Articles | Volume 26, issue 20
https://doi.org/10.5194/acp-26-14823-2026
© Author(s) 2026. 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-26-14823-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
22 Oct 2026
Research article |
| 22 Oct 2026
| 22 Oct 2026
From direct emission factors to inverse and indirect impact factors of road traffic: influence of emerging and unregulated pollutants
Lauri K. Savolainen
Aerosol Physics Laboratory, Physics Unit, Tampere University, 33014 Tampere, Finland
Aerosol Physics Laboratory, Physics Unit, Tampere University, 33014 Tampere, Finland
Heidi Hellén
Atmospheric Composition Research, Finnish Meteorological Institute, 00101 Helsinki, Finland
Henna Lintusaari
Aerosol Physics Laboratory, Physics Unit, Tampere University, 33014 Tampere, Finland
Milja Jäppi
Aerosol Physics Laboratory, Physics Unit, Tampere University, 33014 Tampere, Finland
Jarkko V. Niemi
Helsinki Region Environmental Services Authority (HSY), 00240 Helsinki, Finland
Kimmo Teinilä
Atmospheric Composition Research, Finnish Meteorological Institute, 00101 Helsinki, Finland
Minna Aurela
Atmospheric Composition Research, Finnish Meteorological Institute, 00101 Helsinki, Finland
Markus Lampimäki
Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki, Finland
Anu Kousa
Helsinki Region Environmental Services Authority (HSY), 00240 Helsinki, Finland
Janne Lampilahti
Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki, Finland
Katrianne Lehtipalo
Atmospheric Composition Research, Finnish Meteorological Institute, 00101 Helsinki, Finland
Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki, Finland
Tuukka Petäjä
Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki, Finland
Miikka Dal Maso
Aerosol Physics Laboratory, Physics Unit, Tampere University, 33014 Tampere, Finland
Hanna E. Manninen
Helsinki Region Environmental Services Authority (HSY), 00240 Helsinki, Finland
Hilkka Timonen
Atmospheric Composition Research, Finnish Meteorological Institute, 00101 Helsinki, Finland
Topi Rönkkö
Aerosol Physics Laboratory, Physics Unit, Tampere University, 33014 Tampere, Finland
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Adeeb Ktaish, Nahid Atashi, Ola Surakhi, Yu Zhao, Tianyi Zhao, Martha Arbayani Zaidan, Tuukka Petäjä, Tuija Jokinen, Wei Du, Markku Kulmala, and Tareq Hussein
Aerosol Research Discuss., https://doi.org/10.5194/ar-2026-42, https://doi.org/10.5194/ar-2026-42, 2026
Preprint under review for AR
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We developed a regression model to predict particle number concentrations across size ranges using meteorological variables and trace gases at SMEAR stations in Helsinki, Hyytiälä, and Värriö. The model performed well and captured diurnal and seasonal variability. Five scenarios showed that training data selection, recency, and duration influence performance, with limited benefits from older data. These findings guide training data selection and support future forecasting.
Eva Sommer, Mattia Busato, Pedro Rato, Hannah Klebach, Nirvan Bhattacharyya, Yuanlong Huang, Didier Lombard, Bernhard Mentler, Zhensen Zheng, Theodoros Aivaliotis, João Almeida, Louis-Philippe De Menezes, Ilia Krasin, Robert Kristic, Giulio Malaguti, Pierre Minginette, Sylvain Ravat, Emiliano Urrutia, Stefan Karl Weber, Lubna Dada, Jenna De Vivo, Milin Kaniyodical Sebastian, Paap Koemets, Felix Kunkler, Wiebke Scholz, Prashant Tripathi, Jens Voigtländer, Theodoros Christoudias, Joachim Curtius, Neil Donahue, Imad El Haddad, Roberto Guida, Armin Hansel, Hartwig Harder, Xu-Cheng He, Liine Heikkinen, Heikki Junninen, Markku Kulmala, Katrianne Lehtipalo, Ottmar Möhler, Mira Pöhlker, Rainer Volkamer, Paul Martin Winkler, Richard C. Flagan, Antti Onnela, Serge Mathot, and Jasper Kirkby
EGUsphere, https://doi.org/10.5194/egusphere-2026-6281, https://doi.org/10.5194/egusphere-2026-6281, 2026
This preprint is open for discussion and under review for Atmospheric Measurement Techniques (AMT).
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We present FLOTUS, an oxidation flow tube system developed as an extension to the CERN CLOUD chamber. FLOTUS allows us to simulate atmospheric ageing across a wide range of temperatures, oxidation conditions and gas mixtures. We characterise the flow conditions through simulations and measurements and we demonstrate the production of particles with different sizes and chemical compositions. The gases and particles can be analysed directly or transferred into the CLOUD chamber for further study.
Abdur Rahman, Juha Kangasluoma, Santtu Mikkonen, Tareq Hussein, Tuukka Petäjä, Sasu Tarkoma, and Martha Arbayani Zaidan
Aerosol Research Discuss., https://doi.org/10.5194/ar-2026-39, https://doi.org/10.5194/ar-2026-39, 2026
Preprint under review for AR
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PNSDs are vital for aerosol analysis, but traditional log-Gaussian models struggle with asymmetric modes. We introduce AeroMiG, an Inverse-Gamma framework that accurately models overlapping, asymmetric distributions. It models asymmetric and overlapping PNSDs, outperforms log-Gaussian models in speed and accuracy, maintains consistent performance across NPF events, and interprets Inverse-Gamma parameters for modal properties.
Gaurav Kumar Srivastav, Aasif Ahmad Wagay, Janne Lampilahti, Jaswant Rathore, Ravi Kumar Kunchala, Dilip Ganguly, Markku Kulmala, Tuukka Petäjä, Pauli Paasonen, Roseline C. Thakur, and Shahzad Gani
Atmos. Chem. Phys., 26, 14917–14938, https://doi.org/10.5194/acp-26-14917-2026, https://doi.org/10.5194/acp-26-14917-2026, 2026
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Particle formation events affect climate and air quality. Using measurements of particle number concentrations down to very small particles (~3 nm) in polluted northern India, we show that these events occur frequently in summer under reduced background particle load. However, in this environment, emissions and changing air masses can mask or distort these events, making them difficult to detect. Such environments require adaptation of standard analytical methods used in cleaner regions.
Lisa J. Beck, Rolf Weller, Totti Laitinen, Markku Kulmala, Douglas Worsnop, Janne Lampilahti, Heikki Junninen, and Mikko Sipilä
EGUsphere, https://doi.org/10.5194/egusphere-2026-6198, https://doi.org/10.5194/egusphere-2026-6198, 2026
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
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Snowstorms create large numbers of tiny electrically charged particles, but their composition and formation have been poorly understood. We measured these particles in Antarctica over three months and found that they consist mainly of sea salt, sodium chloride. During blizzards, their concentration rose to tens of times above those in calm weather. These findings reveal an under-explored source of atmospheric ions that may contribute to the formation of airborne particles and clouds.
Fobang Liu, Yun Zhang, Siyao Yue, Helmi-Marja K. Keskinen, Tuukka Petäjä, Markku Kulmala, Pingqing Fu, Thorsten Hoffmann, Kai Wang, and Haijie Tong
Atmos. Chem. Phys., 26, 14655–14669, https://doi.org/10.5194/acp-26-14655-2026, https://doi.org/10.5194/acp-26-14655-2026, 2026
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Reactive oxygen species (ROS) produced by airborne particles are linked to adverse health effects, but the organic compounds responsible remain unclear. We developed a new molecular framework to classify complex organic compounds using advanced mass spectrometry. The framework shows that particles rich in oxidized organic compounds produce more ROS per unit mass, while polluted urban air produces more total ROS mainly because of higher particle concentrations.
Jiali Shen, Yaowei Li, Jiangyi Zhang, Zhaojin An, Putian Zhou, Henning Finkenzeller, Paxton Juuti, Jyri Mikkila, Netta Vinkvist, Siddharth Iyer, Juha Kangasluoma, Tuukka Petäjä, Matti Rissanen, Aleksei Shcherbinin, Frank N. Keutsch, and Xu-Cheng He
EGUsphere, https://doi.org/10.5194/egusphere-2026-5947, https://doi.org/10.5194/egusphere-2026-5947, 2026
This preprint is open for discussion and under review for Atmospheric Measurement Techniques (AMT).
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Gases emitted by trees, such as isoprene, form molecules high in the atmosphere that help create new particles, but this chemistry is hard to measure and interpret. We developed a framework that combines an optimised Orbitrap mass spectrometer, which identifies molecules from their precise mass, with a computer model that separates true chemistry from reactor effects. Tested on isoprene, it revealed missing products and the role of light, offering a transferable tool for studying other gases.
Neha Deot, Vijay Kanawade, Harald Stark, Mihai Ciobanu, Douglas Worsnop, Katrianne Lehtipalo, and Tuija Jokinen
EGUsphere, https://doi.org/10.5194/egusphere-2026-4412, https://doi.org/10.5194/egusphere-2026-4412, 2026
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
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We investigated why new atmospheric particles form during summer in Cyprus, when photochemical activity is strongest but particle formation is not frequent. By combining particle measurements with molecular-level ion chemistry, trace gases, and meteorology, we found particle formation on about one-third of the days. Sulfuric acid dominated daytime cluster chemistry, while organic compounds became more important at night, revealing a clear daily shift in the earliest stages of particle formation.
Cecilia Righi, Mihai Ciobanu, Neha Deot, Tuija Jokinen, Chengfeng Liu, Qi Yuan, Lauriane L. J. Quéléver, Spiro Jorga, Veronika Pospisilova, Lisa J. Beck, Mario Simon, Marcel Zauner-Wieczorek, Andreas Kürten, Ruben Soler, Teresa Vera, Amalia Muñoz, Lauri R. Ahonen, Chao Yan, Tuukka Petäjä, and Nina Sarnela
Atmos. Meas. Tech., 19, 6357–6378, https://doi.org/10.5194/amt-19-6357-2026, https://doi.org/10.5194/amt-19-6357-2026, 2026
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Chemical ionization mass spectrometry is widely used to detect condensable vapors as sulfuric acid and highly oxygenated organic molecules, but results across studies are not always comparable. In summer 2024, an intercomparison campaign involving six instruments was conducted at a boreal forest site. Comparable measurements were achievable when all calibration and correction factors were applied. Instrument behavior depended more on inlet design and operating conditions than reagent ion choice.
Dominic Heslin-Rees, Peter Tunved, Diego Aliaga, Janne Lampilahti, Ilona Riipinen, Annica M. L. Ekman, Ki-Tae Park, Martina Mazzini, Stefania Gilardoni, Roseline Thakur, Kihong Park, Young Jun Yoon, Kitack Lee, Mikko Sipilä, Mauro Mazzola, and Radovan Krejci
Aerosol Research, 4, 457–483, https://doi.org/10.5194/ar-4-457-2026, https://doi.org/10.5194/ar-4-457-2026, 2026
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New particles form in the atmosphere and can influence the climate. We studied Arctic new particle formation (NPF) from 2022 to 2024 at the Zeppelin Observatory, on Svalbard. NPF occurs from April to November, peaking in late spring as sunlight increases. Some particles measured on-site grow large enough to seed clouds. Sunlight and existing aerosol particles strongly impact the likelihood of NPF, which mainly originates from marine regions, particularly the Greenland Sea.
Anna Bengs, Mrisha Koirala, Chengfeng Liu, Henning Finkenzeller, Cecilia Righi, Sebastian Holm, Lauri Ahonen, Veli Kolhinen, Rima Baalbaki, Fabian Schmidt-Ott, Yiliang Liu, Jianfei Peng, Tuukka Petäjä, Markku Kulmala, Nina Sarnela, Runlong Cai, and Juha Kangasluoma
EGUsphere, https://doi.org/10.5194/egusphere-2026-5681, https://doi.org/10.5194/egusphere-2026-5681, 2026
This preprint is open for discussion and under review for Atmospheric Measurement Techniques (AMT).
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Forests emit trace gases that react to form compounds relevant to air quality and climate. Identifying them is difficult because common instruments cannot fully separate molecules of similar mass. We compared three mass spectrometers with different resolving power in a Finnish forest. The highest-resolution instrument identified far more molecules, and using its results to reanalyze the others' data nearly tripled the number identified, improving identification in widely used equipment.
Kanika Taneja, Silvia M. Calderón, Harri Kokkola, Juha Tonttila, Sami Romakkaniemi, Seethala Chellappan, Antti Arola, Antti Lipponen, Taina Yli-Juuti, Snehitha M. Kommula, Tuukka Petäjä, Markku Kulmala, and Tero Mielonen
EGUsphere, https://doi.org/10.5194/egusphere-2026-4750, https://doi.org/10.5194/egusphere-2026-4750, 2026
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Vegetation can cool the climate by releasing gases that form aerosols, which scatter sunlight and brighten clouds. To quantify this feedback in Finland and the United States, we combine field measurements of aerosols and satellite observations of clouds. It is essential to select near-ideal clouds; otherwise, cloud-related cooling is underestimated. Cloud cooling matched aerosol cooling at the clean site in Finland and was nearly three times stronger at the rural site in the United States.
Aasif Ahmad Wagay, Pauli Paasonen, Tuukka Petäjä, Victoria Sinclair, Sarath Guttikunda, and Shahzad Gani
EGUsphere, https://doi.org/10.5194/egusphere-2026-4950, https://doi.org/10.5194/egusphere-2026-4950, 2026
This preprint is open for discussion and under review for Earth System Dynamics (ESD).
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Urbanization changes temperature, winds, and boundary layer height, affecting heat exposure and air quality. We develop a framework to quantify these changes across 20 global megacities using WRF simulations. Urban effects are generally stronger inland, while terrain and ocean can influence the apparent signal. Because these variables control atmospheric mixing and pollutant dispersion, understanding urban changes is essential for assessing air quality and exposure.
Ekaterina Ezhova, Üllar Rannik, Santeri Tuovinen, Olga Garmash, Otso Peräkylä, Piaopiao Ke, Topi Laanti, Janne Lampilahti, Markus Lampimäki, Anna Lintunen, Veli-Matti Kerminen, Janne Rinne, Timo Vesala, and Markku Kulmala
Atmos. Chem. Phys., 26, 13463–13483, https://doi.org/10.5194/acp-26-13463-2026, https://doi.org/10.5194/acp-26-13463-2026, 2026
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In boreal region, emissions from plants contribute to formation and growth of aerosol particles. Measurements suggest that concentration of small ions, which could be produced locally, differ in forests and agricultural fields. As a step to interpretation, we explain the concept of local aerosol production and estimate a spatial scale of an ecosystem needed to produce small ions. This scale is about few km in open areas such as agricultural fields and 500 m in the pine forest with closed canopy.
Sami D. Harni, Delun Li, Ville Silvonen, Laura Salo, Teemu Lepistö, Toni Tykkä, Mohamed Elsayed, Luis Barreira, Sanna Saarikoski, Ilpo Kulmala, Jarkko V. Niemi, Heidi Hellén, Arto Säämänen, Topi Rönkkö, and Hilkka Timonen
Aerosol Research Discuss., https://doi.org/10.5194/ar-2026-32, https://doi.org/10.5194/ar-2026-32, 2026
Preprint under review for AR
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In this study, indoor and outdoor pollutant concentrations were measured in a mechanically ventilated building in the immediate vicinity of a busy international airport. The measurement period included a strong long-range transport event. Clear differences in indoor outdoor ratios were observed between different pollutants and between normal and long-range transport periods. This study highlights the significance of a intake filtration system in indoor pollutant concentration management.
Tinghan Zhang, Wei Du, Xinran Zhang, Janne Lampilahti, Chengfeng Liu, Zehao Zou, Men Xia, Qi Yuan, Qiaozhi Zha, Jing Cai, Yiyang Wang, Tom Kokkonen, Katrianne Lehtipalo, Tuukka Petäjä, Veli-Matti Kerminen, Chao Yan, Jingkun Jiang, Yongchun Liu, and Markku Kulmala
EGUsphere, https://doi.org/10.5194/egusphere-2026-5379, https://doi.org/10.5194/egusphere-2026-5379, 2026
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
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New particle formation (NPF) is an important source of atmospheric aerosols, but weak events are often overlooked by traditional classification. We applied continuous nanoparticle ranking and particle size distribution normalization to four-year observations from a Finnish boreal forest and the megacity of Beijing. The results show that NPF intensity is governed by source–sink competition and that particle formation and growth are not necessarily controlled by the same atmospheric conditions.
Liine Heikkinen, Rahul Ranjan, Sini Talvinen, Niels Behr, Sara M. Blichner, Maura Dewey, Lauri R. Ahonen, Mikael Ehn, Annica M. L. Ekman, Radovan Krejci, Tuukka Petäjä, Peter Tunved, and Ilona Riipinen
EGUsphere, https://doi.org/10.5194/egusphere-2026-5082, https://doi.org/10.5194/egusphere-2026-5082, 2026
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The impacts of clouds on atmospheric particulate matter (PM) composition are not well understood. Here, we use a new method to infer these interactions as particle number size distributions with bimodal shapes serve as markers of chemical cloud processing. Using concurrent PM composition data from a boreal forest in Finland, we find cloud chemistry to enrich PM in sulfate, but no enhanced formation of organics was observed, despite the abundance of precursors emitted by the forest.
Qianzhe Sun, Ruichen Zhou, Sho Ohata, Chiaki Shirota, Tuukka Petäjä, Ilona Jaakkola, Lauri Ahonen, Markku Kulmala, and Michihiro Mochida
Atmos. Chem. Phys., 26, 12813–12836, https://doi.org/10.5194/acp-26-12813-2026, https://doi.org/10.5194/acp-26-12813-2026, 2026
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Source identification of atmospheric aerosols is crucial for understanding their properties and resulting environmental impacts. By mass spectrometry for aerosol samples, organic aerosols in a European boreal forest were apportioned to five source-related types based on chemical structure, highlighting the importance of biomass-originated organics. Polarity-based fractionation advanced source apportionment, which is expected to improve the capability of property analysis for organic aerosols.
