with ozonesondes to identify drifts.
Roeland Van Malderen, Anne M. Thompson, Debra E. Kollonige, Ryan M. Stauffer, Herman G. J. Smit, Eliane Maillard Barras, Corinne Vigouroux, Irina Petropavlovskikh, Thierry Leblanc, Valérie Thouret, Pawel Wolff, Peter Effertz, David W. Tarasick, Deniz Poyraz, Gérard Ancellet, Marie-Renée De Backer, Stéphanie Evan, Victoria Flood, Matthias M. Frey, James W. Hannigan, José L. Hernandez, Marco Iarlori, Bryan J. Johnson, Nicholas Jones, Rigel Kivi, Emmanuel Mahieu, Glen McConville, Katrin Müller, Tomoo Nagahama, Justus Notholt, Ankie Piters, Natalia Prats, Richard Querel, Dan Smale, Wolfgang Steinbrecht, Kimberly Strong, and Ralf Sussmann
Atmos. Chem. Phys., 25, 7187–7225, https://doi.org/10.5194/acp-25-7187-2025, https://doi.org/10.5194/acp-25-7187-2025, 2025
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Tropospheric ozone is an important greenhouse gas and is an air pollutant. The time variability of tropospheric ozone is mainly driven by anthropogenic emissions. In this paper, we study the distribution and time variability of ozone from harmonized ground-based observations from five different measurement techniques. Our findings provide clear standard references for atmospheric models and evolving tropospheric ozone satellite data for the 2000–2022 period.
María Cazorla, Melissa Trujillo, Rodrigo Seguel, and Laura Gallardo
Atmos. Chem. Phys., 25, 7087–7109, https://doi.org/10.5194/acp-25-7087-2025, https://doi.org/10.5194/acp-25-7087-2025, 2025
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The current climate and environmental crises impose the need to take actions in cities to curb ozone as a pollutant and a climate forcer. This endeavor is challenging in understudied regions. In this work we analyze how reducing levels of precursor chemicals would affect ozone formation in Quito, Ecuador, and Santiago, Chile.
Catalina Poraicu, Jean-François Müller, Trissevgeni Stavrakou, Crist Amelynck, Bert W. D. Verreyken, Niels Schoon, Corinne Vigouroux, Nicolas Kumps, Jérôme Brioude, Pierre Tulet, and Camille Mouchel-Vallon
Atmos. Chem. Phys., 25, 6903–6941, https://doi.org/10.5194/acp-25-6903-2025, https://doi.org/10.5194/acp-25-6903-2025, 2025
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We investigated the sources and impacts of nitrogen oxides and organic compounds over a remote tropical island. Simulations of the high-resolution Weather Research and Forecasting model coupled with chemistry (WRF-Chem) were evaluated using in situ Fourier transform infrared spectroscopy (FTIR) and satellite measurements. This work highlights gaps in current models, like missing sources of key organic compounds and inaccuracies in emission inventories, emphasizing the importance of improving chemical and dynamical processes in atmospheric modelling for budget estimates in tropical regions.
Xiaoyu Sun, Katrin Müller, Mathias Palm, Christoph Ritter, Denghui Ji, Tim Balthasar Röpke, and Justus Notholt
Atmos. Chem. Phys., 25, 6881–6902, https://doi.org/10.5194/acp-25-6881-2025, https://doi.org/10.5194/acp-25-6881-2025, 2025
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We studied how air moves from the lower atmosphere to the stratosphere over the tropical western Pacific. Using observations and air tracking, we found that, in winter, air ascends and cold temperatures freeze water out, drying it before it enters the stratosphere. In summer, air tends to sink after cloud formation. This process affects water vapor amounts in the stratosphere, influencing the greenhouse effect and climate.
Yuhang Zhang, Huan Yu, Isabelle De Smedt, Jintai Lin, Nicolas Theys, Michel Van Roozendael, Gaia Pinardi, Steven Compernolle, Ruijing Ni, Fangxuan Ren, Sijie Wang, Lulu Chen, Jos Van Geffen, Mengyao Liu, Alexander M. Cede, Martin Tiefengraber, Alexis Merlaud, Martina M. Friedrich, Andreas Richter, Ankie Piters, Vinod Kumar, Vinayak Sinha, Thomas Wagner, Yongjoo Choi, Hisahiro Takashima, Yugo Kanaya, Hitoshi Irie, Robert Spurr, Wenfu Sun, and Lorenzo Fabris
Atmos. Meas. Tech., 18, 1561–1589, https://doi.org/10.5194/amt-18-1561-2025, https://doi.org/10.5194/amt-18-1561-2025, 2025
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We developed an advanced algorithm for global retrieval of TROPOspheric Monitoring Instrument (TROPOMI) HCHO and NO2 vertical column densities with much improved consistency. Sensitivity tests demonstrate the complexity and nonlinear interactions of auxiliary parameters in the air mass factor calculation. An improved agreement is found with measurements from a global ground-based instrument network. The scientific retrieval provides a useful source of information for studies combining HCHO and NO2.
Irina Petropavlovskikh, Jeannette D. Wild, Kari Abromitis, Peter Effertz, Koji Miyagawa, Lawrence E. Flynn, Eliane Maillard Barras, Robert Damadeo, Glen McConville, Bryan Johnson, Patrick Cullis, Sophie Godin-Beekmann, Gerard Ancellet, Richard Querel, Roeland Van Malderen, and Daniel Zawada
Atmos. Chem. Phys., 25, 2895–2936, https://doi.org/10.5194/acp-25-2895-2025, https://doi.org/10.5194/acp-25-2895-2025, 2025
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Observational records show that stratospheric ozone is recovering in accordance with the implementation of the Montreal Protocol and its amendments. Natural ozone variability complicates the detection of small trends. This study optimizes a statistical model fit in ground-station-based observational records by adding parameters that interpret seasonal and long-term changes in atmospheric circulation and airmass mixing, which reduces uncertainties in detecting the stratospheric ozone recovery.
Swathi Maratt Satheesan, Kai-Uwe Eichmann, Mark Weber, Roeland Van Malderen, Ryan Stauffer, and David Tarasick
EGUsphere, https://doi.org/10.5194/egusphere-2025-306, https://doi.org/10.5194/egusphere-2025-306, 2025
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This study presents the CLCD (CHORA Local Cloud Decision) algorithm for retrieving near-global tropospheric ozone using TROPOMI data. The approach refines the Convective Cloud Differential method by using a local cloud reference sector to minimize errors from stratospheric ozone variability, particularly in mid-latitudes. Validation against ground-based data shows good accuracy, highlighting its potential for improving air quality monitoring and supporting current and future satellite missions.
