Articles | Volume 18, issue 22
https://doi.org/10.5194/amt-18-6979-2025
© 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/amt-18-6979-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
24 Nov 2025
Research article |
| 24 Nov 2025
| 24 Nov 2025
Laboratory and field characterization of an atmospheric pressure transverse chemical ionization ion-molecule reaction region
Phil Rund
Department of Atmospheric and Climate Science, University of Washington, Seattle, WA, 98195, USA
Ben H. Lee
Department of Atmospheric and Climate Science, University of Washington, Seattle, WA, 98195, USA
Siddharth Iyer
Aerosol Physics Laboratory, Tampere University, Tampere, Pirkanmaa, Finland
Gordon A. Novak
NOAA Chemical Sciences Lab, Boulder, CO 80305, USA
Jake T. Vallow
Wolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York, United Kingdom
Joel A. Thornton
CORRESPONDING AUTHOR
Department of Atmospheric and Climate Science, University of Washington, Seattle, WA, 98195, USA
Related authors
No articles found.
Shawon Barua, Avinash Kumar, Prasenjit Seal, Siddharth Iyer, and Matti Rissanen
EGUsphere, https://doi.org/10.5194/egusphere-2025-5207, https://doi.org/10.5194/egusphere-2025-5207, 2025
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
Short summary
This work illustrates how long chain linear aldehydes have the potential to undergo atmospheric autoxidation and lead to prompt formation of condensable material which subsequently contributes to aerosol formation, deteriorating the air quality of urban atmospheres. We performed laboratory experiments using state-of-the-art mass spectrometry technique combined with a flow reactor under atmospheric conditions to resolve the autoxidation mechanism of n-aldehydes initiated by a common oxidant.
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, Margarita Reza, Rainer Volkamer, Kelvin H. Bates, Alfonso Saiz-Lopez, Anoop S. Mahajan, and Becky Alexander
EGUsphere, https://doi.org/10.5194/egusphere-2025-4725, https://doi.org/10.5194/egusphere-2025-4725, 2025
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.
Loren Temple, Stuart Young, Thomas Bannan, Stephanie Batten, Stéphane Bauguitte, Hugh Coe, Eve Grant, Stuart Lacy, James Lee, Emily Matthews, Dominika Pasternak, Samuel Rogers, Andrew Rollins, Jake Vallow, Mingxi Yang, and Pete Edwards
EGUsphere, https://doi.org/10.5194/egusphere-2025-3678, https://doi.org/10.5194/egusphere-2025-3678, 2025
Short summary
Short summary
Sulfur dioxide (SO2) is a key precursor to aerosol formation, particularly in remote marine environments, ultimately affecting cloud properties and climate. Accurate quantification of atmospheric SO2 is therefore crucial. This work compares a custom-built laser-based instrument to two commercial SO2 analysers during measurements from a large research aircraft. Our results show that this custom-built system offers greater sensitivity at time resolutions required for aircraft measurements.
Carley D. Fredrickson, Scott J. Janz, Lok N. Lamsal, Ursula A. Jongebloed, Joshua L. Laughner, and Joel A. Thornton
Atmos. Meas. Tech., 18, 3669–3689, https://doi.org/10.5194/amt-18-3669-2025, https://doi.org/10.5194/amt-18-3669-2025, 2025
Short summary
Short summary
We present an analysis of high-resolution remote sensing measurements of nitrogen-containing trace gases emitted by wildfires. The measurements were made using an instrument on the NASA ER-2 aircraft in the summer of 2019. We find that time-resolved fire intensity is critical to quantify trace gas emissions over a fire's entire lifespan. These findings have implications for improving air pollution forecasts downwind of wildfires using computer models of atmospheric chemistry and meteorology.
Joseph O. Palmo, Colette L. Heald, Donald R. Blake, Ilann Bourgeois, Matthew Coggon, Jeff Collett, Frank Flocke, Alan Fried, Georgios Gkatzelis, Samuel Hall, Lu Hu, Jose L. Jimenez, Pedro Campuzano-Jost, I-Ting Ku, Benjamin Nault, Brett Palm, Jeff Peischl, Ilana Pollack, Amy Sullivan, Joel Thornton, Carsten Warneke, Armin Wisthaler, and Lu Xu
EGUsphere, https://doi.org/10.5194/egusphere-2025-1969, https://doi.org/10.5194/egusphere-2025-1969, 2025
Short summary
Short summary
This study investigates ozone production within wildfire smoke plumes as they age, using both aircraft observations and models. We find that the chemical environment and resulting ozone production within smoke changes as plumes evolve, with implications for climate and public health.
Xinyue Shao, Yaman Liu, Xinyi Dong, Minghuai Wang, Ruochong Xu, Joel A. Thornton, Duseong S. Jo, Man Yue, Wenxiang Shen, Manish Shrivastava, Stephen R. Arnold, and Ken S. Carslaw
EGUsphere, https://doi.org/10.5194/egusphere-2025-1526, https://doi.org/10.5194/egusphere-2025-1526, 2025
Short summary
Short summary
Highly Oxygenated Organic Molecules (HOMs) are key precursors of secondary organic aerosols (SOA). Incorporating the HOMs chemical mechanism into a global climate model allows for a reasonable reproduction of observed HOM characteristics. HOM-SOA constitutes a significant fraction of global SOA, and its distribution and formation pathways exhibit strong sensitivity to uncertainties in autoxidation processes and peroxy radical branching ratios.