Ross J. Herbert, Larissa Lacher, Alexander Böhmländer, Mark D. Tarn, Antoine Canzi, Aidan Pantoya, Evelyn Freney, Kristina Höhler, Pia Bogert, Céline Planche, Ping Tian, Michael Adams, Sarah Barr, David Brus, Nicole Büttner, Martin Daily, Konstantinos Doulgeris, Konstantinos Eleftheriadis, Grant Forster, Romy Fösig, Dimitrios G. Georgakopoulos, Maria I. Gini, A. Gannet Hallar, Radovan Krejci, Elke Ludewig, Mauro Mazzola, Ian B. McCubbin, Athanasios Nenes, Tuukka Petäjä, Joseph Robinson, Franziska Vogel, Paul Zieger, Stephen Arnold, Kenneth S. Carslaw, Naruki Hiranuma, Ottmar Möhler, and Benjamin J. Murray
Earth Syst. Sci. Data, 18, 6465–6483, https://doi.org/10.5194/essd-18-6465-2026, https://doi.org/10.5194/essd-18-6465-2026, 2026
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Ice formation in sub-zero clouds is influenced by airborne particles called ice-nucleating particles (INPs), whose concentrations vary substantially over short time and spatial scales. To assess the role of INPs in our climate, a comprehensive and consistent global dataset is essential. Our GloPINE model-ready dataset is a major step in this direction, comprising 36,000 measurements made using a single instrument design (PINE) over 70,000 hours of operation at 20 Northern Hemisphere sites.
Sanna Saarikoski, Minna Aurela, Jarkko V. Niemi, Luis M. F. Barreira, Jussi Hoivala, Hanna Manninen, Topi Rönkkö, and Hilkka Timonen
Atmos. Chem. Phys., 26, 11817–11833, https://doi.org/10.5194/acp-26-11817-2026, https://doi.org/10.5194/acp-26-11817-2026, 2026
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This study analyzed submicron organic aerosol (OA) at a Helsinki traffic site (2018–2024) using aerosol mass spectrometer. Findings show that traffic OA includes both hydrocarbons (HOA) and oxygenated traffic-related OA (TrOA). TrOA peaks later in morning than HOA, likely due to atmospheric processing or modern vehicle emissions. Using only HOA to estimate traffic primary OA may cause a 50 % underestimation indicating that traffic OA is complicated, involving both primary and secondary aerosols.
Sara M. Blichner, Theodore Khadir, Sini Talvinen, Paulo Artaxo, Liine Heikkinen, Harri Kokkola, Radovan Krejci, Muhammed Irfan, Twan van Noije, Tuukka Petäjä, Christopher Pöhlker, Øyvind Seland, Carl Svenhag, Antti Vartiainen, and Ilona Riipinen
Atmos. Chem. Phys., 26, 11281–11307, https://doi.org/10.5194/acp-26-11281-2026, https://doi.org/10.5194/acp-26-11281-2026, 2026
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This study looks at how well climate models capture the impact of rain on particles that help form cloud droplets. Using data from three measurement stations and applying both a correlation analysis and a machine learning approach, we found that models often miss how new particles form after rain and struggle in cold environments. This matters because these particles influence cloud formation and climate.
Anouk Marsal, Fabrizia Cavalli, Elise Di Antonio, Stephan Houdier, Pamela Dominutti, Sophie Darfeuil, Jean-Luc Jaffrezo, Stéphane Sauvage, Jean-Philippe Putaud, Ian S. Mudway, Athanasios Nenes, Aikaterini Bougiatioti, Nikolaos Mihalopoulos, André S. H. Prévôt, Despina Paraskevopoulou, Ana Cvitešić Kušan, Sanja Frka, Ana Kroflič, Ajda Delić, Blanka Tariba Lovaković, Andreja Jurič, Carolina Molina, Daniele Contini, Maria Rachele Guascito, Mathilde Lintz, Davy Rousset, Hartmut Herrmann, Eduardo J. d. S. Souza, Frédéric Ledoux, Marc Fadel, Haoran Yu, Jianzhen Yu, Maria Teresa Baeza Romero, Maria Cerrato-Alvarez, Marloes F. van Os, Mathilde N. Delaval, Yamaris Mercedes Mena Cabrera, Nicole Trieu, Greg Evans, Nuria Galindo, Noelia Gómez-Sanchez, Hana Hlaváčková, Pavel Mikuška, Shrutika Kadam, Pourya Shahpoury, Purificación López-Mahía, Jorge Moreda-Piñeiro, Rico K. Y. Cheung, Markus Kalberer, Micol Introna, Sarah S. Steimer, Zhuoying Lin, Suzanne E. Paulson, Saima Iram, Svetlana Stevanovic, Thomas Audoux, Laurent Y. Alleman, Jianing Liu, Ting Fang, P. S. Ganesh Subramanian, Vishal Verma, Tuukka Petäjä, Xavier Querol, Gerard Hoek, Roy M. Harrison, and Gaëlle Uzu
EGUsphere, https://doi.org/10.5194/egusphere-2026-3918, https://doi.org/10.5194/egusphere-2026-3918, 2026
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This collaborative work from 26 worldwide laboratories assessed the measurement of atmospheric particles' oxidative potential (OP) using a common protocol. OP is a metric designed to inform on particles’ harmful effects. Over half of the laboratories obtained satisfactory results, and some critical steps such as liquid handling and OP mathematical determination were identified. Recommendations for future measurements and interlaboratory comparisons are also provided.
Luis M. F. Barreira, Delun Li, Jussi Hoivala, Minna Aurela, Aki Virkkula, Jarkko V. Niemi, Hanna E. Manninen, Topi Rönkkö, Hilkka Timonen, and Sanna Saarikoski
Aerosol Research Discuss., https://doi.org/10.5194/ar-2026-28, https://doi.org/10.5194/ar-2026-28, 2026
Revised manuscript accepted for AR
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Urban street canyon measurements during spring showed that submicron particles (PM1) dominated light absorption and black carbon from traffic exhaust, while coarse particles (PM2.5–PM10) became important during dust resuspension events. Size-resolved optical and chemical analyses revealed strong source-dependency, with coarse fractions influencing absorption metrics and source apportionment, especially during street dust events, which highlighted the importance of selected particle size cut-off.
Samuel Ruhl, Matthias Kohl, Rima Baalbaki, Christos Xenofontos, Ryan Vella, Sergey Gromov, Xu-Cheng He, Jiali Shen, Dina Alfaouri, Samira Atabakhsh, Lubna Dada, Jenna DeVivo, Jonathan Duplissy, Imad El Haddad, Hartwig Harder, Tuija Jokinen, Heikki Junninen, Vijay P. Kanawade, Milin K. Sebastian, Hannah Klebach, Markku Kulmala, Felix Kunkler, Jos Lelieveld, Katrianne Lehtipalo, Clara J. Lietzke, Lu Liu, Roy Mauldin, Bernhard Mentler, Ottmar Möhler, Tuukka Petäjä, Douglas M. Russell, Mario Simon, Roseline C. Thakur, Wenjuan Yu, Jiangyi Zhang, Zhensen Zheng, Jasper Kirkby, Holger Tost, Theodoros Christoudias, Rolf Sander, and Andrea Pozzer
EGUsphere, https://doi.org/10.5194/egusphere-2026-4020, https://doi.org/10.5194/egusphere-2026-4020, 2026
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Marine microbes release sulfur gases that form tiny particles able to seed clouds. Using a global chemistry-climate model, we compare four schemes for how these gases oxidise and test them against ship and ground measurements. We find that methanesulfonic acid can drive new particle formation as strongly as sulfuric acid over the cold Southern Ocean, supplying around 25 % of the cloud-forming particles there, a natural, climate-relevant source that models often overlook.
Aino Ovaska, Daniel Holmberg, Elio Rauth, Mansour Alghamdi, Paulo Artaxo, Eija Asmi, John Backman, Benjamin Bergmans, Matthew Boyer, Liezl Bredenkamp, Maurizio Busetto, Delano Campos De Oliveira, Juan Andrés Casquero-Vera, Darius Ceburnis, Tak Chan, Tommy Chan, Sebastien Conil, Daniele Contini, Suzanne Crumeyrolle, Valentin Duflot, Kostas Eleftheriadis, Johan Esveld, Ekaterina Ezhova, Markus Fiebig, Shahzad Gani, Olga Garmash, Francisco Gómez-Moreno, Roy M. Harrison, Andras Hoffer, Rakesh Hooda, Antti Hyvärinen, Tareq Hussein, Jorma Joutsensaari, Nikos Kalivitis, Heinz Kaminski, Jutta Kesti, Radovan Krejci, Adam Kristensson, Chongai Kuang, Markku Kulmala, Lauri Laakso, Ari Leskinen, Heikki Lihavainen, Andreas Massling, Maik Merkel, Steffen Noe, Jakub Ondracek, Noemí Perez, Jean-Eudes Petit, Tuukka Petäjä, Michael Pikridas, Christopher Pöhlker, Mira Pöhlker, Jean-Philippe Putaud, Ximeng Qi, Cristina Reche, Sergio Rodríguez, Petr Roztocil, Jean Sciare, Karine Sellegri, Dongjie Shang, Ashish Singh, Mikko Sipilä, Henrik Skov, Mar Sorribas, Tamanna Subba, Junying Sun, Peter Tunved, Ville Vakkari, Pieter G. Van Zyl, Aki Virkkula, Jens Voigtländer, Kay Weinhold, Alfred Wiedensohler, Hee-Jung Yoo, Putian Zhou, Kai Puolamäki, Tuomo Nieminen, Veli-Matti Kerminen, Victoria A. Sinclair, and Pauli Paasonen
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2026-415, https://doi.org/10.5194/essd-2026-415, 2026
Preprint under review for ESSD
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All clouds form around aerosol particles, and their abundance influences cloud properties. In turn, clouds affect climate by changing how energy moves through the atmosphere, making them important for climate change. To better understand these interactions, we need accurate information on how many aerosol particles are in the atmosphere. Therefore, we have developed a new 21-year global dataset of particle concentrations relevant for cloud formation.
Heidi Hellén, Toni Tykkä, Elli Suhonen, Kimmo Teinilä, Teemu Lepistö, Jarkko V. Niemi, Topi Rönkkö, Hilkka Timonen, and Arnaud P. Praplan
EGUsphere, https://doi.org/10.5194/egusphere-2026-4128, https://doi.org/10.5194/egusphere-2026-4128, 2026
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This study presents a new approach to quantify anthropogenic terpene emissions by measuring VOCs during winter, when biogenic emissions are negligible. Measurements in Helsinki showed that although anthropogenic terpenes accounted for less than 1 % of VOC mass, they made a disproportionately large contribution to atmospheric reactivity. The findings highlight the importance of including anthropogenic terpene emissions in urban air quality studies and atmospheric chemistry models.
Chengfeng Liu, Otso Peräkylä, Lauri Ahonen, Ilona Ylivinkka, Petri Keronen, Douglas R. Worsnop, Tuukka Petäjä, Markku Kulmala, Mikael Ehn, and Nina Sarnela
EGUsphere, https://doi.org/10.5194/egusphere-2026-2773, https://doi.org/10.5194/egusphere-2026-2773, 2026
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Forests emit invisible vapors that form climate-regulating atmospheric particles. To track these seasonal changes, we continuously analyzed forest air for four years. We discovered that heavier plant emissions (sesquiterpenes and diterpenes)—rather than the lighter ones (monoterpenes) previously assumed—may drive particle creation in spring and summer. This insight is crucial for predicting how forests will influence the global climate as temperatures rise.
Yusheng Wu, Zoé Brasseur, Dimitri Castarède, Paavo Heikkilä, Jorma Keskinen, Ottmar Möhler, Markku Kulmala, Tuukka Petäjä, Erik S. Thomson, and Jonathan Duplissy
Aerosol Research, 4, 293–309, https://doi.org/10.5194/ar-4-293-2026, https://doi.org/10.5194/ar-4-293-2026, 2026
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Clouds in cold regions affect climate and precipitation, but their behavior depends on rare airborne particles that help ice form. We measured these particles over several months in a Finnish forest and compared them with many environmental observations. We found that ice formation in winter was largely unpredictable, while in spring and summer it was more strongly linked to particle amount and composition. This shows that local conditions are needed to better represent clouds in climate models.
Kimmo Teinilä, Teemu Lepistö, Jarkko V. Niemi, Harri Portin, Anssi Julkunen, Anu Kousa, Joel Kuula, Hanna E. Manninen, Pasi Aalto, Tuukka Petäjä, Topi Rönkkö, Erkka Saukko, and Hilkka Timonen
Atmos. Meas. Tech., 19, 4505–4516, https://doi.org/10.5194/amt-19-4505-2026, https://doi.org/10.5194/amt-19-4505-2026, 2026
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Particle number concentrations were measured with condensation particle counters and diffusion-based sensors at two different urban environments in Helsinki in 2022. The measurement sites were traffic related and background urban sites. The aim of the study was to investigate suitability of using diffusion-based sensors in urban air quality monitoring to obtain particle number concentrations and challenges related to this.
Sujai Banerji, Touqeer Gill, Veli-Matti Kerminen, and Tuukka Petäjä
EGUsphere, https://doi.org/10.5194/egusphere-2026-3400, https://doi.org/10.5194/egusphere-2026-3400, 2026
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We studied how dust and pollen episodes change airborne particles at a forest research site in southern Finland. Using long-term measurements of particle light, mass, and size, we found that both episodes can look similar in light-based records, but they affect particle sizes differently. This means light measurements alone can misidentify the cause of a particle episode. The work helps improve interpretation of atmospheric monitoring records and avoid overconfident source claims in future work.
Martina Mazzini, Diego Aliaga, Janne Lamphilati, Martin Gysel-Beer, Benjamin Tobias Brem, Robin Lewis Modini, Dominic Heslin-Rees, Tareq Hussein, Marco Zanatta, Paolo Cristofanelli, Federico Bianchi, Markku Kulmala, and Angela Marinoni
Atmos. Chem. Phys., 26, 8893–8912, https://doi.org/10.5194/acp-26-8893-2026, https://doi.org/10.5194/acp-26-8893-2026, 2026
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This study investigates particle number size distribution at two high-altitude European stations to better understand the mechanisms driving new particle formation (NPF) in the free troposphere. Interestingly, despite a consistently higher background of freshly nucleated particles at Jungfraujoch, NPF events were more frequent and intense at Monte Cimone, which also shows higher formation and growth rates, likely due to the proximity of the polluted planetary boundary layer from the Po Valley.
Wenche Aas, Thérèse Salameh, Robert Wegener, Heidi Hellén, Jean-Luc Jaffrezo, Pontus Roldin, Elisabeth Alonso-Blanco, Andres Alastuey, Crist Amelynck, Jgor Arduini, Benjamin Bergmans, Marie Bertrand, Agnes Borbon, Efstratios Bourtsoukidis, Laetitia Bouvier, David Butterfield, Iris Buxbaum, Darius Ceburnis, Anja Claude, Augustin Colette, Aurélie Colomb, Sophie Darfeuil, James Dernie, Maximilien Desservettaz, Elías Díaz-Ramiro, Marvin Dufresne, René Dubus, Mario Duval, Marie Dury, Anna Font, Kirsten N. Fossum, Evelyn Freney, Gotzon Gangoiti, Yao Ge, Maria Carmen Gomez, Francisco J. Gómez-Moreno, Marie Gohy, Valérie Gros, Paul Hamer, Bryan Hellack, Hartmut Herrmann, Robert Holla, Adéla Holubová, Niels R. Jensen, Tuija Jokinen, Matthew Jones, Uwe Käfer, Lukas Kesper, Dieter Klemp, Dagmar Kubistin, Angela Marinoni, Martina Mazzini, Vy Ngoc Thuy Dinh, Jurgita Ovadnevaite, Tuukka Petäjä, Miguel Portillo-Estrada, Jitka Přívozníková, Jean-Philippe Putaud, Stefan Reimann, Laura Renzi, Veronique Riffault, Stuart Ritchie, Chris Robins, Begoña Artíñano Rodríguez de Torres, Laurent Poulain, Julian Rüdiger, Agnieszka Sanocka, Estibaliz Saez de Camara Oleaga, Niels Schoon, Roger Seco, Ivan Simmons, Leïla Simon, David Simpson, Sverre Solberg, Emmanuel Tison, August Thomasson, Svetlana Tsyro, Marsailidh Twigg, Toni Tykkä, Bert Verreyken, Ågot Watne, Katie Williams, Ana Maria Yáñez-Serrano, Karen Yeung, Ilona Ylivinkka, and Karl Espen Yttri
Atmos. Chem. Phys., 26, 8717–8751, https://doi.org/10.5194/acp-26-8717-2026, https://doi.org/10.5194/acp-26-8717-2026, 2026
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A one-week intensive measurement campaign during the 2022 European heatwave included monitoring of ozone, volatile organic compounds, aerosol chemical composition, and organic tracers to investigate air pollution sources. Results showed that emissions from vegetation and human activities contributed to peaks in ozone and secondary organic aerosol particles. Differences between measurements and model simulations underline the need for better characterization of sources and formation pathways.
Neil M. Donahue, Lubna Dada, Dominik Stolzenburg, Eva Sommer, Mario Simon, Meredith Schervish, Jenna DeVivo, Alexandra Stinchfield, Natalie Burton, Nirvan Bhattacharyya, Brandon Lopez, Mingyi Wang, Wiebke Scholz, João Almeida, Bin Zhao, Martin Heinritzi, Hamish Gordon, Armin Hansel, Joachim Curtius, Katrianne Lehtipalo, Imad El Haddad, Jasper Kirkby, Richard Flagan, Markku Kulmala, and Douglas Worsnop
Atmos. Chem. Phys., 26, 8311–8339, https://doi.org/10.5194/acp-26-8311-2026, https://doi.org/10.5194/acp-26-8311-2026, 2026
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A new theory has the potential to accurately describe changes to atmospheric particle formation from the pre-industrial to the present and onwards along socioeconomic pathways addressing air pollution and climate. The model places organic nucleation in the context of the Volatility Basis Set and reveals a competition between chemistry, which accelerates as temperature rises, and vapor pressure, which drops as temperature decreases. The model reproduces observations from the CERN (European Organization for Nuclear Research) CLOUD (Cosmics Leaving Outdoor Droplets) chamber.
