Atmospheric Chemistry and Physics (Feb 2024)
Elucidating the mechanisms of atmospheric new particle formation in the highly polluted Po Valley, Italy
- J. Cai,
- J. Sulo,
- Y. Gu,
- S. Holm,
- R. Cai,
- S. Thomas,
- A. Neuberger,
- A. Neuberger,
- F. Mattsson,
- F. Mattsson,
- M. Paglione,
- S. Decesari,
- M. Rinaldi,
- R. Yin,
- D. Aliaga,
- W. Huang,
- Y. Li,
- Y. Li,
- Y. Gramlich,
- Y. Gramlich,
- G. Ciarelli,
- L. Quéléver,
- N. Sarnela,
- K. Lehtipalo,
- K. Lehtipalo,
- N. Zannoni,
- C. Wu,
- W. Nie,
- J. Kangasluoma,
- C. Mohr,
- C. Mohr,
- M. Kulmala,
- M. Kulmala,
- M. Kulmala,
- Q. Zha,
- Q. Zha,
- D. Stolzenburg,
- D. Stolzenburg,
- F. Bianchi
Affiliations
- J. Cai
- Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, 00014 Helsinki, Finland
- J. Sulo
- Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, 00014 Helsinki, Finland
- Y. Gu
- Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, 00014 Helsinki, Finland
- S. Holm
- Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, 00014 Helsinki, Finland
- R. Cai
- Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, 00014 Helsinki, Finland
- S. Thomas
- Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, 00014 Helsinki, Finland
- A. Neuberger
- Department of Environmental Science, Stockholm University, 11418 Stockholm, Sweden
- A. Neuberger
- Bolin Centre for Climate Research, 11418 Stockholm, Sweden
- F. Mattsson
- Department of Environmental Science, Stockholm University, 11418 Stockholm, Sweden
- F. Mattsson
- Bolin Centre for Climate Research, 11418 Stockholm, Sweden
- M. Paglione
- National Research Council of Italy – Institute of Atmospheric Sciences and Climate (CNR-ISAC), 40129 Bologna, Italy
- S. Decesari
- National Research Council of Italy – Institute of Atmospheric Sciences and Climate (CNR-ISAC), 40129 Bologna, Italy
- M. Rinaldi
- National Research Council of Italy – Institute of Atmospheric Sciences and Climate (CNR-ISAC), 40129 Bologna, Italy
- R. Yin
- Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, 00014 Helsinki, Finland
- D. Aliaga
- Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, 00014 Helsinki, Finland
- W. Huang
- Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, 00014 Helsinki, Finland
- Y. Li
- Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, 00014 Helsinki, Finland
- Y. Li
- Laboratory of Atmospheric and Earth System Research, School of Atmospheric Sciences, Nanjing University, Nanjing, 210023, China
- Y. Gramlich
- Department of Environmental Science, Stockholm University, 11418 Stockholm, Sweden
- Y. Gramlich
- Bolin Centre for Climate Research, 11418 Stockholm, Sweden
- G. Ciarelli
- Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, 00014 Helsinki, Finland
- L. Quéléver
- Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, 00014 Helsinki, Finland
- N. Sarnela
- Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, 00014 Helsinki, Finland
- K. Lehtipalo
- Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, 00014 Helsinki, Finland
- K. Lehtipalo
- Finnish Meteorological Institute, 00560 Helsinki, Finland
- N. Zannoni
- National Research Council of Italy – Institute of Atmospheric Sciences and Climate (CNR-ISAC), 40129 Bologna, Italy
- C. Wu
- Department of Chemistry and Molecular Biology, Atmospheric Science, University of Gothenburg, 41296 Gothenburg, Sweden
- W. Nie
- Laboratory of Atmospheric and Earth System Research, School of Atmospheric Sciences, Nanjing University, Nanjing, 210023, China
- J. Kangasluoma
- Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, 00014 Helsinki, Finland
- C. Mohr
- Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland
- C. Mohr
- Department of Environmental System Science, ETH Zurich, 8092 Zurich, Switzerland
- M. Kulmala
- Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, 00014 Helsinki, Finland
- M. Kulmala
- Laboratory of Atmospheric and Earth System Research, School of Atmospheric Sciences, Nanjing University, Nanjing, 210023, China
- M. Kulmala
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
- Q. Zha
- Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, 00014 Helsinki, Finland
- Q. Zha
- Laboratory of Atmospheric and Earth System Research, School of Atmospheric Sciences, Nanjing University, Nanjing, 210023, China
- D. Stolzenburg
- Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, 00014 Helsinki, Finland
- D. Stolzenburg
- Institute for Materials Chemistry, TU Wien, 1060 Vienna, Austria
- F. Bianchi
- Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, 00014 Helsinki, Finland
- DOI
- https://doi.org/10.5194/acp-24-2423-2024
- Journal volume & issue
-
Vol. 24
pp. 2423 – 2441
Abstract
New particle formation (NPF) is a major source of aerosol particles and cloud condensation nuclei in the troposphere, playing an important role in both air quality and climate. Frequent NPF events have been observed in heavily polluted urban environments, contributing to the aerosol number concentration by a significant amount. The Po Valley region in northern Italy has been characterized as a hotspot for high aerosol loadings and frequent NPF events in southern Europe. However, the mechanisms of NPF and growth in this region are not completely understood. In this study, we conducted a continuous 2-month measurement campaign with state-of-the-art instruments to elucidate the NPF and growth mechanisms in northern Italy. Our results demonstrate that frequent NPF events (66 % of all days during the measurement campaign) are primarily driven by abundant sulfuric acid (8.5×106 cm−3) and basic molecules in this area. In contrast, oxygenated organic molecules from the atmospheric oxidation of volatile organic compounds (VOCs) appear to play a minor role in the initial cluster formation but contribute significantly to the consecutive growth process. Regarding alkaline molecules, amines are insufficient to stabilize all sulfuric acid clusters in the Po Valley. Ion cluster measurements and kinetic models suggest that ammonia (10 ppb) must therefore also play a role in the nucleation process. Generally, the high formation rates of sub-2 nm particles (87 cm−3 s−1) and nucleation-mode growth rates (5.1 nm h−1) as well as the relatively low condensational sink (8.9×10-3 s−1) will result in a high survival probability for newly formed particles, making NPF crucial for the springtime aerosol number budget. Our results also indicate that reducing key pollutants, such as SO2, amine and NH3, could help to substantially decrease the particle number concentrations in the Po Valley region.