Alfred W. Mayhew, Lauri Franzon, Kelvin H. Bates, Theo Kurtén, Felipe D. Lopez-Hilfiker, Claudia Mohr, Andrew R. Rickard, Joel A. Thornton, and Jessica D. Haskins
EGUsphere, https://doi.org/10.5194/egusphere-2025-1922, https://doi.org/10.5194/egusphere-2025-1922, 2025
Short summary
Short summary
This work outlines an investigation into an understudied atmospheric chemical reaction pathway with the potential to form particulate pollution that has important impacts on air quality and climate. We suggest that this chemical pathway is responsible for a large fraction of the atmospheric particulate matter observed in tropical forested regions, but we also highlight the need for further ambient and lab investigations to inform an accurate representation of this process in atmospheric models.
Dominika Pasik, Thomas Golin Almeida, Emelda Ahongshangbam, Siddharth Iyer, and Nanna Myllys
Atmos. Chem. Phys., 25, 4313–4331, https://doi.org/10.5194/acp-25-4313-2025, https://doi.org/10.5194/acp-25-4313-2025, 2025
Short summary
Short summary
We used quantum chemistry methods to investigate the oxidation mechanisms of acyl peroxy radicals (APRs) with various monoterpenes. Our findings reveal unique oxidation pathways for different monoterpenes, leading to either chain-terminating products or highly reactive intermediates that can contribute to particle formation in the atmosphere. This research highlights APRs as potentially significant but underexplored atmospheric oxidants that may influence future approaches to modelling climate.
Chris J. Wright, Joel A. Thornton, Lyatt Jaeglé, Yang Cao, Yannian Zhu, Jihu Liu, Randall Jones II, Robert Holzworth, Daniel Rosenfeld, Robert Wood, Peter Blossey, and Daehyun Kim
Atmos. Chem. Phys., 25, 2937–2946, https://doi.org/10.5194/acp-25-2937-2025, https://doi.org/10.5194/acp-25-2937-2025, 2025
Short summary
Short summary
Aerosol particles influence clouds, which exert a large forcing on solar radiation and freshwater. To better understand the mechanisms by which aerosol influences thunderstorms, we look at the two busiest shipping lanes in the world, where recent regulations have reduced sulfur emissions by nearly an order of magnitude. We find that the reduction in emissions has been accompanied by a dramatic decrease in both lightning and the number of droplets in clouds over the shipping lanes.
Delaney B. Kilgour, Christopher M. Jernigan, Olga Garmash, Sneha Aggarwal, Shengqian Zhou, Claudia Mohr, Matt E. Salter, Joel A. Thornton, Jian Wang, Paul Zieger, and Timothy H. Bertram
Atmos. Chem. Phys., 25, 1931–1947, https://doi.org/10.5194/acp-25-1931-2025, https://doi.org/10.5194/acp-25-1931-2025, 2025
Short summary
Short summary
We report simultaneous measurements of dimethyl sulfide (DMS) and hydroperoxymethyl thioformate (HPMTF) in the eastern North Atlantic. We use an observationally constrained box model to show that cloud loss is the dominant sink of HPMTF in this region over 6 weeks, resulting in large reductions in DMS-derived products that contribute to aerosol formation and growth. Our findings indicate that fast cloud processing of HPMTF must be included in global models to accurately capture the sulfur cycle.
Matthieu Riva, Veronika Pospisilova, Carla Frege, Sebastien Perrier, Priyanka Bansal, Spiro Jorga, Patrick Sturm, Joel A. Thornton, Urs Rohner, and Felipe Lopez-Hilfiker
Atmos. Meas. Tech., 17, 5887–5901, https://doi.org/10.5194/amt-17-5887-2024, https://doi.org/10.5194/amt-17-5887-2024, 2024
Short summary
Short summary
We present a newly designed reduced-pressure chemical ionization reactor for detection of gas-phase organic and inorganic species. The system operates through the combined use of vacuum ultraviolet ionization and photosensitizers to generate numerous adduct ionization schemes. As a result, it offers the ability to simultaneously measure a wide variety of organic and inorganic species in terms of compound volatility and functionality, while being largely independent of changes in sample humidity.
Chuanyang Shen, Xiaoyan Yang, Joel Thornton, John Shilling, Chenyang Bi, Gabriel Isaacman-VanWertz, and Haofei Zhang
Atmos. Chem. Phys., 24, 6153–6175, https://doi.org/10.5194/acp-24-6153-2024, https://doi.org/10.5194/acp-24-6153-2024, 2024
Short summary
Short summary
In this work, a condensed multiphase isoprene oxidation mechanism was developed to simulate isoprene SOA formation from chamber and field studies. Our results show that the measured isoprene SOA mass concentrations can be reasonably reproduced. The simulation results indicate that multifunctional low-volatility products contribute significantly to total isoprene SOA. Our findings emphasize that the pathways to produce these low-volatility species should be considered in models.
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
Short summary
Short summary
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.