Manuel Bettineschi, Arineh Cholakian, Victoria Sinclair, Katerina Sindelarova, Arnaud P. Praplan, Steven J. Thomas, Tuukka Petäjä, Federico Bianchi, and Giancarlo Ciarelli
Atmos. Chem. Phys., 26, 8067–8088, https://doi.org/10.5194/acp-26-8067-2026, https://doi.org/10.5194/acp-26-8067-2026, 2026
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We studied how forests in Finland release natural gases that affect air quality and climate. Existing models strongly overestimated these emissions because they used overly simple forest descriptions. By adding detailed information on tree species, we greatly improved agreement with real measurements. This means more realistic estimates of particle formation in the air. Our results show that accurate forest data are essential for reliable climate and air quality predictions.
Tilman Leo Hohenberger, Marya el Malki, Antoon Visschedijk, Marc Guevara, Martin Otto Paul Ramacher, Alessandro Marongiu, Guido Giuseppe Lanzani, Giuseppe Fossati, Anu Kousa, Eleni Athanasopoulou, Anastasia Kakouri, and Jeroen Kuenen
Earth Syst. Sci. Data, 18, 3959–3978, https://doi.org/10.5194/essd-18-3959-2026, https://doi.org/10.5194/essd-18-3959-2026, 2026
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Spatial road transport emission data is fundamental for challenges of air pollution and climate change. In the existing European CAMS-REG (Copernicus Atmosphere Service-regional) inventory, several improvement opportunities exist, especially an underestimation in urban centers of ~35 %. We calculate emissions by combining gap-filled road information and emission factors, for the first time giving detailed emissions for most roads in Europe. With this, our dataset is much closer in line with independently combined city inventories.
Paul D. Hamer, Miha Markelj, Oscar Rojas-Munoz, Bertrand Bonan, Jean-Christophe Calvet, Virginie Marécal, Alex Guenther, Heidi Trimmel, Islen Vallejo, Sabine Eckhardt, Gabriela Sousa Santos, Katerina Sindelarova, David Simpson, Norbert Schmidbauer, Heidi Hellén, Pascal Rubli, Stefan Reimann, Anja Claude, Dagmar Kubistin, Julie Cozic, James Dernie, and Leonor Tarrasón
Earth Syst. Sci. Data, 18, 3635–3669, https://doi.org/10.5194/essd-18-3635-2026, https://doi.org/10.5194/essd-18-3635-2026, 2026
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Plants release gases like isoprene that can form ozone and affect air quality. Using models and satellite data, we mapped the emissions of isoprene from plants across Europe and found that droughts can reduce leaf growth, leading to lower emissions. This shows that to understand and predict air quality, we must also understand how drought impacts vegetation. Our findings highlight the value of linking extreme weather, plant health, and pollution in models of the Earth system as a whole.
Neil M. Donahue, Victoria Hofbauer, Henning Finkenzeller, Dominik Stolzenburg, Paulus S. Bauer, Randall Chiu, Lubna Dada, Jonathan Duplissy, Xu-Cheng He, Martin Heinritzi, Christopher R. Hoyle, Andreas Kürten, Aleksandr Kvashnin, Katrianne Lehtipalo, Naser Mahfouz, Vladimir Makhmutov, Roy L. Mauldin III, Ugo Molteni, Lauriane L. J. Quéléver, Matti Rissanen, Siegfried Schobesberger, Mario Simon, Andrea C. Wagner, Mingyi Wang, Chao Yan, Penglin Ye, Ilona Riipinen, Hamish Gordon, Joachim Curtius, Armin Hansel, Imad El Haddad, Markku Kulmala, Douglas R. Worsnop, Rainer Volkamer, Paul M. Winkler, Jasper Kirkby, and Richard Flagan
Atmos. Meas. Tech., 19, 3363–3396, https://doi.org/10.5194/amt-19-3363-2026, https://doi.org/10.5194/amt-19-3363-2026, 2026
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We describe accurate measurement of particle formation and growth in the CERN CLOUD (European Council for Nuclear Research Cosmics Leaving OUtdoor Droplets) chamber, using a suite of gas- and particle-phase instruments. The interconnected measurements establish high accuracy in key particle properties and critically important gas-phase sulfuric acid. This is a template for accurate calibration of similar experiments and thus accurate determination of aerosol nucleation and growth rates, which are an important source of uncertainty in climate science.
Myriam Agrò, Manuel Bettineschi, Silvia Melina, Diego Aliaga, Andrea Bergomi, Beatrice Biffi, Alessandro Bigi, Giancarlo Ciarelli, Cristina Colombi, Paola Fermo, Ivan Grigioni, Veli-Matti Kerminen, Markku Kulmala, Janne Lampilahti, Angela Marinoni, Celestine Oliewo, Juha Sulo, Gianluigi Valli, Roberta Vecchi, Tuukka Petäjä, Katrianne Lehtipalo, and Federico Bianchi
Atmos. Chem. Phys., 26, 6521–6539, https://doi.org/10.5194/acp-26-6521-2026, https://doi.org/10.5194/acp-26-6521-2026, 2026
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This study investigates new particle formation (NPF) in Milan, the most populated city in the Po Valley (Italy), using one year of particle number size distribution data (1.2–480 nm). NPF is enhanced under cleaner air conditions with lower pollution, reduced condensation sink, stronger ventilation, and stronger northwesterly winds (e.g., Foehn events). In contrast, longer air mass residence time in the Po Valley and higher air mass exposure to anthropogenic emissions suppress it.
Teemu Lepistö, Hilkka Timonen, Topi Rönkkö, and Miikka Dal Maso
Atmos. Chem. Phys., 26, 4215–4230, https://doi.org/10.5194/acp-26-4215-2026, https://doi.org/10.5194/acp-26-4215-2026, 2026
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Condensation of vapour molecules onto aerosol particles is a key process regarding aerosol health and climate effects. The condensation sink (CS) estimates the attachment rate of vapour molecules onto existing particles. Here, we explore the concept of size-resolved CS as many of the effects related to condensation are dependent on the size of the existing particles. Our results show clear location-dependent differences in the CS size distributions which may have not been considered before.
Herbert G. Hartl, Janne Lampilahti, Rima Baalbaki, Lauri Ahonen, Tommy Chan, Tinghang Zhang, Joonas Vanhanen, Joonas Purén, Gerhard Steiner, Sebastian Schmitt, Torsten Tritscher, Amine Koched, Manuel Granzin, Petr Roztocil, Silja Häme, Tuukka Petäjä, and Katrianne Lehtipalo
Aerosol Research, 4, 133–152, https://doi.org/10.5194/ar-4-133-2026, https://doi.org/10.5194/ar-4-133-2026, 2026
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Small airborne particles influence how clouds form and how they affect the climate. Our study compared eight different instruments that measure the size distributions of these particles to understand the instruments' strengths and weaknesses. We found that some systems are more accurate, whereas others are more sensitive at tiny sizes. These results will help to improve future monitoring of air quality and climate processes.
Katariina Kylämäki, Milja Jäppi, Leïla Simon, Wojciech Honkisz, Petteri Marjanen, Laura Salo, Teemu Lepistö, Henna Lintusaari, Luis Barreira, Hannu Kuutti, Matti Rissanen, Piotr Bielaczyc, Hilkka Timonen, Päivi Aakko-Saksa, and Topi Rönkkö
EGUsphere, https://doi.org/10.5194/egusphere-2026-224, https://doi.org/10.5194/egusphere-2026-224, 2026
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Oxidation flow reactors (OFRs) simulate atmospheric aging of e.g. anthropogenic emissions. In this study, we aged exhaust from passenger cars in two OFRs with different designs. On average, the OFRs produced comparable particle size distributions and emission factors. However, there were differences between the OFRs in secondary particle formation depending on the fuel and technology of the car and the differences were mostly explained by OFR design.
Santeri Tuovinen, Janne Lampilahti, Nina Sarnela, Chengfeng Liu, Yongchun Liu, Markku Kulmala, and Veli-Matti Kerminen
Aerosol Research, 4, 37–62, https://doi.org/10.5194/ar-4-37-2026, https://doi.org/10.5194/ar-4-37-2026, 2026
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Charged molecular clusters, called small ions, are always present in the atmosphere. Few studies have focused on their size distribution, and, motivated by this, we study the size of small ions and how it varies in Hyytiälä, Finland, and Beijing, China. We find that the relationship between small ion size and low-volatility vapor concentrations is strong in Hyytiälä. In both locations, we find that the small ion size has a positive relationship with cluster formation and growth.
Petri Clusius, Metin Baykara, Carlton Xavier, Putian Zhou, Juniper Tyree, Benjamin Foreback, Mikko Äijälä, Frans Graeffe, Tuukka Petäjä, Markku Kulmala, Pauli Paasonen, Paul I. Palmer, and Michael Boy
Atmos. Chem. Phys., 26, 1967–1992, https://doi.org/10.5194/acp-26-1967-2026, https://doi.org/10.5194/acp-26-1967-2026, 2026
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Cloud condensation nuclei are necessary to form clouds, and their size distribution affects cloud properties and therefore Earth’s energy budget. This study modelled the origins of cloud condensation nuclei at SMEAR II, Hyytiälä, Finland, and found that primary emissions and new particle formation separately contribute to more than half of the condensation nuclei, but they suppress each other, leading to current concentrations. Largest condensation nuclei originated mostly from emissions.
Fanni Mylläri, Niina Kuittinen, Minna Aurela, Teemu Lepistö, Paavo Heikkilä, Laura Salo, Lassi Markkula, Panu Karjalainen, Joel Kuula, Sami Harni, Katriina Kyllönen, Satu Similä, Katriina Kirvelä, Joakim Autio, Marko Palonen, Jouni Valtatie, Anna Häyrinen, Hilkka Timonen, and Topi Rönkkö
Aerosol Research, 4, 23–35, https://doi.org/10.5194/ar-4-23-2026, https://doi.org/10.5194/ar-4-23-2026, 2026
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This study examined particle emissions from a large-scale biomass heating plant. Efficient flue gas cleaning, especially with bag-house filters, significantly reduced primary emissions. However, the potential for secondary aerosol formation was found to be 100–1000 times higher than primary emissions, highlighting the need for further research to support air quality and climate goals.
Maija Peltola, Roseline Thakur, Kurt Spence, Janne Lampilahti, Ronja Mäkelä, Sasu Karttunen, Ekaterina Ezhova, Sami Haapanala, Aki Vähä, Juha Kangasluoma, Tommy Chan, Pauli Paasonen, Joanna Norkko, Alf Norkko, Markku Kulmala, and Mikael Ehn
Atmos. Chem. Phys., 26, 489–513, https://doi.org/10.5194/acp-26-489-2026, https://doi.org/10.5194/acp-26-489-2026, 2026
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Here, we report aerosol properties from a new atmospheric observatory established at the Finnish Baltic Sea Coast. Aerosol formation was observed when air masses crossed over the continent whereas less newly formed particles were observed when the winds were from the sea. Aerosol formation was favoured by low condensation sink and sunny dry conditions.
Sami D. Harni, Lasse Johansson, Jarkko V. Niemi, Ville Silvonen, Juan Andrés Casquero-Vera, Anu Kousa, Krista Luoma, Viet Le, David Brus, Konstantinos Doulgeris, Topi Rönkkö, Hanna E. Manninen, Tuukka Petäjä, and Hilkka Timonen
Atmos. Chem. Phys., 25, 18719–18738, https://doi.org/10.5194/acp-25-18719-2025, https://doi.org/10.5194/acp-25-18719-2025, 2025
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A three-month-long measurement campaign was conducted at Espoo, Finland, in spring 2023. The measurement campaign studied the effect of the noise barrier on pollutant concentration gradients on the side of a major highway. The studied pollutants included PM10, PM2.5, lung deposited surface area (LDSA), particle number concentration (PNC), NO2, and black carbon (BC). The noise barrier was found to be effective in reducing, especially the concentration of particulate pollutants.
Janne Lampilahti, Pauli Paasonen, Santeri Tuovinen, Katrianne Lehtipalo, Veli-Matti Kerminen, and Markku Kulmala
Aerosol Research, 3, 637–647, https://doi.org/10.5194/ar-3-637-2025, https://doi.org/10.5194/ar-3-637-2025, 2025
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We developed a new automated method for calculating aerosol particle growth rates. We found that the method produces results comparable to conventional approaches, while offering improved speed and ease of use.
Rahul Ranjan, Maura Dewey, Liine Heikkinen, Lauri R. Ahonen, Krista Luoma, Paul Bowen, Tuukka Petäjä, Annica M. L. Ekman, Daniel G. Partridge, and Ilona Riipinen
Atmos. Chem. Phys., 25, 17275–17300, https://doi.org/10.5194/acp-25-17275-2025, https://doi.org/10.5194/acp-25-17275-2025, 2025
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We use multi-year measurements of cloud condensation nuclei (CCN) at a boreal forest site to inversely infer size-resolved aerosol chemical composition. We find that inorganic species are more enriched in the larger end (accumulation mode) of the sub-micron aerosol population while organics often dominate the smaller end (Aitken mode). Our approach demonstrates the potential of long-term CCN measurements to infer size-resolved chemical composition of sub-micron aerosol.
Aino Ovaska, Elio Rauth, Daniel Holmberg, Paulo Artaxo, John Backman, Benjamin Bergmans, Don Collins, Marco Aurélio Franco, Shahzad Gani, Roy M. Harrison, Rakesh K. Hooda, Tareq Hussein, Antti-Pekka Hyvärinen, Kerneels Jaars, Adam Kristensson, Markku Kulmala, Lauri Laakso, Ari Laaksonen, Nikolaos Mihalopoulos, Colin O'Dowd, Jakub Ondracek, Tuukka Petäjä, Kristina Plauškaitė, Mira Pöhlker, Ximeng Qi, Peter Tunved, Ville Vakkari, Alfred Wiedensohler, Kai Puolamäki, Tuomo Nieminen, Veli-Matti Kerminen, Victoria A. Sinclair, and Pauli Paasonen
Aerosol Research, 3, 589–618, https://doi.org/10.5194/ar-3-589-2025, https://doi.org/10.5194/ar-3-589-2025, 2025
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We trained machine learning models to estimate the number of aerosol particles large enough to form clouds and generated daily estimates for the entire globe. The models performed well in many continental regions but struggled in remote and marine areas. Still, this approach offers a way to quantify these particles in areas that lack direct measurements, helping us understand their influence on clouds and climate on a global scale.
Mojtaba Bezaatpour, Miikka Dal Maso, and Matti Rissanen
Geosci. Model Dev., 18, 9189–9217, https://doi.org/10.5194/gmd-18-9189-2025, https://doi.org/10.5194/gmd-18-9189-2025, 2025
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We developed a computer program that can read chemical formulas and identify key features in thousands of organic compounds. This helps scientists estimate how easily these compounds evaporate, which is important for understanding air pollution and climate. We tested the program using real-world data and found it to be highly accurate. Our work makes it faster and easier to study the behavior of many complex chemicals in the atmosphere.
Sujai Banerji, Krista Luoma, Ilona Ylivinkka, Lauri Ahonen, Veli-Matti Kerminen, and Tuukka Petäjä
Atmos. Chem. Phys., 25, 16895–16914, https://doi.org/10.5194/acp-25-16895-2025, https://doi.org/10.5194/acp-25-16895-2025, 2025
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We studied supermicron aerosol particles (PM1–10) for 12 years at a Finnish boreal forest by subtracting PM1 from total measurements. This allowed us to examine their optical and mass properties, seasonal patterns and events like pollen and dust. We also measured particles >10 µm using filters, which are missed by optical instruments. These large particles significantly influence light scattering.
Arya Mukherjee, Anni Hartikainen, Markus Somero, Viljami Luostari, Mika Ihalainen, Christopher P. Rüger, Timo Kekäläinen, Ville H. Nissinen, Luis M. F. Barreira, Hanna Koponen, Tuukka Kokkola, Delun Li, Lejish Vettikkat, Pasi Yli-Pirilä, Muhammad Shahzaib, Meri M. Ruppel, Ville Vakkari, Kerneels Jaars, Stefan J. Siebert, Angela Buchholz, Kajar Köster, Pieter G. van Zyl, Hilkka Timonen, Niko Kinnunen, Janne Jänis, Annele Virtanen, Aki Virkkula, and Olli Sippula
Atmos. Chem. Phys., 25, 16747–16774, https://doi.org/10.5194/acp-25-16747-2025, https://doi.org/10.5194/acp-25-16747-2025, 2025
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Warming climate is predicted to increase boreal and peatland fires in Northern Eurasia. Limited studies have characterized light absorbing aerosol emissions from these biomasses, thus necessitating this work. Brown carbon (BrC) emitted from laboratory-scale biomass burning had weak light absorptivities based on their complex refractive index values. A combustion temperature dependent light absorptivity continuum existed for emitted BrC. Photochemical aging decreased BrC light absorptivity.
Joel Kuula, Juho Karhu, Tommi Mikkonen, Aki Virkkula, Hilkka Timonen, Tuomas Hieta, and Markku Vainio
Aerosol Research Discuss., https://doi.org/10.5194/ar-2025-38, https://doi.org/10.5194/ar-2025-38, 2025
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Black carbon particles absorb sunlight and warm the climate, but their properties change in the atmosphere. We measured how changes in soot particle shape affect size-resolved light absorption. Our results show that compacted particles absorb more light, although this effect can reverse due to competing physical processes.
Ilona Ylivinkka, Helmi-Marja Keskinen, Lauri R. Ahonen, Liine Heikkinen, Pasi P. Aalto, Tuomo Nieminen, Katrianne Lehtipalo, Krista Luoma, Sujai Banerji, Juho Aalto, Janne Levula, Jutta Kesti, Ekaterina Ezhova, Markku Kulmala, and Tuukka Petäjä
Aerosol Research, 3, 503–520, https://doi.org/10.5194/ar-3-503-2025, https://doi.org/10.5194/ar-3-503-2025, 2025
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Three different particulate matter (PM) measurement techniques were compared in Finland, showing good correlation (R about 0.8). Although the measured PM concentrations were low, decreasing trends were observed in all seasons. The decrease followed the trends observed in concentrations of anthropogenic pollutants, resulting from the EU legislation to improve air quality. The highest PM concentrations were measured in summer, indicating the dominance of organic compounds to the PM mass.