Min Huang, Gregory R. Carmichael, Kevin W. Bowman, Isabelle De Smedt, Andreas Colliander, Michael H. Cosh, Sujay V. Kumar, Alex B. Guenther, Scott J. Janz, Ryan M. Stauffer, Anne M. Thompson, Niko M. Fedkin, Robert J. Swap, John D. Bolten, and Alicia T. Joseph
Atmos. Chem. Phys., 25, 1449–1476, https://doi.org/10.5194/acp-25-1449-2025, https://doi.org/10.5194/acp-25-1449-2025, 2025
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We use model simulations along with multiplatform, multidisciplinary observations and a range of analysis methods to estimate and understand the distributions, temporal changes, and impacts of reactive nitrogen and ozone over the most populous US region that has undergone significant environmental changes. Deposition, biogenic emissions, and extra-regional sources have been playing increasingly important roles in controlling pollutant budgets in this area as local anthropogenic emissions drop.
Takuji Sugidachi, Masatomo Fujiwara, Kensaku Shimizu, Shin-Ya Ogino, Junko Suzuki, and Ruud J. Dirksen
Atmos. Meas. Tech., 18, 509–531, https://doi.org/10.5194/amt-18-509-2025, https://doi.org/10.5194/amt-18-509-2025, 2025
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A Peltier-based chilled-mirror hygrometer, SKYDEW, has been developed to measure tropospheric and stratospheric water vapor. Continuous accurate measurements of water vapor are essential for climate monitoring. More than 40 soundings with SKYDEW have been conducted since 2011 to evaluate the performance. The result of soundings at tropical and midlatitudes demonstrated that SKYDEW is able to measure up to an altitude of 20–25 km for daytime soundings and above 25 km for nighttime soundings.
Sarah E. Hancock, Daniel J. Jacob, Zichong Chen, Hannah Nesser, Aaron Davitt, Daniel J. Varon, Melissa P. Sulprizio, Nicholas Balasus, Lucas A. Estrada, María Cazorla, Laura Dawidowski, Sebastián Diez, James D. East, Elise Penn, Cynthia A. Randles, John Worden, Ilse Aben, Robert J. Parker, and Joannes D. Maasakkers
Atmos. Chem. Phys., 25, 797–817, https://doi.org/10.5194/acp-25-797-2025, https://doi.org/10.5194/acp-25-797-2025, 2025
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We quantify 2021 methane emissions in South America at up to 25 km × 25 km resolution using satellite methane observations. We find a 55 % upward adjustment to anthropogenic emission inventories, including those reported to the UN Framework Convention on Climate Change under the Paris Agreement. Our estimates match inventories for Brazil, Bolivia, and Paraguay but are much higher for other countries. Livestock emissions (65 % of anthropogenic emissions) show the largest discrepancies.
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.
Brice Barret, Pierre Loicq, Eric Le Flochmoën, Yasmine Bennouna, Juliette Hadji-Lazaro, Daniel Hurtmans, and Bastien Sauvage
Atmos. Meas. Tech., 18, 129–149, https://doi.org/10.5194/amt-18-129-2025, https://doi.org/10.5194/amt-18-129-2025, 2025
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Profiles of carbon monoxide (CO) retrieved from the Infrared Atmospheric Sounding Interferometer (IASI) with the SOftware for a Fast Retrieval of IASI Data (SOFRID) and Fast Optimal Retrievals on Layers for IASI (FORLI) are validated with 8500 observations at 33 airports from the In-service Aircraft for a Global Observing System (IAGOS) for 2008–2019. IASI retrievals underestimate CO, with stronger bias in the middle to upper troposphere for SOFRID and in the lower troposphere for FORLI.
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.
Zhou Zang, Jane Liu, David Tarasick, Omid Moeini, Jianchun Bian, Jinqiang Zhang, Anne M. Thompson, Roeland Van Malderen, Herman G. J. Smit, Ryan M. Stauffer, Bryan J. Johnson, and Debra E. Kollonige
Atmos. Chem. Phys., 24, 13889–13912, https://doi.org/10.5194/acp-24-13889-2024, https://doi.org/10.5194/acp-24-13889-2024, 2024
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The Trajectory-mapped Ozonesonde dataset for the Stratosphere and Troposphere (TOST) provides a global-scale, long-term ozone climatology that is horizontally and vertically resolved. In this study, we improved, updated and validated TOST from 1970 to 2021. Based on this TOST dataset, we characterized global ozone variations spatially in both the troposphere and stratosphere and temporally by season and decade. We also showed a stagnant lower stratospheric ozone variation since the late 1990s.
Jiansheng Zou, Kaley A. Walker, Patrick E. Sheese, Chris D. Boone, Ryan M. Stauffer, Anne M. Thompson, and David W. Tarasick
Atmos. Meas. Tech., 17, 6983–7005, https://doi.org/10.5194/amt-17-6983-2024, https://doi.org/10.5194/amt-17-6983-2024, 2024
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Ozone measurements from the ACE-FTS satellite instrument have been compared to worldwide balloon-borne ozonesonde profiles using pairs of closely spaced profiles and monthly averaged profiles. ACE-FTS typically measures more ozone in the stratosphere by up to 10 %. The long-term stability of the ACE-FTS ozone data is good, exhibiting small (but non-significant) drifts of less than 3 % per decade in the stratosphere. Lower in the profiles, the calculated drifts are larger (up to 10 % per decade).
Flossie Brown, Gerd Folberth, Stephen Sitch, Paulo Artaxo, Marijn Bauters, Pascal Boeckx, Alexander W. Cheesman, Matteo Detto, Ninong Komala, Luciana Rizzo, Nestor Rojas, Ines dos Santos Vieira, Steven Turnock, Hans Verbeeck, and Alfonso Zambrano
Atmos. Chem. Phys., 24, 12537–12555, https://doi.org/10.5194/acp-24-12537-2024, https://doi.org/10.5194/acp-24-12537-2024, 2024
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Ozone is a pollutant that is detrimental to human and plant health. Ozone monitoring sites in the tropics are limited, so models are often used to understand ozone exposure. We use measurements from the tropics to evaluate ozone from the UK Earth system model, UKESM1. UKESM1 is able to capture the pattern of ozone in the tropics, except in southeast Asia, although it systematically overestimates it at all sites. This work highlights that UKESM1 can capture seasonal and hourly variability.
Swathi Maratt Satheesan, Kai-Uwe Eichmann, John P. Burrows, Mark Weber, Ryan Stauffer, Anne M. Thompson, and Debra Kollonige
Atmos. Meas. Tech., 17, 6459–6484, https://doi.org/10.5194/amt-17-6459-2024, https://doi.org/10.5194/amt-17-6459-2024, 2024
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CHORA, an advanced cloud convective differential technique, enhances the accuracy of tropospheric-ozone retrievals. Unlike the traditional Pacific cloud reference sector scheme, CHORA introduces a local-cloud reference sector and an alternative approach (CLCT) for precision. Analysing monthly averaged TROPOMI data from 2018 to 2022 and validating with SHADOZ ozonesonde data, CLCT outperforms other methods and so is the preferred choice, especially in future geostationary satellite missions.