Wei Huang, Cheng Wu, Linyu Gao, Yvette Gramlich, Sophie L. Haslett, Joel Thornton, Felipe D. Lopez-Hilfiker, Ben H. Lee, Junwei Song, Harald Saathoff, Xiaoli Shen, Ramakrishna Ramisetty, Sachchida N. Tripathi, Dilip Ganguly, Feng Jiang, Magdalena Vallon, Siegfried Schobesberger, Taina Yli-Juuti, and Claudia Mohr
Atmos. Chem. Phys., 24, 2607–2624, https://doi.org/10.5194/acp-24-2607-2024, https://doi.org/10.5194/acp-24-2607-2024, 2024
Short summary
Short summary
We present distinct molecular composition and volatility of oxygenated organic aerosol particles in different rural, urban, and mountain environments. We do a comprehensive investigation of the relationship between the chemical composition and volatility of oxygenated organic aerosol particles across different systems and environments. This study provides implications for volatility descriptions of oxygenated organic aerosol particles in different model frameworks.
Xu-Cheng He, Jiali Shen, Siddharth Iyer, Paxton Juuti, Jiangyi Zhang, Mrisha Koirala, Mikko M. Kytökari, Douglas R. Worsnop, Matti Rissanen, Markku Kulmala, Norbert M. Maier, Jyri Mikkilä, Mikko Sipilä, and Juha Kangasluoma
Atmos. Meas. Tech., 16, 4461–4487, https://doi.org/10.5194/amt-16-4461-2023, https://doi.org/10.5194/amt-16-4461-2023, 2023
Short summary
Short summary
In this study, the upgraded multi-scheme chemical ionisation inlet 2 is presented. Sulfuric acid, hypoiodous acid, iodine, sulfur dioxide, and hydroperoxyl radicals are calibrated, and the improved ion optics allow us to detect sulfuric acid and iodine-containing molecules at as low as a few parts per quadrillion by volume. Additionally, we confirm the reliable detection of iodic acid using both the nitrate and bromide chemical ionisation methods under atmospherically relevant conditions.
Shawon Barua, Siddharth Iyer, Avinash Kumar, Prasenjit Seal, and Matti Rissanen
Atmos. Chem. Phys., 23, 10517–10532, https://doi.org/10.5194/acp-23-10517-2023, https://doi.org/10.5194/acp-23-10517-2023, 2023
Short summary
Short summary
This work illustrates how a common volatile hydrocarbon, hexanal, has the potential to undergo atmospheric autoxidation that leads to prompt formation of condensable material that subsequently contributes to aerosol formation, deteriorating the air quality of urban atmospheres. We used the combined state-of-the-art quantum chemical modeling and experimental flow reactor experiments under atmospheric conditions to resolve the autoxidation mechanism of hexanal initiated by a common oxidant.
Sophie L. Haslett, David M. Bell, Varun Kumar, Jay G. Slowik, Dongyu S. Wang, Suneeti Mishra, Neeraj Rastogi, Atinderpal Singh, Dilip Ganguly, Joel Thornton, Feixue Zheng, Yuanyuan Li, Wei Nie, Yongchun Liu, Wei Ma, Chao Yan, Markku Kulmala, Kaspar R. Daellenbach, David Hadden, Urs Baltensperger, Andre S. H. Prevot, Sachchida N. Tripathi, and Claudia Mohr
Atmos. Chem. Phys., 23, 9023–9036, https://doi.org/10.5194/acp-23-9023-2023, https://doi.org/10.5194/acp-23-9023-2023, 2023
Short summary
Short summary
In Delhi, some aspects of daytime and nighttime atmospheric chemistry are inverted, and parodoxically, vehicle emissions may be limiting other forms of particle production. This is because the nighttime emissions of nitrogen oxide (NO) by traffic and biomass burning prevent some chemical processes that would otherwise create even more particles and worsen the urban haze.
Siegfried Schobesberger, Emma L. D'Ambro, Lejish Vettikkat, Ben H. Lee, Qiaoyun Peng, David M. Bell, John E. Shilling, Manish Shrivastava, Mikhail Pekour, Jerome Fast, and Joel A. Thornton
Atmos. Meas. Tech., 16, 247–271, https://doi.org/10.5194/amt-16-247-2023, https://doi.org/10.5194/amt-16-247-2023, 2023
Short summary
Short summary
We present a new, highly sensitive technique for measuring atmospheric ammonia, an important trace gas that is emitted mainly by agriculture. We deployed the instrument on an aircraft during research flights over rural Oklahoma. Due to its fast response, we could analyze correlations with turbulent winds and calculate ammonia emissions from nearby areas at 1 to 2 km resolution. We observed high spatial variability and point sources that are not resolved in the US National Emissions Inventory.
Alfred W. Mayhew, Ben H. Lee, Joel A. Thornton, Thomas J. Bannan, James Brean, James R. Hopkins, James D. Lee, Beth S. Nelson, Carl Percival, Andrew R. Rickard, Marvin D. Shaw, Peter M. Edwards, and Jaqueline F. Hamilton
Atmos. Chem. Phys., 22, 14783–14798, https://doi.org/10.5194/acp-22-14783-2022, https://doi.org/10.5194/acp-22-14783-2022, 2022
Short summary
Short summary
Isoprene nitrates are chemical species commonly found in the atmosphere that are important for their impacts on air quality and climate. This paper compares 3 different representations of the chemistry of isoprene nitrates in computational models highlighting cases where the choice of chemistry included has significant impacts on the concentration and composition of the modelled nitrates. Calibration of mass spectrometers is also shown to be an important factor when analysing isoprene nitrates.