Kaisa Rissanen, Juho Aalto, Jaana Bäck, Heidi Hellén, Toni Tykkä, and Alain Paquette
Atmos. Chem. Phys., 25, 15415–15435, https://doi.org/10.5194/acp-25-15415-2025, https://doi.org/10.5194/acp-25-15415-2025, 2025
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Urban trees emit biogenic volatile organic compounds (BVOC) that affect air quality through the formation of ozone and particulate matter. Trees in Montreal and Helsinki did not emit more BVOCs than expected based on measurements from forest trees, but the emissions varied between individual trees and growth environments. Avoiding high-BVOC emitting tree species and management strategies that protect trees from BVOC-inducing stress factors would help minimise their negative air quality impacts.
Antti Vartiainen, Santtu Mikkonen, Ville Leinonen, Tuukka Petäjä, Alfred Wiedensohler, Thomas Kühn, and Tuuli Miinalainen
Atmos. Meas. Tech., 18, 5763–5782, https://doi.org/10.5194/amt-18-5763-2025, https://doi.org/10.5194/amt-18-5763-2025, 2025
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Global climate models, commonly used for climate predictions, struggle at capturing local-scale variations in air quality. We have used measurements of ultrafine particles (UFPs), a less understood air pollutant with potentially significant health implications, for training machine learning models that can substantially reduce the inaccuracy in UFP concentrations predicted by a climate model. This approach could aid epidemiological studies of ultrafine particles by extending exposure records.
Sander Mirme, Rima Balbaaki, Hanna Elina Manninen, Paap Koemets, Eva Sommer, Birte Rörup, Yusheng Wu, Joao Almeida, Sebastian Ehrhart, Stefan Karl Weber, Joschka Pfeifer, Juha Kangasluoma, Markku Kulmala, and Jasper Kirkby
Atmos. Meas. Tech., 18, 5717–5728, https://doi.org/10.5194/amt-18-5717-2025, https://doi.org/10.5194/amt-18-5717-2025, 2025
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The Cluster Ion Counter (CIC, Airel OÜ) is a novel instrument that simultaneously measures positive and negative ion concentrations below 5 nm. It provides high detection efficiency, low noise, a rapid time response, and excellent reliability, confirmed in lab experiments and at the CERN CLOUD chamber. Its design enables precise, robust long-term measurements, facilitating versatile applications in diverse environments, from laboratory settings to field and potential airborne research.
Frans Graeffe, Kalle Kupi, Hilkka Timonen, and Mikael Ehn
Atmos. Chem. Phys., 25, 10837–10851, https://doi.org/10.5194/acp-25-10837-2025, https://doi.org/10.5194/acp-25-10837-2025, 2025
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Alkanes are a major part of anthropogenic emissions in urban areas, and known for producing secondary organic aerosol (SOA). We measured SOA yields of seven alkanes and their oxygenated derivatives in oxidation flow reactor (OFR) measurements to assess their role in SOA formation. In addition, we observed that cyclic structure enhances SOA production. Furthermore, our observations indicate that multi-generational hydroxyl radical (OH) oxidation is important in the SOA formation.
Anastasia Lampilahti, Olga Garmash, Diego Aliaga, Mikhail Arshinov, Denis Davydov, Boris Belan, Janne Lampilahti, Veli-Matti Kerminen, Tuukka Petäjä, Markku Kulmala, and Ekaterina Ezhova
Aerosol Research, 3, 441–459, https://doi.org/10.5194/ar-3-441-2025, https://doi.org/10.5194/ar-3-441-2025, 2025
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New particle formation (NPF) is a process of forming new aerosol particles in the atmosphere. It was widely studied in boreal forest areas in Finland and Estonia, but its features and precursors in a Siberian boreal forest remained unclear. We did a comprehensive analysis using data from state-of-the-art instruments and implement both traditional and new methods of data analysis. Understanding these processes helps us grasp how Siberia’s atmosphere evolves and contributes to global climate dynamics.
Tinghan Zhang, Ximeng Qi, Janne Lampilahti, Liangduo Chen, Xuguang Chi, Wei Nie, Xin Huang, Zehao Zou, Wei Du, Tom Kokkonen, Tuukka Petäjä, Katrianne Lehtipalo, Veli-Matti Kerminen, Aijun Ding, and Markku Kulmala
Atmos. Chem. Phys., 25, 10027–10048, https://doi.org/10.5194/acp-25-10027-2025, https://doi.org/10.5194/acp-25-10027-2025, 2025
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By comparing air ions at two flagship sites – a boreal forest site in Finland and a megacity site in eastern China – we characterized ion concentrations and their roles in new particle formation (NPF) across contrasting environments. The ion-induced fraction was much higher in the clean boreal forest. However, earlier activation of charged particles and high ion-induced fraction during quiet NPF in the megacity site imply a non-negligible role for ion-induced NPF in polluted urban areas.
Piaopiao Ke, Anna Lintunen, Pasi Kolari, Annalea Lohila, Santeri Tuovinen, Janne Lampilahti, Roseline Thakur, Maija Peltola, Otso Peräkylä, Tuomo Nieminen, Ekaterina Ezhova, Mari Pihlatie, Asta Laasonen, Markku Koskinen, Helena Rautakoski, Laura Heimsch, Tom Kokkonen, Aki Vähä, Ivan Mammarella, Steffen Noe, Jaana Bäck, Veli-Matti Kerminen, and Markku Kulmala
Biogeosciences, 22, 3235–3251, https://doi.org/10.5194/bg-22-3235-2025, https://doi.org/10.5194/bg-22-3235-2025, 2025
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Our research explores diverse ecosystems’ roles in climate cooling via the concept of CarbonSink+ potential. We measured CO2 uptake and local aerosol production in forests, farms, peatlands, urban gardens, and coastal areas across Finland and Estonia. The long-term data reveal that, while forests are vital with regard to CarbonSink+ potential, farms and urban gardens also play significant roles. These insights can help optimize management policy of natural resources to mitigate global warming.
J. Tapio Elomaa, Krista Luoma, Sami D. Harni, Aki Virkkula, Hilkka Timonen, and Tuukka Petäjä
Aerosol Research, 3, 293–314, https://doi.org/10.5194/ar-3-293-2025, https://doi.org/10.5194/ar-3-293-2025, 2025
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Black carbon (BC) is a pollutant from combustion that affects the climate and is harmful to health. We tested four different small BC sensors with a reference in Helsinki. The sensors compared well with the reference. As a sensor network they were able to capture differences in BC. Changes in temperature (T) and relative humidity (RH) caused error in the measurements. To reduce the effects of T and RH on BC sensors, more robust boxes should be developed, or corrections should be applied.
Xinyang Li, Tuomo Nieminen, Rima Baalbaki, Putian Zhou, Pauli Paasonen, Risto Makkonen, Martha Arbayani Zaidan, Nina Sarnela, Chao Yan, Tuija Jokinen, Imre Salma, Máté Vörösmarty, Tuukka Petäjä, Veli-Matti Kerminen, Markku Kulmala, and Lubna Dada
Aerosol Research, 3, 271–291, https://doi.org/10.5194/ar-3-271-2025, https://doi.org/10.5194/ar-3-271-2025, 2025
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Particle formation rate is one of the key factors in studying the physical properties of aerosols. By developing powerful and simple semi-empirical particle formation rate models, we can predict particle formation rates and compare them with real-time measurements to aid in discovering hidden particle formation mechanisms as well as global simulations of particle population to fill the knowledge gap caused by the uncertainty in aerosol cooling effects on Earth's atmosphere.
Kimmo Teinilä, Sanna Saarikoski, Henna Lintusaari, Teemu Lepistö, Petteri Marjanen, Minna Aurela, Heidi Hellén, Toni Tykkä, Markus Lampimäki, Janne Lampilahti, Luis Barreira, Timo Mäkelä, Leena Kangas, Juha Hatakka, Sami Harni, Joel Kuula, Jarkko V. Niemi, Harri Portin, Jaakko Yli-Ojanperä, Ville Niemelä, Milja Jäppi, Katrianne Lehtipalo, Joonas Vanhanen, Liisa Pirjola, Hanna E. Manninen, Tuukka Petäjä, Topi Rönkkö, and Hilkka Timonen
Atmos. Chem. Phys., 25, 4907–4928, https://doi.org/10.5194/acp-25-4907-2025, https://doi.org/10.5194/acp-25-4907-2025, 2025
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Physical and chemical properties of particulate matter and concentrations of trace gases were measured in a street canyon in Helsinki, Finland, and an urban background site in January–February 2022 to investigate the effect of wintertime conditions on pollutants. State-of-the-art instruments and a mobile laboratory were used, and the measurement data were analysed further with modelling tools like positive matrix factorization and the Pollution Detection Algorithm.
Neha Deot, Vijay P. Kanawade, Alkistis Papetta, Rima Baalbaki, Michael Pikridas, Franco Marenco, Markku Kulmala, Jean Sciare, Katrianne Lehtipalo, and Tuija Jokinen
Aerosol Research, 3, 139–154, https://doi.org/10.5194/ar-3-139-2025, https://doi.org/10.5194/ar-3-139-2025, 2025
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We studied how nanoparticles form in the atmosphere at two different altitudes in Cyprus, focusing on how meteorology impacts this process. Using data from two sites, we found that air from lower regions carries particles up to higher areas, affecting air quality and potentially climate. Our findings help improve understanding of how particles form and grow in the air, which is important for predicting changes in climate and air pollution in the future.
Fidel Pankratov, Alexander Mahura, Oleg Katz, Tuukka Petäjä, Valentin Popov, and Vladimir Masloboev
EGUsphere, https://doi.org/10.5194/egusphere-2025-393, https://doi.org/10.5194/egusphere-2025-393, 2025
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During polar springs low concentrations of atmospheric mercury (Hg) in the atmospheric surface layer are frequently observed. Presence of elevated Hg (in springs of 2010–2011) is not typical, and such increases are determined by the atmospheric transport at regional scales. Atmospheric trajectories showed that the source elevated Hg in the Arctic (at Amderma station) is linked with active phases of the volcanic eruptions in Iceland. It is an anomaly in terms of the global Hg pollution dynamics.
Juho Karhu, Tommi Mikkonen, Joel Kuula, Aki Virkkula, Erkki Ikonen, Markku Vainio, Hilkka Timonen, and Tuomas Hieta
Aerosol Research, 3, 113–124, https://doi.org/10.5194/ar-3-113-2025, https://doi.org/10.5194/ar-3-113-2025, 2025
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We present a new photoacoustic instrument for simultaneous measurement of aerosol light absorption at multiple wavelengths. High performance is reached by using an optically read cantilever microphone, which allows for highly sensitive absorption measurements at a compact size. Performance in field conditions is demonstrated with black carbon monitoring at an air quality measurement station, where our results agree well with reference instruments deployed at the site.
Hector Navarro-Barboza, Jordi Rovira, Vincenzo Obiso, Andrea Pozzer, Marta Via, Andres Alastuey, Xavier Querol, Noemi Perez, Marjan Savadkoohi, Gang Chen, Jesus Yus-Díez, Matic Ivancic, Martin Rigler, Konstantinos Eleftheriadis, Stergios Vratolis, Olga Zografou, Maria Gini, Benjamin Chazeau, Nicolas Marchand, Andre S. H. Prevot, Kaspar Dallenbach, Mikael Ehn, Krista Luoma, Tuukka Petäjä, Anna Tobler, Jaroslaw Necki, Minna Aurela, Hilkka Timonen, Jarkko Niemi, Olivier Favez, Jean-Eudes Petit, Jean-Philippe Putaud, Christoph Hueglin, Nicolas Pascal, Aurélien Chauvigné, Sébastien Conil, Marco Pandolfi, and Oriol Jorba
Atmos. Chem. Phys., 25, 2667–2694, https://doi.org/10.5194/acp-25-2667-2025, https://doi.org/10.5194/acp-25-2667-2025, 2025
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Brown carbon (BrC) absorbs ultraviolet (UV) and visible light, influencing climate. This study explores BrC's imaginary refractive index (k) using data from 12 European sites. Residential emissions are a major organic aerosol (OA) source in winter, while secondary organic aerosol (SOA) dominates in summer. Source-specific k values were derived, improving model accuracy. The findings highlight BrC's climate impact and emphasize source-specific constraints in atmospheric models.
Benjamin Heutte, Nora Bergner, Hélène Angot, Jakob B. Pernov, Lubna Dada, Jessica A. Mirrielees, Ivo Beck, Andrea Baccarini, Matthew Boyer, Jessie M. Creamean, Kaspar R. Daellenbach, Imad El Haddad, Markus M. Frey, Silvia Henning, Tiia Laurila, Vaios Moschos, Tuukka Petäjä, Kerri A. Pratt, Lauriane L. J. Quéléver, Matthew D. Shupe, Paul Zieger, Tuija Jokinen, and Julia Schmale
Atmos. Chem. Phys., 25, 2207–2241, https://doi.org/10.5194/acp-25-2207-2025, https://doi.org/10.5194/acp-25-2207-2025, 2025
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Limited aerosol measurements in the central Arctic hinder our understanding of aerosol–climate interactions in the region. Our year-long observations of aerosol physicochemical properties during the MOSAiC expedition reveal strong seasonal variations in aerosol chemical composition, where the short-term variability is heavily affected by storms in the Arctic. Local wind-generated particles are shown to be an important source of cloud seeds, especially in autumn.
Giannis Ioannidis, Nikoletta Bouloti, Paul Tremper, Chaofan Li, Christos Boikos, Nikolaos Rapkos, Till Riedel, Miikka Dal Maso, and Leonidas Ntziachristos
EGUsphere, https://doi.org/10.5194/egusphere-2025-193, https://doi.org/10.5194/egusphere-2025-193, 2025
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This study introduces SOMA (Secondary Organic Module for Aerosol) to model SOA formation in urban environments, using VOC oxidation inputs from GECKO-A. Based on SOA formation experiments, SOMA incorporates correction factors for calibration purposes. A CFD model simulates toluene dispersion in Augsburg, and it’s linked to SOMA to show that background SOA contributes 21–53 % of total mass, fading after 7 hours, providing better understanding of SOA formation dynamics.
Yiliang Liu, Arttu Yli-Kujala, Fabian Schmidt-Ott, Sebastian Holm, Lauri Ahonen, Tommy Chan, Joonas Enroth, Joonas Vanhanen, Runlong Cai, Tuukka Petäjä, Markku Kulmala, Yang Chen, and Juha Kangasluoma
Atmos. Meas. Tech., 18, 431–442, https://doi.org/10.5194/amt-18-431-2025, https://doi.org/10.5194/amt-18-431-2025, 2025
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Accurate measurement of nanoparticles is crucial for understanding their impact on new particle formation and climate change. In this study, we calibrated the Particle Size Magnifier version 2.0 (PSM 2.0), using both laboratory-generated and atmospheric particles. Some differences were observed in the calibration results, with direct calibration using atmospheric particles enhancing measurement accuracy.
Xiansheng Liu, Xun Zhang, Marvin Dufresne, Tao Wang, Lijie Wu, Rosa Lara, Roger Seco, Marta Monge, Ana Maria Yáñez-Serrano, Marie Gohy, Paul Petit, Audrey Chevalier, Marie-Pierre Vagnot, Yann Fortier, Alexia Baudic, Véronique Ghersi, Grégory Gille, Ludovic Lanzi, Valérie Gros, Leïla Simon, Heidi Héllen, Stefan Reimann, Zoé Le Bras, Michelle Jessy Müller, David Beddows, Siqi Hou, Zongbo Shi, Roy M. Harrison, William Bloss, James Dernie, Stéphane Sauvage, Philip K. Hopke, Xiaoli Duan, Taicheng An, Alastair C. Lewis, James R. Hopkins, Eleni Liakakou, Nikolaos Mihalopoulos, Xiaohu Zhang, Andrés Alastuey, Xavier Querol, and Thérèse Salameh
Atmos. Chem. Phys., 25, 625–638, https://doi.org/10.5194/acp-25-625-2025, https://doi.org/10.5194/acp-25-625-2025, 2025
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This study examines BTEX (benzene, toluene, ethylbenzene, xylenes) pollution in urban areas across seven European countries. Analyzing data from 22 monitoring sites, we found traffic and industrial activities significantly impact BTEX levels, with peaks during rush hours. The risk from BTEX exposure remains moderate, especially in high-traffic and industrial zones, highlighting the need for targeted air quality management to protect public health and improve urban air quality.
Joel Kuula, Juho Karhu, Tommi Mikkonen, Patrick Grahn, Aki Virkkula, Hilkka Timonen, Tuomas Hieta, and Markku Vainio
Aerosol Research, 3, 1–13, https://doi.org/10.5194/ar-3-1-2025, https://doi.org/10.5194/ar-3-1-2025, 2025
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We developed a new method to measure how particles absorb light as they change in size, which is critical for understanding their climate impact. Our approach uses a sensitive instrument that measures light absorption directly from particles in real time. By pairing this with a device that sorts particles by size, we achieved accurate size-resolved measurements. Our findings closely match theoretical models, offering a promising tool for future research into how particles influence climate.
Matthew Boyer, Diego Aliaga, Lauriane L. J. Quéléver, Silvia Bucci, Hélène Angot, Lubna Dada, Benjamin Heutte, Lisa Beck, Marina Duetsch, Andreas Stohl, Ivo Beck, Tiia Laurila, Nina Sarnela, Roseline C. Thakur, Branka Miljevic, Markku Kulmala, Tuukka Petäjä, Mikko Sipilä, Julia Schmale, and Tuija Jokinen
Atmos. Chem. Phys., 24, 12595–12621, https://doi.org/10.5194/acp-24-12595-2024, https://doi.org/10.5194/acp-24-12595-2024, 2024
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We analyze the seasonal cycle and sources of gases that are relevant for the formation of aerosol particles in the central Arctic. Since theses gases can form new particles, they can influence Arctic climate. We show that the sources of these gases are associated with changes in the Arctic environment during the year, especially with respect to sea ice. Therefore, the concentration of these gases will likely change in the future as the Arctic continues to warm.