Yasin Elshorbany, Jerald R. Ziemke, Sarah Strode, Hervé Petetin, Kazuyuki Miyazaki, Isabelle De Smedt, Kenneth Pickering, Rodrigo J. Seguel, Helen Worden, Tamara Emmerichs, Domenico Taraborrelli, Maria Cazorla, Suvarna Fadnavis, Rebecca R. Buchholz, Benjamin Gaubert, Néstor Y. Rojas, Thiago Nogueira, Thérèse Salameh, and Min Huang
Atmos. Chem. Phys., 24, 12225–12257, https://doi.org/10.5194/acp-24-12225-2024, https://doi.org/10.5194/acp-24-12225-2024, 2024
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We investigated tropospheric ozone spatial variability and trends from 2005 to 2019 and related those to ozone precursors on global and regional scales. We also investigate the spatiotemporal characteristics of the ozone formation regime in relation to ozone chemical sources and sinks. Our analysis is based on remote sensing products of the tropospheric column of ozone and its precursors, nitrogen dioxide, formaldehyde, and total column CO, as well as ozonesonde data and model simulations.
Audrey Gaudel, Ilann Bourgeois, Meng Li, Kai-Lan Chang, Jerald Ziemke, Bastien Sauvage, Ryan M. Stauffer, Anne M. Thompson, Debra E. Kollonige, Nadia Smith, Daan Hubert, Arno Keppens, Juan Cuesta, Klaus-Peter Heue, Pepijn Veefkind, Kenneth Aikin, Jeff Peischl, Chelsea R. Thompson, Thomas B. Ryerson, Gregory J. Frost, Brian C. McDonald, and Owen R. Cooper
Atmos. Chem. Phys., 24, 9975–10000, https://doi.org/10.5194/acp-24-9975-2024, https://doi.org/10.5194/acp-24-9975-2024, 2024
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The study examines tropical tropospheric ozone changes. In situ data from 1994–2019 display increased ozone, notably over India, Southeast Asia, and Malaysia and Indonesia. Sparse in situ data limit trend detection for the 15-year period. In situ and satellite data, with limited sampling, struggle to consistently detect trends. Continuous observations are vital over the tropical Pacific Ocean, Indian Ocean, western Africa, and South Asia for accurate ozone trend estimation in these regions.
Andrew O. Langford, Raul J. Alvarez II, Kenneth C. Aikin, Sunil Baidar, W. Alan Brewer, Steven S. Brown, Matthew M. Coggan, Patrick D. Cullis, Jessica Gilman, Georgios I. Gkatzelis, Detlev Helmig, Bryan J. Johnson, K. Emma Knowland, Rajesh Kumar, Aaron D. Lamplugh, Audra McClure-Begley, Brandi J. McCarty, Ann M. Middlebrook, Gabriele Pfister, Jeff Peischl, Irina Petropavlovskikh, Pamela S. Rickley, Andrew W. Rollins, Scott P. Sandberg, Christoph J. Senff, and Carsten Warneke
EGUsphere, https://doi.org/10.5194/egusphere-2024-1938, https://doi.org/10.5194/egusphere-2024-1938, 2024
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High ozone (O3) formed by reactions of nitrogen oxides (NOx) and volatile organic compounds (VOCs) can harm human health and welfare. High O3 is usually associated with hot summer days, but under certain conditions, high O3 can also form under winter conditions. In this study, we describe a high O3 event that occurred in Colorado during the COVID-19 quarantine that was caused in part by the decrease in traffic, and in part by a shallow inversion created by descent of stratospheric air.
Pierre Tulet, Joel Van Baelen, Pierre Bosser, Jérome Brioude, Aurélie Colomb, Philippe Goloub, Andrea Pazmino, Thierry Portafaix, Michel Ramonet, Karine Sellegri, Melilotus Thyssen, Léa Gest, Nicolas Marquestaut, Dominique Mékiès, Jean-Marc Metzger, Gilles Athier, Luc Blarel, Marc Delmotte, Guillaume Desprairies, Mérédith Dournaux, Gaël Dubois, Valentin Duflot, Kevin Lamy, Lionel Gardes, Jean-François Guillemot, Valérie Gros, Joanna Kolasinski, Morgan Lopez, Olivier Magand, Erwan Noury, Manuel Nunes-Pinharanda, Guillaume Payen, Joris Pianezze, David Picard, Olivier Picard, Sandrine Prunier, François Rigaud-Louise, Michael Sicard, and Benjamin Torres
Earth Syst. Sci. Data, 16, 3821–3849, https://doi.org/10.5194/essd-16-3821-2024, https://doi.org/10.5194/essd-16-3821-2024, 2024
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The MAP-IO program aims to compensate for the lack of atmospheric and oceanographic observations in the Southern Ocean by equipping the ship Marion Dufresne with a set of 17 scientific instruments. This program collected 700 d of measurements under different latitudes, seasons, sea states, and weather conditions. These new data will support the calibration and validation of numerical models and the understanding of the atmospheric composition of this region of Earth.
Rodrigo J. Seguel, Lucas Castillo, Charlie Opazo, Néstor Y. Rojas, Thiago Nogueira, María Cazorla, Mario Gavidia-Calderón, Laura Gallardo, René Garreaud, Tomás Carrasco-Escaff, and Yasin Elshorbany
Atmos. Chem. Phys., 24, 8225–8242, https://doi.org/10.5194/acp-24-8225-2024, https://doi.org/10.5194/acp-24-8225-2024, 2024
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Trends of surface ozone were examined across South America. Our findings indicate that ozone trends in major South American cities either increase or remain steady, with no signs of decline. The upward trends can be attributed to chemical regimes that efficiently convert nitric oxide into nitrogen dioxide. Additionally, our results suggest a climate penalty for ozone driven by meteorological conditions that favor wildfire propagation in Chile and extensive heat waves in southern Brazil.
Arno Keppens, Serena Di Pede, Daan Hubert, Jean-Christopher Lambert, Pepijn Veefkind, Maarten Sneep, Johan De Haan, Mark ter Linden, Thierry Leblanc, Steven Compernolle, Tijl Verhoelst, José Granville, Oindrila Nath, Ann Mari Fjæraa, Ian Boyd, Sander Niemeijer, Roeland Van Malderen, Herman G. J. Smit, Valentin Duflot, Sophie Godin-Beekmann, Bryan J. Johnson, Wolfgang Steinbrecht, David W. Tarasick, Debra E. Kollonige, Ryan M. Stauffer, Anne M. Thompson, Angelika Dehn, and Claus Zehner
Atmos. Meas. Tech., 17, 3969–3993, https://doi.org/10.5194/amt-17-3969-2024, https://doi.org/10.5194/amt-17-3969-2024, 2024
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The Sentinel-5P satellite operated by the European Space Agency has carried the TROPOspheric Monitoring Instrument (TROPOMI) around the Earth since October 2017. This mission also produces atmospheric ozone profile data which are described in detail for May 2018 to April 2023. Independent validation using ground-based reference measurements demonstrates that the operational ozone profile product mostly fully and at least partially complies with all mission requirements.
Jayanarayanan Kuttippurath, Gopalakrishna Pillai Gopikrishnan, Rolf Müller, Sophie Godin-Beekmann, and Jerome Brioude
Atmos. Chem. Phys., 24, 6743–6756, https://doi.org/10.5194/acp-24-6743-2024, https://doi.org/10.5194/acp-24-6743-2024, 2024
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The current understanding and observational evidence do not provide any support for the possibility of an ozone hole occurring outside Antarctica today with respect to the present-day stratospheric halogen levels.