Ruochong Xu, Joel A. Thornton, Ben H. Lee, Yanxu Zhang, Lyatt Jaeglé, Felipe D. Lopez-Hilfiker, Pekka Rantala, and Tuukka Petäjä
Atmos. Chem. Phys., 22, 5477–5494, https://doi.org/10.5194/acp-22-5477-2022, https://doi.org/10.5194/acp-22-5477-2022, 2022
Short summary
Short summary
Monoterpenes are emitted into the atmosphere by vegetation and by the use of certain consumer products. Reactions of monoterpenes in the atmosphere lead to low-volatility products that condense to grow particulate matter or participate in new particle formation and, thus, affect air quality and climate. We use a model of atmospheric chemistry and transport to evaluate the global-scale importance of recent updates to our understanding of monoterpene chemistry in particle formation and growth.
Arto Heitto, Kari Lehtinen, Tuukka Petäjä, Felipe Lopez-Hilfiker, Joel A. Thornton, Markku Kulmala, and Taina Yli-Juuti
Atmos. Chem. Phys., 22, 155–171, https://doi.org/10.5194/acp-22-155-2022, https://doi.org/10.5194/acp-22-155-2022, 2022
Short summary
Short summary
For atmospheric aerosol particles to take part in cloud formation, they need to be at least a few tens of nanometers in diameter. By using a particle condensation model, we investigated how two types of chemical reactions, oligomerization and decomposition, of organic molecules inside the particle may affect the growth of secondary aerosol particles to these sizes. We show that the effect is potentially significant, which highlights the importance of increasing understanding of these processes.
Zachary C. J. Decker, Michael A. Robinson, Kelley C. Barsanti, Ilann Bourgeois, Matthew M. Coggon, Joshua P. DiGangi, Glenn S. Diskin, Frank M. Flocke, Alessandro Franchin, Carley D. Fredrickson, Georgios I. Gkatzelis, Samuel R. Hall, Hannah Halliday, Christopher D. Holmes, L. Gregory Huey, Young Ro Lee, Jakob Lindaas, Ann M. Middlebrook, Denise D. Montzka, Richard Moore, J. Andrew Neuman, John B. Nowak, Brett B. Palm, Jeff Peischl, Felix Piel, Pamela S. Rickly, Andrew W. Rollins, Thomas B. Ryerson, Rebecca H. Schwantes, Kanako Sekimoto, Lee Thornhill, Joel A. Thornton, Geoffrey S. Tyndall, Kirk Ullmann, Paul Van Rooy, Patrick R. Veres, Carsten Warneke, Rebecca A. Washenfelder, Andrew J. Weinheimer, Elizabeth Wiggins, Edward Winstead, Armin Wisthaler, Caroline Womack, and Steven S. Brown
Atmos. Chem. Phys., 21, 16293–16317, https://doi.org/10.5194/acp-21-16293-2021, https://doi.org/10.5194/acp-21-16293-2021, 2021
Short summary
Short summary
To understand air quality impacts from wildfires, we need an accurate picture of how wildfire smoke changes chemically both day and night as sunlight changes the chemistry of smoke. We present a chemical analysis of wildfire smoke as it changes from midday through the night. We use aircraft observations from the FIREX-AQ field campaign with a chemical box model. We find that even under sunlight typical
nighttimechemistry thrives and controls the fate of key smoke plume chemical processes.
Xuan Wang, Daniel J. Jacob, William Downs, Shuting Zhai, Lei Zhu, Viral Shah, Christopher D. Holmes, Tomás Sherwen, Becky Alexander, Mathew J. Evans, Sebastian D. Eastham, J. Andrew Neuman, Patrick R. Veres, Theodore K. Koenig, Rainer Volkamer, L. Gregory Huey, Thomas J. Bannan, Carl J. Percival, Ben H. Lee, and Joel A. Thornton
Atmos. Chem. Phys., 21, 13973–13996, https://doi.org/10.5194/acp-21-13973-2021, https://doi.org/10.5194/acp-21-13973-2021, 2021
Short summary
Short summary
Halogen radicals have a broad range of implications for tropospheric chemistry, air quality, and climate. We present a new mechanistic description and comprehensive simulation of tropospheric halogens in a global 3-D model and compare the model results with surface and aircraft measurements. We find that halogen chemistry decreases the global tropospheric burden of ozone by 11 %, NOx by 6 %, and OH by 4 %.
Rongrong Wu, Luc Vereecken, Epameinondas Tsiligiannis, Sungah Kang, Sascha R. Albrecht, Luisa Hantschke, Defeng Zhao, Anna Novelli, Hendrik Fuchs, Ralf Tillmann, Thorsten Hohaus, Philip T. M. Carlsson, Justin Shenolikar, François Bernard, John N. Crowley, Juliane L. Fry, Bellamy Brownwood, Joel A. Thornton, Steven S. Brown, Astrid Kiendler-Scharr, Andreas Wahner, Mattias Hallquist, and Thomas F. Mentel
Atmos. Chem. Phys., 21, 10799–10824, https://doi.org/10.5194/acp-21-10799-2021, https://doi.org/10.5194/acp-21-10799-2021, 2021
Short summary
Short summary
Isoprene is the biogenic volatile organic compound with the largest emissions rates. The nighttime reaction of isoprene with the NO3 radical has a large potential to contribute to SOA. We classified isoprene nitrates into generations and proposed formation pathways. Considering the potential functionalization of the isoprene nitrates we propose that mainly isoprene dimers contribute to SOA formation from the isoprene NO3 reactions with at least a 5 % mass yield.