Sami D. Harni, Minna Aurela, Sanna Saarikoski, Jarkko V. Niemi, Harri Portin, Hanna Manninen, Ville Leinonen, Pasi Aalto, Phil K. Hopke, Tuukka Petäjä, Topi Rönkkö, and Hilkka Timonen
Atmos. Chem. Phys., 24, 12143–12160, https://doi.org/10.5194/acp-24-12143-2024, https://doi.org/10.5194/acp-24-12143-2024, 2024
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In this study, particle number size distribution data were used in a novel way in positive matrix factorization analysis to find aerosol source profiles in the area. Measurements were made in Helsinki at a street canyon and urban background sites between February 2015 and June 2019. Five different aerosol sources were identified. These sources underline the significance of traffic-related emissions in urban environments despite recent improvements in emission reduction technologies.
Franziska Vogel, Michael P. Adams, Larissa Lacher, Polly B. Foster, Grace C. E. Porter, Barbara Bertozzi, Kristina Höhler, Julia Schneider, Tobias Schorr, Nsikanabasi S. Umo, Jens Nadolny, Zoé Brasseur, Paavo Heikkilä, Erik S. Thomson, Nicole Büttner, Martin I. Daily, Romy Fösig, Alexander D. Harrison, Jorma Keskinen, Ulrike Proske, Jonathan Duplissy, Markku Kulmala, Tuukka Petäjä, Ottmar Möhler, and Benjamin J. Murray
Atmos. Chem. Phys., 24, 11737–11757, https://doi.org/10.5194/acp-24-11737-2024, https://doi.org/10.5194/acp-24-11737-2024, 2024
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Primary ice formation in clouds strongly influences their properties; hence, it is important to understand the sources of ice-nucleating particles (INPs) and their variability. We present 2 months of INP measurements in a Finnish boreal forest using a new semi-autonomous INP counting device based on gas expansion. These results show strong variability in INP concentrations, and we present a case that the INPs we observe are, at least some of the time, of biological origin.
Markku Kulmala, Santeri Tuovinen, Sander Mirme, Paap Koemets, Lauri Ahonen, Yongchun Liu, Heikki Junninen, Tuukka Petäjä, and Veli-Matti Kerminen
Aerosol Research, 2, 291–301, https://doi.org/10.5194/ar-2-291-2024, https://doi.org/10.5194/ar-2-291-2024, 2024
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With the recently developed CIC (Cluster Ion Counter) instrument, we can observe dynamics of small air ions and intermediate air ions. Furthermore, we can observe condensation sink and formation and growth rates for intermediated ions.
Zoé Brasseur, Julia Schneider, Janne Lampilahti, Ville Vakkari, Victoria A. Sinclair, Christina J. Williamson, Carlton Xavier, Dmitri Moisseev, Markus Hartmann, Pyry Poutanen, Markus Lampimäki, Markku Kulmala, Tuukka Petäjä, Katrianne Lehtipalo, Erik S. Thomson, Kristina Höhler, Ottmar Möhler, and Jonathan Duplissy
Atmos. Chem. Phys., 24, 11305–11332, https://doi.org/10.5194/acp-24-11305-2024, https://doi.org/10.5194/acp-24-11305-2024, 2024
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Ice-nucleating particles (INPs) strongly influence the formation of clouds by initiating the formation of ice crystals. However, very little is known about the vertical distribution of INPs in the atmosphere. Here, we present aircraft measurements of INP concentrations above the Finnish boreal forest. Results show that near-surface INPs are efficiently transported and mixed within the boundary layer and occasionally reach the free troposphere.
Teemu Lepistö, Henna Lintusaari, Laura Salo, Ville Silvonen, Luis M. F. Barreira, Jussi Hoivala, Lassi Markkula, Jarkko V. Niemi, Jakub Ondracek, Kimmo Teinilä, Hanna E. Manninen, Sanna Saarikoski, Hilkka Timonen, Miikka Dal Maso, and Topi Rönkkö
Aerosol Research, 2, 271–289, https://doi.org/10.5194/ar-2-271-2024, https://doi.org/10.5194/ar-2-271-2024, 2024
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The performances of different particle lung-deposited surface area (LDSAal) measurement methods (Partector, ELPI+, SMPS/DMPS) were compared in ambient conditions. As LDSAal is a health-relevant metric and rather easy to utilise in air quality monitoring, it is crucial to know how the different methods agree, as there are clear differences in their operation. In all, a comparison of different methods can be complicated; still, the methods agree rather well in terms of local pollution (< 400 nm).
Alex Rowell, James Brean, David C. S. Beddows, Zongbo Shi, Avinash Kumar, Matti Rissanen, Miikka Dal Maso, Peter Mettke, Kay Weinhold, Maik Merkel, and Roy M. Harrison
Atmos. Chem. Phys., 24, 10349–10361, https://doi.org/10.5194/acp-24-10349-2024, https://doi.org/10.5194/acp-24-10349-2024, 2024
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Ions enhance the formation and growth rates of new particles, affecting the Earth's radiation budget. Despite these effects, there is little published data exploring the sources of ions in the urban environment and their role in new particle formation (NPF). Here we show that natural ion sources dominate in urban environments, while traffic is a secondary source. Ions contribute up to 12.7 % of the formation rate of particles, indicating that they are important for forming urban PM.
Alex Rowell, James Brean, David C. S. Beddows, Tuukka Petäjä, Máté Vörösmarty, Imre Salma, Jarkko V. Niemi, Hanna E. Manninen, Dominik van Pinxteren, Thomas Tuch, Kay Weinhold, Zongbo Shi, and Roy M. Harrison
Atmos. Chem. Phys., 24, 9515–9531, https://doi.org/10.5194/acp-24-9515-2024, https://doi.org/10.5194/acp-24-9515-2024, 2024
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Different sources of airborne particles in the atmospheres of four European cities were distinguished by recognising their particle size distributions using a statistical procedure, positive matrix factorisation. The various sources responded differently to the changes in emissions associated with COVID-19 lockdowns, and the reasons are investigated. While traffic emissions generally decreased, particles formed from reactions of atmospheric gases decreased in some cities but increased in others.
Yusheng Zhang, Feixue Zheng, Zemin Feng, Chaofan Lian, Weigang Wang, Xiaolong Fan, Wei Ma, Zhuohui Lin, Chang Li, Gen Zhang, Chao Yan, Ying Zhang, Veli-Matti Kerminen, Federico Bianch, Tuukka Petäjä, Juha Kangasluoma, Markku Kulmala, and Yongchun Liu
Atmos. Chem. Phys., 24, 8569–8587, https://doi.org/10.5194/acp-24-8569-2024, https://doi.org/10.5194/acp-24-8569-2024, 2024
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The nitrous acid (HONO) budget was validated during a COVID-19 lockdown event. The main conclusions are (1) HONO concentrations showed a significant decrease from 0.97 to 0.53 ppb during lockdown; (2) vehicle emissions accounted for 53 % of nighttime sources, with the heterogeneous conversion of NO2 on ground surfaces more important than aerosol; and (3) the dominant daytime source shifted from the homogenous reaction between NO and OH (51 %) to nitrate photolysis (53 %) during lockdown.
Pauli Simonen, Miikka Dal Maso, Pinja Prauda, Anniina Hoilijoki, Anette Karppinen, Pekka Matilainen, Panu Karjalainen, and Jorma Keskinen
Atmos. Meas. Tech., 17, 3219–3236, https://doi.org/10.5194/amt-17-3219-2024, https://doi.org/10.5194/amt-17-3219-2024, 2024
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Secondary aerosol is formed in the atmosphere from gaseous emissions. Oxidation flow reactors used in secondary aerosol research do not immediately respond to changes in the inlet concentration of gases because of their broad transfer functions. This may result in incorrect secondary aerosol production factors determined for vehicles. We studied the extent of possible errors and found that oxidation flow reactors with faster responses result in smaller errors.
Santeri Tuovinen, Janne Lampilahti, Veli-Matti Kerminen, and Markku Kulmala
Aerosol Research, 2, 93–105, https://doi.org/10.5194/ar-2-93-2024, https://doi.org/10.5194/ar-2-93-2024, 2024
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Atmospheric intermediate ions can be used to study atmospheric new particle formation (NPF). Here we aimed to find the optimal ion diameter for this purpose on a local scale. To fulfill our aim, we used ion size number distribution data from the SMEAR II measurement station, Hyytiälä, Finland. We found that concentrations of ions between 2.0–2.3 nm are the best suited for characterization of local intermediate ion formation and could be used to detect and evaluate the strength of local NPF.
Liine Heikkinen, Daniel G. Partridge, Sara Blichner, Wei Huang, Rahul Ranjan, Paul Bowen, Emanuele Tovazzi, Tuukka Petäjä, Claudia Mohr, and Ilona Riipinen
Atmos. Chem. Phys., 24, 5117–5147, https://doi.org/10.5194/acp-24-5117-2024, https://doi.org/10.5194/acp-24-5117-2024, 2024
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The organic vapor condensation with water vapor (co-condensation) in rising air below clouds is modeled in this work over the boreal forest because the forest air is rich in organic vapors. We show that the number of cloud droplets can increase by 20 % if considering co-condensation. The enhancements are even larger if the air contains many small, naturally produced aerosol particles. Such conditions are most frequently met in spring in the boreal forest.
Heidi Hellén, Rostislav Kouznetsov, Kaisa Kraft, Jukka Seppälä, Mika Vestenius, Jukka-Pekka Jalkanen, Lauri Laakso, and Hannele Hakola
Atmos. Chem. Phys., 24, 4717–4731, https://doi.org/10.5194/acp-24-4717-2024, https://doi.org/10.5194/acp-24-4717-2024, 2024
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Mixing ratios of C2-C5 NMHCs and methanethiol were measured on an island in the Baltic Sea using an in situ gas chromatograph. Shipping emissions were found to be an important source of ethene, ethyne, propene, and benzene. High summertime mixing ratios of methanethiol and dependence of mixing ratios on seawater temperature and height indicated the biogenic origin to possibly be phytoplankton or macroalgae. These emissions may have a strong impact on SO2 production and new particle formation.
Markku Kulmala, Diego Aliaga, Santeri Tuovinen, Runlong Cai, Heikki Junninen, Chao Yan, Federico Bianchi, Yafang Cheng, Aijun Ding, Douglas R. Worsnop, Tuukka Petäjä, Katrianne Lehtipalo, Pauli Paasonen, and Veli-Matti Kerminen
Aerosol Research, 2, 49–58, https://doi.org/10.5194/ar-2-49-2024, https://doi.org/10.5194/ar-2-49-2024, 2024
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Atmospheric new particle formation (NPF), together with secondary production of particulate matter in the atmosphere, dominates aerosol particle number concentrations and submicron particle mass loads in many environments globally. In this opinion paper, we describe the paradigm shift to understand NPF in a continuous way instead of using traditional binary event–non-event analysis.
Jian Zhao, Valter Mickwitz, Yuanyuan Luo, Ella Häkkinen, Frans Graeffe, Jiangyi Zhang, Hilkka Timonen, Manjula Canagaratna, Jordan E. Krechmer, Qi Zhang, Markku Kulmala, Juha Kangasluoma, Douglas Worsnop, and Mikael Ehn
Atmos. Meas. Tech., 17, 1527–1543, https://doi.org/10.5194/amt-17-1527-2024, https://doi.org/10.5194/amt-17-1527-2024, 2024
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Organic aerosol constitutes a significant portion of atmospheric fine particles but is less characterized due to its vast number of constituents. Recently, we developed a system for online measurements of particle-phase highly oxygenated organic molecules (HOMs). In this work, we systematically characterized the system, developed a new unit to enhance its performance, and demonstrated the essential role of thermograms in inferring volatility and quantifying HOMs in organic aerosols.
Shiyi Lai, Ximeng Qi, Xin Huang, Sijia Lou, Xuguang Chi, Liangduo Chen, Chong Liu, Yuliang Liu, Chao Yan, Mengmeng Li, Tengyu Liu, Wei Nie, Veli-Matti Kerminen, Tuukka Petäjä, Markku Kulmala, and Aijun Ding
Atmos. Chem. Phys., 24, 2535–2553, https://doi.org/10.5194/acp-24-2535-2024, https://doi.org/10.5194/acp-24-2535-2024, 2024
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By combining in situ measurements and chemical transport modeling, this study investigates new particle formation (NPF) on the southeastern Tibetan Plateau. We found that the NPF was driven by the presence of biogenic gases and the transport of anthropogenic precursors. The NPF was vertically heterogeneous and shaped by the vertical mixing. This study highlights the importance of anthropogenic–biogenic interactions and meteorological dynamics in NPF in this climate-sensitive region.
Jing Cai, Juha Sulo, Yifang Gu, Sebastian Holm, Runlong Cai, Steven Thomas, Almuth Neuberger, Fredrik Mattsson, Marco Paglione, Stefano Decesari, Matteo Rinaldi, Rujing Yin, Diego Aliaga, Wei Huang, Yuanyuan Li, Yvette Gramlich, Giancarlo Ciarelli, Lauriane Quéléver, Nina Sarnela, Katrianne Lehtipalo, Nora Zannoni, Cheng Wu, Wei Nie, Juha Kangasluoma, Claudia Mohr, Markku Kulmala, Qiaozhi Zha, Dominik Stolzenburg, and Federico Bianchi
Atmos. Chem. Phys., 24, 2423–2441, https://doi.org/10.5194/acp-24-2423-2024, https://doi.org/10.5194/acp-24-2423-2024, 2024
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By combining field measurements, simulations and recent chamber experiments, we investigate new particle formation (NPF) and growth in the Po Valley, where both haze and frequent NPF occur. Our results show that sulfuric acid, ammonia and amines are the dominant NPF precursors there. A high NPF rate and a lower condensation sink lead to a greater survival probability for newly formed particles, highlighting the importance of gas-to-particle conversion for aerosol concentrations.
Juha Sulo, Joonas Enroth, Aki Pajunoja, Joonas Vanhanen, Katrianne Lehtipalo, Tuukka Petäjä, and Markku Kulmala
Aerosol Research, 2, 13–20, https://doi.org/10.5194/ar-2-13-2024, https://doi.org/10.5194/ar-2-13-2024, 2024
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We present a novel version of an aerosol number size distribution instrument, showcasing its capability to measure particle number concentration and particle number size distribution between 1 and 12 nm. Our results show that the instrument agrees well with existing instrumentation and allows for both the accurate measurement of the smallest particles and overlap with more conventional aerosol number size distribution instruments.
Ying Zhang, Duzitian Li, Xu-Cheng He, Wei Nie, Chenjuan Deng, Runlong Cai, Yuliang Liu, Yishuo Guo, Chong Liu, Yiran Li, Liangduo Chen, Yuanyuan Li, Chenjie Hua, Tingyu Liu, Zongcheng Wang, Jiali Xie, Lei Wang, Tuukka Petäjä, Federico Bianchi, Ximeng Qi, Xuguang Chi, Pauli Paasonen, Yongchun Liu, Chao Yan, Jingkun Jiang, Aijun Ding, and Markku Kulmala
Atmos. Chem. Phys., 24, 1873–1893, https://doi.org/10.5194/acp-24-1873-2024, https://doi.org/10.5194/acp-24-1873-2024, 2024
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This study conducts a long-term observation of gaseous iodine oxoacids in two Chinese megacities, revealing their ubiquitous presence with peak concentrations (up to 0.1 pptv) in summer. Our analysis suggests a mix of terrestrial and marine sources for iodine. Additionally, iodic acid is identified as a notable contributor to sub-3 nm particle growth and particle survival probability.
Leena Kangas, Jaakko Kukkonen, Mari Kauhaniemi, Kari Riikonen, Mikhail Sofiev, Anu Kousa, Jarkko V. Niemi, and Ari Karppinen
Atmos. Chem. Phys., 24, 1489–1507, https://doi.org/10.5194/acp-24-1489-2024, https://doi.org/10.5194/acp-24-1489-2024, 2024
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Residential wood combustion is a major source of fine particulate matter. This study has evaluated the contribution of residential wood combustion to fine particle concentrations and its year-to-year and seasonal variation in te Helsinki metropolitan area. The average concentrations attributed to wood combustion in winter were up to 10- or 15-fold compared to summer. Wood combustion caused 12 % to 14 % of annual fine particle concentrations. In winter, the contribution ranged from 16 % to 21 %.
Giancarlo Ciarelli, Sara Tahvonen, Arineh Cholakian, Manuel Bettineschi, Bruno Vitali, Tuukka Petäjä, and Federico Bianchi
Geosci. Model Dev., 17, 545–565, https://doi.org/10.5194/gmd-17-545-2024, https://doi.org/10.5194/gmd-17-545-2024, 2024
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The terrestrial ecosystem releases large quantities of biogenic gases in the Earth's Atmosphere. These gases can effectively be converted into so-called biogenic aerosol particles and, eventually, affect the Earth's climate. Climate prediction varies greatly depending on how these processes are represented in model simulations. In this study, we present a detailed model evaluation analysis aimed at understanding the main source of uncertainty in predicting the formation of biogenic aerosols.
Heidi Hellén, Toni Tykkä, Simon Schallhart, Evdokia Stratigou, Thérèse Salameh, and Maitane Iturrate-Garcia
Atmos. Meas. Tech., 17, 315–333, https://doi.org/10.5194/amt-17-315-2024, https://doi.org/10.5194/amt-17-315-2024, 2024
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Even though online measurements of biogenic volatile organic compounds (BVOCs) are becoming more common, the use of sorbent tubes is expected to continue because they offer greater spatial coverage and no infrastructure is required for sampling. In this study the sorbent tube sampling method was optimized and evaluated for the determination of BVOCs in gas-phase samples. Tenax TA sorbent tubes were found to be suitable for the quantitative measurements of C10–C15 BVOCs.
