Feng X, Lin HP, Fu TM, Sulprizio MP, Zhuang JW, JACOB DJ, Tian H, Ma YP, Zhang LJ, Wang XL, et al. WRF-GC (v2.0): online two-way coupling of WRF (v3.9.1.1) and GEOS-Chem (v12.7.2) for modeling regional atmospheric chemistry-meteorology interactions. Geoscientific Model Development. 2021;14:3741-3768.
Zheng Y, Chen Q, Cheng X, Mohr C, Cai J, Huang W, Shrivastava M, Ye P, Fu P, Shi X, et al. Precursors and Pathways Leading to Enhanced Secondary Organic Aerosol Formation during Severe Haze Episodes. Environmental Science & Technology [Internet]. 2021. 访问链接
Chen Y, Zheng P, Wang Z, Pu W, Tan Y, Yu C, Xia M, Wang W, Guo J, Huang D, et al. Secondary Formation and Impacts of Gaseous Nitro-Phenolic Compounds in the Continental Outflow Observed at a Background Site in South China. Environmental Science & Technology [Internet]. 2021. 访问链接
Liao K, Chen Q, Liu Y, Li Y, Lambe AT, Zhu T, Huang R-J, Zheng Y, Cheng X, Miao R, et al. Secondary Organic Aerosol Formation of Fleet Vehicle Emissions in China: Potential Seasonality of Spatial Distributions. Environmental Science & Technology. 2021;55(11):7276-7286.
Cheng X, Chen Q, Li Y, Huang G, Liu Y, Lu S, Zheng Y, Qiu W, Lu K, Qiu X, et al. Secondary Production of Gaseous Nitrated Phenols in Polluted Urban Environments. Environmental Science & Technology. 2021;55(8):4410-4419.
Li Y, Liu B, Ye J, Jia T, Khuzestani RB, Sun JY, Cheng X, Zheng Y, Li X, Wu C, et al. Unmanned Aerial Vehicle Measurements of Volatile Organic Compounds over a Subtropical Forest in China and Implications for Emission Heterogeneity. ACS Earth and Space Chemistry. 2021;5:247-256.
Shi X, Qiu X, Chen Q, Chen S, Hu M, Rudich Y, Zhu T. Organic Iodine Compounds in Fine Particulate Matter from a Continental Urban Region: Insights into Secondary Formation in the Atmosphere. Environmental Science & Technology. 2021;55:1508-1514.
Liu Z, Zhou M, Chen Y, Chen D, Pan Y, Song T, Ji D, Chen Q, Zhang L. The nonlinear response of fine particulate matter pollution to ammonia emission reductions in North China. Environmental Research Letters. 2021;16:034014.Abstract
Recent Chinese air pollution actions have significantly lowered the levels of fine particulate matter (PM2.5) in North China via controlling emissions of sulfur dioxide (SO2) and nitrogen oxides (NO x ) together with primary aerosols, while the emissions of another precursor, ammonia (NH3), have not yet been regulated. This raises a question that how effective the NH3 emission controls can be on the mitigation of PM2.5 pollution along with the reduction of SO2 and NO x emissions. Here we use a regional air quality model to investigate this issue focusing on the PM2.5 pollution in North China for January and July 2015. We find that the efficiency of the PM2.5 reduction is highly sensitive to the NH3 emission and its reduction intensity. Reductions in the population-weighted PM2.5 concentration (PWC) in the Beijing–Tianjin–Hebei region are only 1.4–3.8 μg m−3 (1.1%–2.9% of PM2.5) with 20%–40% NH3 emission reductions, but could reach 8.1–26.7 μg m−3 (6.2%–21%) with 60%–100% NH3 emission reductions in January 2015. Besides, the 2015–2017 emission changes (mainly reduction in SO2 emissions) could lower the PM2.5 control efficiency driven by the NH3 reduction by up to 30% for high NH3 emission conditions, while lead to no change or increase in the efficiency when NH3 emissions become low. NO x emission reductions may enhance the wintertime PM2.5 pollution due to the weakened titration effect and can be offset by simultaneously controlling NH3 emissions. Our results emphasize the need to jointly consider NH3 with SO2 and NO x emission controls when designing PM2.5 pollution mitigation strategies.
Lee DS, Fahey DW, Skowron A, Allen MR, Burkhardt U, Chen Q, Doherty SJ, Freeman S, Forster PM, Fuglestvedt J, et al. The contribution of global aviation to anthropogenic climate forcing for 2000 to 2018. Atmospheric Environment. 2021;244:117834.
Miao R, Chen Q, Shrivastava M, Chen Y, Zhang L, Hu J, Zheng Y, Liao K. Process-based and observation-constrained SOA simulations in China: the role of semivolatile and intermediate-volatility organic compounds and OH levels. Atmospheric Chemistry and Physics. 2021;21:16183-16201.
