Articles | Volume 24, issue 9
https://doi.org/10.5194/acp-24-5659-2024
© Author(s) 2024. 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-24-5659-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Opinion
| Highlight paper
| 
15 May 2024
Opinion | Highlight paper |
| 15 May 2024
| 15 May 2024
Opinion: A research roadmap for exploring atmospheric methane removal via iron salt aerosol
Katrine A. Gorham
CORRESPONDING AUTHOR
Spark Climate Solutions, Covina, CA 91723, USA
Sam Abernethy
Spark Climate Solutions, Covina, CA 91723, USA
Tyler R. Jones
Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80303, USA
Peter Hess
Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
Natalie M. Mahowald
Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY 14853, USA
Daphne Meidan
Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Blas Cabrera, Spanish National Research Council, 28006 Madrid, Spain
Matthew S. Johnson
Department of Chemistry, University of Copenhagen, 2100 Copenhagen Ø, Denmark
Maarten M. J. W. van Herpen
Acacia Impact Innovation, 5384 BB Bernheze, the Netherlands
Yangyang Xu
Department of Atmospheric Sciences, Texas A&M University, College Station, TX 77843, USA
Alfonso Saiz-Lopez
Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Blas Cabrera, Spanish National Research Council, 28006 Madrid, Spain
Thomas Röckmann
Institute for Marine and Atmospheric Research Utrecht, Department of Physics, Faculty of Science, Utrecht University, 3584 CS Utrecht, the Netherlands
Chloe A. Brashear
Institute for Marine and Atmospheric Research Utrecht, Department of Physics, Faculty of Science, Utrecht University, 3584 CS Utrecht, the Netherlands
Erika Reinhardt
Spark Climate Solutions, Covina, CA 91723, USA
David Mann
Spark Climate Solutions, Covina, CA 91723, USA
Related authors
No articles found.
Stephen J. Harris, Sven Krautwurst, Jorg Hacker, Mark Lunt, Borchardt Jakob, Mei Bai, Hartmut Boesch, Tarra Brain, John Philip Burrows, Shakti Chakravarty, Robert A. Field, Rebecca E. Fisher, James L. France, Konstantin Gerilowski, Oke Huhs, Wolfgang Junkermann, Bryce F. J. Kelly, Martin Kumm, Mathias Lanoisellé, Wolfgang Lieff, Andrew McGrath, Adrian Murphy, Thomas Röckmann, Zoe Salmon, Josua Schindewolf, Jakob Thoböll, Carina van der Veen, and Heinrich Bovensmann
EGUsphere, https://doi.org/10.5194/egusphere-2026-772, https://doi.org/10.5194/egusphere-2026-772, 2026
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
Short summary
The accuracy of methods used to estimate and report fugitive methane emissions from Australian coal mines remains unclear. This study compares airborne emission rate estimates with reported estimates from 17 coal mines in the Bowen Basin, a region accounting for 45 % of national coal production. Results show good agreement for underground coal mines, but poor agreement for surface coal mines, suggesting improvements to surface coal mine reporting methods is needed to improve inventory reporting.
Allison R. Moon, Leyang Liu, Xuan Wang, Yuk-Chun Chan, Alyson Fritzmann, Ryan Pound, Amy Lees, Lewis Marden, Mat Evans, Lucy J. Carpenter, Jochen Stutz, Joel A. Thornton, Gordon Novak, Andrew Rollins, Gregory P. Schill, Xu-Cheng He, Henning Finkenzeller, Mago Reza, Rainer Volkamer, Kelvin H. Bates, Alfonso Saiz-Lopez, Anoop S. Mahajan, and Becky Alexander
Atmos. Chem. Phys., 26, 2353–2389, https://doi.org/10.5194/acp-26-2353-2026, https://doi.org/10.5194/acp-26-2353-2026, 2026
Short summary
Short summary
Global chemical transport models previously treated aerosols as a sink for reactive iodine (Iy); however, aerosol iodide is also a source of Iy via heterogeneous reactions involving hypohalous acids and halogen nitrates. We implemented this chemistry into GEOS-Chem, in addition to explicitly representing three aerosol iodine types: soluble organic iodine (SOI), iodide, and iodate. We found that aerosol recycling of iodide to form Iy is more than twice as fast as the other Iy sources combined.
Thomas Röckmann, Malika Menoud, Jacoline van Es, Carina van der Veen, Hossein Maazallahi, Pawel Jagoda, Jaroslav M. Necki, Jakub Bartyzel, Piotr Korben, Sara Defratyka, Martina Schmidt, Marius Corbu, Sebastian Iancu, Andreea Calcan, Magdalena Ardelean, Sorin Ghemulet, Cristian Pop, Andrei Radovici, Alexandru Mereuta, Horatiu Stefanie, and Calin Baciu
Atmos. Chem. Phys., 26, 723–731, https://doi.org/10.5194/acp-26-723-2026, https://doi.org/10.5194/acp-26-723-2026, 2026
Short summary
Short summary
We report the isotopic composition of CH4 emitted from 48 installations in the gas production region of Transylvania, Romania which confirm the biogenic origin of the Transylvanian gas, produced by hydrogenotrophic CO2 reduction. This is similar to values reported previously from natural seeps and natural gas in a major city in the region. However, is more depleted in heavy isotopes than the oil-associated gas emitted in the Southern Romanian Plain, and gas leakages in the city of Bucharest.
Lisa Ardoin, Catherine Larose, Jean-Louis Tison, Christoph Keuschnig, Vasileios Gkinis, Saïda El Amri, Pierre-Henry Blard, Paul Bierman, Thomas Blunier, Dorthe Dahl-Jensen, Charlotte Maistriau, Jørgen-Peder Steffensen, Thomas Röckmann, and François Fripiat
EGUsphere, https://doi.org/10.5194/egusphere-2025-6204, https://doi.org/10.5194/egusphere-2025-6204, 2026
Short summary
Short summary
We investigated gas dynamics at the ice–bed interface of two Greenland ice cores to assess methane and carbon dioxide behaviour beneath ice sheets. At Camp Century, methane diffuses into the ice and is partly oxidized. At GRIP, methane remains preserved despite oxygen. These contrasts suggest that methane oxidation is controlled by local basal conditions, including ice thickness and substrate availability.
Paul Waldmann, Max Eckl, Leon Knez, Klaus-Dirk Gottschaldt, Alina Fiehn, Christian Mallaun, Michał Gałkowski, Christoph Kiemle, Ronald Hutjes, Thomas Röckmann, Huilin Chen, and Anke Roiger
Atmos. Meas. Tech., 19, 185–210, https://doi.org/10.5194/amt-19-185-2026, https://doi.org/10.5194/amt-19-185-2026, 2026
Short summary
Short summary
Nitrous oxide and methane emissions from agriculture need to be reduced, therefore emissions must be understood to effectively mitigate them. This is the first approach to measure those emissions aircraft-based, to assess their magnitude and drivers. We identified emission hotspots and temporal changes in agricultural emissions in the Netherlands. Our approach is applicable to further greenhouse gas emitters, therefore it builds a step towards more comprehensive emission quantification.
Robbert P. J. Moonen, Getachew A. Adnew, Jordi Vilà-Guerau de Arellano, David J. Bonell Fontas, and Thomas Röckmann
EGUsphere, https://doi.org/10.5194/egusphere-2025-5969, https://doi.org/10.5194/egusphere-2025-5969, 2025
Short summary
Short summary
We used high-frequency H₂O and CO₂ isotope measurements at ATTO to separate water vapour and carbon dioxide fluxes into their component processes. During midday, ~95 % of evapotranspiration came from plant transpiration. Isotopes also revealed the balance between photosynthesis and respiration, showing strong sensitivity to leaf CO₂ ratios. These results improve understanding of Amazon ecosystem function.
Sara M. Defratyka, Julianne M. Fernandez, Getachew A. Adnew, Guannan Dong, Peter M. J. Douglas, Daniel L. Eldridge, Giuseppe Etiope, Thomas Giunta, Mojhgan A. Haghnegahdar, Alexander N. Hristov, Nicole Hultquist, Iñaki Vadillo, Josue Jautzy, Ji-Hyun Kim, Jabrane Labidi, Ellen Lalk, Wil Leavitt, Jiawen Li, Li-Hung Lin, Jiarui Liu, Lucía Ojeda, Shuhei Ono, Jeemin H. Rhim, Thomas Röckmann, Barbara Sherwood Lollar, Malavika Sivan, Jiayang Sun, Gregory T. Ventura, David T. Wang, Edward D. Young, Naizhong Zhang, and Tim Arnold
Earth Syst. Sci. Data, 17, 6889–6910, https://doi.org/10.5194/essd-17-6889-2025, https://doi.org/10.5194/essd-17-6889-2025, 2025
Short summary
Short summary
Measurement of methane’s doubly substituted isotopologues at natural abundances holds promise for better constraining the Earth’s atmospheric CH4 budget. We compiled 1475 measurements from field samples and laboratory experiments, conducted since 2014, to facilitate the differentiation of CH4 formation pathways and processes, to identify existing gaps limiting application of Δ13CH3D and Δ12CH2D2, and to develop isotope ratio source signature inputs for global CH4 flux modelling.
Bibhasvata Dasgupta, Sudhanshu Pandey, Sander Houweling, Malika Menoud, Carina van der Veen, John Miller, Ben Riddell-Young, Sylvia Englund Michel, Peter Sperlich, Shinji Morimoto, Ryo Fujita, Ingeborg Levin, Cordelia Veidt, Stephen Platt, Christine Groot Zwaaftink, Cathrine Lund Myhre, Ceres Woolley Maisch, Rebecca Fisher, Euan G. Nisbet, James France, Rowena Moss, Nicola Warwick, and Thomas Röckmann
EGUsphere, https://doi.org/10.5194/egusphere-2025-5571, https://doi.org/10.5194/egusphere-2025-5571, 2025
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
Short summary
Methane is a strong greenhouse gas, and its rise since the mid-2000s is debated in terms of sources and sinks. Using top-down and bottom-up data, along with inversion models and methane isotopes (δ13C-CH4 and δD-CH4), we find that wetlands are the primary driver of post-2006 increases, followed by agriculture and fossil fuels. Methane's lifetime has decreased by about 0.1 years. We also assess how isotope signatures and sink processes influence uncertainties.
Bibhasvata Dasgupta, Malika Menoud, Carina van der Veen, Ingeborg Levin, Cordelia Veidt, Heiko Moossen, Sylvia Englund Michel, Peter Sperlich, Shinji Morimoto, Ryo Fujita, Taku Umezawa, Stephen Platt, Christine Groot Zwaaftink, Cathrine Lund Myhre, Rebecca Fisher, David Lowry, Euan G. Nisbet, James France, Ceres Woolley Maisch, Gordon Brailsford, Rowena Moss, Daisuke Goto, Sudhanshu Pandey, Sander Houweling, Nicola Warwick, and Thomas Röckmann
Atmos. Meas. Tech., 18, 6591–6607, https://doi.org/10.5194/amt-18-6591-2025, https://doi.org/10.5194/amt-18-6591-2025, 2025
Short summary
Short summary
We combined long-term methane mole fraction and isotope measurements from eight laboratories that sample high-latitude stations to compare, offset correct and harmonise the datasets into a hemisphere merged timeseries. Because each laboratory uses slightly different methods, we adjusted the data to make it directly comparable. This allowed us to create a consistent record of atmospheric methane concentration and its isotopes from 1988 to 2023.