Juan Andrés Casquero-Vera, Daniel Pérez-Ramírez, Hassan Lyamani, Fernando Rejano, Andrea Casans, Gloria Titos, Francisco José Olmo, Lubna Dada, Simo Hakala, Tareq Hussein, Katrianne Lehtipalo, Pauli Paasonen, Antti Hyvärinen, Noemí Pérez, Xavier Querol, Sergio Rodríguez, Nikos Kalivitis, Yenny González, Mansour A. Alghamdi, Veli-Matti Kerminen, Andrés Alastuey, Tuukka Petäjä, and Lucas Alados-Arboledas
Atmos. Chem. Phys., 23, 15795–15814, https://doi.org/10.5194/acp-23-15795-2023, https://doi.org/10.5194/acp-23-15795-2023, 2023
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Here we present the first study of the effect of mineral dust on the inhibition/promotion of new particle formation (NPF) events in different dust-influenced areas. Unexpectedly, we show that the occurrence of NPF events is highly frequent during mineral dust outbreaks, occurring even during extreme dust outbreaks. We also show that the occurrence of NPF events during mineral dust outbreaks significantly affects the potential cloud condensation nuclei budget.
Diego Aliaga, Santeri Tuovinen, Tinghan Zhang, Janne Lampilahti, Xinyang Li, Lauri Ahonen, Tom Kokkonen, Tuomo Nieminen, Simo Hakala, Pauli Paasonen, Federico Bianchi, Doug Worsnop, Veli-Matti Kerminen, and Markku Kulmala
Aerosol Research, 1, 81–92, https://doi.org/10.5194/ar-1-81-2023, https://doi.org/10.5194/ar-1-81-2023, 2023
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We introduce a novel method for evaluating days when small particles are formed in the atmosphere. Instead of the traditional binary division between event and non-event days, our method, known as "nano ranking analysis", provides a continuous, non-categorical metric for each day. By utilizing data from Hyytiälä, Finland, we show that our approach effectively quantifies these events. This innovative method paves the way for a deeper understanding of the factors influencing particle formation.
Markku Kulmala, Anna Lintunen, Hanna Lappalainen, Annele Virtanen, Chao Yan, Ekaterina Ezhova, Tuomo Nieminen, Ilona Riipinen, Risto Makkonen, Johanna Tamminen, Anu-Maija Sundström, Antti Arola, Armin Hansel, Kari Lehtinen, Timo Vesala, Tuukka Petäjä, Jaana Bäck, Tom Kokkonen, and Veli-Matti Kerminen
Atmos. Chem. Phys., 23, 14949–14971, https://doi.org/10.5194/acp-23-14949-2023, https://doi.org/10.5194/acp-23-14949-2023, 2023
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To be able to meet global grand challenges, we need comprehensive open data with proper metadata. In this opinion paper, we describe the SMEAR (Station for Measuring Earth surface – Atmosphere Relations) concept and include several examples (cases), such as new particle formation and growth, feedback loops and the effect of COVID-19, and what has been learned from these investigations. The future needs and the potential of comprehensive observations of the environment are summarized.
Steven Job Thomas, Toni Tykkä, Heidi Hellén, Federico Bianchi, and Arnaud P. Praplan
Atmos. Chem. Phys., 23, 14627–14642, https://doi.org/10.5194/acp-23-14627-2023, https://doi.org/10.5194/acp-23-14627-2023, 2023
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The study employed total ozone reactivity to demonstrate how emissions of Norway spruce readily react with ozone and could be a major ozone sink, particularly under stress. Additionally, this approach provided insight into the limitations of current analytical techniques that measure the compounds present or emitted into the atmosphere. The study shows how the technique used was not enough to measure all compounds emitted, and this could potentially underestimate various atmospheric processes.
Magdalena Okuljar, Olga Garmash, Miska Olin, Joni Kalliokoski, Hilkka Timonen, Jarkko V. Niemi, Pauli Paasonen, Jenni Kontkanen, Yanjun Zhang, Heidi Hellén, Heino Kuuluvainen, Minna Aurela, Hanna E. Manninen, Mikko Sipilä, Topi Rönkkö, Tuukka Petäjä, Markku Kulmala, Miikka Dal Maso, and Mikael Ehn
Atmos. Chem. Phys., 23, 12965–12983, https://doi.org/10.5194/acp-23-12965-2023, https://doi.org/10.5194/acp-23-12965-2023, 2023
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Highly oxygenated organic molecules (HOMs) form secondary organic aerosol that affects air quality and health. In this study, we demonstrate that in a moderately polluted city with abundant vegetation, the composition of HOMs is largely controlled by the effect of NOx on the biogenic volatile organic compound oxidation. Comparing the results from two nearby stations, we show that HOM composition and formation pathways can change considerably within small distances in urban environments.
Jean-Philippe Putaud, Enrico Pisoni, Alexander Mangold, Christoph Hueglin, Jean Sciare, Michael Pikridas, Chrysanthos Savvides, Jakub Ondracek, Saliou Mbengue, Alfred Wiedensohler, Kay Weinhold, Maik Merkel, Laurent Poulain, Dominik van Pinxteren, Hartmut Herrmann, Andreas Massling, Claus Nordstroem, Andrés Alastuey, Cristina Reche, Noemí Pérez, Sonia Castillo, Mar Sorribas, Jose Antonio Adame, Tuukka Petaja, Katrianne Lehtipalo, Jarkko Niemi, Véronique Riffault, Joel F. de Brito, Augustin Colette, Olivier Favez, Jean-Eudes Petit, Valérie Gros, Maria I. Gini, Stergios Vratolis, Konstantinos Eleftheriadis, Evangelia Diapouli, Hugo Denier van der Gon, Karl Espen Yttri, and Wenche Aas
Atmos. Chem. Phys., 23, 10145–10161, https://doi.org/10.5194/acp-23-10145-2023, https://doi.org/10.5194/acp-23-10145-2023, 2023
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Many European people are still exposed to levels of air pollution that can affect their health. COVID-19 lockdowns in 2020 were used to assess the impact of the reduction in human mobility on air pollution across Europe by comparing measurement data with values that would be expected if no lockdown had occurred. We show that lockdown measures did not lead to consistent decreases in the concentrations of fine particulate matter suspended in the air, and we investigate why.
Simo Hakala, Ville Vakkari, Heikki Lihavainen, Antti-Pekka Hyvärinen, Kimmo Neitola, Jenni Kontkanen, Veli-Matti Kerminen, Markku Kulmala, Tuukka Petäjä, Tareq Hussein, Mamdouh I. Khoder, Mansour A. Alghamdi, and Pauli Paasonen
Atmos. Chem. Phys., 23, 9287–9321, https://doi.org/10.5194/acp-23-9287-2023, https://doi.org/10.5194/acp-23-9287-2023, 2023
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Things are not always as they first seem in ambient aerosol measurements. Observations of decreasing particle sizes are often interpreted as resulting from particle evaporation. We show that such observations can counterintuitively be explained by particles that are constantly growing in size. This requires one to account for the previous movements of the observed air. Our explanation implies a larger number of larger particles, meaning more significant effects of aerosols on climate and health.
Dimitri Castarède, Zoé Brasseur, Yusheng Wu, Zamin A. Kanji, Markus Hartmann, Lauri Ahonen, Merete Bilde, Markku Kulmala, Tuukka Petäjä, Jan B. C. Pettersson, Berko Sierau, Olaf Stetzer, Frank Stratmann, Birgitta Svenningsson, Erik Swietlicki, Quynh Thu Nguyen, Jonathan Duplissy, and Erik S. Thomson
Atmos. Meas. Tech., 16, 3881–3899, https://doi.org/10.5194/amt-16-3881-2023, https://doi.org/10.5194/amt-16-3881-2023, 2023
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Clouds play a key role in Earth’s climate by influencing the surface energy budget. Certain types of atmospheric aerosols, called ice-nucleating particles (INPs), induce the formation of ice in clouds and, thus, often initiate precipitation formation. The Portable Ice Nucleation Chamber 2 (PINCii) is a new instrument developed to study ice formation and to conduct ambient measurements of INPs, allowing us to investigate the sources and properties of the atmospheric aerosols that can act as INPs.
Guangdong Niu, Ximeng Qi, Liangduo Chen, Lian Xue, Shiyi Lai, Xin Huang, Jiaping Wang, Xuguang Chi, Wei Nie, Veli-Matti Kerminen, Tuukka Petäjä, Markku Kulmala, and Aijun Ding
Atmos. Chem. Phys., 23, 7521–7534, https://doi.org/10.5194/acp-23-7521-2023, https://doi.org/10.5194/acp-23-7521-2023, 2023
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The reported below-cloud wet-scavenging coefficients (BWSCs) are much higher than theoretical data, but the reason remains unclear. Based on long-term observation, we find that air mass changing during rainfall events causes the overestimation of BWSCs. Thus, the discrepancy in BWSCs between observation and theory is not as large as currently believed. To obtain reasonable BWSCs and parameterizations from field observations, the effect of air mass changes needs to be considered.
Jonas Elm, Aladár Czitrovszky, Andreas Held, Annele Virtanen, Astrid Kiendler-Scharr, Benjamin J. Murray, Daniel McCluskey, Daniele Contini, David Broday, Eirini Goudeli, Hilkka Timonen, Joan Rosell-Llompart, Jose L. Castillo, Evangelia Diapouli, Mar Viana, Maria E. Messing, Markku Kulmala, Naděžda Zíková, and Sebastian H. Schmitt
Aerosol Research, 1, 13–16, https://doi.org/10.5194/ar-1-13-2023, https://doi.org/10.5194/ar-1-13-2023, 2023
Santeri Tuovinen, Janne Lampilahti, Veli-Matti Kerminen, and Markku Kulmala
EGUsphere, https://doi.org/10.5194/egusphere-2023-1108, https://doi.org/10.5194/egusphere-2023-1108, 2023
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Atmospheric ions can be used to characterize and detect atmospheric new particle formation. In this study we aimed to find the optimal ion diameter for this purpose within a local scale. To fulfill our aim, we used ion size number distribution data from SMEAR II measurement station, Hyytiälä, Finland. We found that negative ions between 2.0–2.3 nm are the best suited for characterization of local NPF, with minimized influence of transported ions.
Joschka Pfeifer, Naser G. A. Mahfouz, Benjamin C. Schulze, Serge Mathot, Dominik Stolzenburg, Rima Baalbaki, Zoé Brasseur, Lucia Caudillo, Lubna Dada, Manuel Granzin, Xu-Cheng He, Houssni Lamkaddam, Brandon Lopez, Vladimir Makhmutov, Ruby Marten, Bernhard Mentler, Tatjana Müller, Antti Onnela, Maxim Philippov, Ana A. Piedehierro, Birte Rörup, Meredith Schervish, Ping Tian, Nsikanabasi S. Umo, Dongyu S. Wang, Mingyi Wang, Stefan K. Weber, André Welti, Yusheng Wu, Marcel Zauner-Wieczorek, Antonio Amorim, Imad El Haddad, Markku Kulmala, Katrianne Lehtipalo, Tuukka Petäjä, António Tomé, Sander Mirme, Hanna E. Manninen, Neil M. Donahue, Richard C. Flagan, Andreas Kürten, Joachim Curtius, and Jasper Kirkby
Atmos. Chem. Phys., 23, 6703–6718, https://doi.org/10.5194/acp-23-6703-2023, https://doi.org/10.5194/acp-23-6703-2023, 2023
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Attachment rate coefficients between ions and charged aerosol particles determine their lifetimes and may also influence cloud dynamics and aerosol processing. Here we present novel experiments that measure ion–aerosol attachment rate coefficients for multiply charged aerosol particles under atmospheric conditions in the CERN CLOUD chamber. Our results provide experimental discrimination between various theoretical models.
Lucía Caudillo, Mihnea Surdu, Brandon Lopez, Mingyi Wang, Markus Thoma, Steffen Bräkling, Angela Buchholz, Mario Simon, Andrea C. Wagner, Tatjana Müller, Manuel Granzin, Martin Heinritzi, Antonio Amorim, David M. Bell, Zoé Brasseur, Lubna Dada, Jonathan Duplissy, Henning Finkenzeller, Xu-Cheng He, Houssni Lamkaddam, Naser G. A. Mahfouz, Vladimir Makhmutov, Hanna E. Manninen, Guillaume Marie, Ruby Marten, Roy L. Mauldin, Bernhard Mentler, Antti Onnela, Tuukka Petäjä, Joschka Pfeifer, Maxim Philippov, Ana A. Piedehierro, Birte Rörup, Wiebke Scholz, Jiali Shen, Dominik Stolzenburg, Christian Tauber, Ping Tian, António Tomé, Nsikanabasi Silas Umo, Dongyu S. Wang, Yonghong Wang, Stefan K. Weber, André Welti, Marcel Zauner-Wieczorek, Urs Baltensperger, Richard C. Flagan, Armin Hansel, Jasper Kirkby, Markku Kulmala, Katrianne Lehtipalo, Douglas R. Worsnop, Imad El Haddad, Neil M. Donahue, Alexander L. Vogel, Andreas Kürten, and Joachim Curtius
Atmos. Chem. Phys., 23, 6613–6631, https://doi.org/10.5194/acp-23-6613-2023, https://doi.org/10.5194/acp-23-6613-2023, 2023
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In this study, we present an intercomparison of four different techniques for measuring the chemical composition of nanoparticles. The intercomparison was performed based on the observed chemical composition, calculated volatility, and analysis of the thermograms. We found that the methods generally agree on the most important compounds that are found in the nanoparticles. However, they do see different parts of the organic spectrum. We suggest potential explanations for these differences.
Anton Rusanen, Kristo Hõrrak, Lauri R. Ahonen, Tuomo Nieminen, Pasi P. Aalto, Pasi Kolari, Markku Kulmala, Tuukka Petäjä, and Heikki Junninen
Atmos. Meas. Tech., 16, 2781–2793, https://doi.org/10.5194/amt-16-2781-2023, https://doi.org/10.5194/amt-16-2781-2023, 2023
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We present a framework for setting up SMEAR (Station for Measuring Ecosystem–Atmosphere Relations) type measurement station data flows. This framework, called SMEARcore, consists of modular open-source software components that can be chosen to suit various station configurations. The benefits of using this framework are automation of routine operations and real-time monitoring of measurement results.
Eka Dian Pusfitasari, Jose Ruiz-Jimenez, Aleksi Tiusanen, Markus Suuronen, Jesse Haataja, Yusheng Wu, Juha Kangasluoma, Krista Luoma, Tuukka Petäjä, Matti Jussila, Kari Hartonen, and Marja-Liisa Riekkola
Atmos. Chem. Phys., 23, 5885–5904, https://doi.org/10.5194/acp-23-5885-2023, https://doi.org/10.5194/acp-23-5885-2023, 2023
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A miniaturized air-sampling drone system was successfully applied for the collection of volatile organic compounds (VOCs) and for the measurement of black carbon (BC) and total particle number concentrations in atmospheric air. Here we report, for the first time, the vertical profiles of BC and aerosol number concentrations above the boreal forest in Hyytiälä (Finland) at high altitudes close to the boundary layer in autumn 2021. VOC composition with its distribution was studied as well.
Dominik Stolzenburg, Tiia Laurila, Pasi Aalto, Joonas Vanhanen, Tuukka Petäjä, and Juha Kangasluoma
Atmos. Meas. Tech., 16, 2471–2483, https://doi.org/10.5194/amt-16-2471-2023, https://doi.org/10.5194/amt-16-2471-2023, 2023
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Size-distribution measurements of ultrafine particles are of special interest as they can be used to estimate the atmospheric significance of new particle formation, a process which is thought to influence the global climate. Here we show that improved counting statistics in size-distribution measurements through the usage of higher sampling flows can significantly reduce the uncertainties in such calculations.
Rujing Yin, Xiaoxiao Li, Chao Yan, Runlong Cai, Ying Zhou, Juha Kangasluoma, Nina Sarnela, Janne Lampilahti, Tuukka Petäjä, Veli-Matti Kerminen, Federico Bianchi, Markku Kulmala, and Jingkun Jiang
Atmos. Chem. Phys., 23, 5279–5296, https://doi.org/10.5194/acp-23-5279-2023, https://doi.org/10.5194/acp-23-5279-2023, 2023
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Atmospheric cluster ions are important constituents in the atmosphere. However, the quantitative research on their compositions is still limited, especially in urban environments. Here we demonstrate the feasibility of an in situ quantification method of cluster ions measured by a high-resolution mass spectrometer and reveal their governing factors, sources, and sinks in urban Beijing through quantitative analysis of cluster ions, reagent ions, neutral molecules, and condensation sink.
Qiaozhi Zha, Wei Huang, Diego Aliaga, Otso Peräkylä, Liine Heikkinen, Alkuin Maximilian Koenig, Cheng Wu, Joonas Enroth, Yvette Gramlich, Jing Cai, Samara Carbone, Armin Hansel, Tuukka Petäjä, Markku Kulmala, Douglas Worsnop, Victoria Sinclair, Radovan Krejci, Marcos Andrade, Claudia Mohr, and Federico Bianchi
Atmos. Chem. Phys., 23, 4559–4576, https://doi.org/10.5194/acp-23-4559-2023, https://doi.org/10.5194/acp-23-4559-2023, 2023
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We investigate the chemical composition of atmospheric cluster ions from January to May 2018 at the high-altitude research station Chacaltaya (5240 m a.s.l.) in the Bolivian Andes. With state-of-the-art mass spectrometers and air mass history analysis, the measured cluster ions exhibited distinct diurnal and seasonal patterns, some of which contributed to new particle formation. Our study will improve the understanding of atmospheric ions and their role in high-altitude new particle formation.
Ella Häkkinen, Jian Zhao, Frans Graeffe, Nicolas Fauré, Jordan E. Krechmer, Douglas Worsnop, Hilkka Timonen, Mikael Ehn, and Juha Kangasluoma
Atmos. Meas. Tech., 16, 1705–1721, https://doi.org/10.5194/amt-16-1705-2023, https://doi.org/10.5194/amt-16-1705-2023, 2023
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Highly oxygenated compounds contribute to the formation and growth of atmospheric organic aerosol and thus impact the global climate. Knowledge of their transformations and fate after condensing into the particle phase has been limited by the lack of suitable detection techniques. Here, we present an online method for measuring highly oxygenated compounds from organic aerosol. We evaluate the performance of the method and demonstrate that the method is applicable to different organic species.