Kai-Lan Chang, Owen R. Cooper, Audrey Gaudel, Irina Petropavlovskikh, Peter Effertz, Gary Morris, and Brian C. McDonald
Atmos. Chem. Phys., 24, 6197–6218, https://doi.org/10.5194/acp-24-6197-2024, https://doi.org/10.5194/acp-24-6197-2024, 2024
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A great majority of observational trend studies of free tropospheric ozone use sparsely sampled ozonesonde and aircraft measurements as reference data sets. A ubiquitous assumption is that trends are accurate and reliable so long as long-term records are available. We show that sampling bias due to sparse samples can persistently reduce the trend accuracy, and we highlight the importance of maintaining adequate frequency and continuity of observations.
Ryan M. Stauffer, Anne M. Thompson, Debra E. Kollonige, Ninong Komala, Habib Khirzin Al-Ghazali, Dian Yudha Risdianto, Ambun Dindang, Ahmad Fairudz bin Jamaluddin, Mohan Kumar Sammathuria, Norazura Binti Zakaria, Bryan J. Johnson, and Patrick D. Cullis
Atmos. Chem. Phys., 24, 5221–5234, https://doi.org/10.5194/acp-24-5221-2024, https://doi.org/10.5194/acp-24-5221-2024, 2024
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SHADOZ balloon-borne ozone measurements over equatorial Southeast Asia from 1998–2022 reveal that ozone increases during the early months of the year are linked to reduced convective storm activity, which typically redistributes and cleans the atmosphere of ozone. These findings challenge models to replicate the trends produced by the SHADOZ and meteorological observations and emphasize the importance of studying monthly or seasonal instead of annual changes for understanding ozone trends.
Katrin Müller, Peter von der Gathen, and Markus Rex
Atmos. Chem. Phys., 24, 4693–4716, https://doi.org/10.5194/acp-24-4693-2024, https://doi.org/10.5194/acp-24-4693-2024, 2024
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The transport history of tropospheric air masses above the tropical western Pacific is studied by local ozone and relative humidity profile measurements from Palau. A prominent anti-correlation between both tracers separates air masses of different origin and genesis. Back trajectories confirm a local convective origin of the year-round humid ozone-poor background. Anomalously dry ozone-rich air is generated in tropical Asia by pollution and dehydrated during transport via radiative cooling.
Andrea Orfanoz-Cheuquelaf, Carlo Arosio, Alexei Rozanov, Mark Weber, Annette Ladstätter-Weißenmayer, John P. Burrows, Anne M. Thompson, Ryan M. Stauffer, and Debra E. Kollonige
Atmos. Meas. Tech., 17, 1791–1809, https://doi.org/10.5194/amt-17-1791-2024, https://doi.org/10.5194/amt-17-1791-2024, 2024
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Valuable information on the tropospheric ozone column (TrOC) can be obtained globally by combining space-borne limb and nadir measurements (limb–nadir matching, LNM). This study describes the retrieval of TrOC from the OMPS instrument (since 2012) using the LNM technique. The OMPS-LNM TrOC was compared with ozonesondes and other satellite measurements, showing a good agreement with a negative bias within 1 to 4 DU. This new dataset is suitable for pollution studies.
Romain Salignat, Matti Rissanen, Siddharth Iyer, Jean-Luc Baray, Pierre Tulet, Jean-Marc Metzger, Jérôme Brioude, Karine Sellegri, and Clémence Rose
Atmos. Chem. Phys., 24, 3785–3812, https://doi.org/10.5194/acp-24-3785-2024, https://doi.org/10.5194/acp-24-3785-2024, 2024
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Using mass spectrometry data collected at the Maïdo Observatory (2160 m a.s.l., Réunion), we provide the first detailed analysis of molecular cluster chemical composition specifically in the marine free troposphere. The abundance of the identified species is related both to in situ meteorological parameters and air mass history, which also provide insight into their origin. Our work makes an important contribution to documenting the chemistry and physics of the marine free troposphere.
Katrin Müller, Jordis S. Tradowsky, Peter von der Gathen, Christoph Ritter, Sharon Patris, Justus Notholt, and Markus Rex
Atmos. Chem. Phys., 24, 2169–2193, https://doi.org/10.5194/acp-24-2169-2024, https://doi.org/10.5194/acp-24-2169-2024, 2024
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The Palau Atmospheric Observatory is introduced as an ideal site to detect changes in atmospheric composition and dynamics above the remote tropical western Pacific. We focus on the ozone sounding program from 2016–2021, including El Niño 2016. The year-round high convective activity is reflected in dominant low tropospheric ozone and high relative humidity. Their seasonal distributions are unique compared to other tropical sites and are modulated by the Intertropical Convergence Zone.
Glenn-Michael Oomen, Jean-François Müller, Trissevgeni Stavrakou, Isabelle De Smedt, Thomas Blumenstock, Rigel Kivi, Maria Makarova, Mathias Palm, Amelie Röhling, Yao Té, Corinne Vigouroux, Martina M. Friedrich, Udo Frieß, François Hendrick, Alexis Merlaud, Ankie Piters, Andreas Richter, Michel Van Roozendael, and Thomas Wagner
Atmos. Chem. Phys., 24, 449–474, https://doi.org/10.5194/acp-24-449-2024, https://doi.org/10.5194/acp-24-449-2024, 2024
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Natural emissions from vegetation have a profound impact on air quality for their role in the formation of harmful tropospheric ozone and organic aerosols, yet these emissions are highly uncertain. In this study, we quantify emissions of organic gases over Europe using high-quality satellite measurements of formaldehyde. These satellite observations suggest that emissions from vegetation are much higher than predicted by models, especially in southern Europe.
Herman G. J. Smit, Deniz Poyraz, Roeland Van Malderen, Anne M. Thompson, David W. Tarasick, Ryan M. Stauffer, Bryan J. Johnson, and Debra E. Kollonige
Atmos. Meas. Tech., 17, 73–112, https://doi.org/10.5194/amt-17-73-2024, https://doi.org/10.5194/amt-17-73-2024, 2024
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This paper revisits fundamentals of ECC ozonesonde measurements to develop and characterize a methodology to correct for the fast and slow time responses using the JOSIE (Jülich Ozone Sonde Intercomparison Experiment) simulation chamber data. Comparing the new corrected ozonesonde profiles to an accurate ozone UV photometer (OPM) as reference allows us to evaluate the time response correction (TRC) method and to determine calibration functions traceable to one reference with 5 % uncertainty.