Daniel P. Johnson and Matthew S. Johnson
EGUsphere, https://doi.org/10.21203/rs.3.rs-3966645/v2, https://doi.org/10.21203/rs.3.rs-3966645/v2, 2025
This preprint is open for discussion and under review for Atmospheric Measurement Techniques (AMT).
Short summary
Short summary
We developed a new way to calculate how light moves through the atmosphere when it is strongly scattered by clouds, dust, or surfaces. Existing tools often become unstable under such conditions, but our method, called EigenFlux, remains accurate and efficient. This makes it possible to better interpret satellite and ground-based observations of the atmosphere, which in turn helps improve air quality studies and climate research.
Sophie L. Baartman, Steven M. Driever, Maarten L. J. Wassenaar, Linda M. J. Kooijmans, Nerea Ubierna, Leon Mossink, Maria E. Popa, Ara Cho, Lisa Wingate, Thomas Röckmann, Steven M. A. C. van Heuven, and Maarten C. Krol
Biogeosciences, 22, 5683–5703, https://doi.org/10.5194/bg-22-5683-2025, https://doi.org/10.5194/bg-22-5683-2025, 2025
Short summary
Short summary
Carbonyl sulfide (COS) is a proposed tracer for gross primary production. For the first time, COS and carbon dioxide (CO2) uptake fluxes and isotope discrimination were jointly measured in sunflower and papyrus plants, using a flow-through plant chamber approach and varying light availability. COS isotope discrimination did not differ significantly between the species, nor with changes in light. CO2 fluxes and isotope values provided additional valuable information for data interpretation.
Elinor Tuffnell, Emma Leedham-Elvidge, William Sturges, Harald Bönisch, Karina Adcock, Paul Fraser, Paul Krummel, David Oram, Ray Langenfelds, Thomas Röckmann, Luke Western, Jens Mühle, and Johannes Laube
EGUsphere, https://doi.org/10.5194/egusphere-2025-4941, https://doi.org/10.5194/egusphere-2025-4941, 2025
Short summary
Short summary
The greater the stratospheric lifetime of chlorofluorocarbons (CFCs), the longer they will deplete ozone. This paper investigates four longer-lived CFCs, and discovers two of them have much shorter lifetimes than previously believed. Demonstrating emissions of these compounds are higher than assumed, to account for their abundance. Unusually this paper uses stratospheric whole-air samples, rather than models or lab-based experiments, to derive policy-relevant metrics for these compounds.
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
Short summary
Short summary
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.
Robbert P. J. Moonen, Getachew A. Adnew, Jordi Vilà-Guerau de Arellano, Oscar K. Hartogensis, David J. Bonell Fontas, Shujiro Komiya, Sam P. Jones, and Thomas Röckmann
Atmos. Chem. Phys., 25, 12197–12212, https://doi.org/10.5194/acp-25-12197-2025, https://doi.org/10.5194/acp-25-12197-2025, 2025
Short summary
Short summary
Understory ejections are distinct turbulent features emerging in prime tall-forest ecosystems. We share a method to isolate understory ejections based on H2O–CO2 anomaly quadrants. From these, we calculate the flux contributions of understory ejections and all flux quadrants. In addition, we show that a distinctly depleted isotopic composition can be found in the ejected water vapour. Finally, we explored the role of clouds as a potential trigger for understory ejections.
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
Short summary
Short summary
The first comprehensive dataset of tropospheric ozone over oceans/polar regions is presented, including 77 ship/buoy and 48 aircraft campaign observations (1977–2022, 0–5000 m altitude), supplemented by ozonesonde and surface data. Air masses isolated from land for 72+ hours are systematically selected as essentially oceanic. Among the 11 global regions, they show daytime decreases of 11–16 % in the tropics, while near-zero depletions are rare, unlike in the Arctic, implying different mechanisms.
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
Short summary
Short summary
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.
Judith Tettenborn, Daniel Zavala-Araiza, Daan Stroeken, Hossein Maazallahi, Carina van der Veen, Arjan Hensen, Ilona Velzeboer, Pim van den Bulk, Felix Vogel, Lawson Gillespie, Sebastien Ars, James France, David Lowry, Rebecca Fisher, and Thomas Röckmann
Atmos. Meas. Tech., 18, 3569–3584, https://doi.org/10.5194/amt-18-3569-2025, https://doi.org/10.5194/amt-18-3569-2025, 2025
Short summary
Short summary
Measurements of methane with vehicle-based sensors are an effective method to identify and quantify leaks from urban gas distribution systems. We deliberately released methane in different environments and calibrated the response of different methane analysers when they transected the plumes in a vehicle. We derived an improved statistical function for consistent emission estimations using different instruments. Repeated transects reduce the uncertainty in emission rate estimates.
Lison Soussaintjean, Jochen Schmitt, Joël Savarino, J. Andy Menking, Edward J. Brook, Barbara Seth, Vladimir Lipenkov, Thomas Röckmann, and Hubertus Fischer
EGUsphere, https://doi.org/10.5194/egusphere-2025-3108, https://doi.org/10.5194/egusphere-2025-3108, 2025
Short summary
Short summary
Nitrous oxide (N2O) produced in dust-rich Antarctic ice complicates the reconstruction of past atmospheric levels from ice core records. Using isotope analysis, we show that N2O forms from two nitrogen precursors, one being nitrate. For the first time, we demonstrate that the site preference (SP) of N2O reflects the isotopic difference between these precursors, not the production pathway, which challenges the common interpretation of SP.
Getachew Agmuas Adnew, Gerbrand Koren, Neha Mehendale, Sergey Gromov, Maarten Krol, and Thomas Röckmann
Atmos. Meas. Tech., 18, 2701–2719, https://doi.org/10.5194/amt-18-2701-2025, https://doi.org/10.5194/amt-18-2701-2025, 2025
Short summary
Short summary
This study presents high-precision measurements of ∆′17O(CO2). Key findings include the extension of the N2O–∆′17O correlation to the upper troposphere and the identification of significant differences in the N2O–∆′17O slope in StratoClim samples. Additionally, the ∆′17O measurements are used to estimate global stratospheric production and surface removal of ∆′17O, providing an independent estimate of global vegetation CO2 exchange.
Juan A. Añel, Juan-Carlos Antuña-Marrero, Antonio Cid Samamed, Celia Pérez-Souto, Laura de la Torre, Maria Antonia Valente, Yuri Brugnara, Alfonso Saiz-Lopez, and Luis Gimeno
Earth Syst. Sci. Data, 17, 2437–2446, https://doi.org/10.5194/essd-17-2437-2025, https://doi.org/10.5194/essd-17-2437-2025, 2025
Short summary
Short summary
Ozone (discovered in 1837) was first measured in 1847 using paper strips that reacted with ozone, providing an indication of its concentration based on colour changes. Here, we present the data, covering over 60 years of daily observations conducted along the eastern Atlantic coast, spanning from the tropics to the northern extratropics.
Gerrit Kuhlmann, Foteini Stavropoulou, Stefan Schwietzke, Daniel Zavala-Araiza, Andrew Thorpe, Andreas Hueni, Lukas Emmenegger, Andreea Calcan, Thomas Röckmann, and Dominik Brunner
Atmos. Chem. Phys., 25, 5371–5385, https://doi.org/10.5194/acp-25-5371-2025, https://doi.org/10.5194/acp-25-5371-2025, 2025
Short summary
Short summary
A measurement campaign in 2019 found that methane emissions from oil and gas in Romania were significantly higher than reported. In 2021, our follow-up campaign using airborne remote sensing showed a marked decreases in emissions by 20 %–60 % due to improved infrastructure. The study highlights the importance of measurement-based emission monitoring and illustrates the value of a multi-scale assessment integrating ground-based observations with large-scale airborne remote sensing campaigns.
Natalie M. Mahowald, Longlei Li, Julius Vira, Marje Prank, Douglas S. Hamilton, Hitoshi Matsui, Ron L. Miller, P. Louis Lu, Ezgi Akyuz, Daphne Meidan, Peter Hess, Heikki Lihavainen, Christine Wiedinmyer, Jenny Hand, Maria Grazia Alaimo, Célia Alves, Andres Alastuey, Paulo Artaxo, Africa Barreto, Francisco Barraza, Silvia Becagli, Giulia Calzolai, Shankararaman Chellam, Ying Chen, Patrick Chuang, David D. Cohen, Cristina Colombi, Evangelia Diapouli, Gaetano Dongarra, Konstantinos Eleftheriadis, Johann Engelbrecht, Corinne Galy-Lacaux, Cassandra Gaston, Dario Gomez, Yenny González Ramos, Roy M. Harrison, Chris Heyes, Barak Herut, Philip Hopke, Christoph Hüglin, Maria Kanakidou, Zsofia Kertesz, Zbigniew Klimont, Katriina Kyllönen, Fabrice Lambert, Xiaohong Liu, Remi Losno, Franco Lucarelli, Willy Maenhaut, Beatrice Marticorena, Randall V. Martin, Nikolaos Mihalopoulos, Yasser Morera-Gómez, Adina Paytan, Joseph Prospero, Sergio Rodríguez, Patricia Smichowski, Daniela Varrica, Brenna Walsh, Crystal L. Weagle, and Xi Zhao
Atmos. Chem. Phys., 25, 4665–4702, https://doi.org/10.5194/acp-25-4665-2025, https://doi.org/10.5194/acp-25-4665-2025, 2025
Short summary
Short summary
Aerosol particles are an important part of the Earth system, but their concentrations are spatially and temporally heterogeneous, as well as being variable in size and composition. Here, we present a new compilation of PM2.5 and PM10 aerosol observations, focusing on the spatial variability across different observational stations, including composition, and demonstrate a method for comparing the data sets to model output.
Chloe A. Brashear, Tyler R. Jones, Valerie Morris, Bruce H. Vaughn, William H. G. Roberts, William B. Skorski, Abigail G. Hughes, Richard Nunn, Sune Olander Rasmussen, Kurt M. Cuffey, Bo M. Vinther, Todd Sowers, Christo Buizert, Vasileios Gkinis, Christian Holme, Mari F. Jensen, Sofia E. Kjellman, Petra M. Langebroek, Florian Mekhaldi, Kevin S. Rozmiarek, Jonathan W. Rheinlænder, Margit H. Simon, Giulia Sinnl, Silje Smith-Johnsen, and James W. C. White
Clim. Past, 21, 529–546, https://doi.org/10.5194/cp-21-529-2025, https://doi.org/10.5194/cp-21-529-2025, 2025
Short summary
Short summary
We use a series of spectral techniques to quantify the strength of high-frequency climate variability in northeastern Greenland to 50 000 ka before present. Importantly, we find that variability consistently decreases hundreds of years prior to Dansgaard–Oeschger warming events. Model simulations suggest a change in North Atlantic sea ice behavior contributed to this pattern, thus providing new information on the conditions which preceded abrupt climate change during the Last Glacial Period.
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
Short summary
Short summary
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.
Chenrui Diao, Yangyang Xu, Aixue Hu, and Zhili Wang
Atmos. Chem. Phys., 25, 2167–2180, https://doi.org/10.5194/acp-25-2167-2025, https://doi.org/10.5194/acp-25-2167-2025, 2025
Short summary
Short summary
Industrial aerosol increases in Asia and reductions in North America and Europe in 1980–2020 influenced climate changes over the Pacific Ocean differently. Asian aerosols caused El Niño-like temperature patterns and slightly weakened the natural variation in the North Pacific, while reduced emissions of western countries led to extensive warming in middle–high latitudes of the North Pacific. Human impacts on the Pacific climate may change when emission reduction occurs over Asia in the future.