Meri Räty, Larisa Sogacheva, Helmi-Marja Keskinen, Veli-Matti Kerminen, Tuomo Nieminen, Tuukka Petäjä, Ekaterina Ezhova, and Markku Kulmala
Atmos. Chem. Phys., 23, 3779–3798, https://doi.org/10.5194/acp-23-3779-2023, https://doi.org/10.5194/acp-23-3779-2023, 2023
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We utilised back trajectories to identify the source region of air masses arriving in Hyytiälä, Finland, and their travel time over forests. Combined with atmospheric observations, they revealed how air mass transport over the Fennoscandian boreal forest during the growing season produced an accumulation of cloud condensation nuclei and humidity, promoting cloudiness and precipitation. By 55 h of transport, air masses appeared to reach a balanced state with the forest environment.
Sanna Saarikoski, Heidi Hellén, Arnaud P. Praplan, Simon Schallhart, Petri Clusius, Jarkko V. Niemi, Anu Kousa, Toni Tykkä, Rostislav Kouznetsov, Minna Aurela, Laura Salo, Topi Rönkkö, Luis M. F. Barreira, Liisa Pirjola, and Hilkka Timonen
Atmos. Chem. Phys., 23, 2963–2982, https://doi.org/10.5194/acp-23-2963-2023, https://doi.org/10.5194/acp-23-2963-2023, 2023
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This study elucidates properties and sources of volatile organic compounds (VOCs) and organic aerosol (OA) in a traffic environment. Anthropogenic VOCs (aVOCs) were clearly higher than biogenic VOCs (bVOCs), but bVOCs produced a larger portion of oxidation products. OA consisted mostly of oxygenated OA, representing secondary OA (SOA). SOA was partly associated with bVOCs, but it was also related to long-range transport. Primary OA originated mostly from traffic.
Lejish Vettikkat, Pasi Miettinen, Angela Buchholz, Pekka Rantala, Hao Yu, Simon Schallhart, Tuukka Petäjä, Roger Seco, Elisa Männistö, Markku Kulmala, Eeva-Stiina Tuittila, Alex B. Guenther, and Siegfried Schobesberger
Atmos. Chem. Phys., 23, 2683–2698, https://doi.org/10.5194/acp-23-2683-2023, https://doi.org/10.5194/acp-23-2683-2023, 2023
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Wetlands cover a substantial fraction of the land mass in the northern latitudes, from northern Europe to Siberia and Canada. Yet, their isoprene and terpene emissions remain understudied. Here, we used a state-of-the-art measurement technique to quantify ecosystem-scale emissions from a boreal wetland during an unusually warm spring/summer. We found that the emissions from this wetland were (a) higher and (b) even more strongly dependent on temperature than commonly thought.
Matthew Boyer, Diego Aliaga, Jakob Boyd Pernov, Hélène Angot, Lauriane L. J. Quéléver, Lubna Dada, Benjamin Heutte, Manuel Dall'Osto, David C. S. Beddows, Zoé Brasseur, Ivo Beck, Silvia Bucci, Marina Duetsch, Andreas Stohl, Tiia Laurila, Eija Asmi, Andreas Massling, Daniel Charles Thomas, Jakob Klenø Nøjgaard, Tak Chan, Sangeeta Sharma, Peter Tunved, Radovan Krejci, Hans Christen Hansson, Federico Bianchi, Katrianne Lehtipalo, Alfred Wiedensohler, Kay Weinhold, Markku Kulmala, Tuukka Petäjä, Mikko Sipilä, Julia Schmale, and Tuija Jokinen
Atmos. Chem. Phys., 23, 389–415, https://doi.org/10.5194/acp-23-389-2023, https://doi.org/10.5194/acp-23-389-2023, 2023
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The Arctic is a unique environment that is warming faster than other locations on Earth. We evaluate measurements of aerosol particles, which can influence climate, over the central Arctic Ocean for a full year and compare the data to land-based measurement stations across the Arctic. Our measurements show that the central Arctic has similarities to but also distinct differences from the stations further south. We note that this may change as the Arctic warms and sea ice continues to decline.
Mykhailo Savenets, Larysa Pysarenko, Svitlana Krakovska, Alexander Mahura, and Tuukka Petäjä
Atmos. Chem. Phys., 22, 15777–15791, https://doi.org/10.5194/acp-22-15777-2022, https://doi.org/10.5194/acp-22-15777-2022, 2022
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The paper explores the spatio-temporal variability of black carbon during a wildfire in August 2010, with a focus on Ukraine. As a research tool, the seamless Enviro-HIRLAM modelling system is used for investigating the atmospheric transport of aerosol particles emitted by wildfires from remote and local sources. The results of this study improve our understanding of the physical and chemical processes and the interactions of aerosols in the atmosphere.
Juha Sulo, Janne Lampilahti, Xuemeng Chen, Jenni Kontkanen, Tuomo Nieminen, Veli-Matti Kerminen, Tuukka Petäjä, Markku Kulmala, and Katrianne Lehtipalo
Atmos. Chem. Phys., 22, 15223–15242, https://doi.org/10.5194/acp-22-15223-2022, https://doi.org/10.5194/acp-22-15223-2022, 2022
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We measured atmospheric ion concentrations continuously in a boreal forest between 2005 and 2021 and observed an increasing interannual trend. The increase in cluster ion concentrations can be largely explained by an overall decreasing level of anthropogenic aerosols in the boreal forest. This suggests that the role of ions in atmospheric new particle formation may be more important in the future.
Loïc Gonzalez Carracedo, Katrianne Lehtipalo, Lauri R. Ahonen, Nina Sarnela, Sebastian Holm, Juha Kangasluoma, Markku Kulmala, Paul M. Winkler, and Dominik Stolzenburg
Atmos. Chem. Phys., 22, 13153–13166, https://doi.org/10.5194/acp-22-13153-2022, https://doi.org/10.5194/acp-22-13153-2022, 2022
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Fast nanoparticle growth is essential for the survival of new aerosol particles in the atmosphere and hence their contribution to the climate. We show that using naturally charged ions for growth calculations can cause a significant error. During the diurnal cycle, the importance of ion-induced and neutral nucleation varies, causing the ion population to have a slower measurable apparent growth. Results suggest that data from ion spectrometers need to be considered with great care below 3 nm.
Ville Leinonen, Harri Kokkola, Taina Yli-Juuti, Tero Mielonen, Thomas Kühn, Tuomo Nieminen, Simo Heikkinen, Tuuli Miinalainen, Tommi Bergman, Ken Carslaw, Stefano Decesari, Markus Fiebig, Tareq Hussein, Niku Kivekäs, Radovan Krejci, Markku Kulmala, Ari Leskinen, Andreas Massling, Nikos Mihalopoulos, Jane P. Mulcahy, Steffen M. Noe, Twan van Noije, Fiona M. O'Connor, Colin O'Dowd, Dirk Olivie, Jakob B. Pernov, Tuukka Petäjä, Øyvind Seland, Michael Schulz, Catherine E. Scott, Henrik Skov, Erik Swietlicki, Thomas Tuch, Alfred Wiedensohler, Annele Virtanen, and Santtu Mikkonen
Atmos. Chem. Phys., 22, 12873–12905, https://doi.org/10.5194/acp-22-12873-2022, https://doi.org/10.5194/acp-22-12873-2022, 2022
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We provide the first extensive comparison of detailed aerosol size distribution trends between in situ observations from Europe and five different earth system models. We investigated aerosol modes (nucleation, Aitken, and accumulation) separately and were able to show the differences between measured and modeled trends and especially their seasonal patterns. The differences in model results are likely due to complex effects of several processes instead of certain specific model features.
Chao Yan, Yicheng Shen, Dominik Stolzenburg, Lubna Dada, Ximeng Qi, Simo Hakala, Anu-Maija Sundström, Yishuo Guo, Antti Lipponen, Tom V. Kokkonen, Jenni Kontkanen, Runlong Cai, Jing Cai, Tommy Chan, Liangduo Chen, Biwu Chu, Chenjuan Deng, Wei Du, Xiaolong Fan, Xu-Cheng He, Juha Kangasluoma, Joni Kujansuu, Mona Kurppa, Chang Li, Yiran Li, Zhuohui Lin, Yiliang Liu, Yuliang Liu, Yiqun Lu, Wei Nie, Jouni Pulliainen, Xiaohui Qiao, Yonghong Wang, Yifan Wen, Ye Wu, Gan Yang, Lei Yao, Rujing Yin, Gen Zhang, Shaojun Zhang, Feixue Zheng, Ying Zhou, Antti Arola, Johanna Tamminen, Pauli Paasonen, Yele Sun, Lin Wang, Neil M. Donahue, Yongchun Liu, Federico Bianchi, Kaspar R. Daellenbach, Douglas R. Worsnop, Veli-Matti Kerminen, Tuukka Petäjä, Aijun Ding, Jingkun Jiang, and Markku Kulmala
Atmos. Chem. Phys., 22, 12207–12220, https://doi.org/10.5194/acp-22-12207-2022, https://doi.org/10.5194/acp-22-12207-2022, 2022
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Atmospheric new particle formation (NPF) is a dominant source of atmospheric ultrafine particles. In urban environments, traffic emissions are a major source of primary pollutants, but their contribution to NPF remains under debate. During the COVID-19 lockdown, traffic emissions were significantly reduced, providing a unique chance to examine their relevance to NPF. Based on our comprehensive measurements, we demonstrate that traffic emissions alone are not able to explain the NPF in Beijing.
Sini Isokääntä, Paul Kim, Santtu Mikkonen, Thomas Kühn, Harri Kokkola, Taina Yli-Juuti, Liine Heikkinen, Krista Luoma, Tuukka Petäjä, Zak Kipling, Daniel Partridge, and Annele Virtanen
Atmos. Chem. Phys., 22, 11823–11843, https://doi.org/10.5194/acp-22-11823-2022, https://doi.org/10.5194/acp-22-11823-2022, 2022
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This research employs air mass history analysis and observations to study how clouds and precipitation affect atmospheric aerosols during transport to a boreal forest site. The mass concentrations of studied chemical species showed exponential decrease as a function of accumulated rain along the air mass route. Our analysis revealed in-cloud sulfate formation, while no major changes in organic mass were seen. Most of the in-cloud-formed sulfate could be assigned to particle sizes above 200 nm.
Benjamin Foreback, Lubna Dada, Kaspar R. Daellenbach, Chao Yan, Lili Wang, Biwu Chu, Ying Zhou, Tom V. Kokkonen, Mona Kurppa, Rosaria E. Pileci, Yonghong Wang, Tommy Chan, Juha Kangasluoma, Lin Zhuohui, Yishou Guo, Chang Li, Rima Baalbaki, Joni Kujansuu, Xiaolong Fan, Zemin Feng, Pekka Rantala, Shahzad Gani, Federico Bianchi, Veli-Matti Kerminen, Tuukka Petäjä, Markku Kulmala, Yongchun Liu, and Pauli Paasonen
Atmos. Chem. Phys., 22, 11089–11104, https://doi.org/10.5194/acp-22-11089-2022, https://doi.org/10.5194/acp-22-11089-2022, 2022
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This study analyzed air quality in Beijing during the Chinese New Year over 7 years, including data from a new in-depth measurement station. This is one of few studies to look at long-term impacts, including the outcome of firework restrictions starting in 2018. Results show that firework pollution has gone down since 2016, indicating a positive result from the restrictions. Results of this study may be useful in making future decisions about the use of fireworks to improve air quality.
Hannele Hakola, Ditte Taipale, Arnaud Praplan, Simon Schallhart, Steven Thomas, Toni Tykkä, Aku Helin, Jaana Bäck, and Heidi Hellén
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2022-478, https://doi.org/10.5194/acp-2022-478, 2022
Revised manuscript not accepted
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Norway spruce is one of the main tree species growing in the boreal area. We show that volatile organic compound emission potentials and compound composition vary a lot. We have investigated if e.g. growing location or age of a tree could explain the variations. Recognizing this observed large variability in spruce BVOC emissions (precursors for new particle formation processes), we also tested the consequences of this variability in simulations of aerosol formation.
Ivo Beck, Hélène Angot, Andrea Baccarini, Lubna Dada, Lauriane Quéléver, Tuija Jokinen, Tiia Laurila, Markus Lampimäki, Nicolas Bukowiecki, Matthew Boyer, Xianda Gong, Martin Gysel-Beer, Tuukka Petäjä, Jian Wang, and Julia Schmale
Atmos. Meas. Tech., 15, 4195–4224, https://doi.org/10.5194/amt-15-4195-2022, https://doi.org/10.5194/amt-15-4195-2022, 2022
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We present the pollution detection algorithm (PDA), a new method to identify local primary pollution in remote atmospheric aerosol and trace gas time series. The PDA identifies periods of contaminated data and relies only on the target dataset itself; i.e., it is independent of ancillary data such as meteorological variables. The parameters of all pollution identification steps are adjustable so that the PDA can be tuned to different locations and situations. It is available as open-access code.
Karine Sartelet, Youngseob Kim, Florian Couvidat, Maik Merkel, Tuukka Petäjä, Jean Sciare, and Alfred Wiedensohler
Atmos. Chem. Phys., 22, 8579–8596, https://doi.org/10.5194/acp-22-8579-2022, https://doi.org/10.5194/acp-22-8579-2022, 2022
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A methodology is defined to estimate number emissions from an inventory providing mass emissions. Number concentrations are simulated over Greater Paris using different nucleation parameterisations (binary, ternary involving sulfuric acid and ammonia, and heteromolecular involving sulfuric acid and extremely low-volatility organics, ELVOCs). The comparisons show that ternary nucleation may not be a dominant process for new particle formation in cities, but they stress the role of ELVOCs.
Lisa J. Beck, Siegfried Schobesberger, Heikki Junninen, Janne Lampilahti, Antti Manninen, Lubna Dada, Katri Leino, Xu-Cheng He, Iida Pullinen, Lauriane L. J. Quéléver, Anna Franck, Pyry Poutanen, Daniela Wimmer, Frans Korhonen, Mikko Sipilä, Mikael Ehn, Douglas R. Worsnop, Veli-Matti Kerminen, Tuukka Petäjä, Markku Kulmala, and Jonathan Duplissy
Atmos. Chem. Phys., 22, 8547–8577, https://doi.org/10.5194/acp-22-8547-2022, https://doi.org/10.5194/acp-22-8547-2022, 2022
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The presented article introduces an overview of atmospheric ions and their composition above the boreal forest. We provide the results of an extensive airborne measurement campaign with an air ion mass spectrometer and particle measurements, showing their diurnal evolution within the boundary layer and free troposphere. In addition, we compare the airborne dataset with the co-located data from the ground at SMEAR II station, Finland.
Lauriane L. J. Quéléver, Lubna Dada, Eija Asmi, Janne Lampilahti, Tommy Chan, Jonathan E. Ferrara, Gustavo E. Copes, German Pérez-Fogwill, Luis Barreira, Minna Aurela, Douglas R. Worsnop, Tuija Jokinen, and Mikko Sipilä
Atmos. Chem. Phys., 22, 8417–8437, https://doi.org/10.5194/acp-22-8417-2022, https://doi.org/10.5194/acp-22-8417-2022, 2022
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Understanding how aerosols form is crucial for correctly modeling the climate and improving future predictions. This work provides extensive analysis of aerosol particles and their precursors at Marambio Station, Antarctic Peninsula. We show that sulfuric acid, ammonia, and dimethylamine are key contributors to the frequent new particle formation events observed at the site. We discuss nucleation mechanisms and highlight the need for targeted measurement to fully understand these processes.
Miska Olin, Magdalena Okuljar, Matti P. Rissanen, Joni Kalliokoski, Jiali Shen, Lubna Dada, Markus Lampimäki, Yusheng Wu, Annalea Lohila, Jonathan Duplissy, Mikko Sipilä, Tuukka Petäjä, Markku Kulmala, and Miikka Dal Maso
Atmos. Chem. Phys., 22, 8097–8115, https://doi.org/10.5194/acp-22-8097-2022, https://doi.org/10.5194/acp-22-8097-2022, 2022
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Atmospheric new particle formation is an important source of the total particle number concentration in the atmosphere. Several parameters for predicting new particle formation events have been suggested before, but the results have been inconclusive. This study proposes an another predicting parameter, related to a specific type of highly oxidized organic molecules, especially for similar locations to the measurement site in this study, which was a coastal agricultural site in Finland.
Roseline C. Thakur, Lubna Dada, Lisa J. Beck, Lauriane L. J. Quéléver, Tommy Chan, Marjan Marbouti, Xu-Cheng He, Carlton Xavier, Juha Sulo, Janne Lampilahti, Markus Lampimäki, Yee Jun Tham, Nina Sarnela, Katrianne Lehtipalo, Alf Norkko, Markku Kulmala, Mikko Sipilä, and Tuija Jokinen
Atmos. Chem. Phys., 22, 6365–6391, https://doi.org/10.5194/acp-22-6365-2022, https://doi.org/10.5194/acp-22-6365-2022, 2022
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Every year intense cyanobacterial and macroalgal blooms occur in the Baltic Sea and in the coastal areas surrounding Helsinki, yet no studies have addressed the impact of biogenic emissions from these blooms on gas vapor concentrations, which in turn could influence new particle formation. This is the first study of its kind to address the chemistry driving new particle formation (NPF) during a bloom period in this region, highlighting the role of biogenic sulfuric acid and iodic acid.
Matthias Karl, Liisa Pirjola, Tiia Grönholm, Mona Kurppa, Srinivasan Anand, Xiaole Zhang, Andreas Held, Rolf Sander, Miikka Dal Maso, David Topping, Shuai Jiang, Leena Kangas, and Jaakko Kukkonen
Geosci. Model Dev., 15, 3969–4026, https://doi.org/10.5194/gmd-15-3969-2022, https://doi.org/10.5194/gmd-15-3969-2022, 2022
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The community aerosol dynamics model MAFOR includes several advanced features: coupling with an up-to-date chemistry mechanism for volatile organic compounds, a revised Brownian coagulation kernel that takes into account the fractal geometry of soot particles, a multitude of nucleation parameterizations, size-resolved partitioning of semi-volatile inorganics, and a hybrid method for the formation of secondary organic aerosols within the framework of condensation and evaporation.
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
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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.