Yann Cohen, Didier Hauglustaine, Bastien Sauvage, Susanne Rohs, Patrick Konjari, Ulrich Bundke, Andreas Petzold, Valérie Thouret, Andreas Zahn, and Helmut Ziereis
Atmos. Chem. Phys., 23, 14973–15009, https://doi.org/10.5194/acp-23-14973-2023, https://doi.org/10.5194/acp-23-14973-2023, 2023
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The upper troposphere–lower stratosphere (UTLS) is a key region regarding the lower atmospheric composition. This study consists of a comprehensive evaluation of an up-to-date chemistry–climate model in this layer, using regular in situ measurements based on passenger aircraft. For this purpose, a specific software (Interpol-IAGOS) has been updated and made publicly available. The model reproduces the carbon monoxide peaks due to biomass burning over the continental tropics particularly well.
Leonard Kirago, Örjan Gustafsson, Samuel Mwaniki Gaita, Sophie L. Haslett, Michael J. Gatari, Maria Elena Popa, Thomas Röckmann, Christoph Zellweger, Martin Steinbacher, Jörg Klausen, Christian Félix, David Njiru, and August Andersson
Atmos. Chem. Phys., 23, 14349–14357, https://doi.org/10.5194/acp-23-14349-2023, https://doi.org/10.5194/acp-23-14349-2023, 2023
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This study provides ground-observational evidence that supports earlier suggestions that savanna fires are the main emitters and modulators of carbon monoxide gas in Africa. Using isotope-based techniques, the study has shown that about two-thirds of this gas is emitted from savanna fires, while for urban areas, in this case Nairobi, primary sources approach 100 %. The latter has implications for air quality policy, suggesting primary emissions such as traffic should be targeted.
Maria Tsivlidou, Bastien Sauvage, Yasmine Bennouna, Romain Blot, Damien Boulanger, Hannah Clark, Eric Le Flochmoën, Philippe Nédélec, Valérie Thouret, Pawel Wolff, and Brice Barret
Atmos. Chem. Phys., 23, 14039–14063, https://doi.org/10.5194/acp-23-14039-2023, https://doi.org/10.5194/acp-23-14039-2023, 2023
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The tropics are a region where the ozone increase has been most apparent since 1980 and where observations are sparse. Using aircraft, satellite, and model data, we document the characteristics of tropospheric ozone and CO over the whole tropics for the last 2 decades. We explore the origin of the observed CO anomalies and investigate transport processes driving the tropical CO and O3 distribution. Our study highlights the importance of anthropogenic emissions, mostly over the northern tropics.
Jay Herman, Jerald Ziemke, and Richard McPeters
Atmos. Meas. Tech., 16, 4693–4707, https://doi.org/10.5194/amt-16-4693-2023, https://doi.org/10.5194/amt-16-4693-2023, 2023
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Fourier series multivariate linear regression trends (% per decade) in ozone were estimated from the Merged Ozone Data Set (MOD) from 1979 to 2021 in two different regimes, from 1979 to TA (the date when ozone stopped decreasing) and TA to 2021. The derived TA is a latitude-dependent date, ranging from 1994 to 1998. TA(θ) is a marker for photochemistry dynamics models attempting to represent ozone change over the past 42 years.
Vitali Fioletov, Xiaoyi Zhao, Ihab Abboud, Michael Brohart, Akira Ogyu, Reno Sit, Sum Chi Lee, Irina Petropavlovskikh, Koji Miyagawa, Bryan J. Johnson, Patrick Cullis, John Booth, Glen McConville, and C. Thomas McElroy
Atmos. Chem. Phys., 23, 12731–12751, https://doi.org/10.5194/acp-23-12731-2023, https://doi.org/10.5194/acp-23-12731-2023, 2023
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Stratospheric ozone within the Southern Hemisphere springtime polar vortex has been a subject of intense research since the discovery of the Antarctic ozone hole. The wintertime ozone in the vortex is less studied. We show that the recent wintertime ozone values over the South Pole were about 12 % below the pre-1980s level; i.e., the decline there was nearly twice as large as that over southern midlatitudes. Thus, wintertime ozone there can be used as an indicator of the ozone layer state.
Xiaoyu Sun, Mathias Palm, Katrin Müller, Jonas Hachmeister, and Justus Notholt
Atmos. Chem. Phys., 23, 7075–7090, https://doi.org/10.5194/acp-23-7075-2023, https://doi.org/10.5194/acp-23-7075-2023, 2023
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The tropical western Pacific (TWP) is an active interhemispheric transport region contributing significantly to the global climate. A method to determine the chemical equator was developed by model simulations of a virtual passive tracer to analyze transport in the tropics, with a focus on the TWP region. We compare the chemical equator with tropical rain belts and wind fields and obtain a vertical pattern of interhemispheric transport processes which shows tilt structure in certain seasons.
Ka Lok Chan, Pieter Valks, Klaus-Peter Heue, Ronny Lutz, Pascal Hedelt, Diego Loyola, Gaia Pinardi, Michel Van Roozendael, François Hendrick, Thomas Wagner, Vinod Kumar, Alkis Bais, Ankie Piters, Hitoshi Irie, Hisahiro Takashima, Yugo Kanaya, Yongjoo Choi, Kihong Park, Jihyo Chong, Alexander Cede, Udo Frieß, Andreas Richter, Jianzhong Ma, Nuria Benavent, Robert Holla, Oleg Postylyakov, Claudia Rivera Cárdenas, and Mark Wenig
Earth Syst. Sci. Data, 15, 1831–1870, https://doi.org/10.5194/essd-15-1831-2023, https://doi.org/10.5194/essd-15-1831-2023, 2023
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This paper presents the theoretical basis as well as verification and validation of the Global Ozone Monitoring Experiment-2 (GOME-2) daily and monthly level-3 products.
Bryan J. Johnson, Patrick Cullis, John Booth, Irina Petropavlovskikh, Glen McConville, Birgit Hassler, Gary A. Morris, Chance Sterling, and Samuel Oltmans
Atmos. Chem. Phys., 23, 3133–3146, https://doi.org/10.5194/acp-23-3133-2023, https://doi.org/10.5194/acp-23-3133-2023, 2023
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In 1986, soon after the discovery of the Antarctic ozone hole, NOAA began year-round ozonesonde observations at South Pole Station to measure vertical profiles of ozone and temperature from the surface to 35 km. Balloon-borne ozonesondes launched at this unique site allow for tracking all phases of the yearly springtime ozone hole beginning in late winter and after sunrise, when rapid ozone depletion begins over the South Pole throughout the month of September.
Alkuin M. Koenig, Olivier Magand, Bert Verreyken, Jerome Brioude, Crist Amelynck, Niels Schoon, Aurélie Colomb, Beatriz Ferreira Araujo, Michel Ramonet, Mahesh K. Sha, Jean-Pierre Cammas, Jeroen E. Sonke, and Aurélien Dommergue
Atmos. Chem. Phys., 23, 1309–1328, https://doi.org/10.5194/acp-23-1309-2023, https://doi.org/10.5194/acp-23-1309-2023, 2023
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The global distribution of mercury, a potent neurotoxin, depends on atmospheric transport, chemistry, and interactions between the Earth’s surface and the air. Our understanding of these processes is still hampered by insufficient observations. Here, we present new data from a mountain observatory in the Southern Hemisphere. We give insights into mercury concentrations in air masses coming from aloft, and we show that tropical mountain vegetation may be a daytime source of mercury to the air.