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
Short summary
Short summary
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.
Svend L. Bager, Luna Zamok, Stephan P. A. Sauer, and Matthew S. Johnson
EGUsphere, https://doi.org/10.48550/arXiv.2401.10053, https://doi.org/10.48550/arXiv.2401.10053, 2025
Preprint archived
Short summary
Short summary
In this work we have studied by means of quantum chemical calculations at the CCSD(T) or CASPT2 level the kinetics of reactions of both bromine and iodine compounds with Hg, which are discussed to lead to the atmospheric oxidation of Hg. The particular interest is in the question whether the reactions with iodine compounds are as fast as the corresponding reactions with bromine compounds and therefore could also contribute to mercury depletion events.
Mingxu Liu, Hitoshi Matsui, Douglas S. Hamilton, Sagar D. Rathod, Kara D. Lamb, and Natalie M. Mahowald
Atmos. Chem. Phys., 24, 13115–13127, https://doi.org/10.5194/acp-24-13115-2024, https://doi.org/10.5194/acp-24-13115-2024, 2024
Short summary
Short summary
Atmospheric aerosol deposition provides bioavailable iron to promote marine primary production, yet the estimates of its fluxes remain highly uncertain. This study, by performing global aerosol simulations, demonstrates that iron-containing particle size upon emission is a critical factor in regulating soluble iron input to open oceans. Further observational constraints on this are needed to reduce modeling uncertainties.
Michael S. Town, Hans Christian Steen-Larsen, Sonja Wahl, Anne-Katrine Faber, Melanie Behrens, Tyler R. Jones, and Arny Sveinbjornsdottir
The Cryosphere, 18, 3653–3683, https://doi.org/10.5194/tc-18-3653-2024, https://doi.org/10.5194/tc-18-3653-2024, 2024
Short summary
Short summary
A polar snow isotope dataset from northeast Greenland shows that snow changes isotopically after deposition. Summer snow sometimes enriches in oxygen-18, making it seem warmer than it actually was when the snow fell. Deuterium excess sometimes changes after deposition, making the snow seem to come from warmer, closer, or more humid places. After a year of aging, deuterium excess of summer snow layers always increases. Reinterpretation of deuterium excess used in climate models is necessary.
Hella van Asperen, Thorsten Warneke, Alessandro Carioca de Araújo, Bruce Forsberg, Sávio José Filgueiras Ferreira, Thomas Röckmann, Carina van der Veen, Sipko Bulthuis, Leonardo Ramos de Oliveira, Thiago de Lima Xavier, Jailson da Mata, Marta de Oliveira Sá, Paulo Ricardo Teixeira, Julie Andrews de França e Silva, Susan Trumbore, and Justus Notholt
Biogeosciences, 21, 3183–3199, https://doi.org/10.5194/bg-21-3183-2024, https://doi.org/10.5194/bg-21-3183-2024, 2024
Short summary
Short summary
Carbon monoxide (CO) is regarded as an important indirect greenhouse gas. Soils can emit and take up CO, but, until now, uncertainty remains as to which process dominates in tropical rainforests. We present the first soil CO flux measurements from a tropical rainforest. Based on our observations, we report that tropical rainforest soils are a net source of CO. In addition, we show that valley streams and inundated areas are likely additional hot spots of CO in the ecosystem.
Jin Ma, Linda M. J. Kooijmans, Norbert Glatthor, Stephen A. Montzka, Marc von Hobe, Thomas Röckmann, and Maarten C. Krol
Atmos. Chem. Phys., 24, 6047–6070, https://doi.org/10.5194/acp-24-6047-2024, https://doi.org/10.5194/acp-24-6047-2024, 2024
Short summary
Short summary
The global budget of atmospheric COS can be optimised by inverse modelling using TM5-4DVAR, with the co-constraints of NOAA surface observations and MIPAS satellite data. We found reduced COS biosphere uptake from inversions and improved land and ocean separation using MIPAS satellite data assimilation. Further improvements are expected from better quantification of COS ocean and biosphere fluxes.
Heesung Chong, Gonzalo González Abad, Caroline R. Nowlan, Christopher Chan Miller, Alfonso Saiz-Lopez, Rafael P. Fernandez, Hyeong-Ahn Kwon, Zolal Ayazpour, Huiqun Wang, Amir H. Souri, Xiong Liu, Kelly Chance, Ewan O'Sullivan, Jhoon Kim, Ja-Ho Koo, William R. Simpson, François Hendrick, Richard Querel, Glen Jaross, Colin Seftor, and Raid M. Suleiman
Atmos. Meas. Tech., 17, 2873–2916, https://doi.org/10.5194/amt-17-2873-2024, https://doi.org/10.5194/amt-17-2873-2024, 2024
Short summary
Short summary
We present a new bromine monoxide (BrO) product derived using radiances measured from OMPS-NM on board the Suomi-NPP satellite. This product provides nearly a decade of global stratospheric and tropospheric column retrievals, a feature that is currently rare in publicly accessible datasets. Both stratospheric and tropospheric columns from OMPS-NM demonstrate robust performance, exhibiting good agreement with ground-based observations collected at three stations (Lauder, Utqiagvik, and Harestua).
Malavika Sivan, Thomas Röckmann, Carina van der Veen, and Maria Elena Popa
Atmos. Meas. Tech., 17, 2687–2705, https://doi.org/10.5194/amt-17-2687-2024, https://doi.org/10.5194/amt-17-2687-2024, 2024
Short summary
Short summary
We have set up a measurement system for methane-clumped isotopologues. We have built an extraction and purification system to extract pure methane for these measurements, for samples of various origins, including atmospheric air, for which we need to process about 1000 L of air for one measurement. We report here the technical setup for extraction and measurements, as well as the calibration, and we give an overview of the samples measured so far.
Marie K. Mikkelsen, Jesper B. Liisberg, Maarten M. J. W. van Herpen, Kurt V. Mikkelsen, and Matthew S. Johnson
Aerosol Research, 2, 31–47, https://doi.org/10.5194/ar-2-31-2024, https://doi.org/10.5194/ar-2-31-2024, 2024
Short summary
Short summary
We analyze the mechanism whereby sunlight and iron catalyze the production of chlorine from chloride in sea spray aerosol. This process occurs naturally over the North Atlantic and is the single most important source of chlorine. We investigate the mechanism using quantum chemistry, laboratory experiments, and aqueous chemistry modelling. The process will change depending on competing ions, light distribution, acidity, and chloride concentration.
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
Short summary
Short summary
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.
Natalie M. Mahowald, Longlei Li, Julius Vira, Marje Prank, Douglas S. Hamilton, Hitoshi Matsui, Ron L. Miller, Louis Lu, Ezgi Akyuz, Daphne Meidan, Peter Hess, Heikki Lihavainen, Christine Wiedinmyer, Jenny Hand, Maria Grazia Alaimo, Célia Alves, Andres Alastuey, Paulo Artaxo, Africa Barreto, Francisco Barraza, Silvia Becagli, Giulia Calzolai, Shankarararman Chellam, Ying Chen, Patrick Chuang, David D. Cohen, Cristina Colombi, Evangelia Diapouli, Gaetano Dongarra, Konstantinos Eleftheriadis, Corinne Galy-Lacaux, Cassandra Gaston, Dario Gomez, Yenny González Ramos, Hannele Hakola, Roy M. Harrison, Chris Heyes, Barak Herut, Philip Hopke, Christoph Hüglin, Maria Kanakidou, Zsofia Kertesz, Zbiginiw Klimont, Katriina Kyllönen, Fabrice Lambert, Xiaohong Liu, Remi Losno, Franco Lucarelli, Willy Maenhaut, Beatrice Marticorena, Randall V. Martin, Nikolaos Mihalopoulos, Yasser Morera-Gomez, Adina Paytan, Joseph Prospero, Sergio Rodríguez, Patricia Smichowski, Daniela Varrica, Brenna Walsh, Crystal Weagle, and Xi Zhao
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2024-1, https://doi.org/10.5194/essd-2024-1, 2024
Preprint withdrawn
Short summary
Short summary
Aerosol particles can interact with incoming solar radiation and outgoing long wave radiation, change cloud properties, affect photochemistry, impact surface air quality, and when deposited impact surface albedo of snow and ice, and modulate carbon dioxide uptake by the land and ocean. Here we present a new compilation of aerosol observations including composition, a methodology for comparing the datasets to model output, and show the implications of these results using one model.
Natalie M. Mahowald, Longlei Li, Samuel Albani, Douglas S. Hamilton, and Jasper F. Kok
Atmos. Chem. Phys., 24, 533–551, https://doi.org/10.5194/acp-24-533-2024, https://doi.org/10.5194/acp-24-533-2024, 2024
Short summary
Short summary
Estimating past aerosol radiative effects and their uncertainties is an important topic in climate science. Aerosol radiative effects propagate into large uncertainties in estimates of how present and future climate evolves with changing greenhouse gas emissions. A deeper understanding of how aerosols interacted with the atmospheric energy budget under past climates is hindered in part by a lack of relevant paleo-observations and in part because less attention has been paid to the problem.
Alina Fiehn, Maximilian Eckl, Julian Kostinek, Michał Gałkowski, Christoph Gerbig, Michael Rothe, Thomas Röckmann, Malika Menoud, Hossein Maazallahi, Martina Schmidt, Piotr Korbeń, Jarosław Neçki, Mila Stanisavljević, Justyna Swolkień, Andreas Fix, and Anke Roiger
Atmos. Chem. Phys., 23, 15749–15765, https://doi.org/10.5194/acp-23-15749-2023, https://doi.org/10.5194/acp-23-15749-2023, 2023
Short summary
Short summary
During the CoMet mission in the Upper Silesian Coal Basin (USCB) ground-based and airborne air samples were taken and analyzed for the isotopic composition of CH4 to derive the mean signature of the USCB and source signatures of individual coal mines. Using δ2H signatures, the biogenic emissions from the USCB account for 15 %–50 % of total emissions, which is underestimated in common emission inventories. This demonstrates the importance of δ2H-CH4 observations for methane source apportionment.
Robbert P. J. Moonen, Getachew A. Adnew, Oscar K. Hartogensis, Jordi Vilà-Guerau de Arellano, David J. Bonell Fontas, and Thomas Röckmann
Atmos. Meas. Tech., 16, 5787–5810, https://doi.org/10.5194/amt-16-5787-2023, https://doi.org/10.5194/amt-16-5787-2023, 2023
Short summary
Short summary
Isotope fluxes allow for net ecosystem gas exchange fluxes to be partitioned into sub-components like plant assimilation, respiration and transpiration, which can help us better understand the environmental drivers of each partial flux. We share the results of a field campaign isotope fluxes were derived using a combination of laser spectroscopy and eddy covariance. We found lag times and high frequency signal loss in the isotope fluxes we derived and present methods to correct for both.
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
Short summary
Short summary
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.
