Measurement report: Vertical and temporal variability of near-surface ozone production rate and sensitivity in an urban area in Pearl River Delta (PRD) region, China DOI Creative Commons
Jun Zhou, Chunsheng Zhang, Aiming Liu

et al.

Published: Jan. 22, 2024

Abstract. Understanding the near-ground vertical and temporal photochemical O3 formation mechanism is important to mitigate pollution. Here, we measured profiles of its precursors at six different heights from 5-335 m using a newly built observation system in Pearl River Delta (PRD) region, China. The net ozone production rate (P(O3)net) sensitivities various were diagnosed an observation-based model coupled with Master Chemical Mechanism (MCM v3.3.1). Moreover, for assessment performance causative factors behind pollution episodes, was 5 ground level utilizing custom-built detection system. In total three episodes two non-episodes captured. identified found be jointly influenced by both physical transport, local reactions play dominate role. high index agreement (IOA) calculated comparing modelled P(O3)net values indicated rationality investigate variability modelling results. However, generally higher than values, particularly under NOx conditions, which may indicate potential underestimation RO2 model. Throughout measurement period, contribution reaction pathways remained consistent across heights, HO2+NO as major pathway, followed RO2+NO. We saw decreased increase height, primarily attributed anthropogenic organic compounds (AVOC) oxygenated volatile (OVOC). regimes similar during non-episodes, located either (VOCs) sensitive regime or transition more VOCs. Diurnally, typically VOCs morning noon time, but transitional afternoon around 16:00 LT. are most AVOC OVOC, suggests that targeting VOCs, especially control measures practical feasible site. analysis mechanisms near surface this study provides critical foundational knowledge formulating effective short-term emergency long-term strategies combat PRD region

Language: Английский

Quantitative evidence from VOCs source apportionment reveals O3 control strategies in northern and southern China DOI Creative Commons
Zhenyu Wang,

Xiao Tian,

Jie Li

et al.

Environment International, Journal Year: 2023, Volume and Issue: 172, P. 107786 - 107786

Published: Jan. 30, 2023

Ground-level ozone (O3) pollution has received widespread attention because its rising trend and adverse ecological impacts. However, the extremely strong photochemical reactions of precursor volatile organic compounds (VOCs) increase difficulty reducing VOCs emissions to alleviate O3. Here, we carried out a one-year comprehensive observation in two representative cities, Tianjin (TJ, Northern China) Guangzhou (GZ, Southern China). By revealing concentration characteristics three different types VOCs, i.e., initial without reaction (In-VOCs), consumed (C-VOCs), measured after (M-VOCs), elucidated important role C-VOCs formation Although overall trends were similar both average level GZ was 8.2 ppbv higher than that TJ, loss greater by 2.2 ppbv. In addition, various drivers affecting O3 generation from specifically explored, it found most alkenes TJ key substances for rapid compared aromatics GZ. Meanwhile, favorable meteorological conditions such as high temperature (T > 31 °C T 33 GZ), low relative humidity (56% 45% stable atmospheric environment (proper pressure gentle wind speed) also contribute More importantly, combined chemical kinetics receptor model quantify three-type source contributions assess potential impact sources on production, thus proposing environmental abatement technologies corresponding VOCs. The differences comparison results highlight need reduce sources, which provides insights future clean air policies development.

Language: Английский

Citations

34
Assessment of long tubing in measuring atmospheric trace gases: applications on tall towers DOI Creative Commons
Xiaobing Li, Chunsheng Zhang, Aiming Liu

et al.

Environmental Science Atmospheres, Journal Year: 2023, Volume and Issue: 3(3), P. 506 - 520

Published: Jan. 1, 2023

Negligible losses were observed for many atmospheric trace species after traversing the PFA Teflon tubing that was hundreds of meters in length.

Language: Английский

Citations

24
Sources of Wintertime Atmospheric Organic Pollutants in a Large Canadian City: Insights from Particle and Gas Phase Measurements DOI
Laura-Hélèna Rivellini, Spiro Jorga, Yutong Wang

et al.

ACS ES&T Air, Journal Year: 2024, Volume and Issue: 1(7), P. 690 - 703

Published: May 3, 2024

Although atmospheric organic pollutants have been extensively studied to elucidate summertime urban photochemical air pollution, uncertainties remain concerning the quality of wintertime in large northern North American cities. Here, we used online mass spectrometric measurements volatile compounds (VOCs) and aerosol (OA), combined with positive matrix factorization (PMF), identify sources downtown Toronto, Canada during February–March 2023. In some cases, comparable PMF factors were identified for both VOCs OA, such as from traffic, cooking, background oxygenated sources. However, VOC yielded additional information, a factor associated human-related emissions VOCs. Additionally, yields two traffic factors: one likely related gasoline diesel use. Despite cold relatively dark conditions, OA grow intensity daytime, indicative activity, whereas cooking enhanced morning late evening due timing vehicle use, boundary layer effects. This study illustrates benefits that arise parallel source–receptor analyses gases particles.

Language: Английский

Citations

13
Significance of Volatile Organic Compounds to Secondary Pollution Formation and Health Risks Observed during a Summer Campaign in an Industrial Urban Area DOI Creative Commons
Li Cao,

Qihui Men,

Zihao Zhang

et al.