Zoé Brasseur, Dimitri Castarède, Erik S. Thomson, Michael P. Adams, Saskia Drossaart van Dusseldorp, Paavo Heikkilä, Kimmo Korhonen, Janne Lampilahti, Mikhail Paramonov, Julia Schneider, Franziska Vogel, Yusheng Wu, Jonathan P. D. Abbatt, Nina S. Atanasova, Dennis H. Bamford, Barbara Bertozzi, Matthew Boyer, David Brus, Martin I. Daily, Romy Fösig, Ellen Gute, Alexander D. Harrison, Paula Hietala, Kristina Höhler, Zamin A. Kanji, Jorma Keskinen, Larissa Lacher, Markus Lampimäki, Janne Levula, Antti Manninen, Jens Nadolny, Maija Peltola, Grace C. E. Porter, Pyry Poutanen, Ulrike Proske, Tobias Schorr, Nsikanabasi Silas Umo, János Stenszky, Annele Virtanen, Dmitri Moisseev, Markku Kulmala, Benjamin J. Murray, Tuukka Petäjä, Ottmar Möhler, and Jonathan Duplissy
Atmos. Chem. Phys., 22, 5117–5145, https://doi.org/10.5194/acp-22-5117-2022, https://doi.org/10.5194/acp-22-5117-2022, 2022
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The present measurement report introduces the ice nucleation campaign organized in Hyytiälä, Finland, in 2018 (HyICE-2018). We provide an overview of the campaign settings, and we describe the measurement infrastructure and operating procedures used. In addition, we use results from ice nucleation instrument inter-comparison to show that the suite of these instruments deployed during the campaign reports consistent results.
Aki Virkkula, Henrik Grythe, John Backman, Tuukka Petäjä, Maurizio Busetto, Christian Lanconelli, Angelo Lupi, Silvia Becagli, Rita Traversi, Mirko Severi, Vito Vitale, Patrick Sheridan, and Elisabeth Andrews
Atmos. Chem. Phys., 22, 5033–5069, https://doi.org/10.5194/acp-22-5033-2022, https://doi.org/10.5194/acp-22-5033-2022, 2022
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Optical properties of surface aerosols at Dome C, Antarctica, in 2007–2013 and their potential source areas are presented. The equivalent black carbon (eBC) mass concentrations were compared with eBC measured at three other Antarctic sites: the South Pole (SPO) and two coastal sites, Neumayer and Syowa. Transport analysis suggests that South American BC emissions are the largest contributor to eBC at Dome C.
Joel Kuula, Hilkka Timonen, Jarkko V. Niemi, Hanna E. Manninen, Topi Rönkkö, Tareq Hussein, Pak Lun Fung, Sasu Tarkoma, Mikko Laakso, Erkka Saukko, Aino Ovaska, Markku Kulmala, Ari Karppinen, Lasse Johansson, and Tuukka Petäjä
Atmos. Chem. Phys., 22, 4801–4808, https://doi.org/10.5194/acp-22-4801-2022, https://doi.org/10.5194/acp-22-4801-2022, 2022
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Modern and up-to-date policies and air quality management strategies are instrumental in tackling global air pollution. As the European Union is preparing to revise Ambient Air Quality Directive 2008/50/EC, this paper initiates discussion on selected features of the directive that we believe would benefit from a reassessment. The scientific community has the most recent and deepest understanding of air pollution; thus, its contribution is essential.
Hanna K. Lappalainen, Tuukka Petäjä, Timo Vihma, Jouni Räisänen, Alexander Baklanov, Sergey Chalov, Igor Esau, Ekaterina Ezhova, Matti Leppäranta, Dmitry Pozdnyakov, Jukka Pumpanen, Meinrat O. Andreae, Mikhail Arshinov, Eija Asmi, Jianhui Bai, Igor Bashmachnikov, Boris Belan, Federico Bianchi, Boris Biskaborn, Michael Boy, Jaana Bäck, Bin Cheng, Natalia Chubarova, Jonathan Duplissy, Egor Dyukarev, Konstantinos Eleftheriadis, Martin Forsius, Martin Heimann, Sirkku Juhola, Vladimir Konovalov, Igor Konovalov, Pavel Konstantinov, Kajar Köster, Elena Lapshina, Anna Lintunen, Alexander Mahura, Risto Makkonen, Svetlana Malkhazova, Ivan Mammarella, Stefano Mammola, Stephany Buenrostro Mazon, Outi Meinander, Eugene Mikhailov, Victoria Miles, Stanislav Myslenkov, Dmitry Orlov, Jean-Daniel Paris, Roberta Pirazzini, Olga Popovicheva, Jouni Pulliainen, Kimmo Rautiainen, Torsten Sachs, Vladimir Shevchenko, Andrey Skorokhod, Andreas Stohl, Elli Suhonen, Erik S. Thomson, Marina Tsidilina, Veli-Pekka Tynkkynen, Petteri Uotila, Aki Virkkula, Nadezhda Voropay, Tobias Wolf, Sayaka Yasunaka, Jiahua Zhang, Yubao Qiu, Aijun Ding, Huadong Guo, Valery Bondur, Nikolay Kasimov, Sergej Zilitinkevich, Veli-Matti Kerminen, and Markku Kulmala
Atmos. Chem. Phys., 22, 4413–4469, https://doi.org/10.5194/acp-22-4413-2022, https://doi.org/10.5194/acp-22-4413-2022, 2022
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We summarize results during the last 5 years in the northern Eurasian region, especially from Russia, and introduce recent observations of the air quality in the urban environments in China. Although the scientific knowledge in these regions has increased, there are still gaps in our understanding of large-scale climate–Earth surface interactions and feedbacks. This arises from limitations in research infrastructures and integrative data analyses, hindering a comprehensive system analysis.
Tuija Jokinen, Katrianne Lehtipalo, Roseline Cutting Thakur, Ilona Ylivinkka, Kimmo Neitola, Nina Sarnela, Totti Laitinen, Markku Kulmala, Tuukka Petäjä, and Mikko Sipilä
Atmos. Chem. Phys., 22, 2237–2254, https://doi.org/10.5194/acp-22-2237-2022, https://doi.org/10.5194/acp-22-2237-2022, 2022
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New particle formation is an important source of cloud condensation nuclei; however, long-term measurements of aerosol-forming vapors are close to nonexistent in the Arctic. Here, we report 7 months of CI-APi-TOF measurements of sulfuric acid, iodic acid, methane sulfonic acid and the sum of highly oxygenated organic molecules from the SMEAR I station in the Finnish subarctic. The results help us to understand atmospheric chemical processes and aerosol formation in this rapidly changing area.
Pak Lun Fung, Martha A. Zaidan, Jarkko V. Niemi, Erkka Saukko, Hilkka Timonen, Anu Kousa, Joel Kuula, Topi Rönkkö, Ari Karppinen, Sasu Tarkoma, Markku Kulmala, Tuukka Petäjä, and Tareq Hussein
Atmos. Chem. Phys., 22, 1861–1882, https://doi.org/10.5194/acp-22-1861-2022, https://doi.org/10.5194/acp-22-1861-2022, 2022
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We developed an input-adaptive mixed-effects model, which was automatised to select the best combination of input variables, including up to three fixed effect variables and three time indictors as random effect variables. We tested the model to estimate lung-deposited surface area (LDSA), which correlates well with human health. The results show the inclusion of time indicators improved the sensitivity and the accuracy of the model so that it could serve as a network of virtual sensors.
Peifeng Su, Jorma Joutsensaari, Lubna Dada, Martha Arbayani Zaidan, Tuomo Nieminen, Xinyang Li, Yusheng Wu, Stefano Decesari, Sasu Tarkoma, Tuukka Petäjä, Markku Kulmala, and Petri Pellikka
Atmos. Chem. Phys., 22, 1293–1309, https://doi.org/10.5194/acp-22-1293-2022, https://doi.org/10.5194/acp-22-1293-2022, 2022
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We regarded the banana shapes in the surface plots as a special kind of object (similar to cats) and applied an instance segmentation technique to automatically identify the new particle formation (NPF) events (especially the strongest ones), in addition to their growth rates, start times, and end times. The automatic method generalized well on datasets collected in different sites, which is useful for long-term data series analysis and obtaining statistical properties of NPF events.
Miska Olin, David Patoulias, Heino Kuuluvainen, Jarkko V. Niemi, Topi Rönkkö, Spyros N. Pandis, Ilona Riipinen, and Miikka Dal Maso
Atmos. Chem. Phys., 22, 1131–1148, https://doi.org/10.5194/acp-22-1131-2022, https://doi.org/10.5194/acp-22-1131-2022, 2022
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An emission factor particle size distribution was determined from the measurements at an urban traffic site. It was used in updating a pre-existing emission inventory, and regional modeling was performed after the update. Emission inventories typically underestimate nanoparticle emissions due to challenges in determining them with high certainty. This update reveals that the simulated aerosol levels have previously been underestimated especially for urban areas and for sub-50 nm particles.
Jutta Kesti, John Backman, Ewan J. O'Connor, Anne Hirsikko, Eija Asmi, Minna Aurela, Ulla Makkonen, Maria Filioglou, Mika Komppula, Hannele Korhonen, and Heikki Lihavainen
Atmos. Chem. Phys., 22, 481–503, https://doi.org/10.5194/acp-22-481-2022, https://doi.org/10.5194/acp-22-481-2022, 2022
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In this study we combined aerosol particle measurements at the surface with a scanning Doppler lidar providing vertical profiles of the atmosphere to study the effect of different boundary layer conditions on aerosol particle properties in the understudied Arabian Peninsula region. The instrumentation used in this study enabled us to identify periods when pollution from remote sources was mixed down to the surface and initiated new particle formation in the growing boundary layer.
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
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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.
Lukas Fischer, Martin Breitenlechner, Eva Canaval, Wiebke Scholz, Marcus Striednig, Martin Graus, Thomas G. Karl, Tuukka Petäjä, Markku Kulmala, and Armin Hansel
Atmos. Meas. Tech., 14, 8019–8039, https://doi.org/10.5194/amt-14-8019-2021, https://doi.org/10.5194/amt-14-8019-2021, 2021
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Ecosystems emit biogenic volatile organic compounds (BVOCs), which are then oxidized in the atmosphere, contributing to ozone and secondary aerosol formation. While flux measurements of BVOCs are state of the art, flux measurements of the less volatile oxidation products are difficult to achieve due to inlet losses. Here we present first flux measurements, utilizing a novel PTR3 instrument in combination with a specially designed wall-less inlet we put on top of the Hyytiälä tower in Finland.
Ying Zhou, Simo Hakala, Chao Yan, Yang Gao, Xiaohong Yao, Biwu Chu, Tommy Chan, Juha Kangasluoma, Shahzad Gani, Jenni Kontkanen, Pauli Paasonen, Yongchun Liu, Tuukka Petäjä, Markku Kulmala, and Lubna Dada
Atmos. Chem. Phys., 21, 17885–17906, https://doi.org/10.5194/acp-21-17885-2021, https://doi.org/10.5194/acp-21-17885-2021, 2021
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We characterized the connection between new particle formation (NPF) events in terms of frequency, intensity and growth at a near-highway location in central Beijing and at a background mountain site 80 km away. Due to the substantial contribution of NPF to the global aerosol budget, identifying the conditions that promote the occurrence of regional NPF events could help understand their contribution on a large scale and would improve their implementation in global models.
Mikko Sipilä, Nina Sarnela, Kimmo Neitola, Totti Laitinen, Deniz Kemppainen, Lisa Beck, Ella-Maria Duplissy, Salla Kuittinen, Tuuli Lehmusjärvi, Janne Lampilahti, Veli-Matti Kerminen, Katrianne Lehtipalo, Pasi P. Aalto, Petri Keronen, Erkki Siivola, Pekka A. Rantala, Douglas R. Worsnop, Markku Kulmala, Tuija Jokinen, and Tuukka Petäjä
Atmos. Chem. Phys., 21, 17559–17576, https://doi.org/10.5194/acp-21-17559-2021, https://doi.org/10.5194/acp-21-17559-2021, 2021
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Metallurgical industry in Kola peninsula is a large source of air pollution in the (sub-)Arctic domain. Sulfur dioxide emissions from the ore smelters are transported across large areas. We investigated sulfur dioxide and its transformation to sulfuric acid aerosol particles during winter months in Finnish Lapland, close to Kola industrial areas. We observed intense formation of new aerosol particles despite the low solar radiation intensity, often required for new particle formation elsewhere.
Lucía Caudillo, Birte Rörup, Martin Heinritzi, Guillaume Marie, Mario Simon, Andrea C. Wagner, Tatjana Müller, Manuel Granzin, Antonio Amorim, Farnoush Ataei, Rima Baalbaki, Barbara Bertozzi, Zoé Brasseur, Randall Chiu, Biwu Chu, Lubna Dada, Jonathan Duplissy, Henning Finkenzeller, Loïc Gonzalez Carracedo, Xu-Cheng He, Victoria Hofbauer, Weimeng Kong, Houssni Lamkaddam, Chuan P. Lee, Brandon Lopez, Naser G. A. Mahfouz, Vladimir Makhmutov, Hanna E. Manninen, Ruby Marten, Dario Massabò, Roy L. Mauldin, Bernhard Mentler, Ugo Molteni, Antti Onnela, Joschka Pfeifer, Maxim Philippov, Ana A. Piedehierro, Meredith Schervish, Wiebke Scholz, Benjamin Schulze, Jiali Shen, Dominik Stolzenburg, Yuri Stozhkov, Mihnea Surdu, Christian Tauber, Yee Jun Tham, Ping Tian, António Tomé, Steffen Vogt, Mingyi Wang, Dongyu S. Wang, Stefan K. Weber, André Welti, Wang Yonghong, Wu Yusheng, Marcel Zauner-Wieczorek, Urs Baltensperger, Imad El Haddad, Richard C. Flagan, Armin Hansel, Kristina Höhler, Jasper Kirkby, Markku Kulmala, Katrianne Lehtipalo, Ottmar Möhler, Harald Saathoff, Rainer Volkamer, Paul M. Winkler, Neil M. Donahue, Andreas Kürten, and Joachim Curtius
Atmos. Chem. Phys., 21, 17099–17114, https://doi.org/10.5194/acp-21-17099-2021, https://doi.org/10.5194/acp-21-17099-2021, 2021
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We performed experiments in the CLOUD chamber at CERN at low temperatures to simulate new particle formation in the upper free troposphere (at −30 ºC and −50 ºC). We measured the particle and gas phase and found that most of the compounds present in the gas phase are detected as well in the particle phase. The major compounds in the particles are C8–10 and C18–20. Specifically, we showed that C5 and C15 compounds are detected in a mixed system with isoprene and α-pinene at −30 ºC, 20 % RH.
Clémence Rose, Martine Collaud Coen, Elisabeth Andrews, Yong Lin, Isaline Bossert, Cathrine Lund Myhre, Thomas Tuch, Alfred Wiedensohler, Markus Fiebig, Pasi Aalto, Andrés Alastuey, Elisabeth Alonso-Blanco, Marcos Andrade, Begoña Artíñano, Todor Arsov, Urs Baltensperger, Susanne Bastian, Olaf Bath, Johan Paul Beukes, Benjamin T. Brem, Nicolas Bukowiecki, Juan Andrés Casquero-Vera, Sébastien Conil, Konstantinos Eleftheriadis, Olivier Favez, Harald Flentje, Maria I. Gini, Francisco Javier Gómez-Moreno, Martin Gysel-Beer, Anna Gannet Hallar, Ivo Kalapov, Nikos Kalivitis, Anne Kasper-Giebl, Melita Keywood, Jeong Eun Kim, Sang-Woo Kim, Adam Kristensson, Markku Kulmala, Heikki Lihavainen, Neng-Huei Lin, Hassan Lyamani, Angela Marinoni, Sebastiao Martins Dos Santos, Olga L. Mayol-Bracero, Frank Meinhardt, Maik Merkel, Jean-Marc Metzger, Nikolaos Mihalopoulos, Jakub Ondracek, Marco Pandolfi, Noemi Pérez, Tuukka Petäjä, Jean-Eudes Petit, David Picard, Jean-Marc Pichon, Veronique Pont, Jean-Philippe Putaud, Fabienne Reisen, Karine Sellegri, Sangeeta Sharma, Gerhard Schauer, Patrick Sheridan, James Patrick Sherman, Andreas Schwerin, Ralf Sohmer, Mar Sorribas, Junying Sun, Pierre Tulet, Ville Vakkari, Pieter Gideon van Zyl, Fernando Velarde, Paolo Villani, Stergios Vratolis, Zdenek Wagner, Sheng-Hsiang Wang, Kay Weinhold, Rolf Weller, Margarita Yela, Vladimir Zdimal, and Paolo Laj
Atmos. Chem. Phys., 21, 17185–17223, https://doi.org/10.5194/acp-21-17185-2021, https://doi.org/10.5194/acp-21-17185-2021, 2021
Short summary
Short summary
Aerosol particles are a complex component of the atmospheric system the effects of which are among the most uncertain in climate change projections. Using data collected at 62 stations, this study provides the most up-to-date picture of the spatial distribution of particle number concentration and size distribution worldwide, with the aim of contributing to better representation of aerosols and their interactions with clouds in models and, therefore, better evaluation of their impact on climate.
Anna Franck, Dmitri Moisseev, Ville Vakkari, Matti Leskinen, Janne Lampilahti, Veli-Matti Kerminen, and Ewan O'Connor
Atmos. Meas. Tech., 14, 7341–7353, https://doi.org/10.5194/amt-14-7341-2021, https://doi.org/10.5194/amt-14-7341-2021, 2021
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Short summary
We proposed a method to derive a convective boundary layer height, using insects in radar observations, and we investigated the consistency of these retrievals among different radar frequencies (5, 35 and 94 GHz). This method can be applied to radars at other measurement stations and serve as additional way to estimate the boundary layer height during summer. The entrainment zone was also observed by the 5 GHz radar above the boundary layer in the form of a Bragg scatter layer.
Cited articles
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Short summary
The study investigates vehicle fleet emissions of road traffic. Despite technological advances, road traffic is still an important pollution source in urban areas, especially when considering unregulated, but health-relevant, emerging pollutants. We report fuel consumption normalized vehicle fleet emission factors for various regulated and unregulated air pollutants. Also, we show that road traffic has inverse and indirect effects on urban aerosol which are not generally well understood.
The study investigates vehicle fleet emissions of road traffic. Despite technological advances,...
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