Hossein Maazallahi, Antonio Delre, Charlotte Scheutz, Anders M. Fredenslund, Stefan Schwietzke, Hugo Denier van der Gon, and Thomas Röckmann
Atmos. Meas. Tech., 16, 5051–5073, https://doi.org/10.5194/amt-16-5051-2023, https://doi.org/10.5194/amt-16-5051-2023, 2023
Short summary
Short summary
Measurement methods are increasingly deployed to verify reported methane emissions of gas leaks. This study describes unique advantages and limitations of three methods. Two methods are rapidly deployed, but uncertainties and biases exist for some leak locations. In contrast, the suction method could accurately determine leak rates in principle. However, this method, which provides data for the German emission inventory, creates an overall low bias in our study due to non-random site selection.
Tim René de Groot, Anne Margriet Mol, Katherine Mesdag, Pierre Ramond, Rachel Ndhlovu, Julia Catherine Engelmann, Thomas Röckmann, and Helge Niemann
Biogeosciences, 20, 3857–3872, https://doi.org/10.5194/bg-20-3857-2023, https://doi.org/10.5194/bg-20-3857-2023, 2023
Short summary
Short summary
This study investigates methane dynamics in the Wadden Sea. Our measurements revealed distinct variations triggered by seasonality and tidal forcing. The methane budget was higher in warmer seasons but surprisingly high in colder seasons. Methane dynamics were amplified during low tides, flushing the majority of methane into the North Sea or releasing it to the atmosphere. Methanotrophic activity was also elevated during low tide but mitigated only a small fraction of the methane efflux.
Foteini Stavropoulou, Katarina Vinković, Bert Kers, Marcel de Vries, Steven van Heuven, Piotr Korbeń, Martina Schmidt, Julia Wietzel, Pawel Jagoda, Jaroslav M. Necki, Jakub Bartyzel, Hossein Maazallahi, Malika Menoud, Carina van der Veen, Sylvia Walter, Béla Tuzson, Jonas Ravelid, Randulph Paulo Morales, Lukas Emmenegger, Dominik Brunner, Michael Steiner, Arjan Hensen, Ilona Velzeboer, Pim van den Bulk, Hugo Denier van der Gon, Antonio Delre, Maklawe Essonanawe Edjabou, Charlotte Scheutz, Marius Corbu, Sebastian Iancu, Denisa Moaca, Alin Scarlat, Alexandru Tudor, Ioana Vizireanu, Andreea Calcan, Magdalena Ardelean, Sorin Ghemulet, Alexandru Pana, Aurel Constantinescu, Lucian Cusa, Alexandru Nica, Calin Baciu, Cristian Pop, Andrei Radovici, Alexandru Mereuta, Horatiu Stefanie, Alexandru Dandocsi, Bas Hermans, Stefan Schwietzke, Daniel Zavala-Araiza, Huilin Chen, and Thomas Röckmann
Atmos. Chem. Phys., 23, 10399–10412, https://doi.org/10.5194/acp-23-10399-2023, https://doi.org/10.5194/acp-23-10399-2023, 2023
Short summary
Short summary
In this study, we quantify CH4 emissions from onshore oil production sites in Romania at source and facility level using a combination of ground- and drone-based measurement techniques. We show that the total CH4 emissions in our studied areas are much higher than the emissions reported to UNFCCC, and up to three-quarters of the detected emissions are related to operational venting. Our results suggest that oil and gas production infrastructure in Romania holds a massive mitigation potential.
María Gonçalves Ageitos, Vincenzo Obiso, Ron L. Miller, Oriol Jorba, Martina Klose, Matt Dawson, Yves Balkanski, Jan Perlwitz, Sara Basart, Enza Di Tomaso, Jerónimo Escribano, Francesca Macchia, Gilbert Montané, Natalie M. Mahowald, Robert O. Green, David R. Thompson, and Carlos Pérez García-Pando
Atmos. Chem. Phys., 23, 8623–8657, https://doi.org/10.5194/acp-23-8623-2023, https://doi.org/10.5194/acp-23-8623-2023, 2023
Short summary
Short summary
Dust aerosols affect our climate differently depending on their mineral composition. We include dust mineralogy in an atmospheric model considering two existing soil maps, which still have large associated uncertainties. The soil data and the distribution of the minerals in different aerosol sizes are key to our model performance. We find significant regional variations in climate-relevant variables, which supports including mineralogy in our current models and the need for improved soil maps.
Cyril Caram, Sophie Szopa, Anne Cozic, Slimane Bekki, Carlos A. Cuevas, and Alfonso Saiz-Lopez
Geosci. Model Dev., 16, 4041–4062, https://doi.org/10.5194/gmd-16-4041-2023, https://doi.org/10.5194/gmd-16-4041-2023, 2023
Short summary
Short summary
We studied the role of halogenated compounds (containing chlorine, bromine and iodine), emitted by natural processes (mainly above the oceans), in the chemistry of the lower layers of the atmosphere. We introduced this relatively new chemistry in a three-dimensional climate–chemistry model and looked at how this chemistry will disrupt the ozone. We showed that the concentration of ozone decreases by 22 % worldwide and that of the atmospheric detergent, OH, by 8 %.
Andreas Forstmaier, Jia Chen, Florian Dietrich, Juan Bettinelli, Hossein Maazallahi, Carsten Schneider, Dominik Winkler, Xinxu Zhao, Taylor Jones, Carina van der Veen, Norman Wildmann, Moritz Makowski, Aydin Uzun, Friedrich Klappenbach, Hugo Denier van der Gon, Stefan Schwietzke, and Thomas Röckmann
Atmos. Chem. Phys., 23, 6897–6922, https://doi.org/10.5194/acp-23-6897-2023, https://doi.org/10.5194/acp-23-6897-2023, 2023
Short summary
Short summary
Large cities emit greenhouse gases which contribute to global warming. In this study, we measured the release of one important green house gas, methane, in Hamburg. Multiple sources that contribute to methane emissions were located and quantified. Methane sources were found to be mainly caused by human activity (e.g., by release from oil and gas refineries). Moreover, potential natural sources have been located, such as the Elbe River and lakes.
Danny M. Leung, Jasper F. Kok, Longlei Li, Gregory S. Okin, Catherine Prigent, Martina Klose, Carlos Pérez García-Pando, Laurent Menut, Natalie M. Mahowald, David M. Lawrence, and Marcelo Chamecki
Atmos. Chem. Phys., 23, 6487–6523, https://doi.org/10.5194/acp-23-6487-2023, https://doi.org/10.5194/acp-23-6487-2023, 2023
Short summary
Short summary
Desert dust modeling is important for understanding climate change, as dust regulates the atmosphere's greenhouse effect and radiation. This study formulates and proposes a more physical and realistic desert dust emission scheme for global and regional climate models. By considering more aeolian processes in our emission scheme, our simulations match better against dust observations than existing schemes. We believe this work is vital in improving dust representation in climate models.
Truls Andersen, Zhao Zhao, Marcel de Vries, Jaroslaw Necki, Justyna Swolkien, Malika Menoud, Thomas Röckmann, Anke Roiger, Andreas Fix, Wouter Peters, and Huilin Chen
Atmos. Chem. Phys., 23, 5191–5216, https://doi.org/10.5194/acp-23-5191-2023, https://doi.org/10.5194/acp-23-5191-2023, 2023
Short summary
Short summary
The Upper Silesian Coal Basin, Poland, is one of the hot spots of methane emissions in Europe. Using an uncrewed aerial vehicle (UAV), we performed atmospheric measurements of methane concentrations downwind of five ventilation shafts in this region and determined the emission rates from the individual shafts. We found a strong correlation between quantified shaft-averaged emission rates and hourly inventory data, which also allows us to estimate the methane emissions from the entire region.
Manon Rocco, Erin Dunne, Alexia Saint-Macary, Maija Peltola, Theresa Barthelmeß, Neill Barr, Karl Safi, Andrew Marriner, Stacy Deppeler, James Harnwell, Anja Engel, Aurélie Colomb, Alfonso Saiz-Lopez, Mike Harvey, Cliff S. Law, and Karine Sellegri
EGUsphere, https://doi.org/10.5194/egusphere-2023-516, https://doi.org/10.5194/egusphere-2023-516, 2023
Preprint archived
Short summary
Short summary
During the Sea2cloud campaign in the Southern Pacific Ocean, we measured air-sea emissions from phytopankton of two key atmospheric compounds: DMS and MeSH. These compounds are well-known to play a great role in atmospheric chemistry and climate. We see in this paper that these compounds are most emited by the nanophytoplankton population. We provide here parameters for climate models to predict future trends of the emissions of these compounds and their roles and impacts on the global warming.
François Burgay, Rafael Pedro Fernández, Delia Segato, Clara Turetta, Christopher S. Blaszczak-Boxe, Rachael H. Rhodes, Claudio Scarchilli, Virginia Ciardini, Carlo Barbante, Alfonso Saiz-Lopez, and Andrea Spolaor
The Cryosphere, 17, 391–405, https://doi.org/10.5194/tc-17-391-2023, https://doi.org/10.5194/tc-17-391-2023, 2023
Short summary
Short summary
The paper presents the first ice-core record of bromine (Br) in the Antarctic plateau. By the observation of the ice core and the application of atmospheric chemical models, we investigate the behaviour of bromine after its deposition into the snowpack, with interest in the effect of UV radiation change connected to the formation of the ozone hole, the role of volcanic deposition, and the possible use of Br to reconstruct past sea ice changes from ice core collect in the inner Antarctic plateau.
Bryce F. J. Kelly, Xinyi Lu, Stephen J. Harris, Bruno G. Neininger, Jorg M. Hacker, Stefan Schwietzke, Rebecca E. Fisher, James L. France, Euan G. Nisbet, David Lowry, Carina van der Veen, Malika Menoud, and Thomas Röckmann
Atmos. Chem. Phys., 22, 15527–15558, https://doi.org/10.5194/acp-22-15527-2022, https://doi.org/10.5194/acp-22-15527-2022, 2022
Short summary
Short summary
This study explores using the composition of methane of in-flight atmospheric air samples for greenhouse gas inventory verification. The air samples were collected above one of the largest coal seam gas production regions in the world. Adjacent to these gas fields are coal mines, Australia's largest cattle feedlot, and over 1 million grazing cattle. The results are also used to identify methane mitigation opportunities.
Markus Jesswein, Rafael P. Fernandez, Lucas Berná, Alfonso Saiz-Lopez, Jens-Uwe Grooß, Ryan Hossaini, Eric C. Apel, Rebecca S. Hornbrook, Elliot L. Atlas, Donald R. Blake, Stephen Montzka, Timo Keber, Tanja Schuck, Thomas Wagenhäuser, and Andreas Engel
Atmos. Chem. Phys., 22, 15049–15070, https://doi.org/10.5194/acp-22-15049-2022, https://doi.org/10.5194/acp-22-15049-2022, 2022
Short summary
Short summary
This study presents the global and seasonal distribution of the two major brominated short-lived substances CH2Br2 and CHBr3 in the upper troposphere and lower stratosphere based on observations from several aircraft campaigns. They show similar seasonality for both hemispheres, except in the respective hemispheric autumn lower stratosphere. A comparison with the TOMCAT and CAM-Chem models shows good agreement in the annual mean but larger differences in the seasonal consideration.