Toxics, Journal Year: 2024, Volume and Issue: 12(1), P. 34 - 34

Published: Jan. 1, 2024

The chemical complexity and toxicity of volatile organic compounds (VOCs) are primarily encountered through intensive anthropogenic emissions in suburban areas. Here, pollution characteristics, impacts on secondary formation, health risks were investigated continuous in-field measurements from 1–30 June 2020 Nanjing, adjacent to national petrochemical industrial parks China. On average, the total VOCs concentration was 34.47 ± 16.08 ppb, which comprised mostly by alkanes (41.8%) halogenated hydrocarbons (29.4%). In contrast, aromatics (17.4%) dominated ozone formation potential (OFP) aerosol (SOAFP) with 59.6% 58.3%, respectively. Approximately 63.5% emitted industry solvent usage based source apportionment results, followed biogenic 22.3% vehicle 14.2%. Of observed 46 VOC species, hexachlorobutadiene, dibromoethane, butadiene, tetrachloroethane, vinyl chloride contributed as high 98.8% carcinogenic risk, a large fraction ascribed high-level during episodes nighttime. Therefore, mitigation industries would be an effective way reduce conurbation

Language: Английский

Citations

12
Pollution characteristics, source appointment and environmental effect of oxygenated volatile organic compounds in Guangdong-Hong Kong-Macao Greater Bay Area: Implication for air quality management DOI

Guanyong Liu,

Xiaoyao Ma,

Wanying Li

et al.

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 919, P. 170836 - 170836

Published: Feb. 10, 2024

Language: Английский

Citations

11
Characterization of organic vapors by a Vocus proton-transfer-reaction mass spectrometry at a mountain site in southeastern China DOI
Yi Zhang,

Weiqi Xu,

Wei Zhou

et al.

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 919, P. 170633 - 170633

Published: Feb. 9, 2024

Language: Английский

Citations

6
Characteristics of volatile organic compounds (VOCs) at an urban site of Delhi, India: Diurnal and seasonal variation, sources apportionment DOI
T. K. Mandal, Pooja Yadav, Mukesh Kumar

et al.

Urban Climate, Journal Year: 2023, Volume and Issue: 49, P. 101545 - 101545

Published: April 28, 2023

Language: Английский

Citations

16
Nighttime ozone in the lower boundary layer: insights from 3-year tower-based measurements in South China and regional air quality modeling DOI Creative Commons
Guowen He, Cheng He, Haofan Wang

et al.

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(20), P. 13107 - 13124

Published: Oct. 18, 2023

Abstract. Nighttime ozone in the lower boundary layer regulates atmospheric chemistry and surface air quality, but our understanding of its vertical structure impact is largely limited by extreme sparsity direct measurements. Here we present 3-year (2017–2019) measurements (up to 500 m) from Canton Tower Guangzhou, core megacity South China, interpret with a 1-month high-resolution chemical simulation Community Multiscale Air Quality (CMAQ) model. Measurements are available at 10, 118, 168, 488 m, highest (488 measurement platform higher than typical height nighttime stable that allows residual (RL). We find increases altitude throughout day, gradient between 10 m heights (ΔO3/ΔH10–488 3.6–6.4 ppbv hm−1 4.4–5.8 daytime. identify high ratio, defined as ratio concentration averaged over afternoon (14:00–17:00 LT), 69 %–90 % January, April, October, remarkably other three layers (29 %–51 %). Ozone convective mixing provides source RL, strong temperature inversion facilitates ability RL store daytime layer. The tower-based also indicates Ox (Ox= O3+NO2) level can be an effective indicator if not available. further significant influences nocturnal on both following day's quality. During enhancement (NOE) event, observe decrease increase NO2 CO height, contrast their changes surface, feature enhanced mixing. leads NOE event introducing ozone-rich NOx-poor into enter CMAQ model simulations demonstrate positive contribution diffusion (ΔVDIF) 118 negative 168 during event. correlation maximum daily 8 h average (MDA8) ozone. This tied collapse development layer, which supported diagnosis budget, suggesting downward via entrainment important mechanism for aggravating pollution day. bias CMAQ-simulated MDA8 day shows coefficient (r= 0.74) highlighting necessity correct quality accurate prediction Our study thus highlights value long-term coupling dynamics.

Language: Английский

Citations

16
The important contribution of secondary formation and biomass burning to oxidized organic nitrogen (OON) in a polluted urban area: insights from in situ measurements of a chemical ionization mass spectrometer (CIMS) DOI Creative Commons
Yiyu Cai,

Chenshuo Ye,

Wei Chen

et al.

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(15), P. 8855 - 8877

Published: Aug. 9, 2023

Abstract. To investigate the sources and formation mechanism of oxidized organic nitrogen (OON), field measurements OON were conducted using an iodide-adduct chemical ionization mass spectrometer equipped with a Filter Inlet for Gases AEROsols (FIGAERO-CIMS) during fall 2018 in megacity Guangzhou, China. Using levoglucosan as tracer biomass burning emissions, results show that (49±23 %) secondary (51±23 accounted comparable fractions to total particle-phase (pOON) but 24±25 % 76±25 gas-phase (gOON), respectively, signifying important contribution pOON gOON this urban area. Calculations production rates indicated hydroxyl radical (42 nitrate (NO3) (49 oxidation pathways potentially dominated gOON. A high concentration NO3 radicals afternoon was observed, demonstrating daytime might be more than previous recognition. Monoterpenes, found major precursors gOON, mainly from anthropogenic emissions The ratio Ox ([Ox] = [O3] + [NO2]) increased function relative humidity aerosol surface area, indicating heterogeneous reaction pathway pOON. Finally, highly 6 11 oxygen atoms highlighting complex processes ambient air. Overall, our improve understanding dynamic variation atmosphere.

Language: Английский

Citations

15
Wintertime fine aerosol particles composition and its evolution in two megacities of southern and northern China DOI
Yiling J. Cheng, Lu Chen, Hao Wu

et al.

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 914, P. 169778 - 169778

Published: Jan. 3, 2024

Language: Английский

Citations

5