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.
Haolin Wang, Xiao Lu, Daniel J. Jacob, Owen R. Cooper, Kai-Lan Chang, Ke Li, Meng Gao, Yiming Liu, Bosi Sheng, Kai Wu, Tongwen Wu, Jie Zhang, Bastien Sauvage, Philippe Nédélec, Romain Blot, and Shaojia Fan
Atmos. Chem. Phys., 22, 13753–13782, https://doi.org/10.5194/acp-22-13753-2022, https://doi.org/10.5194/acp-22-13753-2022, 2022
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We report significant global tropospheric ozone increases in 1995–2017 based on extensive aircraft and ozonesonde observations. Using GEOS-Chem (Goddard Earth Observing System chemistry model) multi-decadal global simulations, we find that changes in global anthropogenic emissions, in particular the rapid increases in aircraft emissions, contribute significantly to the increases in tropospheric ozone and resulting radiative impact.
Klaus-Peter Heue, Diego Loyola, Fabian Romahn, Walter Zimmer, Simon Chabrillat, Quentin Errera, Jerry Ziemke, and Natalya Kramarova
Atmos. Meas. Tech., 15, 5563–5579, https://doi.org/10.5194/amt-15-5563-2022, https://doi.org/10.5194/amt-15-5563-2022, 2022
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To retrieve tropospheric ozone column information, we subtract stratospheric column data of BASCOE from TROPOMI/S5P total ozone columns.
The new S5P-BASCOE data agree well with existing tropospheric data like OMPS-MERRA-2. The data are also compared to ozone soundings.
The tropospheric ozone columns show the expected temporal and spatial patterns. We will also apply the algorithm to future UV nadir missions like Sentinel 4 or 5 or to recent and ongoing missions like GOME_2 or OMI.
John T. Sullivan, Arnoud Apituley, Nora Mettig, Karin Kreher, K. Emma Knowland, Marc Allaart, Ankie Piters, Michel Van Roozendael, Pepijn Veefkind, Jerry R. Ziemke, Natalya Kramarova, Mark Weber, Alexei Rozanov, Laurence Twigg, Grant Sumnicht, and Thomas J. McGee
Atmos. Chem. Phys., 22, 11137–11153, https://doi.org/10.5194/acp-22-11137-2022, https://doi.org/10.5194/acp-22-11137-2022, 2022
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A TROPOspheric Monitoring Instrument (TROPOMI) validation campaign (TROLIX-19) was held in the Netherlands in September 2019. The research presented here focuses on using ozone lidars from NASA’s Goddard Space Flight Center to better evaluate the characterization of ozone throughout TROLIX-19 as compared to balloon-borne, space-borne and ground-based passive measurements, as well as a global coupled chemistry meteorology model.
Subin Yoon, Alexander Kotsakis, Sergio L. Alvarez, Mark G. Spychala, Elizabeth Klovenski, Paul Walter, Gary Morris, Ernesto Corrales, Alfredo Alan, Jorge A. Diaz, and James H. Flynn
Atmos. Meas. Tech., 15, 4373–4384, https://doi.org/10.5194/amt-15-4373-2022, https://doi.org/10.5194/amt-15-4373-2022, 2022
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SO2 is adverse to human health and the environment. A single SO2 sonde was developed to provide direct SO2 measurement with a greater vertical extent, a lower limit of detection, and less uncertainty relative to the previous dual-sonde method. The single sonde was tested in the field near volcanoes and anthropogenic sources where the sonde measured SO2 ranging from 0.5 to 940 ppb. This lighter-weight payload can be a great candidate to attach to small drones and unmanned aerial vehicles.
Sieglinde Callewaert, Jérôme Brioude, Bavo Langerock, Valentin Duflot, Dominique Fonteyn, Jean-François Müller, Jean-Marc Metzger, Christian Hermans, Nicolas Kumps, Michel Ramonet, Morgan Lopez, Emmanuel Mahieu, and Martine De Mazière
Atmos. Chem. Phys., 22, 7763–7792, https://doi.org/10.5194/acp-22-7763-2022, https://doi.org/10.5194/acp-22-7763-2022, 2022
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A regional atmospheric transport model is used to analyze the factors contributing to CO2, CH4, and CO observations at Réunion Island. We show that the surface observations are dominated by local fluxes and dynamical processes, while the column data are influenced by larger-scale mechanisms such as biomass burning plumes. The model is able to capture the measured time series well; however, the results are highly dependent on accurate boundary conditions and high-resolution emission inventories.
Gérard Ancellet, Sophie Godin-Beekmann, Herman G. J. Smit, Ryan M. Stauffer, Roeland Van Malderen, Renaud Bodichon, and Andrea Pazmiño
Atmos. Meas. Tech., 15, 3105–3120, https://doi.org/10.5194/amt-15-3105-2022, https://doi.org/10.5194/amt-15-3105-2022, 2022
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The 1991–2021 Observatoire de Haute Provence electrochemical concentration cell (ECC) ozonesonde data have been homogenized according to the recommendations of the Ozonesonde Data Quality Assessment panel. Comparisons with ground-based instruments also measuring ozone at the same station (lidar, surface measurements) and with colocated satellite observations show the benefits of this homogenization. Remaining differences between ECC and other observations in the stratosphere are also discussed.
Nora Mettig, Mark Weber, Alexei Rozanov, John P. Burrows, Pepijn Veefkind, Anne M. Thompson, Ryan M. Stauffer, Thierry Leblanc, Gerard Ancellet, Michael J. Newchurch, Shi Kuang, Rigel Kivi, Matthew B. Tully, Roeland Van Malderen, Ankie Piters, Bogumil Kois, René Stübi, and Pavla Skrivankova
Atmos. Meas. Tech., 15, 2955–2978, https://doi.org/10.5194/amt-15-2955-2022, https://doi.org/10.5194/amt-15-2955-2022, 2022
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Vertical ozone profiles from combined spectral measurements in the UV and IR spectral ranges were retrieved by using data from TROPOMI/S5P and CrIS/Suomi-NPP. The vertical resolution and accuracy of the ozone profiles are improved by combining both wavelength ranges compared to retrievals limited to UV or IR spectral data only. The advancement of our TOPAS algorithm for combined measurements is required because in the UV-only retrieval the vertical resolution in the troposphere is very limited.
Nikos Daskalakis, Laura Gallardo, Maria Kanakidou, Johann Rasmus Nüß, Camilo Menares, Roberto Rondanelli, Anne M. Thompson, and Mihalis Vrekoussis
Atmos. Chem. Phys., 22, 4075–4099, https://doi.org/10.5194/acp-22-4075-2022, https://doi.org/10.5194/acp-22-4075-2022, 2022
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Forest fires emit carbon monoxide (CO) that can be transported into the atmosphere far from the sources and reacts to produce ozone (O3) that affects climate, ecosystems and health. O3 is also produced in the stratosphere and can be transported downwards. Using a global numerical model, we found that forest fires can affect CO and O3 even in the South Pacific, the most pristine region of the global ocean, but transport from the stratosphere is a more important O3 source than fires in the region.
