scholarly journals Emission ratios of anthropogenic volatile organic compounds in northern mid-latitude megacities: Observations versus emission inventories in Los Angeles and Paris

2013 ◽  
Vol 118 (4) ◽  
pp. 2041-2057 ◽  
Author(s):  
Agnes Borbon ◽  
J. B. Gilman ◽  
W. C. Kuster ◽  
N. Grand ◽  
S. Chevaillier ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Los Angeles ◽  
Organic Compounds ◽  
Emission Inventories ◽  
Volatile Organic ◽  
Emission Ratios

scholarly journals Chemistry of Volatile Organic Compounds in the Los Angeles basin: Nighttime Removal of Alkenes and Determination of Emission Ratios

2017 ◽  
Vol 122 (21) ◽  
pp. 11,843-11,861 ◽  
Author(s):  
J. A. de Gouw ◽  
J. B. Gilman ◽  
S.-W. Kim ◽  
B. M. Lerner ◽  
G. Isaacman-VanWertz ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Los Angeles ◽  
Organic Compounds ◽  
Los Angeles Basin ◽  
Volatile Organic ◽  
Emission Ratios

A Future Multi-Platform Atmospheric Chemistry Measurement Campaign to Study Oxidation in Mixed Anthropogenic-Biogenic Air Masses

2021 ◽  
Author(s):  
Christopher Cantrell ◽  
Vincent Michoud ◽  
Paola Formenti ◽  
Jean-Francois Doussin ◽  
Stephanie Alhajj Moussa ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Los Angeles ◽  
Organic Compounds ◽  
Atmospheric Chemistry ◽  
Vapor Pressures ◽  
Air Masses ◽  
Measurement Campaign ◽  
Secondary Species ◽  
Volatile Organic ◽  
Urban Plumes

<p>It is well known that the high population density of urban regions leads to significant degradation of the quality of the air because of the emissions of pollutants that are by-products of energy production, transportation, and industry. The composition and chemistry of urban air has been studied for many decades and these studies have led to detailed understanding of the factors controlling, for example, the formation of ozone, peroxyacetyl nitrate and other secondary species. In the last 20 to 30 years, significant progress has been made in reducing emissions of volatile organic compounds (VOCs) and oxides of nitrogen (NO<sub>x</sub>) in urban atmospheres. Substantial reductions in the abundance of secondary compounds, though, have been more elusive.</p><p>Research has continued to reveal more and more details of the complex processes involved in the atmospheric degradation of wide varieties of volatile organic compounds (VOCs) of anthropogenic and biospheric (BVOCs) origins. BVOCs include isoprene, monoterpenes and sesquiterpenes, and oxygenated VOCs (OVOCs, such as small alcohols). Emissions of BVOCs depend on several factors such as plant or tree species, temperature, and photosynthetically active radiation. They consist almost exclusively of unsaturated compounds with chemistry somewhat different from those of typical urban organic compound emissions. Oxidation of VOCs can lead to molecules of low volatility that are prone to uptake into the aerosol phase.</p><p>Recent studies conducted in megacities such as Paris, Mexico City, Los Angeles and those in China have led to significant advances in our understanding of the chemical evolution of urban plumes. However, important scientific questions remain on how mixing of anthropogenic and biogenic air masses modifies the composition of urban plumes and hence their impacts. Indeed, the proximity of cites to areas of strong biogenic emissions is not unusual. Many major cities at mid-latitudes are surrounded by forested areas.</p><p>ACROSS (Atmospheric ChemistRy Of the Suburban foreSt) is an integrative, innovative, multi-scale project awarded under the “Make Our Planet Great Again” (MOPGA) framework that seeks to definitively improve understanding of the impacts of mixing urban and biogenic air masses on the oxidation of atmospheric VOCs. The ACROSS working hypothesis is that this leads to changes in the production of oxygenated VOCs whose properties (e.g. vapor pressures) alter their importance in incorporation into SOA and their roles in production of ozone and other secondary species. Changes are also expected in the efficiency of radical recycling affecting the atmospheric oxidative capacity. Particularly important is NO<sub>x</sub> transport to suburban biogenic environments and the resulting modification of key chemical processes.</p><p>A key highlight of ACROSS is an intensive, multi-platform measurement campaign in the summer of 2022. It will use instruments staged on an airborne platform, a tower in the Rambouillet Forest near Paris, and other ground sites. The data collected from this campaign will be analyzed and studied to extract information about tropospheric oxidation chemistry generally, but also changes observed in the situation of mixed urban and biogenic air masses.</p><p>This presentation will summarize plans for the ACROSS campaign.</p>

scholarly journals Source apportionment of volatile organic compounds in the northwest Indo-Gangetic Plain using a positive matrix factorization model

