Articles | Volume 25, issue 22
https://doi.org/10.5194/acp-25-15785-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-25-15785-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
18 Nov 2025
Research article |
| 18 Nov 2025
| 18 Nov 2025
Simulation of the seasonal and spatial variability of the concentrations and chemical composition of ultrafine particulate matter over Europe
Konstantinos Mataras
Department of Chemical Engineering, University of Patras, Patras, Greece
Evangelia Siouti
Institute of Chemical Engineering Sciences (ICE-HT), Foundation for Research and Technology Hellas (FORTH), Patras, Greece
David Patoulias
Institute of Chemical Engineering Sciences (ICE-HT), Foundation for Research and Technology Hellas (FORTH), Patras, Greece
Spyros N. Pandis
CORRESPONDING AUTHOR
Department of Chemical Engineering, University of Patras, Patras, Greece
Institute of Chemical Engineering Sciences (ICE-HT), Foundation for Research and Technology Hellas (FORTH), Patras, Greece
Related authors
No articles found.
Maria P. Georgopoulou, Kalliopi Florou, Angeliki Matrali, Georgia Starida, Christos Kaltsonoudis, Athanasios Nenes, and Spyros N. Pandis
Atmos. Chem. Phys., 25, 15835–15855, https://doi.org/10.5194/acp-25-15835-2025, https://doi.org/10.5194/acp-25-15835-2025, 2025
Short summary
Short summary
Residential biomass burning is an important wintertime source of aerosols. This study examined the complex diurnal aging cycles on biomass burning aerosol composition and oxidative potential, a key toxicity metric. Additional organic aerosol (OA) mass was produced after the two (day/night and night/day) cycles, varying from 35 to 90 % of the initial OA. The aging of the emissions led to a final oxidative potential increase of 60 % for both cycles.
Georgia A. Argyropoulou, Kalliopi Florou, and Spyros N. Pandis
Atmos. Meas. Tech., 18, 4969–4983, https://doi.org/10.5194/amt-18-4969-2025, https://doi.org/10.5194/amt-18-4969-2025, 2025
Short summary
Short summary
Ultrafine particles (diameter of less than 100 nm) are suspected to cause significant health effects. Accurately measuring their chemical composition and physical properties in real time is challenging due to their low mass and interference from larger particles. This study proposes a method for the continuous, automated measurement of their composition, tested in a pilot field study to explore their chemical characteristics, physical properties, and sources.
Anna Maria Neroladaki, Maria Tsagkaraki, Kyriaki Papoutsidaki, Kalliopi Tavernaraki, Filothei Boufidou, Pavlos Zarmpas, Irini Tsiodra, Eleni Liakakou, Aikaterini Bougiatioti, Giorgos Kouvarakis, Nikos Kalivitis, Christos Kaltsonoudis, Athanasios Karagioras, Dimitrios Balis, Konstantinos Mihailidis, Konstantinos Kourtidis, Stelios Myriokefalitakis, Nikos Hatzianastassiou, Spyros N. Pandis, Athanasios Nenes, Nikolaos Mihalopoulos, and Maria Kanakidou
EGUsphere, https://doi.org/10.5194/egusphere-2025-3223, https://doi.org/10.5194/egusphere-2025-3223, 2025
Short summary
Short summary
Aerosol acidity affects aerosol composition and properties, and therefore climate, human health and ecosystems. We use summer and winter fine aerosol observations at 6 sites across Greece, and a thermodynamic model to calculate the spatial and seasonal variability of aerosol acidity. Aerosols were acidic to moderately acidic and more acidic during summer than winter. The importance of organics for aerosol acidity was small. Depending on location different factors controlled aerosol acidity.
Susanne M. C. Scholz, Vlassis A. Karydis, Georgios I. Gkatzelis, Hendrik Fuchs, Spyros N. Pandis, and Alexandra P. Tsimpidi
EGUsphere, https://doi.org/10.5194/egusphere-2025-2510, https://doi.org/10.5194/egusphere-2025-2510, 2025
Short summary
Short summary
We studied how pollution from cars and trucks contributes to tiny airborne particles that affect air quality and climate. These particles, called secondary organic aerosols, were often underestimated in global models. By improving how certain overlooked emissions from fuel use are represented in our model, we found that their impact is much larger than previously thought. Our results suggest that road traffic plays a far greater role in global air pollution than earlier estimates showed.
David Patoulias, Kalliopi Florou, and Spyros N. Pandis
Geosci. Model Dev., 18, 1103–1118, https://doi.org/10.5194/gmd-18-1103-2025, https://doi.org/10.5194/gmd-18-1103-2025, 2025
Short summary
Short summary
The effect of the assumed atmospheric nucleation mechanism on particle number concentrations and size distribution was investigated. Two quite different mechanisms involving sulfuric acid and ammonia or a biogenic organic vapor gave quite similar results which were consistent with measurements at 26 measurement stations across Europe. The number of larger particles that serve as cloud condensation nuclei showed little sensitivity to the assumed nucleation mechanism.
Andreas Aktypis, Dontavious J. Sippial, Christina N. Vasilakopoulou, Angeliki Matrali, Christos Kaltsonoudis, Andrea Simonati, Marco Paglione, Matteo Rinaldi, Stefano Decesari, and Spyros N. Pandis
Atmos. Chem. Phys., 24, 13769–13791, https://doi.org/10.5194/acp-24-13769-2024, https://doi.org/10.5194/acp-24-13769-2024, 2024
Short summary
Short summary
A dual-chamber system was deployed in two different environments (Po Valley, Italy, and Pertouli forest, Greece) to study the potential of ambient air directly injected into the chambers, to form secondary organic aerosol (SOA). In the Po Valley, the system reacts rapidly, forming large amounts of SOA, while in Pertouli the SOA formation chemistry appears to have been practically terminated before the beginning of most experiments, so there is little additional SOA formation potential left.
