Short-term source apportionment of fine particulate matter with time-dependent profiles using SoFi Pro: exploring the reliability of rolling positive matrix factorization (PMF) applied to bihourly molecular and elemental tracer data DOI Creative Commons
Qiongqiong Wang, Shuhui Zhu, Shan Wang

et al.

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(1), P. 475 - 486

Published: Jan. 12, 2024

Abstract. Positive matrix factorization (PMF) has been widely used to apportion the sources of fine particulate matter (PM2.5) by utilizing PM chemical speciation data measured at receptor site(s). Traditional PMF, which typically relies on long-term observational datasets daily or lower time resolution meet required sample size, its reliability undermined changes in source profiles; thus, it is inherently ill-suited for apportioning sporadic ephemeral pollution events. In this study, we explored short-term apportionment PM2.5 using a set bihourly over period 37 d winter 2019–2020. PMF run with campaign-wide as input (PMFref) was initially conducted obtain reference profiles primary factors. Subsequently, analysis performed Source Finder Professional (SoFi Pro). The sets window length 18 and constrained a-value approach embedded SoFi Pro software. Rolling then fixed step 1 remaining dataset. By applying constraints sources, rolling effectively reproduced individual evidenced slope values close unity (i.e., 0.9–1.0). However, estimation firework emission factor compared PMFref (slope: 0.8). These results suggest unique advantage accurately sources. Although total secondary were well modeled 1.0), larger biases observed variation indicated higher variabilities average relative differences ranging from 42 % 173 %, while exhibited much smaller (relative 8 %–26 %). This study suggests that can be utilized accurately, future efforts are needed improve prediction Additionally, rapid benefit library derived existing measurement data, thereby significantly reducing lag associated modeling techniques.

Language: Английский

Ozone pollution mitigation strategy informed by long-term trends of atmospheric oxidation capacity DOI
Wenjie Wang, Xin Li, Yafang Cheng

et al.

Nature Geoscience, Journal Year: 2023, Volume and Issue: 17(1), P. 20 - 25

Published: Nov. 27, 2023

Language: Английский

Citations

39
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
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
High-time-resolution chemical composition and source apportionment of PM2.5 in northern Chinese cities: implications for policy DOI Creative Commons
Yong Zhang, Jie Tian, Qiyuan Wang

et al.

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(16), P. 9455 - 9471

Published: Aug. 25, 2023

Abstract. Fine particulate matter (PM2.5) pollution is still one of China's most important environmental issues, especially in northern cities during wintertime. In this study, intensive real-time measurement campaigns were conducted Xi'an, Shijiazhuang, and Beijing to investigate the chemical characteristics source contributions PM2.5 explore formation heavy for policy implications. The compositions three all dominated by organic aerosol (OA) nitrate (NO3-). Results apportionment analyzed a hybrid receptor model (HERM) showed that secondary contributed more compared other primary sources. Biomass burning was dominant pilot cities. contribution coal combustion non-negligible Xi'an Shijiazhuang but no longer an contributor capital city due execution strict coal-banning policy. potential mechanisms further explored establishing correlations between sources liquid water content (ALWC) Ox (O3+NO2), respectively. results photochemical oxidation aqueous-phase reaction two pathways formation. According variations, air events occurred classified into types: biomass-combustion-dominated, secondary-formation-source-dominated, combination Additionally, study compares changes composition past decades. suggest clean-energy replacements rural households should be urgently encouraged reduce emissions China, collaborative control on ozone needs continuously promoted weaken atmosphere capacity sake reducing

Language: Английский

Citations

22
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

19
Impact of aging on the sources, volatility, and viscosity of organic aerosols in Chinese outflows DOI Creative Commons
Tingting Feng,

Yingkun Wang,

Weiwei Hu

et al.

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(1), P. 611 - 636

Published: Jan. 16, 2023

Abstract. To investigate the impact of aging on sources, volatility, and viscosity organic aerosol (OA) in Chinese outflows, a high-resolution time-of-flight mass spectrometer (HR-AMS) coupled with thermodenuder (TD) was deployed spring 2018 Dongying, which is regional receptor site metropolitan emissions North China Plain (NCP). The average concentration PM1 31.5±22.7 µg m−3, mainly composed nitrate (33 %) OA (25 %). source apportionment results show that contributed by oxygenated (OOA) from secondary including background-OOA representing background (2.6 m−3) NCP area, transported-OOA oxidized urban emissions. other two factors include aged hydrocarbon-liked (aged-HOA, 28 transported vehicle biomass burning (BBOA, 5 local open burning. volatility total (average C*=3.2×10-4 this study generally lower than reported previous field studies, due to high oxidation level resulting processes during transport. volatilities follow order C*=2.7×10-5 < (3.7×10-4µgm-3)< aged-HOA (8.1×10-4µgm-3)< BBOA (0.012 m−3). Extremely low ambient air indicate oligomers may exist plumes. estimation suggests majority behaves as semisolid (60 %), liquifies at higher relative humidity (RH) (21 solidifies (19 noon when RH high. Finally, estimated mixing time molecules 200 nm varies dramatically minutes night years afternoon, emphasizing need consider its dynamic kinetic limits modeling OA. In general, overall improve our understanding viscosity.

Language: Английский

Citations

18
Quantifying the contributions of meteorology, emissions, and transport to ground-level ozone in the Pearl River Delta, China DOI
Li Jin, Bin Yuan,

Suxia Yang

et al.

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 932, P. 173011 - 173011

Published: May 7, 2024

Language: Английский

Citations

8
Achievements and challenges in improving air quality in China: Analysis of the long-term trends from 2014 to 2022 DOI Creative Commons
Huang Zheng, Shaofei Kong, Jihoon Seo

et al.

Environment International, Journal Year: 2023, Volume and Issue: 183, P. 108361 - 108361

Published: Nov. 30, 2023

Due to the implementation of air pollution control measures in China, quality has significantly improved, although there are still additional issues be addressed. This study used long-term trends pollutants discuss achievements and challenges further improving China. The Kolmogorov-Zurbenko (KZ) filter multiple-linear regression (MLR) were quantify meteorology-related emission-related from 2014 2022 KZ analysis showed that PM2.5 decreased by 7.36 ± 2.92 % yr−1, while daily maximum 8-h ozone (MDA8 O3) an increasing trend with 3.71 2.89 yr−1 decrease increase MDA8 O3 primarily attributed changes emission, relative contribution 85.8% 86.0%, respectively. Meteorology variations, including increased ambient temperature, boundary layer height, reduced humidity, also contributed reduction enhancement O3. exhibited continuous increase, respectively, 2022, variation rates slowed during 2018-2020 compared 2014-2017, highlighting quality, particularly simultaneously reducing recommends NH3 emissions agriculture sector rural areas transport urban levels. Addressing requires precursor gases based on site-specific atmospheric chemistry considerations.

Language: Английский

Citations

16
Secondary aerosol formation drives atmospheric particulate matter pollution over megacities (Beijing and Seoul) in East Asia DOI
Yanting Qiu, Zhijun Wu,

Ruiqi Man

et al.

Atmospheric Environment, Journal Year: 2023, Volume and Issue: 301, P. 119702 - 119702

Published: March 10, 2023

Language: Английский

Citations

14
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