2019 ◽  
Vol 19 (24) ◽  
pp. 15467-15482 ◽  
Author(s):  
◽  
Baerbel Sinha ◽  
Vinayak Sinha
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Waste Disposal ◽  
Isocyanic Acid ◽  
Transport Sector ◽  
Emission Inventories ◽  
Gangetic Plain ◽  
Pmf Model ◽  
Volatile Organic ◽  
Indo Gangetic Plain

Abstract. In this study we undertook quantitative source apportionment for 32 volatile organic compounds (VOCs) measured at a suburban site in the densely populated northwest Indo-Gangetic Plain using the US EPA PMF 5.0 model. Six sources were resolved by the PMF model. In descending order of their contribution to the total VOC burden these are “biofuel use and waste disposal” (23.2 %), “wheat-residue burning”(22.4 %), “cars” (16.2 %), “mixed daytime sources”(15.7 %) “industrial emissions and solvent use”(11.8 %), and “two-wheelers” (8.6 %). Wheat-residue burning is the largest contributor to the total ozone formation potential (32.4 %). For the emerging contaminant isocyanic acid, photochemical formation from precursors (37 %) and wheat-residue burning (25 %) were the largest contributors to human exposure. Wheat-residue burning was also the single largest source of the photochemical precursors of isocyanic acid, namely, formamide, acetamide and propanamide, indicating that this source must be most urgently targeted to reduce human concentration exposure to isocyanic acid in the month of May. Our results highlight that for accurate air quality forecasting and modeling it is essential that emissions are attributed only to the months in which the activity actually occurs. This is important for emissions from crop residue burning, which occur in May and from mid-October to the end of November. The SOA formation potential is dominated by cars (36.9 %) and two-wheelers (21.1 %), which also jointly account for 47% of the human class I carcinogen benzene in the PMF model. This stands in stark contrast to various emission inventories which estimate only a minor contribution of the transport sector to the benzene exposure (∼10 %) and consider residential biofuel use, agricultural residue burning and industry to be more important benzene sources. Overall it appears that none of the emission inventories represent the regional emissions in an ideal manner. Our PMF solution suggests that transport sector emissions may be underestimated by GAINSv5.0 and EDGARv4.3.2 and overestimated by REASv2.1, while the combined effect of residential biofuel use and waste disposal emissions as well as the VOC burden associated with solvent use and industrial sources may be overestimated by all emission inventories. The agricultural waste burning emissions of some of the detected compound groups (ketones, aldehydes and acids) appear to be missing in the EDGARv4.3.2 inventory.

scholarly journals A temporally and spatially resolved validation of emission inventories by measurements of ambient volatile organic compounds in Beijing, China

2014 ◽  
Vol 14 (12) ◽  
pp. 5871-5891 ◽  
Author(s):  
M. Wang ◽  
M. Shao ◽  
W. Chen ◽  
B. Yuan ◽  
S. Lu ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Measurement Data ◽  
Suburban Area ◽  
Urban Site ◽  
Emission Inventories ◽  
Relative Contribution ◽  
Volatile Organic ◽  
Current Emission ◽  
Ambient Measurements

Abstract. Understanding the sources of volatile organic compounds (VOCs) is essential for ground-level ozone and secondary organic aerosol (SOA) abatement measures. We made VOC measurements at 27 sites and online observations at an urban site in Beijing from July 2009 to January 2012. Based on these measurement data, we determined the spatial and temporal distribution of VOCs, estimated their annual emission strengths based on their emission ratios relative to carbon monoxide (CO), and quantified the relative contributions of various sources using the chemical mass balance (CMB) model. These results from ambient measurements were compared with existing emission inventories to evaluate the spatial distribution, species-specific emissions, and source structure of VOCs in Beijing. The measured VOC distributions revealed a hotspot in the southern suburban area of Beijing, whereas current emission inventories suggested that VOC emissions were concentrated in downtown areas. Compared with results derived from ambient measurements, the annual inventoried emissions of oxygenated VOC (OVOC) species and C2–C4 alkanes may be underestimated, while the emissions of styrene and 1,3-butadiene may be overestimated by current inventories. Source apportionment using the CMB model identified vehicular exhaust as the most important VOC source, with the relative contribution of 49%, in good agreement with the 40–51% estimated by emission inventories. The relative contribution of paint and solvent utilization obtained from the CMB model was 14%, significantly lower than the value of 32% reported by one existing inventory. Meanwhile, the relative contribution of liquefied petroleum gas (LPG) usage calculated using the CMB model was 6%, whereas LPG usage contribution was not reported by current emission inventories. These results suggested that VOC emission strengths in southern suburban area of Beijing, annual emissions of C2–C4 alkanes, OVOCs and some alkenes, and the contributions of solvent and paint utilization and LPG usage in current inventories all require significant revisions.