Romanos Foskinis, Ghislain Motos, Maria I. Gini, Olga Zografou, Kunfeng Gao, Stergios Vratolis, Konstantinos Granakis, Ville Vakkari, Kalliopi Violaki, Andreas Aktypis, Christos Kaltsonoudis, Zongbo Shi, Mika Komppula, Spyros N. Pandis, Konstantinos Eleftheriadis, Alexandros Papayannis, and Athanasios Nenes
Atmos. Chem. Phys., 24, 9827–9842, https://doi.org/10.5194/acp-24-9827-2024, https://doi.org/10.5194/acp-24-9827-2024, 2024
Short summary
Short summary
Analysis of modeling, in situ, and remote sensing measurements reveals the microphysical state of orographic clouds and their response to aerosol from the boundary layer and free troposphere. We show that cloud response to aerosol is robust, as predicted supersaturation and cloud droplet number levels agree with those determined from in-cloud measurements. The ability to determine if clouds are velocity- or aerosol-limited allows for novel model constraints and remote sensing products.
Olga Zografou, Maria Gini, Prodromos Fetfatzis, Konstantinos Granakis, Romanos Foskinis, Manousos Ioannis Manousakas, Fotios Tsopelas, Evangelia Diapouli, Eleni Dovrou, Christina N. Vasilakopoulou, Alexandros Papayannis, Spyros N. Pandis, Athanasios Nenes, and Konstantinos Eleftheriadis
Atmos. Chem. Phys., 24, 8911–8926, https://doi.org/10.5194/acp-24-8911-2024, https://doi.org/10.5194/acp-24-8911-2024, 2024
Short summary
Short summary
Characterization of PM1 and positive matrix factorization (PMF) source apportionment of organic and inorganic fractions were conducted at the high-altitude station (HAC)2. Cloud presence reduced PM1, affecting sulfate more than organics. Free-troposphere (FT) conditions showed more black carbon (eBC) than planetary boundary layer (PBL) conditions.
Olga Zografou, Christos Kaltsonoudis, Maria Gini, Angeliki Matrali, Elias Panagiotopoulos, Alexandros Lekkas, Dimitris Papanastasiou, Spyros N. Pandis, and Konstantinos Eleftheriadis
EGUsphere, https://doi.org/10.5194/egusphere-2024-2126, https://doi.org/10.5194/egusphere-2024-2126, 2024
Preprint archived
Short summary
Short summary
A novel charge transfer ionization orthogonal Time-of-Flight Mass Spectrometer (oToF-MS) was field evaluated for the first time during a field campaign at the suburban DEM station in Athens, Greece from May to August 2023 focusing on key ambient Volatile Organic Compounds (VOCs). The results demonstrate the strengths of the new instrument in performing online, real time measurements of ambient VOCs.
Alexandros Milousis, Alexandra P. Tsimpidi, Holger Tost, Spyros N. Pandis, Athanasios Nenes, Astrid Kiendler-Scharr, and Vlassis A. Karydis
Geosci. Model Dev., 17, 1111–1131, https://doi.org/10.5194/gmd-17-1111-2024, https://doi.org/10.5194/gmd-17-1111-2024, 2024
Short summary
Short summary
This study aims to evaluate the newly developed ISORROPIA-lite aerosol thermodynamic module within the EMAC model and explore discrepancies in global atmospheric simulations of aerosol composition and acidity by utilizing different aerosol phase states. Even though local differences were found in regions where the RH ranged from 20 % to 60 %, on a global scale the results are similar. Therefore, ISORROPIA-lite can be a reliable and computationally effective alternative to ISORROPIA II in EMAC.
Stella E. I. Manavi and Spyros N. Pandis
Atmos. Chem. Phys., 24, 891–909, https://doi.org/10.5194/acp-24-891-2024, https://doi.org/10.5194/acp-24-891-2024, 2024
Short summary
Short summary
Organic vapors of intermediate volatility have often been neglected as sources of atmospheric organic aerosol. In this work we use a new approach for their simulation and quantify the contribution of these compounds emitted by transportation sources (gasoline and diesel vehicles) to particulate matter over Europe. The estimated secondary organic aerosol levels are on average 60 % higher than predicted by previous approaches. However, these estimates are probably lower limits.
Andreas Aktypis, Christos Kaltsonoudis, David Patoulias, Panayiotis Kalkavouras, Angeliki Matrali, Christina N. Vasilakopoulou, Evangelia Kostenidou, Kalliopi Florou, Nikos Kalivitis, Aikaterini Bougiatioti, Konstantinos Eleftheriadis, Stergios Vratolis, Maria I. Gini, Athanasios Kouras, Constantini Samara, Mihalis Lazaridis, Sofia-Eirini Chatoutsidou, Nikolaos Mihalopoulos, and Spyros N. Pandis
Atmos. Chem. Phys., 24, 65–84, https://doi.org/10.5194/acp-24-65-2024, https://doi.org/10.5194/acp-24-65-2024, 2024
Short summary
Short summary
Extensive continuous particle number size distribution measurements took place during two summers (2020 and 2021) at 11 sites in Greece for the investigation of the frequency and the spatial extent of new particle formation. The frequency during summer varied from close to zero in southwestern Greece to more than 60 % in the northern, central, and eastern regions. The spatial variability can be explained by the proximity of the sites to coal-fired power plants and agricultural areas.
