Comment on egusphere-2022-1440 DOI Creative Commons
Ru‐Jin Huang

Published: March 2, 2023

Abstract. Fenwei Plain, home to 50 million people in central China, is one of the most polluted regions China. In 2018, Plain designated as three key for “Blue Sky Protection Campaign”, along with Beijing-Tianjin-Hebei (BTH) and Yangtze River Delta (YRD) regions. However, compared BTH YRD, our understanding current status air pollution limited partly due a lack detailed analysis transformation from precursor gases secondary products including organic aerosol (SOA) ozone. Through 7 years (2015–2021) surface monitoring pollutants Xi’an, largest city we show that roughly 2/3 days exceeded either PM2.5 or O3 level-1 quality standard, highlighting severity pollution. Moreover, an increase winter haze was also revealed, constantly elevated reactive oxygenated volatile compounds (OVOCs), particular formaldehyde ozone formation potential over μg m−3 combination reduced NO2. The abrupt decrease NO2, observed during lockdown 2020, provided real-world evidence control measures, targeting only NOx (70 % on average), were insufficient reduce because OVOCs remained high VOC-limited regime. Model simulation results showed NO2 reduction 20–70 %, self-reaction rate between peroxy radicals, pathway SOA formation, intensified by up 75 while further VOCs > %. Therefore, synergic can be achieved through more aggressive their gases. This study elucidates revealing general trend increasing i.e., haze. Controlling gas emissions anticipated curb both which will benefit not just but other

Language: Английский

Heterogeneous variations in wintertime PM2.5 sources, compositions and exposure risks at urban/suburban rural/remote rural areas in the post COVID-19/Clean-Heating period DOI
Z Li,

Zhuangzhuang Ren,

Chen Liu

et al.

Atmospheric Environment, Journal Year: 2024, Volume and Issue: 326, P. 120463 - 120463

Published: March 14, 2024

Language: Английский

Citations

9
Elucidating Secondary Organic Aerosol Processes through High-Resolution Aerosol Mass Spectrometry in Beijing DOI

Weiqi Xu,

Chun Chen, Zhijie Li

et al.

Advances in Atmospheric Sciences, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 24, 2025

Language: Английский

Citations

1
Impacts of biomass burning and photochemical processing on the light absorption of brown carbon in the southeastern Tibetan Plateau DOI Creative Commons
Jie Tian, Qiyuan Wang,

Yongyong Ma

et al.

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(3), P. 1879 - 1892

Published: Feb. 3, 2023

Abstract. Brown carbon (BrC) in the atmosphere can greatly influence aerosol's radiative forcing over Tibetan Plateau (TP) because it has non-negligible capacity of light absorption compared to black (BC); however, our understanding optical properties, sources, and atmospheric processes BrC this region remains limited. In study, a multiple-wavelength Aethalometer coupled with quadrupole aerosol chemical speciation monitor was deployed investigate highly time resolved submicron at southeastern edge TP during pre-monsoon season. The results showed that made substantial contributions (20.0 %–40.2 %) from 370 660 nm. Organic (OA), an alternative BrC, split into biomass burning OA (BBOA) aging photochemical-oxidation-processed oxygenated (po-OOA) by hybrid environmental receptor model analysis. Combined coefficient (babs-BrC), source-specific mass cross sections BBOA (0.61–2.78 m2 g−1) po-OOA (0.30–1.43 370–660 nm were retrieved. On average, babs-BrC (1.3–6.0 Mm−1) comparable all wavelengths. concentration-weighted trajectory analysis most important potential source regions for values located northern Myanmar along China–Myanmar border, indicating cross-border transport Southeast Asia. A “simple efficiency” evaluation further illustrated importance effect high fractional two OAs relative BC (48.8 ± 15.5 %). This study highlights significant origin secondary formation on climate change

Language: Английский

Citations

19
Elucidating ozone and PM2.5 pollution in the Fenwei Plain reveals the co-benefits of controlling precursor gas emissions in winter haze DOI Creative Commons
Chunshui Lin, Ru‐Jin Huang, Haobin Zhong

et al.

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(6), P. 3595 - 3607

Published: March 23, 2023

Abstract. The Fenwei Plain, home to 50 million people in central China, is one of the most polluted regions China. In 2018, Plain was designated as three key for “Blue Sky Protection Campaign”, along with Beijing–Tianjin–Hebei (BTH) and Yangtze River Delta (YRD) regions. However, compared BTH YRD, our understanding current status air pollution limited partly due a lack detailed analysis transformation from precursor gases secondary products including organic aerosol (SOA) ozone. Through 7 years (2015–2021) surface monitoring pollutants Xi'an, largest city we show that roughly two-thirds days exceeded either PM2.5 or O3 level-1 quality standard, highlighting severity pollution. Moreover, an increase winter haze also revealed, constantly elevated reactive oxygenated volatile compounds (OVOCs), particular formaldehyde, ozone formation potential over µg m−3, combination reduced NO2. abrupt decrease NO2, observed during lockdown 2020, provided real-world evidence control measures, targeting only NOx (70 % on average), were insufficient reduce because OVOCs remained high compound (VOC)-limited regime. Model simulation results showed NO2 reduction 20 %–70 %, self-reaction rate between peroxy radicals, pathway SOA formation, intensified by up 75 while further VOCs > %. Therefore, synergic can be achieved through more aggressive their gases. This study elucidates revealing general trend increasing pollution, i.e., haze. Controlling gas emissions anticipated curb both which will benefit not just but other

Language: Английский

Citations

13
Response of organic aerosol in Beijing to emission reductions during the XXIV Olympic Winter Games DOI

Qipeng Qu,

Shuxiao Wang, Bin Zhao

et al.