Longlei Li, Natalie M. Mahowald, Jasper F. Kok, Xiaohong Liu, Mingxuan Wu, Danny M. Leung, Douglas S. Hamilton, Louisa K. Emmons, Yue Huang, Neil Sexton, Jun Meng, and Jessica Wan
Geosci. Model Dev., 15, 8181–8219, https://doi.org/10.5194/gmd-15-8181-2022, https://doi.org/10.5194/gmd-15-8181-2022, 2022
Short summary
Short summary
This study advances mineral dust parameterizations in the Community Atmospheric Model (CAM; version 6.1). Efforts include 1) incorporating a more physically based dust emission scheme; 2) updating the dry deposition scheme; and 3) revising the gravitational settling velocity to account for dust asphericity. Substantial improvements achieved with these updates can help accurately quantify dust–climate interactions using CAM, such as the dust-radiation and dust–cloud interactions.
Louise Bøge Frederickson, Ruta Sidaraviciute, Johan Albrecht Schmidt, Ole Hertel, and Matthew Stanley Johnson
Atmos. Chem. Phys., 22, 13949–13965, https://doi.org/10.5194/acp-22-13949-2022, https://doi.org/10.5194/acp-22-13949-2022, 2022
Short summary
Short summary
Low-cost sensors see additional pollution that is not seen with traditional regional air quality monitoring stations. This additional local pollution is sufficient to cause exceedance of the World Health Organization exposure thresholds. Analysis shows that a significant amount of the NO2 pollution we observe is local, mainly due to road traffic. This article demonstrates how networks of nodes containing low-cost pollution sensors can powerfully extend existing monitoring programmes.
Malika Menoud, Carina van der Veen, Dave Lowry, Julianne M. Fernandez, Semra Bakkaloglu, James L. France, Rebecca E. Fisher, Hossein Maazallahi, Mila Stanisavljević, Jarosław Nęcki, Katarina Vinkovic, Patryk Łakomiec, Janne Rinne, Piotr Korbeń, Martina Schmidt, Sara Defratyka, Camille Yver-Kwok, Truls Andersen, Huilin Chen, and Thomas Röckmann
Earth Syst. Sci. Data, 14, 4365–4386, https://doi.org/10.5194/essd-14-4365-2022, https://doi.org/10.5194/essd-14-4365-2022, 2022
Short summary
Short summary
Emission sources of methane (CH4) can be distinguished with measurements of CH4 stable isotopes. We present new measurements of isotope signatures of various CH4 sources in Europe, mainly anthropogenic, sampled from 2017 to 2020. The present database also contains the most recent update of the global signature dataset from the literature. The dataset improves CH4 source attribution and the understanding of the global CH4 budget.
Chaman Gul, Shichang Kang, Siva Praveen Puppala, Xiaokang Wu, Cenlin He, Yangyang Xu, Inka Koch, Sher Muhammad, Rajesh Kumar, and Getachew Dubache
Atmos. Chem. Phys., 22, 8725–8737, https://doi.org/10.5194/acp-22-8725-2022, https://doi.org/10.5194/acp-22-8725-2022, 2022
Short summary
Short summary
This work aims to understand concentrations, spatial variability, and potential source regions of light-absorbing impurities (black carbon aerosols, dust particles, and organic carbon) in the surface snow of central and western Himalayan glaciers and their impact on snow albedo and radiative forcing.
Ye Wang, Natalie Mahowald, Peter Hess, Wenxiu Sun, and Gang Chen
Atmos. Chem. Phys., 22, 7575–7592, https://doi.org/10.5194/acp-22-7575-2022, https://doi.org/10.5194/acp-22-7575-2022, 2022
Short summary
Short summary
PM2.5 is positively related to anticyclonic wave activity (AWA) changes close to the observing sites. Changes between current and future climates in AWA can explain up to 75 % of PM2.5 variability at some stations using a linear regression model. Our analysis indicates that higher PM2.5 concentrations occur when a positive AWA anomaly is prominent, which could be critical for understanding how pollutants respond to changing atmospheric circulation and for developing robust pollution projections.
Hisahiro Takashima, Yugo Kanaya, Saki Kato, Martina M. Friedrich, Michel Van Roozendael, Fumikazu Taketani, Takuma Miyakawa, Yuichi Komazaki, Carlos A. Cuevas, Alfonso Saiz-Lopez, and Takashi Sekiya
Atmos. Chem. Phys., 22, 4005–4018, https://doi.org/10.5194/acp-22-4005-2022, https://doi.org/10.5194/acp-22-4005-2022, 2022
Short summary
Short summary
We have undertaken atmospheric iodine monoxide (IO) observations in the global marine boundary layer with a wide latitudinal coverage and sea surface temperature (SST) range. We conclude that atmospheric iodine is abundant over the Western Pacific warm pool, appearing as an iodine fountain, where ozone (O3) minima occur. Our study also found negative correlations between IO and O3 concentrations over IO maxima, which requires reconsideration of the initiation process of halogen activation.
Stephen M. Platt, Øystein Hov, Torunn Berg, Knut Breivik, Sabine Eckhardt, Konstantinos Eleftheriadis, Nikolaos Evangeliou, Markus Fiebig, Rebecca Fisher, Georg Hansen, Hans-Christen Hansson, Jost Heintzenberg, Ove Hermansen, Dominic Heslin-Rees, Kim Holmén, Stephen Hudson, Roland Kallenborn, Radovan Krejci, Terje Krognes, Steinar Larssen, David Lowry, Cathrine Lund Myhre, Chris Lunder, Euan Nisbet, Pernilla B. Nizzetto, Ki-Tae Park, Christina A. Pedersen, Katrine Aspmo Pfaffhuber, Thomas Röckmann, Norbert Schmidbauer, Sverre Solberg, Andreas Stohl, Johan Ström, Tove Svendby, Peter Tunved, Kjersti Tørnkvist, Carina van der Veen, Stergios Vratolis, Young Jun Yoon, Karl Espen Yttri, Paul Zieger, Wenche Aas, and Kjetil Tørseth
Atmos. Chem. Phys., 22, 3321–3369, https://doi.org/10.5194/acp-22-3321-2022, https://doi.org/10.5194/acp-22-3321-2022, 2022
Short summary
Short summary
Here we detail the history of the Zeppelin Observatory, a unique global background site and one of only a few in the high Arctic. We present long-term time series of up to 30 years of atmospheric components and atmospheric transport phenomena. Many of these time series are important to our understanding of Arctic and global atmospheric composition change. Finally, we discuss the future of the Zeppelin Observatory and emerging areas of future research on the Arctic atmosphere.
Julius Vira, Peter Hess, Money Ossohou, and Corinne Galy-Lacaux
Atmos. Chem. Phys., 22, 1883–1904, https://doi.org/10.5194/acp-22-1883-2022, https://doi.org/10.5194/acp-22-1883-2022, 2022
Short summary
Short summary
Ammonia is one of the main components of nitrogen deposition. Here we use a new model to assess the ammonia emissions from agriculture, the largest anthropogenic source of ammonia. The model results are consistent with earlier estimates over industrialized regions in agreement with observations. However, the model predicts much higher emissions over sub-Saharan Africa compared to earlier estimates. Available observations from surface stations and satellites support these higher emissions.
Zhiyuan Gao, Nicolas-Xavier Geilfus, Alfonso Saiz-Lopez, and Feiyue Wang
Atmos. Chem. Phys., 22, 1811–1824, https://doi.org/10.5194/acp-22-1811-2022, https://doi.org/10.5194/acp-22-1811-2022, 2022
Short summary
Short summary
Every spring in the Arctic, a series of photochemical events occur over the ice-covered ocean, known as bromine explosion events, ozone depletion events, and mercury depletion events. Here we report the re-creation of these events at an outdoor sea ice facility in Winnipeg, Canada, far away from the Arctic. The success provides a new platform with new opportunities to uncover fundamental mechanisms of these Arctic springtime phenomena and how they may change in a changing climate.
Juhi Nagori, Narcisa Nechita-Bândă, Sebastian Oscar Danielache, Masumi Shinkai, Thomas Röckmann, and Maarten Krol
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2022-68, https://doi.org/10.5194/acp-2022-68, 2022
Publication in ACP not foreseen
Short summary
Short summary
The sulfur isotopes (32S and 34S) were studied to understand the sources, sinks and processes of carbonyl sulphide (COS) in the atmosphere. COS is an important source of sulfur aerosol in the stratosphere (SSA). Few measurements of COS and SSA exist, but with our 1D model, we were able to match them and show the importance of COS to sulfate formation. Moreover, we are able to highlight some important processes for the COS budget and where measurements may fill a gap in current knowledge.
Merve Polat, Jesper Baldtzer Liisberg, Morten Krogsbøll, Thomas Blunier, and Matthew S. Johnson
Atmos. Meas. Tech., 14, 8041–8067, https://doi.org/10.5194/amt-14-8041-2021, https://doi.org/10.5194/amt-14-8041-2021, 2021
Short summary
Short summary
We have designed a process for removing methane from a gas stream so that nitrous oxide can be measured without interference. These are both key long-lived greenhouse gases frequently studied in relation to ice cores, plants, water treatment and so on. However, many researchers are not aware of the problem of methane interference, and in addition there have not been good methods available for solving the problem. Here we present and evaluate such a method.
Chenrui Diao, Yangyang Xu, and Shang-Ping Xie
Atmos. Chem. Phys., 21, 18499–18518, https://doi.org/10.5194/acp-21-18499-2021, https://doi.org/10.5194/acp-21-18499-2021, 2021
Short summary
Short summary
Anthropogenic aerosol (AA) emission has shown a zonal redistribution since the 1980s, with a decline in the Western Hemisphere (WH) high latitudes and an increase in the Eastern Hemisphere (EH) low latitudes. This study compares the role of zonally asymmetric forcings affecting the climate. The WH aerosol reduction dominates the poleward shift of the Hadley cell and the North Pacific warming, while the EH AA forcing is largely confined to the emission domain and induces local cooling responses.
Kevin S. Rozmiarek, Bruce H. Vaughn, Tyler R. Jones, Valerie Morris, William B. Skorski, Abigail G. Hughes, Jack Elston, Sonja Wahl, Anne-Katrine Faber, and Hans Christian Steen-Larsen
Atmos. Meas. Tech., 14, 7045–7067, https://doi.org/10.5194/amt-14-7045-2021, https://doi.org/10.5194/amt-14-7045-2021, 2021
Short summary
Short summary
We have designed an unmanned aerial vehicle (UAV) sampling platform for operation in extreme polar environments that is capable of sampling atmospheric water vapor for subsequent measurement of water isotopes. During flight, we measure location, temperature, humidity, and pressure to determine the height of the planetary boundary layer (PBL) using algorithms, allowing for strategic decision-making by the pilot to collect samples in glass flasks contained in the nose cone of the UAV.
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
Short summary
Short summary
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.
Abigail G. Hughes, Sonja Wahl, Tyler R. Jones, Alexandra Zuhr, Maria Hörhold, James W. C. White, and Hans Christian Steen-Larsen
The Cryosphere, 15, 4949–4974, https://doi.org/10.5194/tc-15-4949-2021, https://doi.org/10.5194/tc-15-4949-2021, 2021
Short summary
Short summary
Water isotope records in Greenland and Antarctic ice cores are a valuable proxy for paleoclimate reconstruction and are traditionally thought to primarily reflect precipitation input. However,
post-depositional processes are hypothesized to contribute to the isotope climate signal. In this study we use laboratory experiments, field experiments, and modeling to show that sublimation and vapor–snow isotope exchange can rapidly influence the isotopic composition of the snowpack.