Mingyi Wang, Xu-Cheng He, Henning Finkenzeller, Siddharth Iyer, Dexian Chen, Jiali Shen, Mario Simon, Victoria Hofbauer, Jasper Kirkby, Joachim Curtius, Norbert Maier, Theo Kurtén, Douglas R. Worsnop, Markku Kulmala, Matti Rissanen, Rainer Volkamer, Yee Jun Tham, Neil M. Donahue, and Mikko Sipilä
Atmos. Meas. Tech., 14, 4187–4202, https://doi.org/10.5194/amt-14-4187-2021, https://doi.org/10.5194/amt-14-4187-2021, 2021
Short summary
Short summary
Atmospheric iodine species are often short-lived with low abundance and have thus been challenging to measure. We show that the bromide chemical ionization mass spectrometry, compatible with both the atmospheric pressure and reduced pressure interfaces, can simultaneously detect various gas-phase iodine species. Combining calibration experiments and quantum chemical calculations, we quantify detection sensitivities to HOI, HIO3, I2, and H2SO4, giving detection limits down to < 106 molec. cm-3.
Clémence Rose, Matti P. Rissanen, Siddharth Iyer, Jonathan Duplissy, Chao Yan, John B. Nowak, Aurélie Colomb, Régis Dupuy, Xu-Cheng He, Janne Lampilahti, Yee Jun Tham, Daniela Wimmer, Jean-Marc Metzger, Pierre Tulet, Jérôme Brioude, Céline Planche, Markku Kulmala, and Karine Sellegri
Atmos. Chem. Phys., 21, 4541–4560, https://doi.org/10.5194/acp-21-4541-2021, https://doi.org/10.5194/acp-21-4541-2021, 2021
Short summary
Short summary
Sulfuric acid (H2SO4) is commonly accepted as a key precursor for atmospheric new particle formation. However, direct measurements of [H2SO4] remain challenging, motivating the development of proxies. Using data collected in two different volcanic plumes, we show, under these specific conditions, the good performance of a proxy from the literature and also highlight the benefit of the newly developed proxies for the prediction of the highest [H2SO4] values.
Cited articles
Andrade, F. J., Shelley, J. T., Wetzel, W. C., Webb, M. R., Gamez, G., Ray, S. J., and Hieftje, G. M.: Atmospheric Pressure Chemical Ionization Source. 1. Ionization of Compounds in the Gas Phase, Analytical Chemistry, 80, 2646–2653, https://doi.org/10.1021/ac800156y, 2008. a
Bertram, T. H., Kimmel, J. R., Crisp, T. A., Ryder, O. S., Yatavelli, R. L. N., Thornton, J. A., Cubison, M. J., Gonin, M., and Worsnop, D. R.: A field-deployable, chemical ionization time-of-flight mass spectrometer, Atmos. Meas. Tech., 4, 1471–1479, https://doi.org/10.5194/amt-4-1471-2011, 2011. a, b
Brown, S. S., Dibb, J. E., Stark, H., Aldener, M., Vozella, M., Whitlow, S., Williams, E. J., Lerner, B. M., Jakoubek, R., Middlebrook, A. M., DeGouw, J. A., Warneke, C., Goldan, P. D., Kuster, W. C., Angevine, W. M., Sueper, D. T., Quinn, P. K., Bates, T. S., Meagher, J. F., Fehsenfeld, F. C., and Ravishankara, A. R.: Nighttime removal of NO x in the summer marine boundary layer, Geophysical Research Letters, 31, https://doi.org/10.1029/2004GL019412, 2004. a
Crounse, J. D., McKinney, K. A., Kwan, A. J., and Wennberg, P. O.: Measurement of Gas-Phase Hydroperoxides by Chemical Ionization Mass Spectrometry, Analytical Chemistry, 78, 6726–6732, https://doi.org/10.1021/ac0604235, 2006. a
Dörich, R., Eger, P., Lelieveld, J., and Crowley, J. N.: Iodide CIMS and
Du, M., Voliotis, A., Shao, Y., Wang, Y., Bannan, T. J., Pereira, K. L., Hamilton, J. F., Percival, C. J., Alfarra, M. R., and McFiggans, G.: Combined application of online FIGAERO-CIMS and offline LC-Orbitrap mass spectrometry (MS) to characterize the chemical composition of secondary organic aerosol (SOA) in smog chamber studies, Atmos. Meas. Tech., 15, 4385–4406, https://doi.org/10.5194/amt-15-4385-2022, 2022. a
Feller, D.: The Role of Databases in Support of Computational Chemistry Calculations, Journal of Computational Chemistry, 17, 1571–1586, 1996. a
