Machine Learning Reveals the Parameters Affecting the Gaseous Sulfuric Acid Distribution in a Coastal City: Model Construction and Interpretation DOI
Chen Yang, Hesong Dong, Yuping Chen

et al.

Environmental Science & Technology Letters, Journal Year: 2023, Volume and Issue: 10(11), P. 1045 - 1051

Published: April 12, 2023

Although the fundamental mechanisms of atmospheric new particle formation events are largely associated with gaseous sulfuric acid monomer (SA), parameters affecting SA generation and elimination remain unclear, especially in coastal areas where certain sulfur-containing precursors abundant. In this study, we utilized machine learning (ML) combination field observations to map link between influencing parameters. The developed random forest (RF) model performed well creating simulations an R2 0.90, significant factors were ultraviolet, methanesulfonic (MSA), SO2, condensation sink, relative humidity descending order. Among five factors, MSA served as indicator for species from marine emissions. black box ML was broken determine marginal contribution these output using partial dependence plots centered-individual conditional expectation plots. These results indicated that had a positive impact on performance RF model, co-occurring relationship observed during nocturnal period. Our findings reveal emitted environment have should be considered areas.

Language: Английский

Contribution of Atmospheric Oxygenated Organic Compounds to Particle Growth in an Urban Environment DOI
Xiaohui Qiao, Chao Yan, Xiaoxiao Li

et al.

Environmental Science & Technology, Journal Year: 2021, Volume and Issue: 55(20), P. 13646 - 13656

Published: Sept. 29, 2021

Gas-phase oxygenated organic molecules (OOMs) can contribute substantially to the growth of newly formed particles. However, characteristics OOMs and their contributions particle rate are not well understood in urban areas, which have complex anthropogenic emissions atmospheric conditions. We performed long-term measurement gas-phase Beijing during 2018–2019 using nitrate-based chemical ionization mass spectrometry. OOM concentrations showed clear seasonal variations, with highest summer lowest winter. Correspondingly, calculated rates due condensation were summer, followed by spring, autumn, One prominent feature this environment was a high fraction (∼75%) nitrogen-containing OOMs. These contributed only 50–60% total led condensation, owing slightly higher volatility than non-nitrate By comparing observed rates, we that sulfuric acid its clusters main contributors sub-3 nm particles, significantly promoting 3–25 In wintertime Beijing, however, there missing particles above 3 nm, remain be further investigated.

Language: Английский

Citations

88
Acid–Base Clusters during Atmospheric New Particle Formation in Urban Beijing DOI
Rujing Yin, Chao Yan, Runlong Cai

et al.

Environmental Science & Technology, Journal Year: 2021, Volume and Issue: 55(16), P. 10994 - 11005

Published: Aug. 2, 2021

Molecular clustering is the initial step of atmospheric new particle formation (NPF) that generates numerous secondary particles. Using two online mass spectrometers with and without a chemical ionization inlet, we characterized neutral clusters naturally charged ion during NPF periods in urban Beijing. In clusters, observed pure sulfuric acid (SA) SA-amine SA-ammonia (NH

Language: Английский

Citations

79
The contribution of new particle formation and subsequent growth to haze formation DOI Creative Commons
Markku Kulmala, Runlong Cai, Dominik Stolzenburg

et al.

Environmental Science Atmospheres, Journal Year: 2022, Volume and Issue: 2(3), P. 352 - 361

Published: Jan. 1, 2022

We investigated the contribution of atmospheric new particle formation (NPF) and subsequent growth newly formed particles, characterized by high concentrations fine particulate matter (PM2.5). In addition to having adverse effects on visibility human health, these haze particles may act as cloud condensation nuclei, potentially large influences clouds precipitation. Using observations performed in 2019 Beijing, a polluted megacity China, we showed that variability rates (GR) originating from NPF depend only weakly low-volatile vapor - highly oxidated organic molecules (HOMs) sulphuric acid have no apparent connection with strength or level background pollution. then constrained aerosol dynamic model simulations observations. under conditions typical for Beijing atmosphere, is capable contributing more than 100 μg m-3 PM2.5 mass concentration simultaneously >103 cm-3 (diameter > nm) number concentration. Our reveal NPF, rate pre-existing population are all connected each other. Concerning PM pollution control, our results indicate reducing primary emissions might not result an effective enough decrease total until reduction precursor compounds imposed.