Stylianos Kakavas, Spyros N. Pandis, and Athanasios Nenes
Atmos. Chem. Phys., 23, 13555–13564, https://doi.org/10.5194/acp-23-13555-2023, https://doi.org/10.5194/acp-23-13555-2023, 2023
Short summary
Short summary
Water uptake from organic species in aerosol can affect the partitioning of semi-volatile inorganic compounds but are not considered in global and chemical transport models. We address this with a version of the PM-CAMx model that considers such organic water effects and use it to carry out 1-year aerosol simulations over the continental US. We show that such organic water impacts can increase dry PM1 levels by up to 2 μg m-3 when RH levels and PM1 concentrations are high.
Amir Yazdani, Satoshi Takahama, John K. Kodros, Marco Paglione, Mauro Masiol, Stefania Squizzato, Kalliopi Florou, Christos Kaltsonoudis, Spiro D. Jorga, Spyros N. Pandis, and Athanasios Nenes
Atmos. Chem. Phys., 23, 7461–7477, https://doi.org/10.5194/acp-23-7461-2023, https://doi.org/10.5194/acp-23-7461-2023, 2023
Short summary
Short summary
Organic aerosols directly emitted from wood and pellet stove combustion are found to chemically transform (approximately 15 %–35 % by mass) under daytime aging conditions simulated in an environmental chamber. A new marker for lignin-like compounds is found to degrade at a different rate than previously identified biomass burning markers and can potentially provide indication of aging time in ambient samples.
Petro Uruci, Dontavious Sippial, Anthoula Drosatou, and Spyros N. Pandis
Atmos. Meas. Tech., 16, 3155–3172, https://doi.org/10.5194/amt-16-3155-2023, https://doi.org/10.5194/amt-16-3155-2023, 2023
Short summary
Short summary
In this work we develop an algorithm for the synthesis of the measurements performed in atmospheric simulation chambers regarding the formation of secondary organic aerosol (SOA). Novel features of the algorithm are its ability to use measurements of SOA yields, thermodenuders, and isothermal dilution; its estimation of parameters that can be used directly in atmospheric chemical transport models; and finally its estimates of the uncertainty in SOA formation yields.
Christina N. Vasilakopoulou, Kalliopi Florou, Christos Kaltsonoudis, Iasonas Stavroulas, Nikolaos Mihalopoulos, and Spyros N. Pandis
Atmos. Meas. Tech., 16, 2837–2850, https://doi.org/10.5194/amt-16-2837-2023, https://doi.org/10.5194/amt-16-2837-2023, 2023
Short summary
Short summary
The offline aerosol mass spectrometry technique is a useful tool for the source apportionment of organic aerosol in areas and periods during which an aerosol mass spectrometer is not available. In this work, an improved offline technique was developed and evaluated in an effort to capture most of the partially soluble and insoluble organic aerosol material, reducing the uncertainty of the corresponding source apportionment significantly.
Spiro D. Jorga, Kalliopi Florou, David Patoulias, and Spyros N. Pandis
Atmos. Chem. Phys., 23, 85–97, https://doi.org/10.5194/acp-23-85-2023, https://doi.org/10.5194/acp-23-85-2023, 2023
Short summary
Short summary
We take advantage of this unexpected low, new particle formation frequency in Greece and use a dual atmospheric simulation chamber system with starting point ambient air in an effort to gain insight about the chemical species that is limiting nucleation in this area. A potential nucleation precursor, ammonia, was added in one of the chambers while the other one was used as a reference. The addition of ammonia assisted new particle formation in almost 50 % of the experiments conducted.
Brian T. Dinkelacker, Pablo Garcia Rivera, Ioannis Kioutsioukis, Peter J. Adams, and Spyros N. Pandis
Geosci. Model Dev., 15, 8899–8912, https://doi.org/10.5194/gmd-15-8899-2022, https://doi.org/10.5194/gmd-15-8899-2022, 2022
Short summary
Short summary
The performance of a chemical transport model in reproducing PM2.5 concentrations and composition was evaluated at the finest scale using measurements from regulatory sites as well as a network of low-cost monitors. Total PM2.5 mass is reproduced well by the model during the winter when compared to regulatory measurements, but in the summer PM2.5 is underpredicted, mainly due to difficulties in reproducing regional secondary organic aerosol levels.
Christina Vasilakopoulou, Iasonas Stavroulas, Nikolaos Mihalopoulos, and Spyros N. Pandis
Atmos. Meas. Tech., 15, 6419–6431, https://doi.org/10.5194/amt-15-6419-2022, https://doi.org/10.5194/amt-15-6419-2022, 2022
Short summary
Short summary
Offline aerosol mass spectrometer (AMS) measurements can provide valuable information about ambient organic aerosols when online AMS measurements are not available. In this study, we examine whether and how the low time resolution (usually 24 h) of the offline technique affects source apportionment results. We concluded that use of the daily averages resulted in estimated average contributions that were within 8 % of the total OA compared with the high-resolution analysis.
Stella E. I. Manavi and Spyros N. Pandis
Geosci. Model Dev., 15, 7731–7749, https://doi.org/10.5194/gmd-15-7731-2022, https://doi.org/10.5194/gmd-15-7731-2022, 2022
Short summary
Short summary
The paper describes the first step towards the development of a simulation framework for the chemistry and secondary organic aerosol production of intermediate-volatility organic compounds (IVOCs). These compounds can be a significant source of organic particulate matter. Our approach treats IVOCs as lumped compounds that retain their chemical characteristics. Estimated IVOC emissions from road transport were a factor of 8 higher than emissions used in previous applications.