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 914, P. 170033 - 170033

Published: Jan. 14, 2024

Language: Английский

Citations

4
Evaluating the Effects of Biomass Burning on Severe Haze Formation in a Megacity of Sichuan Basin, Southwestern China DOI Creative Commons

Zhier Bao,

Yiliang Liu, Lingshuo Meng

et al.

Journal of Geophysical Research Atmospheres, Journal Year: 2025, Volume and Issue: 130(2)

Published: Jan. 17, 2025

Abstract Severe haze pollution has long been an environmental problem, which is complicated and poorly understood in the Sichuan Basin (SCB). In this study, a field observation was carried out to investigate factors driving formation urban Chengdu, typical megacity SCB. It found that accumulation of biomass burning organic aerosol (BBOA) played important role Chengdu. The average mass fraction BBOA PM 2.5 increased from ∼1% during clear days ∼10% severe episodes. A method combining backward trajectory analysis with fire spot distribution used evaluate effects regional transport (BB) emissions. results showed concentration by ∼3 times ∼54% when BB emissions were transported adjacent areas Moreover, parameter f 60 (the ratio integrated signal at m/z total component spectrum), indicated impacts emissions, reassessed be 0.54% instead widely value 0.3% previously. Our uncovered importance on SCB provided new insights into pollutant mitigation strategies region.

Language: Английский

Citations

0
Ambient Measurements of Daytime Decay Rates of Levoglucosan, Mannosan, and Galactosan DOI Creative Commons

Qiongqiong Wang,

Shan Wang, Hanzhe Chen

et al.

Journal of Geophysical Research Atmospheres, Journal Year: 2025, Volume and Issue: 130(8)

Published: April 11, 2025

Abstract Quantifying atmospheric degradation of levoglucosan, a highly specific molecular marker for biomass burning (BB) aerosols, is essential in assessing impacts BB on air quality and climate. However, the stability levoglucosan atmosphere has only been evaluated through laboratory experiments or model simulations. Here, we investigated its two co‐emitting isomers, mannosan galactosan, utilizing bihourly measurement data at suburban site Hong Kong over period 4 months. The concentrations three saccharides, upon normalization by BB‐derived potassium, displayed distinct consistent depletion during daytime hours from 08:00 to 16:00, which follows an exponential decay pattern. We calculated individual rate constants saccharides their day‐by‐day kinetics. rates galactosan were 34% 40% higher than that levoglucosan. estimated lifetime was 13 ± 7 hr, ranging 3 46 hr under condition temperature 22 5°C, relative humidity 55 14%. This work provides first kinetic derived real ambient measurements. They are valuable refining predictions concerning aerosol local, regional, global scales.

Language: Английский

Citations

0
Comprehensive the seasonal characterization of atmospheric submicron particles at urban sites in the North China Plain DOI
Peng Xu, Yuan Yang, Wenkang Gao

et al.

Atmospheric Research, Journal Year: 2024, Volume and Issue: 304, P. 107388 - 107388

Published: April 1, 2024

Language: Английский

Citations

3
Characterization and Seasonal Variation of PM2.5 Composition in Xi’an, Northwest China: Oxygenated and Nitrogenous Organic Aerosol DOI Creative Commons
Yijun Shang, Linjie Li,

Tingting Sun

et al.

ACS Earth and Space Chemistry, Journal Year: 2024, Volume and Issue: 8(7), P. 1370 - 1384

Published: June 20, 2024

Oxygenated (CHO) and nitrogenous (CHON) organic aerosols (OA) are important components of fine particulate matter (PM2.5) in urban environments. To achieve a molecular-level understanding the seasonal variation OA fraction, ambient PM2.5 samples collected from April 2018 to March 2019 Xi'an, Northwest China, were analyzed using an iodide Chemical Ionization Mass Spectrometer combined with Filter Inlet for Gases AEROsols (FIGAERO–CIMS). The set compounds identified by FIGAERO–CIMS was estimated represent 28.6% PM2.5. Evaporation temperatures measured indicated that semivolatile (SVOCs) dominant among analytes. Concentrations CHO (6.01 ± 4.24 μg m–3) CHON (3.17 2.34 increased winter, especially during severe haze episode January 2019. comprised up 75.3 3.2% total detected compounds. average carbon oxidation state (OSC¯) slightly elevated summer samples. mainly nitro-aromatics their abundance substantially which attributed extensive biomass burning demonstrated high levels levoglucosan. Biomass-burning related sources accounted 61.0 19.6% 68.3 21.9% concentration autumn respectively, while secondary formation source species spring (70.1 11.6%) (79.8 7.0%). These results emphasize importance as reveal clear need control used heating Xi'an its surroundings.

Language: Английский

Citations

2
Aromatic Nitration Enhances Absorption of Biomass Burning Brown Carbon in an Oxidizing Urban Environment DOI

Jing Duan,

Ru‐Jin Huang, Chunshui Lin

et al.

Environmental Science & Technology, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 19, 2024

Brown carbon (BrC) from biomass burning constitutes a significant portion of light-absorbing components in the atmosphere. Although aging BrC surrogates has been studied many laboratory settings, behavior real-world urban environments is not well understood. In this study, through combination online dynamic monitoring and offline molecular characterization, ambient optical was linked to its changes composition. Enhanced light absorption by consistently observed during periods dominated oxygenated organic aerosol (BBOA), contrast primary emissions or secondary formation aqueous-phase. This enhancement nitrogen-containing compounds BBOA. Detailed alongside analysis environmental parameters, revealed that an increased atmospheric oxidizing capacity, marked elevated levels ozone nighttime NO

Language: Английский

Citations

2