Language: Английский

Citations

64
Insufficient Condensable Organic Vapors Lead to Slow Growth of New Particles in an Urban Environment DOI
Xiaoxiao Li, Yuyang Li, Runlong Cai

et al.

Environmental Science & Technology, Journal Year: 2022, Volume and Issue: 56(14), P. 9936 - 9946

Published: June 24, 2022

Atmospheric new particle formation significantly affects global climate and air quality after newly formed particles grow above ∼50 nm. In polluted urban atmospheres with 1-3 orders of magnitude higher rates than those in clean atmospheres, growth are comparable or even lower for reasons that were previously unclear. Here, we address the slow Beijing advanced measurements size-resolved molecular composition nanoparticles using thermal desorption chemical ionization mass spectrometer gas precursors nitrate CI-APi-ToF. A model combining condensational particle-phase acid-base chemistry was developed to explore mechanisms. The 8-40 nm during events is dominated by organics (∼80%) sulfate (∼13%), remainder from base compounds, nitrate, chloride. With increase sizes, fraction decreases, while slow-desorbed organics, organic acids, increases. simulated consistent measured results most cases, they both indicate vapors H2SO4 major pathway reactions play a minor role. comparison high concentrations gaseous sulfuric acid amines cause rates, concentration condensable comparably under NOx levels, relatively high-volatility nitrogen-containing oxidation products higher. insufficient lead growth, which further causes low survival environments. Thus, some extent, counteract impact on

Language: Английский

Citations

52
The missing base molecules in atmospheric acid–base nucleation DOI Creative Commons
Runlong Cai, Rujing Yin, Chao Yan

et al.

National Science Review, Journal Year: 2022, Volume and Issue: 9(10)

Published: July 25, 2022

Transformation of low-volatility gaseous precursors to new particles affects aerosol number concentration, cloud formation and hence the climate. The clustering acid base molecules is a major mechanism driving fast nucleation initial growth in atmosphere. However, acid-base cluster composition, measured using state-of-the-art mass spectrometers, cannot explain high rate particles. Here we present strong evidence for existence such as amines smallest atmospheric sulfuric clusters prior their detection by spectrometers. We demonstrate that forming (H2SO4)1(amine)1 rate-limiting step H2SO4-amine uptake pathway H2SO4 clusters. proposed very consistent with particle urban Beijing, which dimethylamine key while other bases ammonia may contribute larger Our findings further underline fact amines, even at low concentrations when undetected clusters, can be crucial planetary boundary layer.

Language: Английский

Citations

48
Seasonal variation in oxygenated organic molecules in urban Beijing and their contribution to secondary organic aerosol DOI Creative Commons

Yishuo Guo,

Chao Yan, Yuliang Liu

et al.

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(15), P. 10077 - 10097

Published: Aug. 5, 2022

Abstract. Oxygenated organic molecules (OOMs) are crucial for atmospheric new particle formation and secondary aerosol (SOA) growth. Therefore, understanding their chemical composition, temporal behavior, sources is of great importance. Previous studies on OOMs mainly focus environments where biogenic predominant, yet sites with dominant anthropogenic emissions, such as megacities, have been lacking. Here, we conducted long-term measurements OOMs, covering four seasons the year 2019, in urban Beijing. The OOM concentration was found to be highest summer (1.6×108 cm−3), followed by autumn (7.9×107 spring (5.7×107 cm−3) winter (2.3×107 suggesting that enhanced photo-oxidation together rise temperature promote OOMs. Most contained 5 10 carbon atoms 3 7 effective oxygen (nOeff=nO-2×nN). average nOeff increased increasing capacity, which lowest autumn. By performing a newly developed workflow, were classified into following types: aromatic aliphatic isoprene monoterpene Among them, (29 %–41 %) (26 main contributors all seasons, indicating Beijing dominated sources. contribution significantly (33 %), much higher than those other three (8 %–10 %). Concentrations (0.2–5.3×107 (1.1–8.4×106 lower reported at sites, they possessed nitrogen contents due high NOx levels (9.5–38.3 ppbv – parts per billion volume) With regard content two composed CHO CHON species, while CHON2 ones. Such prominent differences suggest varying pathways between these combining an dynamic model, estimated SOA growth rate through condensation could reach 0.64, 0.61, 0.41, 0.30 µg m−3 h−1 autumn, summer, spring, winter, respectively. Despite similar concentrations former had volatilities and, therefore, showed contributions (46 %–62 latter (14 %–32 contrast, limited low abundances or volatilities, 8 %–12 % %–5 %, Overall, our results improve concentration, seasonal variation, potential impacts can help formulate refined restriction policy specific control areas.