Aristeidis Voliotis, Mao Du, Yu Wang, Yunqi Shao, Thomas J. Bannan, Michael Flynn, Spyros N. Pandis, Carl J. Percival, M. Rami Alfarra, and Gordon McFiggans
Atmos. Chem. Phys., 22, 13677–13693, https://doi.org/10.5194/acp-22-13677-2022, https://doi.org/10.5194/acp-22-13677-2022, 2022
Short summary
Short summary
The addition of a low-yield precursor to the reactive mixture of aVOC and bVOC can increase or decrease the SOA volatility that is system-dependent. Therefore, the SOA volatility of the mixtures cannot always be predicted based on the additivity. In complex mixtures the formation of lower-volatility products likely outweighs the formation of products with higher volatility. The unique products of each mixture contribute significantly to the signal, suggesting interactions can be important.
Brian T. Dinkelacker, Pablo Garcia Rivera, Ksakousti Skyllakou, Peter J. Adams, and Spyros N. Pandis
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2022-648, https://doi.org/10.5194/acp-2022-648, 2022
Revised manuscript not accepted
Short summary
Short summary
A number of factors have influenced the biogenic secondary organic aerosol (SOA) levels in the southeastern US from 2001 to 2010. The increases in temperature have led to an increase of the emissions of biogenic volatile organic compounds by trees and a corresponding increase of the SOA. However, this increase has been balanced by the reductions in the anthropogenic emissions of organic gases and particulate matter as well as of the oxides of nitrogen keeping the biogenic SOA roughly constant.
Pablo Garcia Rivera, Brian T. Dinkelacker, Ioannis Kioutsioukis, Peter J. Adams, and Spyros N. Pandis
Atmos. Chem. Phys., 22, 2011–2027, https://doi.org/10.5194/acp-22-2011-2022, https://doi.org/10.5194/acp-22-2011-2022, 2022
Short summary
Short summary
The contribution of various pollution sources to the variability of fine PM in an urban area was examined using as an example the city of Pittsburgh. Biomass burning aerosol shows the largest variability during the winter with local maxima within the city and in the suburbs. During both periods the largest contributing source to the average PM2.5 is particles from outside the modeling domain. The average population-weighted PM2.5 concentration does not change significantly with resolution.
David Patoulias and Spyros N. Pandis
Atmos. Chem. Phys., 22, 1689–1706, https://doi.org/10.5194/acp-22-1689-2022, https://doi.org/10.5194/acp-22-1689-2022, 2022
Short summary
Short summary
Our simulations indicate that the recently identified production and subsequent condensation effect of extremely low-volatility organic compounds have a smaller-than-expected effect on the total concentration of atmospheric particles. On the other hand, the oxidation of intermediate-volatility organic compounds leads to decreases in the ultrafine-particle concentrations. These results improve our understanding of the links between secondary organic aerosol formation and ultrafine particles.
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
Short summary
Short summary
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.
Ksakousti Skyllakou, Pablo Garcia Rivera, Brian Dinkelacker, Eleni Karnezi, Ioannis Kioutsioukis, Carlos Hernandez, Peter J. Adams, and Spyros N. Pandis
Atmos. Chem. Phys., 21, 17115–17132, https://doi.org/10.5194/acp-21-17115-2021, https://doi.org/10.5194/acp-21-17115-2021, 2021
Short summary
Short summary
Significant reductions in pollutant emissions took place in the US from 1990 to 2010. The reductions in sulfur dioxide emissions from electric-generating units have dominated the reductions in fine particle mass. The reductions in transportation emissions have led to a 30 % reduction of elemental concentrations and of organic particulate matter by a factor of 3. On the other hand, changes in biomass burning and biogenic secondary organic aerosol have been modest.
Spiro D. Jorga, Kalliopi Florou, Christos Kaltsonoudis, John K. Kodros, Christina Vasilakopoulou, Manuela Cirtog, Axel Fouqueau, Bénédicte Picquet-Varrault, Athanasios Nenes, and Spyros N. Pandis
Atmos. Chem. Phys., 21, 15337–15349, https://doi.org/10.5194/acp-21-15337-2021, https://doi.org/10.5194/acp-21-15337-2021, 2021
Short summary
Short summary
We test the hypothesis that significant secondary organic aerosol production can take place even during winter nights through the oxidation of the emitted organic vapors by the nitrate radicals produced during the reaction of ozone and nitrogen oxides. Our experiments, using as a starting point the ambient air of an urban area with high biomass burning activity, demonstrate that, even with sunlight, there is 20 %–70 % additional organic aerosol formed in a few hours.
Aristeidis Voliotis, Yu Wang, Yunqi Shao, Mao Du, Thomas J. Bannan, Carl J. Percival, Spyros N. Pandis, M. Rami Alfarra, and Gordon McFiggans
Atmos. Chem. Phys., 21, 14251–14273, https://doi.org/10.5194/acp-21-14251-2021, https://doi.org/10.5194/acp-21-14251-2021, 2021
Short summary
Short summary
Secondary organic aerosol (SOA) formation from mixtures of volatile precursors can be affected by the molecular interactions of the products. Composition and volatility measurements of SOA formed from mixtures of anthropogenic and biogenic precursors reveal processes that can increase or decrease the SOA volatility. The unique products of the mixture were more oxygenated and less volatile than those from either precursor. Analytical context is provided to explore the SOA volatility in mixtures.
Athanasios Nenes, Spyros N. Pandis, Maria Kanakidou, Armistead G. Russell, Shaojie Song, Petros Vasilakos, and Rodney J. Weber
Atmos. Chem. Phys., 21, 6023–6033, https://doi.org/10.5194/acp-21-6023-2021, https://doi.org/10.5194/acp-21-6023-2021, 2021
Short summary
Short summary
Ecosystems and air quality are affected by the dry deposition of inorganic reactive nitrogen (Nr, the sum of ammonium and nitrate). Its large variability is driven by the large difference in deposition velocity of N when in the gas or particle phase. Here we show that aerosol liquid water and acidity, by affecting gas–particle partitioning, modulate the dry deposition velocity of NH3, HNO3, and Nr worldwide. These effects explain the rapid accumulation of nitrate aerosol during haze events.