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.
Graciela B. Raga, Darrel Baumgardner, Blanca Rios, Yanet Díaz-Esteban, Alejandro Jaramillo, Martin Gallagher, Bastien Sauvage, Pawel Wolff, and Gary Lloyd
Atmos. Chem. Phys., 22, 2269–2292, https://doi.org/10.5194/acp-22-2269-2022, https://doi.org/10.5194/acp-22-2269-2022, 2022
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The In-Service Aircraft for a Global Observing System (IAGOS) is a small fleet of commercial aircraft that carry a suite of meteorological, gas, aerosol, and cloud sensors and have been measuring worldwide for almost 9 years, since late 2011. Extreme ice events (EIEs) have been identified from the IAGOS cloud measurements and linked to surface emissions for biomass and fossil fuel consumption. The results reported here are highly relevant for climate change and flight operations forecasting.
Andrew O. Langford, Christoph J. Senff, Raul J. Alvarez II, Ken C. Aikin, Sunil Baidar, Timothy A. Bonin, W. Alan Brewer, Jerome Brioude, Steven S. Brown, Joel D. Burley, Dani J. Caputi, Stephen A. Conley, Patrick D. Cullis, Zachary C. J. Decker, Stéphanie Evan, Guillaume Kirgis, Meiyun Lin, Mariusz Pagowski, Jeff Peischl, Irina Petropavlovskikh, R. Bradley Pierce, Thomas B. Ryerson, Scott P. Sandberg, Chance W. Sterling, Ann M. Weickmann, and Li Zhang
Atmos. Chem. Phys., 22, 1707–1737, https://doi.org/10.5194/acp-22-1707-2022, https://doi.org/10.5194/acp-22-1707-2022, 2022
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The Fires, Asian, and Stratospheric Transport–Las Vegas Ozone Study (FAST-LVOS) combined lidar, aircraft, and in situ measurements with global models to investigate the contributions of stratospheric intrusions, regional and Asian pollution, and wildfires to background ozone in the southwestern US during May and June 2017 and demonstrated that these processes contributed to background ozone levels that exceeded 70 % of the US National Ambient Air Quality Standard during the 6-week campaign.
Daan Hubert, Klaus-Peter Heue, Jean-Christopher Lambert, Tijl Verhoelst, Marc Allaart, Steven Compernolle, Patrick D. Cullis, Angelika Dehn, Christian Félix, Bryan J. Johnson, Arno Keppens, Debra E. Kollonige, Christophe Lerot, Diego Loyola, Matakite Maata, Sukarni Mitro, Maznorizan Mohamad, Ankie Piters, Fabian Romahn, Henry B. Selkirk, Francisco R. da Silva, Ryan M. Stauffer, Anne M. Thompson, J. Pepijn Veefkind, Holger Vömel, Jacquelyn C. Witte, and Claus Zehner
Atmos. Meas. Tech., 14, 7405–7433, https://doi.org/10.5194/amt-14-7405-2021, https://doi.org/10.5194/amt-14-7405-2021, 2021
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We assess the first 2 years of TROPOMI tropical tropospheric ozone column data. Comparisons to reference measurements by ozonesonde and satellite sensors show that TROPOMI bias (−0.1 to +2.3 DU) and precision (1.5 to 2.5 DU) meet mission requirements. Potential causes of bias and its spatio-temporal structure are discussed, as well as ways to identify sampling errors. Our analysis of known geophysical patterns demonstrates the improved performance of TROPOMI with respect to its predecessors.
Sharmine Akter Simu, Yuzo Miyazaki, Eri Tachibana, Henning Finkenzeller, Jérôme Brioude, Aurélie Colomb, Olivier Magand, Bert Verreyken, Stephanie Evan, Rainer Volkamer, and Trissevgeni Stavrakou
Atmos. Chem. Phys., 21, 17017–17029, https://doi.org/10.5194/acp-21-17017-2021, https://doi.org/10.5194/acp-21-17017-2021, 2021
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The tropical Indian Ocean (IO) is expected to be a significant source of water-soluble organic carbon (WSOC), which is relevant to cloud formation. Our study showed that marine secondary organic formation dominantly contributed to the aerosol WSOC mass at the high-altitude observatory in the southwest IO in the wet season in both marine boundary layer and free troposphere (FT). This suggests that the effect of marine secondary sources is important up to FT, a process missing in climate models.
Song Liu, Pieter Valks, Gaia Pinardi, Jian Xu, Ka Lok Chan, Athina Argyrouli, Ronny Lutz, Steffen Beirle, Ehsan Khorsandi, Frank Baier, Vincent Huijnen, Alkiviadis Bais, Sebastian Donner, Steffen Dörner, Myrto Gratsea, François Hendrick, Dimitris Karagkiozidis, Kezia Lange, Ankie J. M. Piters, Julia Remmers, Andreas Richter, Michel Van Roozendael, Thomas Wagner, Mark Wenig, and Diego G. Loyola
Atmos. Meas. Tech., 14, 7297–7327, https://doi.org/10.5194/amt-14-7297-2021, https://doi.org/10.5194/amt-14-7297-2021, 2021
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In this work, an improved tropospheric NO2 retrieval algorithm from TROPOMI measurements over Europe is presented. The stratospheric estimation is implemented with correction for the dependency of the stratospheric NO2 on the viewing geometry. The AMF calculation is implemented using improved surface albedo, a priori NO2 profiles, and cloud correction. The improved tropospheric NO2 data show good correlations with ground-based MAX-DOAS measurements.
Hannah Clark, Yasmine Bennouna, Maria Tsivlidou, Pawel Wolff, Bastien Sauvage, Brice Barret, Eric Le Flochmoën, Romain Blot, Damien Boulanger, Jean-Marc Cousin, Philippe Nédélec, Andreas Petzold, and Valérie Thouret
Atmos. Chem. Phys., 21, 16237–16256, https://doi.org/10.5194/acp-21-16237-2021, https://doi.org/10.5194/acp-21-16237-2021, 2021
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We examined 27 years of IAGOS (In-service Aircraft for a Global Observing System) profiles at Frankfurt to see if there were unusual features during the spring of 2020 related to COVID-19 lockdowns in Europe. Increased ozone near the surface was partly linked to the reduction in emissions. Carbon monoxide decreased near the surface, but the impact of the lockdowns was offset by polluted air masses from elsewhere. There were small reductions in ozone and carbon monoxide in the free troposphere.
Gaëlle Dufour, Didier Hauglustaine, Yunjiang Zhang, Maxim Eremenko, Yann Cohen, Audrey Gaudel, Guillaume Siour, Mathieu Lachatre, Axel Bense, Bertrand Bessagnet, Juan Cuesta, Jerry Ziemke, Valérie Thouret, and Bo Zheng
Atmos. Chem. Phys., 21, 16001–16025, https://doi.org/10.5194/acp-21-16001-2021, https://doi.org/10.5194/acp-21-16001-2021, 2021
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The IASI observations and the LMDZ-OR-INCA model simulations show negative ozone trends in the Central East China region in the lower free (3–6 km column) and the upper free (6–9 km column) troposphere. Sensitivity studies from the model show that the Chinese anthropogenic emissions contribute to more than 50 % in the trend. The reduction in NOx emissions that has occurred since 2013 in China seems to lead to a decrease in ozone in the free troposphere, contrary to the increase at the surface.