Cheng X, Chen Q, Li YJ, Zheng Y, Liao K, Huang G. Highly oxygenated organic molecules produced by the oxidation of benzene and toluene in a wide range of OH exposure and NOx conditions. Atmospheric Chemistry and Physics. 2021;21:12005-12019.
Song M, Li X, Yang S, Yu X, Zhou S, Yang Y, Chen S, Dong H, Liao K, Chen Q, et al. Spatiotemporal variation, sources, and secondary transformation potential of volatile organic compounds in Xi'an, China. Atmospheric Chemistry and Physics. 2021;21:4939-4958.
Yan C, Yin R, Lu Y, Dada L, Yang D, Fu Y, Kontkanen J, Deng C, Garmash O, Ruan J, et al. The synergistic role of sulfuric acid, bases, and oxidized organics governing new-particle formation in Beijing. Geophysical Research Letters. 2021:e2020GL091944.Abstract
Abstract Intense and frequent new particle formation (NPF) events have been observed in polluted urban environments, yet the dominant mechanisms are still under debate. To understand the key species and governing processes of NPF in polluted urban environments, we conducted comprehensive measurements in downtown Beijing during January – March 2018. We performed detailed analyses on sulfuric acid cluster composition and budget, as well as the chemical and physical properties of oxidized organic molecules. Our results demonstrate that the fast clustering of sulfuric acid (H2SO4) and base molecules triggered the NPF events, and oxidized organic molecules (OOMs) further helped grow the newly formed particles towards climate- and health-relevant sizes. This synergistic role of H2SO4, base species, and OOMs in NPF is likely representative of polluted urban environments where abundant H2SO4 and base species usually co-exist, and OOMs are with moderately low volatility when produced under high NOx concentrations.
Gkatzelis GI, Papanastasiou DK, Karydis VA, Hohaus T, Liu Y, Schmitt SH, Schlag P, Fuchs H, Novelli A, Chen Q, et al. Uptake of water-soluble gas-phase oxidation products drives organic particulate pollution in Beijing. Geophysical Research Letters. 2021:e2020GL091351.Abstract
Abstract Despite the recent decrease in pollution events in Chinese urban areas, the World Health Organization air quality guideline values are still exceeded. Observations from monitoring networks show a stronger decrease of organic aerosol directly emitted to the atmosphere relative to secondary organic aerosol (SOA) generated from oxidation processes. Here, the uptake of water-soluble gas-phase oxidation products is reported as a major SOA contribution to particulate pollution in Beijing, triggered by the increase of aerosol liquid water. In pollution episodes, this pathway is enough to explain the increase in SOA mass, with formaldehyde, acetaldehyde, glycolaldehyde, formic, and acetic acid alone explaining 15 to 25% of the SOA increase. Future mitigation strategies to reduce non-methane volatile organic compound emissions should be considered to reduce organic particulate pollution in China.
Yuan W, Huang RJ, Yang L, Wang T, Duan J, Guo J, Ni H, Chen Y, Chen Q, Li Y, et al. Measurement report: PM2.5-bound nitrated aromatic compounds in Xi'an, Northwest China – seasonal variations and contributions to optical properties of brown carbon. Atmospheric Chemistry and Physics. 2021;21:3685-3697.
Mehra A, Canagaratna M, Bannan TJ, Worrall SD, Bacak A, Priestley M, Liu D, Zhao J, Xu W, Sun Y, et al. Using highly time-resolved online mass spectrometry to examine biogenic and anthropogenic contributions to organic aerosol in Beijing. Faraday Discussions. 2021;226:382-408.Abstract
Organic aerosols, a major constituent of fine particulate mass in megacities, can be directly emitted or formed from secondary processing of biogenic and anthropogenic volatile organic compound emissions. The complexity of volatile organic compound emission sources, speciation and oxidation pathways leads to uncertainties in the key sources and chemistry leading to formation of organic aerosol in urban areas. Historically, online measurements of organic aerosol composition have been unable to resolve specific markers of volatile organic compound oxidation, while offline analysis of markers focus on a small proportion of organic aerosol and lack the time resolution to carry out detailed statistical analysis required to study the dynamic changes in aerosol sources and chemistry. Here we use data collected as part of the joint UK–China Air Pollution and Human Health (APHH-Beijing) collaboration during a field campaign in urban Beijing in the summer of 2017 alongside laboratory measurements of secondary organic aerosol from oxidation of key aromatic precursors (1,3,5-trimethyl benzene, 1,2,4-trimethyl benzene, propyl benzene, isopropyl benzene and 1-methyl naphthalene) to study the anthropogenic and biogenic contributions to organic aerosol. For the first time in Beijing, this study applies positive matrix factorisation to online measurements of organic aerosol composition from a time-of-flight iodide chemical ionisation mass spectrometer fitted with a filter inlet for gases and aerosols (FIGAERO-ToF-I-CIMS). This approach identifies the real-time variations in sources and oxidation processes influencing aerosol composition at a near-molecular level. We identify eight factors with distinct temporal variability, highlighting episodic differences in OA composition attributed to regional influences and in situ formation. These have average carbon numbers ranging from C5–C9 and can be associated with oxidation of anthropogenic aromatic hydrocarbons alongside biogenic emissions of isoprene, α-pinene and sesquiterpenes.