Malika Menoud, Carina van der Veen, Jaroslaw Necki, Jakub Bartyzel, Barbara Szénási, Mila Stanisavljević, Isabelle Pison, Philippe Bousquet, and Thomas Röckmann
Atmos. Chem. Phys., 21, 13167–13185, https://doi.org/10.5194/acp-21-13167-2021, https://doi.org/10.5194/acp-21-13167-2021, 2021
Short summary
Short summary
Using measurements of methane isotopes in ambient air and a 3D atmospheric transport model, in Krakow, Poland, we mainly detected fossil-fuel-related sources, coming from coal mining in Silesia and from the use of natural gas in the city. Emission inventories report large emissions from coal mine activity in Silesia, which is in agreement with our measurements. However, methane sources in the urban area of Krakow related to the use of fossil fuels might be underestimated in the inventories.
Anoop S. Mahajan, Mriganka S. Biswas, Steffen Beirle, Thomas Wagner, Anja Schönhardt, Nuria Benavent, and Alfonso Saiz-Lopez
Atmos. Chem. Phys., 21, 11829–11842, https://doi.org/10.5194/acp-21-11829-2021, https://doi.org/10.5194/acp-21-11829-2021, 2021
Short summary
Short summary
Iodine plays a vital role in oxidation chemistry over Antarctica, with past observations showing highly elevated levels of iodine oxide (IO) leading to severe depletion of boundary layer ozone. We present IO observations over three summers (2015–2017) at the Indian Antarctic bases of Bharati and Maitri. IO was observed during all campaigns with mixing ratios below 2 pptv, which is lower than the peak levels observed in West Antarctica, showing the differences in regional chemistry and emissions.
Xinyi Lu, Stephen J. Harris, Rebecca E. Fisher, James L. France, Euan G. Nisbet, David Lowry, Thomas Röckmann, Carina van der Veen, Malika Menoud, Stefan Schwietzke, and Bryce F. J. Kelly
Atmos. Chem. Phys., 21, 10527–10555, https://doi.org/10.5194/acp-21-10527-2021, https://doi.org/10.5194/acp-21-10527-2021, 2021
Short summary
Short summary
Many coal seam gas (CSG) facilities in the Surat Basin, Australia, are adjacent to other sources of methane, including agricultural, urban, and natural seeps. This makes it challenging to estimate the amount of methane being emitted into the atmosphere from CSG facilities. This research demonstrates that measurements of the carbon and hydrogen stable isotopic composition of methane can distinguish between and apportion methane emissions from CSG facilities, cattle, and many other sources.
Anoop S. Mahajan, Qinyi Li, Swaleha Inamdar, Kirpa Ram, Alba Badia, and Alfonso Saiz-Lopez
Atmos. Chem. Phys., 21, 8437–8454, https://doi.org/10.5194/acp-21-8437-2021, https://doi.org/10.5194/acp-21-8437-2021, 2021
Short summary
Short summary
Using a regional model, we show that iodine-catalysed reactions cause large regional changes in the chemical composition in the northern Indian Ocean, with peak changes of up to 25 % in O3, 50 % in nitrogen oxides (NO and NO2), 15 % in hydroxyl radicals (OH), 25 % in hydroperoxyl radicals (HO2), and up to a 50 % change in the nitrate radical (NO3). These results show the importance of including iodine chemistry in modelling the atmosphere in this region.
Jasper F. Kok, Adeyemi A. Adebiyi, Samuel Albani, Yves Balkanski, Ramiro Checa-Garcia, Mian Chin, Peter R. Colarco, Douglas S. Hamilton, Yue Huang, Akinori Ito, Martina Klose, Danny M. Leung, Longlei Li, Natalie M. Mahowald, Ron L. Miller, Vincenzo Obiso, Carlos Pérez García-Pando, Adriana Rocha-Lima, Jessica S. Wan, and Chloe A. Whicker
Atmos. Chem. Phys., 21, 8127–8167, https://doi.org/10.5194/acp-21-8127-2021, https://doi.org/10.5194/acp-21-8127-2021, 2021
Short summary
Short summary
Desert dust interacts with virtually every component of the Earth system, including the climate system. We develop a new methodology to represent the global dust cycle that integrates observational constraints on the properties and abundance of desert dust with global atmospheric model simulations. We show that the resulting representation of the global dust cycle is more accurate than what can be obtained from a large number of current climate global atmospheric models.
Jasper F. Kok, Adeyemi A. Adebiyi, Samuel Albani, Yves Balkanski, Ramiro Checa-Garcia, Mian Chin, Peter R. Colarco, Douglas S. Hamilton, Yue Huang, Akinori Ito, Martina Klose, Longlei Li, Natalie M. Mahowald, Ron L. Miller, Vincenzo Obiso, Carlos Pérez García-Pando, Adriana Rocha-Lima, and Jessica S. Wan
Atmos. Chem. Phys., 21, 8169–8193, https://doi.org/10.5194/acp-21-8169-2021, https://doi.org/10.5194/acp-21-8169-2021, 2021
Short summary
Short summary
The many impacts of dust on the Earth system depend on dust mineralogy, which varies between dust source regions. We constrain the contribution of the world’s main dust source regions by integrating dust observations with global model simulations. We find that Asian dust contributes more and that North African dust contributes less than models account for. We obtain a dataset of each source region’s contribution to the dust cycle that can be used to constrain dust impacts on the Earth system.
Max Thomas, Johannes C. Laube, Jan Kaiser, Samuel Allin, Patricia Martinerie, Robert Mulvaney, Anna Ridley, Thomas Röckmann, William T. Sturges, and Emmanuel Witrant
Atmos. Chem. Phys., 21, 6857–6873, https://doi.org/10.5194/acp-21-6857-2021, https://doi.org/10.5194/acp-21-6857-2021, 2021
Short summary
Short summary
CFC gases are destroying the Earth's life-protecting ozone layer. We improve understanding of CFC destruction by measuring the isotopic fingerprint of the carbon in the three most abundant CFCs. These are the first such measurements in the main region where CFCs are destroyed – the stratosphere. We reconstruct the atmospheric isotope histories of these CFCs back to the 1950s by measuring air extracted from deep snow and using a model. The model and the measurements are generally consistent.
David Garcia-Nieto, Nuria Benavent, Rafael Borge, and Alfonso Saiz-Lopez
Atmos. Meas. Tech., 14, 2941–2955, https://doi.org/10.5194/amt-14-2941-2021, https://doi.org/10.5194/amt-14-2941-2021, 2021
Short summary
Short summary
Trace gases play a key role in the chemistry of urban atmospheres. Therefore, knowledge about their spatial distribution is needed to fully characterize the air quality in urban areas. Using a new Multi-AXis Differential Optical Absorption Spectroscopy two-dimensional (MAXDOAS-2D) instrument, along with inversion algorithms, we report for the first time two-dimensional maps of NO2 concentrations in the city of Madrid, Spain.
Longlei Li, Natalie M. Mahowald, Ron L. Miller, Carlos Pérez García-Pando, Martina Klose, Douglas S. Hamilton, Maria Gonçalves Ageitos, Paul Ginoux, Yves Balkanski, Robert O. Green, Olga Kalashnikova, Jasper F. Kok, Vincenzo Obiso, David Paynter, and David R. Thompson
Atmos. Chem. Phys., 21, 3973–4005, https://doi.org/10.5194/acp-21-3973-2021, https://doi.org/10.5194/acp-21-3973-2021, 2021
Short summary
Short summary
For the first time, this study quantifies the range of the dust direct radiative effect due to uncertainty in the soil mineral abundance using all currently available information. We show that the majority of the estimated direct radiative effect range is due to uncertainty in the simulated mass fractions of iron oxides and thus their soil abundance, which is independent of the model employed. We therefore prove the necessity of considering mineralogy for understanding dust–climate interactions.
Cited articles
Aschwanden, A., Bartholomaus, T. C., Brinkerhoff, D. J., and Truffer, M.: Brief communication: A roadmap towards credible projections of ice sheet contribution to sea level, The Cryosphere, 15, 5705–5715, https://doi.org/10.5194/tc-15-5705-2021, 2021.
Atkinson, R., Baulch, D. L., Cox, R. A., Crowley, J. N., Hampson, R. F., Hynes, R. G., Jenkin, M. E., Rossi, M. J., Troe, J., and IUPAC Subcommittee: Evaluated kinetic and photochemical data for atmospheric chemistry: Volume II – gas phase reactions of organic species, Atmos. Chem. Phys., 6, 3625–4055, https://doi.org/10.5194/acp-6-3625-2006, 2006.
Azar, C., Martin, J. G., Johansson, D. J. A., and Sterner, T.: The social cost of methane, Climatic Change, 176, 71, https://doi.org/10.1007/s10584-023-03540-1, 2023.
Bock, M., Schmitt, J., Beck, J., Seth, B., Chappellaz, J., and Fischer, H.: Glacial/interglacial wetland, biomass burning, and geologic methane emissions constrained by dual stable isotopic CH4 ice core records, P. Natl. Acad. Sci. USA, 114, E5778–E5786, https://doi.org/10.1073/pnas.1613883114, 2017.
Bondy, A. L., Wang, B., Laskin, A., Craig, R. L., Nhliziyo, M. V., Bertman, S. B., Pratt, K. A., Shepson, P. B., and Ault, A. P.: Inland Sea Spray Aerosol Transport and Incomplete Chloride Depletion: Varying Degrees of Reactive Processing Observed during SOAS, Environ. Sci. Technol., 51, 9533–9542, https://doi.org/10.1021/acs.est.7b02085, 2017.
Carbon180: Setting DAC on Track: Strategies for Hub Implementation, https://static1.squarespace.com/static/5b9362d89d5abb8c51d474f8/t/6261d1890b76863f1047a2dd/1650577901659/Carbon180-SettingDAConTrack.pdf (last access: 7 December 2023), 2022.
Chen, Y., Cheng, Y., Ma, N., Wei, C., Ran, L., Wolke, R., Größ, J., Wang, Q., Pozzer, A., Denier van der Gon, H. A. C., Spindler, G., Lelieveld, J., Tegen, I., Su, H., and Wiedensohler, A.: Natural sea-salt emissions moderate the climate forcing of anthropogenic nitrate, Atmos. Chem. Phys., 20, 771–786, https://doi.org/10.5194/acp-20-771-2020, 2020.
Data for Progress: Advancing Equitable Deployment of Regional DAC Hubs, https://www.filesforprogress.org/memos/advancing-equitable-deployment-of-regional-dac-hubs.pdf (last access: 7 December 2023), 2023.
Dean, J. F., Middelburg, J. J., Röckmann, T., Aerts, R., Blauw, L. G., Egger, M., Jetten, M. S. M., de Jong, A. E. E., Meisel, O. H., Rasigraf, O., Slomp, C. P., in't Zandt, M. H., and Dolman, A. J.: Methane Feedback to the Global Climate System in a Warmer World, Rev. Geophys., 56, 207–250, https://doi.org/10.1002/2017RG000559, 2018.
Diamond, M. S., Gettelman, A., Lebsock, M. D., McComiskey, A., Russell, L. M., Wood, R., and Feingold, G.: To assess marine cloud brightening's technical feasibility, we need to know what to study – and when to stop, P. Natl. Acad. Sci. USA, 119, e2118379119, https://doi.org/10.1073/pnas.2118379119, 2022.