Frisch, M. J., Trucks, G. W., Schlegel, H. B., Scuseria, G. E., Robb, M. A., Cheeseman, J. R., Scalmani, G., Barone, V., Petersson, G. A., Nakatsuji, H., Li, X., Caricato, M., Marenich, A. V., Bloino, J., Janesko, B. G., Gomperts, R., Mennucci, B., Hratchian, H. P., Ortiz, J. V., Izmaylov, A. F., Sonnenberg, J. L., Williams-Young, D., Ding, F., Lipparini, F., Egidi, F., Goings, J., Peng, B., Petrone, A., Henderson, T., Ranasinghe, D., Zakrzewski, V. G., Gao, J., Rega, N., Zheng, G., Liang, W., Hada, M., Ehara, M., Toyota, K., Fukuda, R., Hasegawa, J., Ishida, M., Nakajima, T., Honda, Y., Kitao, O., Nakai, H., Vreven, T., Throssell, K., Montgomery Jr., J. A., Peralta, J. E., Ogliaro, F., Bearpark, M. J., Heyd, J. J., Brothers, E. N., Kudin, K. N., Staroverov, V. N., Keith, T. A., Kobayashi, R., Normand, J., Raghavachari, K., Rendell, A. P., Burant, J. C., Iyengar, S. S., Tomasi, J., Cossi, M., Millam, J. M., Klene, M., Adamo, C., Cammi, R., Ochterski, J. W., Martin, R. L., Morokuma, K., Farkas, O., Foresman, J. B., and Fox, D. J.: Gaussian 16 Revision C.01, Gaussian, Inc., Wallingford CT, https://gaussian.com/gaussian16/ (last access: 20 November 2025), 2016. a
Hinds, W. C.: Aerosol Technology, 2nd edn., 28–31, ISBN 978-1-118-59197-0, 1999. a
Huey, L. G., Hanson, D. R., and Howard, C. J.: Reactions of SF6- and I- with Atmospheric Trace Gases, The Journal of Physical Chemistry, 99, 5001–5008, https://doi.org/10.1021/j100014a021, 1995. a
Hyttinen, N., Pullinen, I., Nissinen, A., Schobesberger, S., Virtanen, A., and Yli-Juuti, T.: Comparison of saturation vapor pressures of α-pinene + O3 oxidation products derived from COSMO-RS computations and thermal desorption experiments, Atmos. Chem. Phys., 22, 1195–1208, https://doi.org/10.5194/acp-22-1195-2022, 2022. a
Iyer, S., Lopez-Hilfiker, F., Lee, B. H., Thornton, J. A., and Kurtén, T.: Modeling the Detection of Organic and Inorganic Compounds Using Iodide-Based Chemical Ionization, The Journal of Physical Chemistry A, 120, 576–587, https://doi.org/10.1021/acs.jpca.5b09837, 2016. a, b, c
Ji, Y., Huey, L. G., Tanner, D. J., Lee, Y. R., Veres, P. R., Neuman, J. A., Wang, Y., and Wang, X.: A vacuum ultraviolet ion source (VUV-IS) for iodide–chemical ionization mass spectrometry: a substitute for radioactive ion sources, Atmos. Meas. Tech., 13, 3683–3696, https://doi.org/10.5194/amt-13-3683-2020, 2020. a, b
Jiang, K., Yu, Z., Wei, Z., Cheng, S., Wang, H., Yan, Z., Shan, L., Huang, J., Yang, B., and Shu, J.: Direct detection of acetonitrile at the pptv level with photoinduced associative ionization time-of-flight mass spectrometry, Analytical Methods, 15, 368–376, https://doi.org/10.1039/D2AY01865A, 2023. a
Jokinen, T., Sipilä, M., Junninen, H., Ehn, M., Lönn, G., Hakala, J., Petäjä, T., Mauldin III, R. L., Kulmala, M., and Worsnop, D. R.: Atmospheric sulphuric acid and neutral cluster measurements using CI-APi-TOF, Atmos. Chem. Phys., 12, 4117–4125, https://doi.org/10.5194/acp-12-4117-2012, 2012. a
Kendall, R. A., Dunning, T. H., and Harrison, R. J.: Electron affinities of the first-row atoms revisited. Systematic basis sets and wave functions, The Journal of Chemical Physics, 96, 6796–6806, https://doi.org/10.1063/1.462569, 1992. a
Kercher, J. P., Riedel, T. P., and Thornton, J. A.: Chlorine activation by N2O5: simultaneous, in situ detection of ClNO2 and N2O5 by chemical ionization mass spectrometry, Atmos. Meas. Tech., 2, 193–204, https://doi.org/10.5194/amt-2-193-2009, 2009. a, b
Krechmer, J., Lopez-Hilfiker, F., Koss, A., Hutterli, M., Stoermer, C., Deming, B., Kimmel, J., Warneke, C., Holzinger, R., Jayne, J., Worsnop, D., Fuhrer, K., Gonin, M., and de Gouw, J.: Evaluation of a New Reagent-Ion Source and Focusing Ion–Molecule Reactor for Use in Proton-Transfer-Reaction Mass Spectrometry, Analytical Chemistry, 90, 12011–12018, https://doi.org/10.1021/acs.analchem.8b02641, 2018. a, b
Lee, B. H., Lopez-Hilfiker, F. D., Mohr, C., Kurtén, T., Worsnop, D. R., and Thornton, J. A.: An Iodide-Adduct High-Resolution Time-of-Flight Chemical-Ionization Mass Spectrometer: Application to Atmospheric Inorganic and Organic Compounds, Environmental Science & Technology, 48, 6309–6317, https://doi.org/10.1021/es500362a, 2014. a, b, c