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.
Victor Lannuque, Bastien Sauvage, Brice Barret, Hannah Clark, Gilles Athier, Damien Boulanger, Jean-Pierre Cammas, Jean-Marc Cousin, Alain Fontaine, Eric Le Flochmoën, Philippe Nédélec, Hervé Petetin, Isabelle Pfaffenzeller, Susanne Rohs, Herman G. J. Smit, Pawel Wolff, and Valérie Thouret
Atmos. Chem. Phys., 21, 14535–14555, https://doi.org/10.5194/acp-21-14535-2021, https://doi.org/10.5194/acp-21-14535-2021, 2021
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The African intertropical troposphere is one of the world areas where the increase in ozone mixing ratio has been most pronounced since 1980 and where high carbon monoxide mixing ratios are found in altitude. In this article, IAGOS aircraft measurements, IASI satellite instrument observations, and SOFT-IO model products are used to explore the seasonal distribution variations and the origin of ozone and carbon monoxide over the African upper troposphere.
Nora Mettig, Mark Weber, Alexei Rozanov, Carlo Arosio, John P. Burrows, Pepijn Veefkind, Anne M. Thompson, Richard Querel, Thierry Leblanc, Sophie Godin-Beekmann, Rigel Kivi, and Matthew B. Tully
Atmos. Meas. Tech., 14, 6057–6082, https://doi.org/10.5194/amt-14-6057-2021, https://doi.org/10.5194/amt-14-6057-2021, 2021
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TROPOMI is a nadir-viewing satellite that has observed global atmospheric trace gases at unprecedented spatial resolution since 2017. The retrieval of ozone profiles with high accuracy has been demonstrated using the TOPAS (Tikhonov regularised Ozone Profile retrievAl with SCIATRAN) algorithm and applying appropriate spectral corrections to TROPOMI UV data. Ozone profiles from TROPOMI were compared to ozonesonde and lidar profiles, showing an agreement to within 5 % in the stratosphere.
Bert Verreyken, Crist Amelynck, Niels Schoon, Jean-François Müller, Jérôme Brioude, Nicolas Kumps, Christian Hermans, Jean-Marc Metzger, Aurélie Colomb, and Trissevgeni Stavrakou
Atmos. Chem. Phys., 21, 12965–12988, https://doi.org/10.5194/acp-21-12965-2021, https://doi.org/10.5194/acp-21-12965-2021, 2021
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We present a 2-year dataset of trace gas concentrations, specifically an array of volatile organic compounds (VOCs), recorded at the Maïdo observatory, a remote tropical high-altitude site located on a small island in the southwest Indian Ocean. We found that island-scale transport is an important driver for the daily cycle of VOC concentrations. During the day, surface emissions from the island affect the atmospheric composition at Maïdo greatly, while at night this impact is strongly reduced.
Isabelle De Smedt, Gaia Pinardi, Corinne Vigouroux, Steven Compernolle, Alkis Bais, Nuria Benavent, Folkert Boersma, Ka-Lok Chan, Sebastian Donner, Kai-Uwe Eichmann, Pascal Hedelt, François Hendrick, Hitoshi Irie, Vinod Kumar, Jean-Christopher Lambert, Bavo Langerock, Christophe Lerot, Cheng Liu, Diego Loyola, Ankie Piters, Andreas Richter, Claudia Rivera Cárdenas, Fabian Romahn, Robert George Ryan, Vinayak Sinha, Nicolas Theys, Jonas Vlietinck, Thomas Wagner, Ting Wang, Huan Yu, and Michel Van Roozendael
Atmos. Chem. Phys., 21, 12561–12593, https://doi.org/10.5194/acp-21-12561-2021, https://doi.org/10.5194/acp-21-12561-2021, 2021
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This paper assess the performances of the TROPOMI formaldehyde observations compared to its predecessor OMI at different spatial and temporal scales. We also use a global network of MAX-DOAS instruments to validate both satellite datasets for a large range of HCHO columns. The precision obtained with daily TROPOMI observations is comparable to monthly OMI observations. We present clear detection of weak HCHO column enhancements related to shipping emissions in the Indian Ocean.
Jianfeng Li, Yuhang Wang, Ruixiong Zhang, Charles Smeltzer, Andrew Weinheimer, Jay Herman, K. Folkert Boersma, Edward A. Celarier, Russell W. Long, James J. Szykman, Ruben Delgado, Anne M. Thompson, Travis N. Knepp, Lok N. Lamsal, Scott J. Janz, Matthew G. Kowalewski, Xiong Liu, and Caroline R. Nowlan
Atmos. Chem. Phys., 21, 11133–11160, https://doi.org/10.5194/acp-21-11133-2021, https://doi.org/10.5194/acp-21-11133-2021, 2021
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Comprehensive evaluations of simulated diurnal cycles of NO2 and NOy concentrations, vertical profiles, and tropospheric vertical column densities at two different resolutions with various measurements during the DISCOVER-AQ 2011 campaign show potential distribution biases of NOx emissions in the National Emissions Inventory 2011 at both 36 and 4 km resolutions, providing another possible explanation for the overestimation of model results.
Romain Blot, Philippe Nedelec, Damien Boulanger, Pawel Wolff, Bastien Sauvage, Jean-Marc Cousin, Gilles Athier, Andreas Zahn, Florian Obersteiner, Dieter Scharffe, Hervé Petetin, Yasmine Bennouna, Hannah Clark, and Valérie Thouret
Atmos. Meas. Tech., 14, 3935–3951, https://doi.org/10.5194/amt-14-3935-2021, https://doi.org/10.5194/amt-14-3935-2021, 2021
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A lack of information about temporal changes in measurement uncertainties is an area of concern for long-term trend studies of the key compounds which have a direct or indirect impact on climate change. The IAGOS program has measured O3 and CO within the troposphere and lower stratosphere for more than 25 years. In this study, we demonstrated that the IAGOS database can be treated as one continuous program and is therefore appropriate for studies of long-term trends.
Cited articles
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Short summary
Ozone profile trends from SHADOZ sondes and IAGOS aircraft show that ozone in the tropical free troposphere (FT) is not growing fast except over equatorial SE Asia. This agrees with HEGIFTOM (Van Malderen et al., 2025), Stauffer et al. (2024) and Gaudel et al. (2024) TOAR-II papers. Other findings are as follows: (1) our trends are independent of method (QR, MLR) and (2) sample number (SN) (i.e., SHADOZ sampling is sufficient), and (3) all ground-based trends constitute the gold standard for satellite-derived trends.
Ozone profile trends from SHADOZ sondes and IAGOS aircraft show that ozone in the tropical free...
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