Impact of harbour emissions on ambient PM10 and PM2.5 in Barcelona (Spain): Evidences of secondary aerosol formation within the urban area

2016 ◽  
Vol 571 ◽  
pp. 237-250 ◽  
Author(s):  
Noemí Pérez ◽  
Jorge Pey ◽  
Cristina Reche ◽  
Joaquim Cortés ◽  
Andrés Alastuey ◽  
...  
2021 ◽  
Vol 150 ◽  
pp. 106426
Author(s):  
Jie Tian ◽  
Qiyuan Wang ◽  
Yong Zhang ◽  
Mengyuan Yan ◽  
Huikun Liu ◽  
...  

2018 ◽  
Author(s):  
Matthias Karl

Abstract. This paper describes the City-scale Chemistry (CityChem) extension of the urban dispersion model EPISODE with the aim to enable chemistry/transport simulations of multiple reactive pollutants on urban scales. The new model is called CityChem-EPISODE. The primary focus is on the simulation of urban ozone concentrations. Ozone is produced in photochemical reaction cycles involving nitrogen oxides (NOx) and volatile organic compounds (VOC) emitted by various anthropogenic activities in the urban area. The performance of the new model was evaluated with a series of synthetic tests and with a first application to the air quality situation in the city of Hamburg, Germany. The model performs fairly well for ozone in terms of temporal correlation and bias at the air quality monitoring stations in Hamburg. In summer afternoons, when photochemical activity is highest, modelled median ozone at an inner-city urban background station was about 30 % lower than the observed median ozone. Inaccuracy of the computed photolysis frequency of nitrogen dioxide (NO2) is the most probable explanation for this. CityChem-EPISODE reproduces the spatial variation of annual mean NO2 concentrations between urban background, traffic and industrial stations. However, the temporal correlation between modelled and observed hourly NO2 concentrations is weak for some of the stations. For daily mean PM10, the performance of CityChem-EPISODE is moderate due to low temporal correlation. The low correlation is linked to uncertainties in the seasonal cycle of the anthropogenic particulate matter (PM) emissions within the urban area. Missing emissions from domestic heating might be an explanation for the too low modelled PM10 in winter months. Four areas of need for improvement have been identified: (1) dry and wet deposition fluxes; (2) treatment of photochemistry in the urban atmosphere; (3) formation of secondary inorganic aerosol (SIA); and (4) formation of biogenic and anthropogenic secondary organic aerosol (SOA). The inclusion of secondary aerosol formation will allow for a better sectorial attribution of observed PM levels. Envisaged applications of the CityChem-EPISODE model are urban air quality studies, environmental impact assessment, sensitivity analysis of sector-specific emission and the assessment of local and regional emission abatement policy options.


2021 ◽  
Vol 21 (10) ◽  
pp. 7963-7981
Author(s):  
Zhaomin Yang ◽  
Li Xu ◽  
Narcisse T. Tsona ◽  
Jianlong Li ◽  
Xin Luo ◽  
...  

Abstract. Aromatic hydrocarbons can dominate the volatile organic compound budget in the urban atmosphere. Among them, 1,2,4-trimethylbenzene (TMB), mainly emitted from solvent use, is one of the most important secondary organic aerosol (SOA) precursors. Although atmospheric SO2 and NH3 levels can affect secondary aerosol formation, the influenced extent of their impact and their detailed driving mechanisms are not well understood. The focus of the present study is to examine the chemical compositions and formation mechanisms of SOA from TMB photooxidation influenced by SO2 and/or NH3. Here, we show that SO2 emission could considerably enhance aerosol particle formation due to SO2-induced sulfate generation and acid-catalyzed heterogeneous reactions. Orbitrap mass spectrometry measurements revealed the generation of not only typical TMB products but also hitherto unidentified organosulfates (OSs) in SO2-added experiments. The OSs designated as being of unknown origin in earlier field measurements were also detected in TMB SOA, indicating that atmospheric OSs might also be originated from TMB photooxidation. For NH3-involved experiments, results demonstrated a positive correlation between NH3 levels and particle volume as well as number concentrations. The effects of NH3 on SOA composition were slight under SO2-free conditions but stronger in the presence of SO2. A series of multifunctional products with carbonyl, alcohols, and nitrate functional groups were tentatively characterized in NH3-involved experiments based on infrared spectra and mass spectrometry analysis. Plausible formation pathways were proposed for detected products in the particle phase. The volatility distributions of products, estimated using parameterization methods, suggested that the detected products gradually condense onto the nucleation particles to contribute to aerosol formation and growth. Our results suggest that strict control of SO2 and NH3 emissions might remarkably reduce organosulfates and secondary aerosol burden in the atmosphere. Updating the aromatic oxidation mechanism in models could result in more accurate treatment of particle formation for urban regions with considerable SO2, NH3, and aromatics emissions.


2019 ◽  
Vol 19 (22) ◽  
pp. 14329-14338 ◽  
Author(s):  
Misti Levy Zamora ◽  
Jianfei Peng ◽  
Min Hu ◽  
Song Guo ◽  
Wilmarie Marrero-Ortiz ◽  
...  

Abstract. Severe wintertime haze events with exceedingly high levels of aerosols have occurred frequently in China in recent years, impacting human health, weather, and the climate. A better knowledge of the formation mechanism and aerosol properties during haze events is helpful for the development of effective mitigation policies. In this study, we present field measurements of aerosol properties at an urban site in Beijing during January and February 2015. A suite of aerosol instruments were deployed to measure a comprehensive set of aerosol chemical and physical properties. The evolution of haze events in winter, dependent on meteorological conditions, consistently involves new particle formation during the clean period and subsequently continuous growth from the nucleation mode particles to submicron particles over the course of multiple days. Particulate organic matter is primarily responsible for producing the nucleation mode particles, while secondary organic and inorganic components jointly contribute to the high aerosol mass observed during haze events. The average effective density and hygroscopic parameter (κ) of ambient particles are approximately 1.37 g cm−3 and 0.25 during the clean period and increase to 1.42 g cm−3 and 0.4 during the polluted period, indicating the formation of secondary inorganic species from the continuous growth of nucleation mode particles. Our results corroborate that the periodic cycles of severe haze formation in Beijing during winter are attributed to the efficient nucleation and secondary aerosol growth under high gaseous precursor concentrations and the stagnant air conditions, highlighting that reductions in emissions of aerosol precursor gases are critical for remedying secondary aerosol formation and thereby mitigating haze pollution.


2021 ◽  
Vol 759 ◽  
pp. 143540
Author(s):  
Jing Ding ◽  
Qili Dai ◽  
Yufen Zhang ◽  
Jiao Xu ◽  
Yanqi Huangfu ◽  
...  

2020 ◽  
Vol 737 ◽  
pp. 140333
Author(s):  
Patrick Roth ◽  
Jiacheng Yang ◽  
Christos Stamatis ◽  
Kelley C. Barsanti ◽  
David R. Cocker ◽  
...  

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