Georgia N. Theodoritsi, Giancarlo Ciarelli, and Spyros N. Pandis
Geosci. Model Dev., 14, 2041–2055, https://doi.org/10.5194/gmd-14-2041-2021, https://doi.org/10.5194/gmd-14-2041-2021, 2021
Short summary
Short summary
Two schemes based on the volatility basis set were used for the simulation of biomass burning organic aerosol (bbOA) in the continental US. The first is the default scheme of the PMCAMx-SR model, and the second is a recently developed scheme based on laboratory experiments. The alternative bbOA scheme predicts much higher concentrations. The default scheme performed better during summer and fall, while the alternative scheme was a little better during spring.
Weiqi Xu, Chun Chen, Yanmei Qiu, Ying Li, Zhiqiang Zhang, Eleni Karnezi, Spyros N. Pandis, Conghui Xie, Zhijie Li, Jiaxing Sun, Nan Ma, Wanyun Xu, Pingqing Fu, Zifa Wang, Jiang Zhu, Douglas R. Worsnop, Nga Lee Ng, and Yele Sun
Atmos. Chem. Phys., 21, 5463–5476, https://doi.org/10.5194/acp-21-5463-2021, https://doi.org/10.5194/acp-21-5463-2021, 2021
Short summary
Short summary
Here aerosol volatility and viscosity at a rural site (Gucheng) and an urban site (Beijing) in the North China Plain (NCP) were investigated in summer and winter. Our results showed that organic aerosol (OA) in winter in the NCP is more volatile than that in summer due to enhanced primary emissions from coal combustion and biomass burning. We also found that OA existed mainly as a solid in winter in Beijing but as semisolids in Beijing in summer and Gucheng in winter.
Stylianos Kakavas, David Patoulias, Maria Zakoura, Athanasios Nenes, and Spyros N. Pandis
Atmos. Chem. Phys., 21, 799–811, https://doi.org/10.5194/acp-21-799-2021, https://doi.org/10.5194/acp-21-799-2021, 2021
Short summary
Short summary
The dependence of aerosol acidity on particle size, location, and altitude over Europe during a summertime period is investigated. Differences of up to 1–4 pH units are predicted between sub- and supermicron particles in northern and southern Europe. Particles of all sizes become increasingly acidic with altitude (0.5–2.5 pH units decrease over 2.5 km). The size-dependent pH differences carry important implications for pH-sensitive processes in the aerosol.
Cited articles
Argyropoulou, G., Patoulias, D., and Pandis, S. N.: Exploring the potential for continuous measurement of ultrafine particle mass concentration (PM0.1) based on measurements of particle number concentration above 50 nm (N50), Aerosol Science and Technology, 57, 1117–1127, https://doi.org/10.1080/02786826.2023.2249075, 2023.
Argyropoulou, G. A., Kaltsonoudis, C., Patoulias, D., and Pandis, S. N.: Novel method for the continuous mass concentration measurement of ultrafine particles (PM0.1) with a water-based condensation particle counter (CPC), Aerosol Science and Technology, 1–12, https://doi.org/10.1080/02786826.2024.2368196, 2024.
Baranizadeh, E., Murphy, B. N., Julin, J., Falahat, S., Reddington, C. L., Arola, A., Ahlm, L., Mikkonen, S., Fountoukis, C., Patoulias, D., Minikin, A., Hamburger, T., Laaksonen, A., Pandis, S. N., Vehkamäki, H., Lehtinen, K. E. J., and Riipinen, I.: Implementation of state-of-the-art ternary new-particle formation scheme to the regional chemical transport model PMCAMx-UF in Europe, Geosci. Model Dev., 9, 2741–2754, https://doi.org/10.5194/gmd-9-2741-2016, 2016.
Colella, P. and Woodward, P. R.: The Piecewise Parabolic Method (PPM) for gas-dynamical simulations, J. Comput. Phys., 54, 174–201, https://doi.org/10.1016/0021-9991(84)90143-8, 1984.
del Águila, A., Sorribas, M., Lyamani, H., Titos, G., Olmo, F. J., Arruda-Moreira, G., Yela, M., and Alados-Arboledas, L.: Sources and physicochemical characteristics of submicron aerosols during three intensive campaigns in Granada (Spain), Atmos. Res., 213, 398–410, https://doi.org/10.1016/j.atmosres.2018.06.004, 2018.
Delfino, R. J., Sioutas, C., and Malik, S.: Potential role of ultrafine particles in associations between airborne particle mass and cardiovascular health, Environ. Health Perspect., 113, 934, https://doi.org/10.1289/EHP.7938, 2005.
ENVIRON: Environ: User's guide to the comprehensive air quality model with extensions (CAMx), version 4.02, Novato, CA, https://www.camx.com/download/source/ (last access: 13 November 2025), 2003.
EPA (Environmental Protection Agency, United States): Integrated science assessment (ISA) for particulate matter, Washington, DC: US Environmental Protection Agency, https://www.epa.gov/isa/integrated-science-assessment-isa-particulate-matter (last access: 13 November 2025), 2019.
EPA (Environmental Protection Agency, United States): Particle pollution exposure, US Environmental Protection Agency, https://www.epa.gov/pmcourse/particle-pollution-exposure, last access: 13 November 2025.
Fahey, K. M. and Pandis, S. N.: Optimizing model performance: variable size resolution in cloud chemistry modeling, Atmos. Environ., 35, 4471–4478, https://doi.org/10.1016/S1352-2310(01)00224-2, 2001.