Lee, B. H., Lopez‐Hilfiker, F. D., Veres, P. R., McDuffie, E. E., Fibiger, D. L., Sparks, T. L., Ebben, C. J., Green, J. R., Schroder, J. C., Campuzano‐Jost, P., Iyer, S., D'Ambro, E. L., Schobesberger, S., Brown, S. S., Wooldridge, P. J., Cohen, R. C., Fiddler, M. N., Bililign, S., Jimenez, J. L., Kurtén, T., Weinheimer, A. J., Jaegle, L., and Thornton, J. A.: Flight Deployment of a High‐Resolution Time‐of‐Flight Chemical Ionization Mass Spectrometer: Observations of Reactive Halogen and Nitrogen Oxide Species, Journal of Geophysical Research: Atmospheres, 123, 7670–7686, https://doi.org/10.1029/2017JD028082, 2018. a
Lee, B. H., Iyer, S., Kurtén, T., Varelas, J. G., Luo, J., Thomson, R. J., and Thornton, J. A.: Ring-opening yields and auto-oxidation rates of the resulting peroxy radicals from OH-oxidation of α-pinene and β-pinene, Environmental Science: Atmospheres, 3, 399–407, https://doi.org/10.1039/D2EA00133K, 2023. a
Liu, X., Deming, B., Pagonis, D., Day, D. A., Palm, B. B., Talukdar, R., Roberts, J. M., Veres, P. R., Krechmer, J. E., Thornton, J. A., de Gouw, J. A., Ziemann, P. J., and Jimenez, J. L.: Effects of gas–wall interactions on measurements of semivolatile compounds and small polar molecules, Atmos. Meas. Tech., 12, 3137–3149, https://doi.org/10.5194/amt-12-3137-2019, 2019. a
Lopez-Hilfiker, F. D., Mohr, C., Ehn, M., Rubach, F., Kleist, E., Wildt, J., Mentel, Th. F., Lutz, A., Hallquist, M., Worsnop, D., and Thornton, J. A.: A novel method for online analysis of gas and particle composition: description and evaluation of a Filter Inlet for Gases and AEROsols (FIGAERO), Atmos. Meas. Tech., 7, 983–1001, https://doi.org/10.5194/amt-7-983-2014, 2014. a, b
Lopez-Hilfiker, F. D., Iyer, S., Mohr, C., Lee, B. H., D'Ambro, E. L., Kurtén, T., and Thornton, J. A.: Constraining the sensitivity of iodide adduct chemical ionization mass spectrometry to multifunctional organic molecules using the collision limit and thermodynamic stability of iodide ion adducts, Atmos. Meas. Tech., 9, 1505–1512, https://doi.org/10.5194/amt-9-1505-2016, 2016. a, b
Neese, F.: The ORCA program system, WIREs Computational Molecular Science, 2, 73–78, https://doi.org/10.1002/wcms.81, 2012. a
Novak, G. A., Vermeuel, M. P., and Bertram, T. H.: Simultaneous detection of ozone and nitrogen dioxide by oxygen anion chemical ionization mass spectrometry: a fast-time-response sensor suitable for eddy covariance measurements, Atmos. Meas. Tech., 13, 1887–1907, https://doi.org/10.5194/amt-13-1887-2020, 2020. a
Palm, B. B., Liu, X., Jimenez, J. L., and Thornton, J. A.: Performance of a new coaxial ion–molecule reaction region for low-pressure chemical ionization mass spectrometry with reduced instrument wall interactions, Atmos. Meas. Tech., 12, 5829–5844, https://doi.org/10.5194/amt-12-5829-2019, 2019. a, b, c, d
Pankow, J. F. and Asher, W. E.: SIMPOL.1: a simple group contribution method for predicting vapor pressures and enthalpies of vaporization of multifunctional organic compounds, Atmos. Chem. Phys., 8, 2773–2796, https://doi.org/10.5194/acp-8-2773-2008, 2008. a
Perdew, J. P., Burke, K., and Ernzerhof, M.: Generalized Gradient Approximation Made Simple, Physical Review Letters, 77, 3865–3868, https://doi.org/10.1103/PhysRevLett.77.3865, 1996. a
Peterson, K. A., Figgen, D., Goll, E., Stoll, H., and Dolg, M.: Systematically convergent basis sets with relativistic pseudopotentials. II. Small-core pseudopotentials and correlation consistent basis sets for the post-d group 16–18 elements, The Journal of Chemical Physics, 119, 11113–11123, https://doi.org/10.1063/1.1622924, 2003. a
Reed, C., Evans, M. J., Crilley, L. R., Bloss, W. J., Sherwen, T., Read, K. A., Lee, J. D., and Carpenter, L. J.: Evidence for renoxification in the tropical marine boundary layer, Atmos. Chem. Phys., 17, 4081–4092, https://doi.org/10.5194/acp-17-4081-2017, 2017. a
Riplinger, C. and Neese, F.: An efficient and near linear scaling pair natural orbital based local coupled cluster method, The Journal of Chemical Physics, 138, https://doi.org/10.1063/1.4773581, 2013. a
Riplinger, C., Sandhoefer, B., Hansen, A., and Neese, F.: Natural triple excitations in local coupled cluster calculations with pair natural orbitals, The Journal of Chemical Physics, 139, https://doi.org/10.1063/1.4821834, 2013. a