Dowell, G., Niederdeppe, J., Vanucchi, J., Dogan, T., Donaghy, K., Jacobson, R., Mahowald, N., Milstein, M., and Zelikova, T. J.: Rooting carbon dioxide removal research in the social sciences, Interface Focus, 10, 20190138, https://doi.org/10.1098/rsfs.2019.0138, 2020.
Emerson, D.: Biogenic Iron Dust: A Novel Approach to Ocean Iron Fertilization as a Means of Large Scale Removal of Carbon Dioxide From the Atmosphere, Front. Mar. Sci., 6, 22, https://doi.org/10.3389/fmars.2019.00022, 2019.
FAO (Food and Agriculture Organization): Free Prior and Informed Consent: An indigenous peoples' right and a good practice for local communities, FAO, United Nations, https://www.fao.org/3/i6190e/i6190e.pdf (last access: 7 December 2023), 2016.
Ferretti, D. F., Miller, J. B., White, J. W., Etheridge, D. M., Lassey, K. R., Lowe, D. C., Meure, C. M., Dreier, M. F., Trudinger, C. M., Van Ommen, T. D., and Langenfelds, R. L.: Unexpected changes to the global methane budget over the past 2000 years, Science, 309, 1714–1717, https://doi.org/10.1126/science.1115193, 2005.
Fischer, H., Siggaard-Andersen, M. L., Ruth, U., Rothlisberger, R., and Wolff, E.: Glacial/interglacial changes in mineral dust and sea-salt records in polar ice cores: sources, transport, and deposition. Rev. Geophys., 45, RG1002, https://doi.org/10.1029/2005RG000192, 2007.
Fischer, H., Behrens, M., Bock, M., Richter, U., Schmitt, J., Loulergue, L., Chappellaz, J., Spahni, R., Blunier, T., Leuenberger, M., and Stocker, T. F.: Changing boreal methane sources and constant biomass burning during the last termination, Nature, 452, 864–867, https://doi.org/10.1038/nature06825, 2008.
Forster, P., Storelvmo, T., Armour, K., Collins, W., Dufresne, J.-L., Frame, D., Lunt, D. J., Mauritsen, T., Palmer, M. D., Watanabe, M., Wild, M., and Zhang, H.: The Earth's Energy Budget, Climate Feedbacks, and Climate Sensitivity, Climate Change 2021: The Physical Science Basis, Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Masson-Delmotte, V., Zhai, P., Pirani, A., Connors, S. L., Péan, C., Berger, S., Caud, N., Chen, Y., Goldfarb, L., Gomis, M. I., Huang, M., Leitzell, K., Lonnoy, E., Matthews, J. B. R., Maycock, T. K., Waterfield, T., Yelekçi, O., Yu, R., and Zhou, B., Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 923–1054, https://doi.org/10.1017/9781009157896.009, 2021.
Gromov, S. S.: Stable isotope composition of atmospheric carbon monoxide: a modeling study, dissertation, Johannes Gutenberg-Universität Mainz, https://openscience.ub.uni-mainz.de/handle/20.500.12030/4250 (last access: 7 December 2023), 2014.
Han, C., Do Hur, S., Han, Y., Lee, K., Hong, S., Erhardt, T., Fischer, H., Svensson, A. M., Steffensen, J. P., and Vallelonga, P.: High-resolution isotopic evidence for a potential Saharan provenance of Greenland glacial dust, Sci. Rep., 8, 15582, https://doi.org/10.1038/s41598-018-33859-0, 2018.
Holmes, C. D.: Methane Feedback on Atmospheric Chemistry: Methods, Models, and Mechanisms, J. Adv. Model Earth Sy., 10, 1087–1099, https://doi.org/10.1002/2017MS001196, 2018.
Horowitz, H. M., Holmes, C., Wright, A., Sherwen, T., Wang, X., Evans, M., Huang, J., Jaegle, L., Chen, Q., Zhai, S., and Alexander, B.: Effects of sea salt aerosol emissions for marine cloud brightening on atmospheric chemistry: Implications for radiative forcing, Geophys. Res. Lett., 47, e2019GL085838, https://doi.org/10.1029/2019GL085838, 2020.
IPCC: AR6 Synthesis Report: Climate Change 2023, https://www.ipcc.ch/report/sixth-assessment-report-cycle/ (last access: 7 December 2023), 2023.
Ito, A.: Global modeling study of potentially bioavailable iron input from shipboard aerosol sources to the ocean, Global Biogeochem. Cy., 27, 1–10, https://doi.org/10.1029/2012GB004378, 2013.
Jackson, R. B., Saunois, M., Bousquet, P., Canadell, J. G., Poulter, B., Stavert, A. R., Bergamaschi, P., Niwa, Y., Segers, A., and Tsuruta, A., Increasing anthropogenic methane emissions arise equally from agricultural and fossil fuel sources, Environ. Res. Lett., 15, 071002, https://doi.org/10.1088/1748-9326/ab9ed2, 2020.
Jackson, R. B., Abernethy, S., Canadell, J. G., Cargnello, M., Davis, S. J., Feron, S., Fuss, S., Heyer, A. J., Hong, C., Jones, C. D., Matthews, H. D., O'Conner, F. M., Pisciotta, M., Rhoda, H. M., de Richter, R., Solomon, E. I., Wilcox, J. L., and Zickfeld, K.: Atmospheric methane removal: a research agenda, Philos. T. Roy. Soc. A, 379, 20200454, https://doi.org/10.1098/rsta.2020.0454, 2021.
Kleinen, T., Gromov, S., Steil, B., and Brovkin, V.: Atmospheric methane underestimated in future climate projections. Environ. Res. Lett., 16, 119502, https://doi.org/10.1088/1748-9326/ac1814, 2021.
Legrand, M., Preunkert, S., Wolff, E., Weller, R., Jourdain, B., and Wagenbach, D.: Year-round records of bulk and size-segregated aerosol composition in central Antarctica (Concordia site) – Part 1: Fractionation of sea-salt particles, Atmos. Chem. Phys., 17, 14039–14054, https://doi.org/10.5194/acp-17-14039-2017, 2017.
Lelieveld, J., Peters, W., Dentener, F. J., and Krol, M. C.: Stability of tropospheric hydroxyl chemistry, J. Geophys. Res., 107, ACH 17-1–ACH 17-11, https://doi.org/10.1029/2002JD002272, 2002.
Lenton, T. M., Held, H., Kriegler, E., Hall, J. W., Lucht, W., Rahmstorf, S., and Schellnhuber, H. J.: Tipping elements in the Earth's climate system, P. Natl. Acad. Sci. USA, 105, 1786–1793, https://doi.org/10.1073/pnas.0705414105, 2008.
Li, L., Mahowald, N. M., Miller, R. L., Pérez García-Pando, C., Klose, M., Hamilton, D. S., Gonçalves Ageitos, M., Ginoux, P., Balkanski, Y., Green, R. O., Kalashnikova, O., Kok, J. F., Obiso, V., Paynter, D., and Thompson, D. R.: Quantifying the range of the dust direct radiative effect due to source mineralogy uncertainty, Atmos. Chem. Phys., 21, 3973–4005, https://doi.org/10.5194/acp-21-3973-2021, 2021.
Li, Q., Fernandez, R. P., Hossaini, R., Iglesias-Suarez, F., Cuevas, C. A., Apel, E. C., Kinnison, D. E., Lamarque, J. F., and Saiz-Lopez, A.: Reactive halogens increase the global methane lifetime and radiative forcing in the 21st century, Nat. Commun., 13, 2768, https://doi.org/10.1038/s41467-022-30456-8, 2022.
Li, Q., Meidan, D., Hess, P., Anel, J. A., Cuevas, C. A., Doney, S., Fernandez, R. P., van Herpen, M., Hoglund-Isaksson, L., Johnson, M. S., Kinnison, D. E., Lamarque, J. F., Röckmann, T., Mahowald, N. M., and Saiz-Lopez, A.: Global environmental implications of atmospheric methane removal through chlorine-mediated chemistry-climate interactions, Nat. Commun., 14, 4045, https://doi.org/10.1038/s41467-023-39794-7, 2023.
Li, Y., Song, Y., Li, X., Kaskaoutis, D. G., Gholami, H., and Li, Y: Disentangling variations of dust concentration in Greenland ice cores over the last glaciation: An overview of current knowledge and new initiative, Earth-Sci. Rev., 242, 104451, https://doi.org/10.1016/j.earscirev.2023.104451, 2023.
Maesano, C. N., Campbell, J. S., Foteinis, S., Furey, V., Hawrot, O., Pike, D., Aeschlimann, S., Reginato, P. L., Goodwin, D. R., Looger, L. L., Boyden, E. S., and Renforth, P.: Geochemical Negative Emissions Technologies: Part II. Roadmap, Front. Clim., 4, 945332, https://doi.org/10.3389/fclim.2022.945332, 2022.
Mahowald, N. M., Hamilton, D. S., Mackey, K. R. M., Moore, J. K., Baker, A. R., Scanza, R. A., and Zhang, Y.: Aerosol trace metal leaching and impacts on marine microorganisms, Nat. Commun., 9, 2614, https://doi.org/10.1038/s41467-018-04970-7, 2018.
Mak, J., Kra, G., Sandomenico, T., and Bergamaschi, P.: The seasonality varying isotopic composition of the sources of carbon monoxide at Barbados, West Indies, J. Geophys. Res., 108, 4635, https://doi.org/10.1029/2003JD003419, 2003.
Matsui, H., Mahowald, N. M., Moteki, N., Hamilton, D. S., Ohata, S., Yoshida, A., Koike, M., Scanza, R. A., and Flanner, M. G.: Anthropogenic combustion iron as a complex climate forcer, Nat. Commun., 9, 1593, https://doi.org/10.1038/s41467-018-03997-0, 2018.
McKay, D. I. A., Stall, A., Abrams, J. F., Winkelmann, R., Sakschewski, B., Loriani, S., Fetzer, I., Cornell, S. E., Rockstrom, J., and Lenton, T. M.: Exceeding 1.5 °C global warming could trigger multiple climate tipping points, Science, 377, eabn7950, https://doi.org/10.1126/science.abn7950, 2022.
Meidan, D., Li, Q., Cuevas, C. A., Doney, S. C., Fernandez, R. P., van Herpen, M. M. J. W., Johnson, M. S., Kinnison, D. E., Li, L., and Hamilton, D. S.: Evaluating the potential of iron-based interventions in methane reduction and climate mitigation, Environ. Res. Lett., 19, 054023, https://doi.org/10.1088/1748-9326/ad3d72, 2024.
Ming, T., Li, W., Yuan, Q., Davies, P., de Richter, R., Peng, C., Deng, Q., Yuan, Y., Caillol, S., and Zhou, N.: Perspectives on removal of atmospheric methane, Advances in Applied Energy, 5, 100085, https://doi.org/10.1016/j.adapen.2022.100085, 2022.
Neumann, R. B., Moorberg, C. J., Lundquist, J. D., Turner, J. C., Waldrop, M. P., McFarland, J. W., Euskirchen, E. S., Edgar, C. W., and Turetsky, M. R.: Warming Effects of Spring Rainfall Increase Methane Emissions From Thawing Permafrost, Geophys. Res. Lett., 46, 1393–1401, https://doi.org/10.1029/2018GL081274, 2019.