Gaydos, T. M., Pinder, R., Koo, B., Fahey, K. M., Yarwood, G., and Pandis, S. N.: Development and application of a three-dimensional aerosol chemical transport model, PMCAMx, Atmos. Environ., 41, 2594–2611, https://doi.org/10.1016/j.atmosenv.2006.11.034, 2007.
Guenther, A., Karl, T., Harley, P., Wiedinmyer, C., Palmer, P. I., and Geron, C.: Estimates of global terrestrial isoprene emissions using MEGAN (Model of Emissions of Gases and Aerosols from Nature), Atmos. Chem. Phys., 6, 3181–3210, https://doi.org/10.5194/acp-6-3181-2006, 2006.
HEI Report: Review panel on ultrafine particles, Understanding the health effects of ambient ultrafine particles HEI Perspectives 3Health Effects Institute, Boston, MA, 122, https://www.healtheffects.org/system/files/Perspectives3.pdf (last access: 13 November 2025), 2013.
Hu, J., Zhang, H., Chen, S., Ying, Q., Wiedinmyer, C., Vandenberghe, F., and Kleeman, M. J.: Identifying PM2.5 and PM0.1 sources for epidemiological studies in California, Environ. Sci. Technol., 48, 4980–4990, https://doi.org/10.1021/ES404810Z, 2014a.
Hu, J., Zhang, H., Chen, S. H., Wiedinmyer, C., Vandenberghe, F., Ying, Q., and Kleeman, M. J.: Predicting primary PM2.5 and PM0.1 trace composition for epidemiological studies in California, Environ. Sci. Technol., 48, 4971–4979, 2014b.
Hu, J., Jathar, S., Zhang, H., Ying, Q., Chen, S.-H., Cappa, C. D., and Kleeman, M. J.: Long-term particulate matter modeling for health effect studies in California – Part 2: Concentrations and sources of ultrafine organic aerosols, Atmos. Chem. Phys., 17, 5379–5391, https://doi.org/10.5194/acp-17-5379-2017, 2017.
Hughes, L. S., Cass, G. R., Gone, J., Ames, M., and Olmez, I.: Physical and chemical characterization of atmospheric ultrafine particles in the Los Angeles area, Environ. Sci. Technol., 32, 1153–1161, 1998.
Jung, J. G., Fountoukis, C., Adams, P. J., and Pandis, S. N.: Simulation of in situ ultrafine particle formation in the eastern United States using PMCAMx-UF, J. Geophys. Res., 115, https://doi.org/10.1029/2009JD012313, 2010.
Kleeman, M. J., Riddle, S. G., Robert, M. A., Jakober, C. A., Fine, P. M., Hays, M. D., Schauer, J. J., and Hannigan, M. P.: Source apportionment of fine (PM1.8) and ultrafine (PM0.1) airborne particulate matter during a severe winter pollution episode, Environ. Sci. Technol., 43, 272–279, 2009.
Kulmala, M., Asmi, A., Lappalainen, H. K., Baltensperger, U., Brenguier, J.-L., Facchini, M. C., Hansson, H.-C., Hov, Ø., O'Dowd, C. D., Pöschl, U., Wiedensohler, A., Boers, R., Boucher, O., de Leeuw, G., Denier van der Gon, H. A. C., Feichter, J., Krejci, R., Laj, P., Lihavainen, H., Lohmann, U., McFiggans, G., Mentel, T., Pilinis, C., Riipinen, I., Schulz, M., Stohl, A., Swietlicki, E., Vignati, E., Alves, C., Amann, M., Ammann, M., Arabas, S., Artaxo, P., Baars, H., Beddows, D. C. S., Bergström, R., Beukes, J. P., Bilde, M., Burkhart, J. F., Canonaco, F., Clegg, S. L., Coe, H., Crumeyrolle, S., D'Anna, B., Decesari, S., Gilardoni, S., Fischer, M., Fjaeraa, A. M., Fountoukis, C., George, C., Gomes, L., Halloran, P., Hamburger, T., Harrison, R. M., Herrmann, H., Hoffmann, T., Hoose, C., Hu, M., Hyvärinen, A., Hõrrak, U., Iinuma, Y., Iversen, T., Josipovic, M., Kanakidou, M., Kiendler-Scharr, A., Kirkevåg, A., Kiss, G., Klimont, Z., Kolmonen, P., Komppula, M., Kristjánsson, J.-E., Laakso, L., Laaksonen, A., Labonnote, L., Lanz, V. A., Lehtinen, K. E. J., Rizzo, L. V., Makkonen, R., Manninen, H. E., McMeeking, G., Merikanto, J., Minikin, A., Mirme, S., Morgan, W. T., Nemitz, E., O'Donnell, D., Panwar, T. S., Pawlowska, H., Petzold, A., Pienaar, J. J., Pio, C., Plass-Duelmer, C., Prévôt, A. S. H., Pryor, S., Reddington, C. L., Roberts, G., Rosenfeld, D., Schwarz, J., Seland, Ø., Sellegri, K., Shen, X. J., Shiraiwa, M., Siebert, H., Sierau, B., Simpson, D., Sun, J. Y., Topping, D., Tunved, P., Vaattovaara, P., Vakkari, V., Veefkind, J. P., Visschedijk, A., Vuollekoski, H., Vuolo, R., Wehner, B., Wildt, J., Woodward, S., Worsnop, D. R., van Zadelhoff, G.-J., Zardini, A. A., Zhang, K., van Zyl, P. G., Kerminen, V.-M., S Carslaw, K., and Pandis, S. N.: General overview: European Integrated project on Aerosol Cloud Climate and Air Quality interactions (EUCAARI) – integrating aerosol research from nano to global scales, Atmos. Chem. Phys., 11, 13061–13143, https://doi.org/10.5194/acp-11-13061-2011, 2011.