Rissanen, M. P., Mikkilä, J., Iyer, S., and Hakala, J.: Multi-scheme chemical ionization inlet (MION) for fast switching of reagent ion chemistry in atmospheric pressure chemical ionization mass spectrometry (CIMS) applications, Atmos. Meas. Tech., 12, 6635–6646, https://doi.org/10.5194/amt-12-6635-2019, 2019. a
Riva, M., Rantala, P., Krechmer, J. E., Peräkylä, O., Zhang, Y., Heikkinen, L., Garmash, O., Yan, C., Kulmala, M., Worsnop, D., and Ehn, M.: Evaluating the performance of five different chemical ionization techniques for detecting gaseous oxygenated organic species, Atmos. Meas. Tech., 12, 2403–2421, https://doi.org/10.5194/amt-12-2403-2019, 2019. a
Robinson, M. A., Neuman, J. A., Huey, L. G., Roberts, J. M., Brown, S. S., and Veres, P. R.: Temperature-dependent sensitivity of iodide chemical ionization mass spectrometers, Atmos. Meas. Tech., 15, 4295–4305, https://doi.org/10.5194/amt-15-4295-2022, 2022. a
Rollins, A. W., Rickly, P. S., Gao, R.-S., Ryerson, T. B., Brown, S. S., Peischl, J., and Bourgeois, I.: Single-photon laser-induced fluorescence detection of nitric oxide at sub-parts-per-trillion mixing ratios, Atmos. Meas. Tech., 13, 2425–2439, https://doi.org/10.5194/amt-13-2425-2020, 2020. a
Slusher, D. L., Huey, L. G., Tanner, D. J., Flocke, F. M., and Roberts, J. M.: A thermal dissociation–chemical ionization mass spectrometry (TD‐CIMS) technique for the simultaneous measurement of peroxyacyl nitrates and dinitrogen pentoxide, Journal of Geophysical Research: Atmospheres, 109, https://doi.org/10.1029/2004JD004670, 2004. a
Swanson, W. F., Holmes, C. D., Simpson, W. R., Confer, K., Marelle, L., Thomas, J. L., Jaeglé, L., Alexander, B., Zhai, S., Chen, Q., Wang, X., and Sherwen, T.: Comparison of model and ground observations finds snowpack and blowing snow aerosols both contribute to Arctic tropospheric reactive bromine, Atmos. Chem. Phys., 22, 14467–14488, https://doi.org/10.5194/acp-22-14467-2022, 2022. a
Weigend, F. and Ahlrichs, R.: Balanced basis sets of split valence, triple zeta valence and quadruple zeta valence quality for H to Rn: Design and assessment of accuracy, Physical Chemistry Chemical Physics, 7, 3297, https://doi.org/10.1039/b508541a, 2005. a
Wolańska, I., Piwowarski, K., Budzyńska, E., and Puton, J.: Effect of Humidity on the Mobilities of Small Ions in Ion Mobility Spectrometry, Analytical Chemistry, 95, 8505–8511, https://doi.org/10.1021/acs.analchem.3c00435, 2023. a
Yang, D., Reza, M., Mauldin, R., Volkamer, R., and Dhaniyala, S.: Performance characterization of a laminar gas inlet, Atmos. Meas. Tech., 17, 1463–1474, https://doi.org/10.5194/amt-17-1463-2024, 2024. a
Zaytsev, A., Breitenlechner, M., Koss, A. R., Lim, C. Y., Rowe, J. C., Kroll, J. H., and Keutsch, F. N.: Using collision-induced dissociation to constrain sensitivity of ammonia chemical ionization mass spectrometry (NH
Zhang, P., Ma, L., Zhao, M., Sun, Y., Chen, W., and Zhang, Y.: The influence of a single water molecule on the reaction of BrO + HO2, Scientific Reports, 13, 13014, https://doi.org/10.1038/s41598-023-28783-x, 2023. a
Zhao, Y., Chan, J. K., Lopez-Hilfiker, F. D., McKeown, M. A., D'Ambro, E. L., Slowik, J. G., Riffell, J. A., and Thornton, J. A.: An electrospray chemical ionization source for real-time measurement of atmospheric organic and inorganic vapors, Atmos. Meas. Tech., 10, 3609–3625, https://doi.org/10.5194/amt-10-3609-2017, 2017. a, b, c, d, e
Short summary
We introduce a custom-built chamber (known as an IMR) for use with a Chemical Ionization Mass Spectrometry (CIMS) gas measurement instrument. The IMR shows large improvements compared to previous designs in reducing non-real signal in the instrument, reducing uncertainties for trace gas studies in the laboratory and the field. We characterize this new IMR and demonstrate its use in analyzing air masses of unknown composition during a field campaign, reporting concentrations of important gases.
We introduce a custom-built chamber (known as an IMR) for use with a Chemical Ionization Mass...