Language: Английский

Citations

45
Iodine oxoacids enhance nucleation of sulfuric acid particles in the atmosphere DOI Open Access
Xu‐Cheng He, Mario Simon, Siddharth Iyer

et al.

Science, Journal Year: 2023, Volume and Issue: 382(6676), P. 1308 - 1314

Published: Dec. 14, 2023

The main nucleating vapor in the atmosphere is thought to be sulfuric acid (H2SO4), stabilized by ammonia (NH3). However, marine and polar regions, NH3 generally low, H2SO4 frequently found together with iodine oxoacids [HIOx, i.e., iodic (HIO3) iodous (HIO2)]. In experiments performed CERN CLOUD (Cosmics Leaving OUtdoor Droplets) chamber, we investigated interplay of HIOx during atmospheric particle nucleation. We that greatly enhances H2SO4(-NH3) nucleation through two different interactions. First, HIO3 strongly binds charged clusters so they drive synergistically. Second, HIO2 substitutes for NH3, forming bound H2SO4-HIO2 acid-base pairs molecular clusters. Global observations imply enhancing rates 10- 10,000-fold regions.

Language: Английский

Citations

41
Increasing contribution of nighttime nitrogen chemistry to wintertime haze formation in Beijing observed during COVID-19 lockdowns DOI
Chao Yan, Yee Jun Tham, Wei Nie

et al.

Nature Geoscience, Journal Year: 2023, Volume and Issue: 16(11), P. 975 - 981

Published: Oct. 12, 2023

Language: Английский

Citations

36
New particle formation induced by anthropogenic–biogenic interactions on the southeastern Tibetan Plateau DOI Creative Commons
Shiyi Lai, Ximeng Qi, Xin Huang

et al.

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(4), P. 2535 - 2553

Published: Feb. 28, 2024

Abstract. New particle formation (NPF) plays a crucial role in the atmospheric aerosol population and has significant implications on climate dynamics, particularly climate-sensitive zones such as Tibetan Plateau (TP). However, our understanding of NPF TP is still limited due to lack comprehensive measurements verified model simulations. To fill this knowledge gap, we conducted an integrated study combining field chemical transport modeling investigate events southeastern during pre-monsoon season. was observed occur frequently clear-sky days TP, contributing significantly cloud condensation nuclei (CCN) budget region. The observational evidence suggests that highly oxygenated organic molecules (HOMs) from monoterpene oxidation participate nucleation TP. After updating chemistry schemes meteorology–chemistry model, well reproduces reveals extensive occurrence across dominant mechanism synergistic sulfuric acid, ammonia, HOMs, driven by anthropogenic precursors South Asia presence abundant biogenic gases. By investigating vertical distribution NPF, find influence More specifically, strong near surface leads intense small particles, which are subsequently transported upward. These particles experience enhanced growth larger sizes upper planetary boundary layer (PBL) favorable conditions lower temperatures reduced sink. As PBL evolves, brought back ground, resulting pronounced increase near-surface concentrations. This highlights important roles anthropogenic–biogenic interactions meteorological dynamics

Language: Английский

Citations

11
An indicator for sulfuric acid–amine nucleation in atmospheric environments DOI
Runlong Cai, Chao Yan, Douglas R. Worsnop

et al.

Aerosol Science and Technology, Journal Year: 2021, Volume and Issue: 55(9), P. 1059 - 1069

Published: May 2, 2021

New particle formation (NPF) occurs frequently in various atmospheric environments and it is a major source of ultrafine particles. This study proposes an indicator, I, for the occurrence NPF atmosphere based on mechanism H2SO4–amine nucleation. It characterizes synergistic effects governing factors nucleation, including H2SO4 concentration, amine concentrations, stability clusters, aerosol surface area concentration. Long-term measurements urban Beijing were used to validate this indicator. Good consistency was found between indicator NPF. usually observed with I > 1 typical conditions Beijing. The derivation expressions also indicate good positive association dimer concentration NPF, as verified by measurements. shown be applicable Shanghai.Copyright © 2021 American Association Aerosol Research

Language: Английский

Citations

52