Kuwayama, T., Ruehl, C. R., and Kleeman, M. J.: Daily trends and source apportionment of ultrafine particulate mass (PM0.1) over an annual cycle in a typical California city, Environ. Sci. Technol., 47, 13957–13966, 2013.
Kwon, H. S., Ryu, M. H., and Carlsten, C.: Ultrafine particles: unique physicochemical properties relevant to health and disease, Experimental & Molecular Medicine, 52, 318–328, https://doi.org/10.1038/s12276-020-0405-1, 2020.
Laurent, O., Hu, J., Li, L., Kleeman, M. J., Bartell, S. M., Cockburn, M., Escobedo, L., and Wu, J.: A statewide nested case–Control study of preterm birth and air pollution by source and composition: California, 2001-2008, Environ Health Perspect., 124, 1479–1486, 2016.
Merikanto, J., Spracklen, D. V., Mann, G. W., Pickering, S. J., and Carslaw, K. S.: Impact of nucleation on global CCN, Atmos. Chem. Phys., 9, 8601–8616, https://doi.org/10.5194/acp-9-8601-2009, 2009.
Murphy, B. N., Sonntag, D., Seltzer, K. M., Pye, H. O. T., Allen, C., Murray, E., Toro, C., Gentner, D. R., Huang, C., Jathar, S., Li, L., May, A. A., and Robinson, A. L.: Reactive organic carbon air emissions from mobile sources in the United States, Atmos. Chem. Phys., 23, 13469–13483, https://doi.org/10.5194/acp-23-13469-2023, 2023.
Odman, M. and Ingram, C.: Multiscale Air Quality Simulation Platform (MAQSIP): Source Code Documentation and Validation, Tech. Rep. ENV-96TR002v1, MCNC North Carolina Supercomputing Center, Research Triangle Park, NC, 1996.
O'Dowd, C. D., Langmann, B., Varghese, S., Scannell, C., Ceburnis, D., and Facchini, M. C.: A combined organic-inorganic sea-spray source function, Geophys. Res. Lett., 35, https://doi.org/10.1029/2007GL030331, 2008.
Ohlwein, S., Kappeler, R., Kutlar Joss, M., Künzli, N., and Hoffmann, B.: Health effects of ultrafine particles: a systematic literature review update of epidemiological evidence, Int. J. Public Health, 64, 547–559, https://doi.org/10.1007/S00038-019-01202-7, 2019.
Ostro, B., Hu, J., Goldberg, D., Reynolds, P., Hertz, A., Bernstein, L., and Kleeman, M. J.: Associations of mortality with long-term exposures to fine and ultrafine particles, species and sources: Results from the California teachers study cohort, Environ Health Perspect., 123, 549–556, 2015.
Patoulias, D. and Pandis, S. N.: Simulation of the effects of low-volatility organic compounds on aerosol number concentrations in Europe, Atmos. Chem. Phys., 22, 1689–1706, https://doi.org/10.5194/acp-22-1689-2022, 2022.
Patoulias, D., Fountoukis, C., Riipinen, I., and Pandis, S. N.: The role of organic condensation on ultrafine particle growth during nucleation events, Atmos. Chem. Phys., 15, 6337–6350, https://doi.org/10.5194/acp-15-6337-2015, 2015.
Patoulias, D., Fountoukis, C., Riipinen, I., Asmi, A., Kulmala, M., and Pandis, S. N.: Simulation of the size-composition distribution of atmospheric nanoparticles over Europe, Atmos. Chem. Phys., 18, 13639–13654, https://doi.org/10.5194/acp-18-13639-2018, 2018.
Phairuang, W., Inerb, M., Hata, M., and Furuuchi, M.: Characteristics of trace elements bound to ambient nanoparticles (PM0.1) and a health risk assessment in southern Thailand, J. Hazard. Mater., 425, 127986, https://doi.org/10.1016/j.jhazmat.2021.127986, 2022.
Putaud, J. P., Van Dingenen, R., Alastuey, A., Bauer, H., Birmili, W., Cyrys, J., Flentje, H., Fuzzi, S., Gehrig, R., Hansson, H. C., Harrison, R. M., Herrmann, H., Hitzenberger, R., Hüglin, C., Jones, A. M., Kasper-Giebl, A., Kiss, G., Kousa, A., Kuhlbusch, T. A. J., Löschau, G., Maenhaut, W., Molnar, A., Moreno, T., Pekkanen, J., Perrino, C., Pitz, M., Puxbaum, H., Querol, X., Rodriguez, S., Salma, I., Schwarz, J., Smolik, J., Schneider, J., Spindler, G., ten Brink, H., Tursic, J., Viana, M., Wiedensohler, A., and Raes, F.: A European aerosol phenomenology – 3: Physical and chemical characteristics of particulate matter from 60 rural, urban, and kerbside sites across Europe, Atmos. Environ., 44, 1308–1320, https://doi.org/10.1016/J.ATMOSENV.2009.12.011, 2010.
Schraufnagel, D. E.: The health effects of ultrafine particles, Exp. Mol. Med., 52, 311–317, https://doi.org/10.1038/S12276-020-0403-3, 2020.
Seinfeld, J. H. and Pandis, S. N.: Atmospheric Chemistry and Physics of Air Pollution- From Air Pollution to Climate Change, 2nd Edition, John Wiley & Sons, Hoboken, New Jersey, 2006.
Sioutas, C., Delfino, R. J., and Singh, M.: Exposure assessment for atmospheric ultrafine particles (UFPs) and implications in epidemiologic research, Environ Health Perspect., 113, 947–955, https://doi.org/10.1289/EHP.7939, 2005.