Nisbet, E. G., Manning, M. R., Dlugokencky, E. J., Michel, S. E., Lan, X., Röckmann, T., Denier van der Gon, H. A. C., Schmitt, J., Palmer, P. I., Dyonisius, M. N., Oh, Y., Fisher, R. E., Lowry, D., France, J. L., White, J. W. C., Brailsford, G., and Bromley, T.: Atmospheric Methane: Comparison Between Methane's Record in 2006–2022 and During Glacial Terminations, Global Biogeochem. Cy., 37, e2023GB007875, https://doi.org/10.1029/2023GB007875, 2023.
NOAA: Trends in Atmospheric Methane, NOAA Global Monitoring Laboratory, Earth System Research Laboratories, https://gml.noaa.gov/ccgg/trends_ch4/, last access: 7 December 2023.
Ocean Visions: Ocean-Based Carbon Dioxide Removal: Road Maps, https://www2.oceanvisions.org/roadmaps/, last access: 7 December 2023.
O'Day, P. A., Pattammattel, A., Aronstein, P., Leppert, V. J., and Forman, H. J.: Iron Speciation in Respirable Particulate Matter and Implications for Human Health, Environ. Sci. Technol., 56, 7006–7016, https://doi.org/10.1021/acs.est.1c06962, 2022.
Oeste, F. D.: Method for cooling the troposphere, https://patentimages.storage.googleapis.com/ac/64/72/49f3c79762e44f/AU2010203265B2.pdf (last access: 7 December 2023), 2009.
Oeste, F. D., de Richter, R., Ming, T., and Caillol, S.: Climate engineering by mimicking natural dust climate control: the iron salt aerosol method, Earth Syst. Dynam., 8, 1–54, https://doi.org/10.5194/esd-8-1-2017, 2017.
Paudel, R., Mahowald, N. M., Hess, P. G. M., Meng, L., and Riley, W. J.: Attribution of changes in global wetland methane emissions from pre-industrial to present using CLM4.5-BGC, Environ. Res. Lett., 11, 034020, https://doi.org/10.1088/1748-9326/11/3/034020, 2016.
Pennacchio, L., van Herpen, M., Meidan, D., Saiz-Lopez, A., and Johnson, M. S.: Catalytic efficiencies for atmospheric methane removal in the high-chlorine regime, ChemRxiv [preprint], https://doi.org/10.26434/chemrxiv-2023-3r8sf, 12 October 2023.
Peng, S., Lin, X., Thompson, R.L., Xi, Y., Liu, G., Hauglustaine, D., Lan, X., Poulter, B., Ramonet, M., Saunois, M., Yin, Y., Zhang, Z., Zheng, B., and Ciais, P.: Wetland emission and atmospheric sink changes explain methane growth in 2020, Nature, 612, 477–482, https://doi.org/10.1038/s41586-022-05447-w, 2022.
Pio, C. A. and Lopes, D. A.: Chlorine loss from marine aerosol in a coastal atmosphere, J. Geophys. Res., 103, 25263–25272, https://doi.org/10.1029/98JD02088, 1998.
Prospero, J. M., Delany, A. C., Delany, A. C., and Carlson, T. N.: The Discovery of African Dust Transport to the Western Hemisphere and the Saharan Air Layer, B. Am. Meteorol. Soc., 102, E1239–E1260, https://doi.org/10.1175/BAMS-D-19-0309.1, 2021.
Pye, H. O. T., Nenes, A., Alexander, B., Ault, A. P., Barth, M. C., Clegg, S. L., Collett Jr., J. L., Fahey, K. M., Hennigan, C. J., Herrmann, H., Kanakidou, M., Kelly, J. T., Ku, I.-T., McNeill, V. F., Riemer, N., Schaefer, T., Shi, G., Tilgner, A., Walker, J. T., Wang, T., Weber, R., Xing, J., Zaveri, R. A., and Zuend, A.: The acidity of atmospheric particles and clouds, Atmos. Chem. Phys., 20, 4809–4888, https://doi.org/10.5194/acp-20-4809-2020, 2020.
Qu, Z., Jacob, D. J., Zhang, Y., Shen, L., Varon, D. J., Lu, X., Scarpelli, T., Bloom, A., Worden, J., and Parker, R. J.: Attribution of the 2020 surge in atmospheric methane by inverse analysis of GOSAT observations, Envion. Res. Lett., 17, 094003, https://doi.org/10.1088/1748-9326/ac8754, 2022.
Röckmann, T., Brenninkmeijer, C. A. M., Crutzen, P. J., and Platt, U.: Short term variations in the
Rodriguez, S., Prospero, J. M., Lopez-Darias, J., Garcia-Alvarez, M. I., Zuidema, P., Nava, S., Lucarelli, F., Gaston, C. J., Galindo, L., and Sosa, E.: Tracking the changes of iron solubility and air pollutants traces as African dust transits the Atlantic in the Saharan dust outbreaks, Atmos. Environ., 246, 118092, https://doi.org/10.1016/j.atmosenv.2020.118092, 2021.
Saiz-Lopez, A., Fernandez, R. P., Li, Q., Cuevas, C. A., Fu, X., Kinnison, D. E., Times, S., Mahajan, A. S., Martin, J. C. G., Iglesias-Suerez, F., Hossaini, R., Plane, J. M. C., Myhre, G., and Lamarque, J. F.: Natural short-lived halogens exert an indirect cooling effect on climate, Nature, 618, 967–973, https://doi.org/10.1038/s41586-023-06119-z, 2023.
Sapart, C. J., Monteil, G., Prokopiou, M., van de Wal, R. S. W., Kaplan, J. O., Sperlich, P., Krumhardt, K. M., Van der Veen, C., Houweling, S., Krol, M. C., Blunier, T., Sowers, T., Martinerie, P., Witrant, E., Dahl-Jensen, D., and Röckmann, T.: Natural and anthropogenic variations in methane sources during the past two millennia, Nature, 490, 85–88, https://doi.org/10.1038/nature11461, 2012.
Seinfeld, J. H. and Pandis, S. N.: Atmospheric chemistry and physics: from air pollution to climate change, John Wiley & Sons, ISBN 0471720186, 2016.
Spark Climate Solutions: Approaches to Atmospheric Methane Removal, https://www.sparkclimate.org/methane-removal/101/approaches, last access: 7 December 2023.
Staniaszek, Z., Griffiths, P. T., Folberth, G. A., O'Connor, F. M., Abraham, N. L., and Archibald, A. T.: The role of future anthropogenic methane emission in air quality and climate, npj Clim. Atmos. Sci, 5, 21, https://doi.org/10.1038/s41612-022-00247-5, 2022.
The Arctic Institute: Sami Council resistance to SCoPEX highlights the complex questions surrounding geoengineering and consent, https://www.thearcticinstitute.org/sami-council-resistance- scopex-highlights-complex-questions-geoengineering-consent/ (last access: 7 December 2023), 2021.
UNEP (United Nations Environment Programme): Global Methane Assessment: Benefits and Costs of Mitigating Methane Emissions, https://www.unep.org/resources/report/global-methane-
assessment-benefits-and-costs-mitigating-methane-emissions (last access: 7 December 2023), 2021.
van Herpen, M. M. J. W., Li, Q., Saiz-Lopez, A., Liisberg, J. B., Röckmann, T., Cuevas, C. A., Fernandez, R. P., Mak, J. E., Mahowald, N. M., Hess, P., Meidan, D., Stuut, J.-B. W., and Johnson, M. S.: Photocatalytic Chlorine Atom Production on Mineral Dust-Sea Spray Aerosols over North Atlantic, P. Natl. Acad. Sci. USA, 120, e2303974120, https://doi.org/10.1073/pnas.2303974120, 2023.
Wang, X., Jacob, D. J., Eastham, S. D., Sulprizio, M. P., Zhu, L., Chen, Q., Alexander, B., Sherwen, T., Evans, M. J., Lee, B. H., Haskins, J. D., Lopez-Hilfiker, F. D., Thornton, J. A., Huey, G. L., and Liao, H.: The role of chlorine in global tropospheric chemistry, Atmos. Chem. Phys., 19, 3981–4003, https://doi.org/10.5194/acp-19-3981-2019, 2019.
Wang, X., Jacob, D. J., Fu, X., Wang, T., Le Breton, M., Hallquist, M., Liu, Z., McDuffie, E. E., and Liao, H.: Effects of Anthropogenic Chlorine on PM2.5 and Ozone Air Quality in China, Environ. Sci. Technol., 54, 9908–9916, https://doi.org/10.1021/acs.est.0c02296, 2020.
Wanser, K., Doherty, S. J., Hurrell, J. W., and Wong, A.: Near-term climate risks and sunlight reflection modification: a roadmap approach for physical science research, Climatic Change, 174, 23, https://doi.org/10.1007/s10584-022-03446-4, 2022.
Wittmer, J. and Zetzsch, C.: Photochemical activation of chlorine by iron oxide aerosol, J. Atmos. Chem., 74, 187–204, https://doi.org/10.1007/s10874-016-9336-6, 2017.
Wittmer, J., Bleicher, S., Ofner, J., and Zetzsch, C.: Iron (III)-induced activation of chloride from artificial sea-salt aerosol, Environ. Chem., 12, 461–475, https://doi.org/10.1071/EN14279, 2015a.
Wittmer, J., Bleicher, S., and Zetzsch, C.: Iron (III)-induced activation of chloride and bromide from modeled salt pans, J. Phys. Chem. A, 119, 4373–4385, https://doi.org/10.1021/jp508006s, 2015b.
Yuan, T., Yu, H., Chin, M., Remer, L. A., McGee, D., and Evan, A.: Anthropogenic decline of African dust: Insights from the Holocene records and beyond, Geophys. Res. Lett., 47, e2020GL089711, https://doi.org/10.1029/2020GL089711, 2020.
Zhang, Z., Poulter, B., Feldman, A. F., Ying, Q., Ciais, P., Peng, S., and Li, X.: Recent intensification of wetland methane feedback, Nat. Clim. Change, 13, 430–433, https://doi.org/10.1038/s41558-023-01629-0, 2023.
Zhu, X. R., Prospero, J. M., and Millero, F. J.: Diel variability of soluble Fe(II) and soluble total Fe in North African dust in the trade winds at Barbados, J. Geophys. Res., 102, 21297–21305, https://doi.org/10.1029/97JD01313, 1997.
Editorial statement
The article is an interesting and provocative paper that derives its ideas from recently published research results and discoveries about the ambivalent role of atmospheric halogens (chlorine) in controlling the global abundance of tropospheric O3, OH and CH4. It discusses and proposes a possible roadmap to explore how artificially released iron chloride aerosols could reduce the atmospheric CH4 burden to mitigate its climate impact. The authors call for interdisciplinary efforts while keeping in mind ethical concerns and social impacts due to the proposed method.
The article is an interesting and provocative paper that derives its ideas from recently...
Short summary
Rapid reduction in atmospheric methane is needed to slow the rate of global warming. Reducing anthropogenic methane emissions is a top priority. However, atmospheric methane is also impacted by rising natural emissions and changing sinks. Studies of possible atmospheric methane removal approaches, such as iron salt aerosols to increase the chlorine radical sink, benefit from a roadmapped approach to understand if there may be viable and socially acceptable ways to decrease future risk.
Rapid reduction in atmospheric methane is needed to slow the rate of global warming. Reducing...
Altmetrics
Final-revised paper
Preprint