Xie Y, Liu XR, Chen Q, Zhang SH. An integrated assessment for achieving the 2 degrees C target pathway in China by 2030. Journal of Cleaner Production. 2020;268.Abstract
China submitted the Greenhouse gas emission reduction target in the form of Nationally Determined Contributions (NDC) to the Paris Agreement. To reduce the negative impact of global warming, a tighter target is needed, such as the 2-degree target. This study investigated how China could reach its emissions peak and decarbonize its economy through different key countermeasures in various sectors in line with the NDC and 2 degrees C targets by 2030. A dynamic CGE model is used to develop ten scenarios that contain two dimensions consisting of two stringency levels of carbon emission limitation and the availability of different low-carbon options. We found that in the baseline scenario, China's total CO2 emissions in 2030 would reach 14.7 Gt. To meet China's NDC target, it is essential to develop non-fossil fuel energy, restrict the over-expansion of energy-intensive industries and improve end-use efficiency. Meanwhile, the global 2 degrees C target poses higher requirements for China to develop various non-fossil technologies both in electricity production and demand sectors, and vigorously promote low-carbon consumption pattern. Furthermore, we estimated the economic impacts and found that if low-carbon measures are adopted properly, the mitigation cost in 2030 could decline by 92 and 226 USD/ton-CO2 under the NDC target and 2 degrees C target, respectively. Accordingly, GDP loss could fall from 3.8% to barely 0.004% under the NDC target, and from 11.6% to 1.6% under the 2 degrees C target. The welfare will almost not be affected significantly under all scenarios. Moreover, carbon reduction will also bring co-benefits on the air pollution improvement in China. (c) 2020 Elsevier Ltd. All rights reserved.
Zhong HB, Huang RJ, Duan J, Lin CS, Gu YF, Wang Y, Li YJ, Zheng Y, Chen Q, Chen Y, et al. Seasonal variations in the sources of organic aerosol in Xi'an, Northwest China: The importance of biomass burning and secondary formation. Science of the Total Environment. 2020;737.Abstract
The Guanzhong basin is a part of the three top priority regions in China's blue sky action as of 2019. Understanding the chemical composition, sources, and atmospheric process of aerosol in this region is therefore imperative for improving air quality. In this study, we present, for the first time, the seasonal variations of organic aerosol (OA) in Xi'an, the largest city in the Guanzhong basin. Biomass burning OA (BBOA) and oxidized OA (OOA) contributed N50% of OA in both autumn and winter. The average concentrations of BBOA in autumn (14.8 +/- 5.1 mu g m(-3)) and winter (11.6 +/- 6.8 mu g m(-3)) were similar. The fractional contribution of BBOA to total OA, however, decreased from 31.9% in autumn to 15.3% in winter, because of enhanced contributions from other sources in winter. The OOA fraction in OA increased largely from 20.9% in autumn to 34.9% in winter, likely due to enhanced emissions of precursors and stagnant meteorological conditions which facilitate the accumulation and secondary formation. A large increase in OOA concentration was observed during polluted days, by a factor of similar to 4 in autumn and similar to 6 in winter compared to clean days. In both seasons, OOA formation was most likely dominated by photochemical oxidation when aerosol liquid water content was b30 mu g m(-3) or by aqueous-phase processes when Ox was b35 ppb. A higher concentration of BBOA was observed for air masses circulated within the Guanzhong basin (16.5-18.1 mu g m(-3)), compared to air masses from Northwest and West (10.9-14.5 mu g m(-3)). Furthermore, compared with OA fraction in non-refractory PM1 in other regions of China, BBOA (17-19%) and coal combustion OA (10-20%) were major emission sources in the Guanzhong Basin and the BTH region, respec-tively, whereas OOA (10-34%) was an important source in all studied regions. (C) 2020 Elsevier B.V. All rights reserved.
Wang T, Huang R-J, Li Y, Chen Q, Chen Y, Yang L, Guo J, Ni H, Hoffmann T, Wang X, et al. One-year characterization of organic aerosol markers in urban Beijing: Seasonal variation and spatiotemporal comparison. Science of the Total Environment. 2020;743.
Huang R-J, Duan J, Li Y, Chen Q, Chen Y, Tang M, Yang L, Ni H, Lin C, Xu W, et al. Effects of NH3 and alkaline metals on the formation of particulate sulfate and nitrate in wintertime Beijing. Science of the Total Environment. 2020;717.