Skamarock, W. C., Klemp, J. B., Dudhi, J., Gill, D. O., Barker, D. M., Duda, M. G., Huang, X.-Y., Wang, W., and Powers, J. G.: A Description of the Advanced Research WRF Version 2, NCAR Technical Note NCAR/TN–468+STR, National Center for Atmospheric Research, Boulder, Colorado, USA, 113, https://doi.org/10.5065/D6DZ069T, 2005.
Skyllakou, K., Murphy, B. N., Megaritis, A. G., Fountoukis, C., and Pandis, S. N.: Contributions of local and regional sources to fine PM in the megacity of Paris, Atmos. Chem. Phys., 14, 2343–2352, https://doi.org/10.5194/acp-14-2343-2014, 2014.
Slinn, S. A. and Slinn, W. G. N.: Predictions for particle deposition on natural waters, Atmos. Environ., 14, 1013–1016, https://doi.org/10.1016/0004-6981(80)90032-3, 1980.
Sofiev, M., Lanne, M., Vankevich, R., Prank, M., Karppinen, A., and Kukkonen, J.: Impact of wild-land fires on European air quality in 2006–2008, WIT Transactions on Ecology and the Environment, 119, 353–361, https://doi.org/10.2495/FIVA080351, 2008a.
Sofiev, M., Vankevich, R., Lanne, M., Koskinen, J., and Kukkonen, J.: On integration of a fire assimilation system and a chemical transport model for near-real time monitoring of the impact of wild-land fires on atmospheric composition and air quality, WIT Transactions on Ecology and the Environment, 119, 343–351, https://doi.org/10.2495/FIVA080341, 2008b.
Venecek, M. A., Yu, X., and Kleeman, M. J.: Predicted ultrafine particulate matter source contribution across the continental United States during summertime air pollution events, Atmos. Chem. Phys., 19, 9399–9412, https://doi.org/10.5194/acp-19-9399-2019, 2019.
Wang, M. and Penner, J. E.: Aerosol indirect forcing in a global model with particle nucleation, Atmos. Chem. Phys., 9, 239–260, https://doi.org/10.5194/acp-9-239-2009, 2009.
Weichenthal, S., Olaniyan, T., Christidis, T., Lavigne, E., Hatzopoulou, M., Van Ryswyk, K., Tjepkema, M., and Burnett, R.: Within-city spatial variations in ambient ultrafine particle concentrations and incident brain tumors in adults, Epidemiology, 31, 177–183, 2020.
Wesely, M. L.: Parameterization of surface resistances to gaseous dry deposition in regional-scale numerical models, Atmos. Environ., 23, 1293–1304, https://doi.org/10.1016/0004-6981(89)90153-4, 1989.
Xue, J., Li, Y., Peppers, J., Wan, C., Kado, N. Y., Green, P. G., Young, T. M., and Kleeman, M. J.: Ultrafine particle emissions from natural gas, biogas, and biomethane combustion, Environ. Sci. Technol., 52, 13619–13628, 2018.
Xue, J., Xue, W., Sowlat, M. H., Sioutas, C., Lolinco, A., Hasson, A., and Kleeman, M. J.: Seasonal and annual source appointment of carbonaceous ultrafine particulate matter (PM0.1) in polluted California cities, Environ. Sci. Technol., 53, 39–49, 2019.
Xue, W. and Kleeman, M. J.: Comparison of size-resolved PM elements measured using aluminum foil and Teflon impaction substrates: Implications for ultrafine particle source apportionment and future sampling networks in California, Sci. Total Environ., 838, 156523, https://doi.org/10.1016/j.scitotenv.2022.156523, 2022.
Xue, W., Xue, J., Shirmohammadi, F., Sioutas, C., Lolinco, A., Hasson, A., and Kleeman, M. J.: Day-of-week patterns for ultrafine particulate matter components at four sites in California, Atmos. Environ., 222, 117088, https://doi.org/10.1016/j.atmosenv.2019.117088, 2020a.
Xue, W., Xue, J., Mousavi, A., Sioutas, C., and Kleeman, M. J.: Positive matrix factorization of ultrafine particle mass (PM0.1) at three sites in California, Sci. Total Environ., 715, 136902, https://doi.org/10.1016/j.scitotenv.2020.136902, 2020b.
Yu, F. and Luo, G.: Simulation of particle size distribution with a global aerosol model: contribution of nucleation to aerosol and CCN number concentrations, Atmos. Chem. Phys., 9, 7691–7710, https://doi.org/10.5194/acp-9-7691-2009, 2009.
Yu, X., Venecek, M., Kumar, A., Hu, J., Tanrikulu, S., Soon, S.-T., Tran, C., Fairley, D., and Kleeman, M. J.: Regional sources of airborne ultrafine particle number and mass concentrations in California, Atmos. Chem. Phys., 19, 14677–14702, https://doi.org/10.5194/acp-19-14677-2019, 2019.
Zhu, Y., Hinds, W. C., Kim, S., and Sioutas, C.: Concentration and size distribution of ultrafine particles near a major highway, J. Air. Waste. Manage. Assoc., 52, 1032–1042, https://doi.org/10.1080/10473289.2002.10470842, 2002.
Short summary
Predicted levels of ultrafine particle mass (PM0.1) vary substantially over Europe with higher values in the summer than in the winter. In summer, PM0.1 was mostly comprised of sulfate (38 %) and secondary organics (32 %). During winter the sulfate fraction increased to 47 % and primary organics contributed 23 %. Correlations between PM0.1 and the regulated PM2.5 were low. This suggests that there are significant differences between the dominant sources and processes of PM0.1 and PM2.5.
Predicted levels of ultrafine particle mass (PM0.1) vary substantially over Europe with higher...
Altmetrics
Final-revised paper
Preprint