Conference Agenda
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WG2: New particle formation (II)
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11:30am - 11:45am
TH2-2: 1 Decoding the Synergistic Effects of Anthropogenic and Biogenic Emissions on New Particle Formation: Insights from CERN CLOUD chamber 1University of Naples Federico II, Italy; 2Paul Scherrer Institute, Italy, Switzerland; 3Goethe University Frankfurt, Germany This study investigates the role of highly oxygenated organic molecules (HOMs) in new particle formation (NPF) within the context of both biogenic and anthropogenic volatile organic compounds (VOCs). Using the CERN CLOUD chamber, we explore the chemical and physical processes that drive gas-to-particle processes under varying atmospheric conditions. The chamber experiments involve the introduction of α-pinene, isoprene, and trimethylbenzene to simulate biogenic and anthropogenic emissions. Real-time monitoring with mass spectrometers and particle analyzers allows for tracking the transition from gas to particle phase, shedding light on how human emissions impact NPF and contribute to atmospheric aerosol formation and climate change.
11:45am - 12:00pm
TH2-2: 2 Exploring the influence of physical and chemical factors on new particle formation in polluted environments 1Department of Chemical Engineering, Indian Institute of Technology Delhi, New Delhi, 110016, India; 2Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, Villigen, Aargau 5232 Switzerland; 3Department of Mechanical Engineering, Indian Institute of Technology Delhi, New Delhi, 110016, India; 4Centre for Atmospheric Sciences, Indian Institute of Technology Delhi, New Delhi, 110016, India NPF is often suppressed in polluted cities due to high CS, yet it occurs in Delhi. We analyzed a year of size distribution and PM₂.₅ composition data to investigate influencing factors. While some studies suggest particle composition affects CS via hygroscopicity, our findings indicate it was not a key factor. Instead, RH variations influenced ALWC, which played a crucial role in promoting or inhibiting NPF. This underscores the variability in polluted environments, where meteorological conditions, especially RH, significantly impact NPF occurrence.
12:00pm - 12:15pm
TH2-2: 3 Enhanced new particle formation in Milan due to low pollution and atmospheric mixing 1University of Helsinki, Finland; 2University of Milan, Italy; 3Regional Agency for Environmental Protection of Lombardy, Italy; 4National Research Council of Italy, Italy; 5University of Modena and Reggio Emilia, Italy The study investigates New Particle Formation (NPF) in Milan, a polluted city in the Po Valley, Italy, over one year (2023 – 2024) by analyzing particle number size distributions. The results reveal a clear seasonal cycle, with winter showing higher concentrations of larger particles due to higher atmospheric stability and heating emissions, while summer exhibits stronger NPF, favored by increased mixing. The analysis shows that strong ventilation, low pollution and low airmass residence time in the Po Valley and exposure to anthropogenic sources promote NPF. These findings enhance our understanding of urban air quality and enable comparisons with other cities.
12:15pm - 12:30pm
TH2-2: 4 Exploring the Role of Oxygenated Organic Molecules in New Particle Formation Events with Explainable Artificial Intelligence 1Department of Chemistry, University of Helsinki, 00560 Helsinki, Finland; 2Division of Environmental Health and Risk Management, School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom; 3Leibniz Institute for Tropospheric Research, Leipzig, 04318, Germany; 4Aerosol Physics laboratory, Tampere University, Tampere, 33720, Finland; 5Department of Applied Physics, Aalto University, Espoo, 11000, Finland; 6Physics Department, TUM School of Natural Sciences, Technical University of Munich, Garching, Germany; 7Atomistic Modelling Center, Munich Data Science Institute, Technical University of Munich, Garching, Germany; 8Munich Center for Machine Learning (MCML); 9Department of Environmental Sciences, Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah, 21589, Saudi Arabia Identifying the specific causes of NPF in urban areas remains challenging. In this study, we employ artificial intelligence approaches to predict the formation rate (J) and examine the role of highly oxygenated organic molecules (HOMs) in NPF events. The models were trained on data collected in August 2022 in two nearby sites in Leipzig, Germany: an urban background and a roadside. The data comprised meteorological variables, NOx, BC, and CIMS (with PMF of HOMs). Our models accurately predicted the J at the background site. Additional analysis identifies sulfuric acid, amines and various HOMs as key factors in predicting J!
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