scholarly journals Multiyear trends in volatile organic compounds in Los Angeles, California: Five decades of decreasing emissions

2012 ◽  
Vol 117 (D21) ◽  
pp. n/a-n/a ◽  
Author(s):  
Carsten Warneke ◽  
Joost A. de Gouw ◽  
John S. Holloway ◽  
Jeff Peischl ◽  
Thomas B. Ryerson ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Los Angeles ◽  
Organic Compounds ◽  
Volatile Organic

scholarly journals VOC emissions, evolutions and contributions to SOA formation at a receptor site in eastern China

2013 ◽  
Vol 13 (17) ◽  
pp. 8815-8832 ◽  
Author(s):  
B. Yuan ◽  
W. W. Hu ◽  
M. Shao ◽  
M. Wang ◽  
W. T. Chen ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Emission Inventory ◽  
Eastern China ◽  
Receptor Site ◽  
Organic Aerosol ◽  
Inventory Data ◽  
Voc Oxidation ◽  
Volatile Organic ◽  
Emission Ratios

Abstract. Volatile organic compounds (VOCs) were measured by two online instruments (GC-FID/MS and PTR-MS) at a receptor site on Changdao Island (37.99° N, 120.70° E) in eastern China. Reaction with OH radical dominated chemical losses of most VOC species during the Changdao campaign. A photochemical-age-based parameterization method is used to calculate VOC emission ratios and to quantify the evolution of ambient VOCs. The calculated emission ratios of most hydrocarbons agree well with those obtained from emission inventory data, but determined emission ratios of oxygenated VOCs (OVOCs) are significantly higher than those from emission inventory data. The photochemical-age-based parameterization method is also used to investigate primary emissions and secondary formation of organic aerosol. The primary emission ratio of organic aerosol (OA) to CO is determined to be 14.9 μg m−3 ppm−1, and secondary organic aeorosols (SOA) are produced at an enhancement ratio of 18.8 μg m−3 ppm−1 to CO after 50 h of photochemical processing in the atmosphere. SOA formation is significantly higher than the level determined from VOC oxidation under both high-NOx (2.0 μg m−3 ppm−1 CO) and low-NOx conditions (6.5 μg m−3 ppm−1 CO). Polycyclic aromatic hydrocarbons (PAHs) and higher alkanes (> C10) account for as high as 17.4% of SOA formation, which suggests semi-volatile organic compounds (SVOCs) may be a large contributor to SOA formation during the Changdao campaign. The SOA formation potential of primary VOC emissions determined from field campaigns in Beijing and Pearl River Delta (PRD) is lower than the measured SOA levels reported in the two regions, indicating SOA formation is also beyond explainable by VOC oxidation in the two city clusters.

scholarly journals PTR-MS measurements of non-methane volatile organic compounds during an intensive field campaign at the summit of Mount Tai, China, in June 2006

2009 ◽  
Vol 9 (6) ◽  
pp. 26697-26734 ◽  
Author(s):  
S. Inomata ◽  
H. Tanimoto ◽  
S. Kato ◽  
J. Suthawaree ◽  
Y. Kanaya ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Transfer Reaction ◽  
Proton Transfer Reaction ◽  
Temporal Variations ◽  
Field Campaign ◽  
Volatile Organic ◽  
Aldehydes And Ketones ◽  
Urban Sites ◽  
Emission Ratios

Abstract. Owing to recent industrialization, Central East China has become a significant source of air pollutants. To examine the processes controlling the chemistry and transport of tropospheric ozone, we continuously measured non-methane volatile organic compounds (NMVOCs) as part of an intensive field campaign at Mount Tai, China, in June 2006 (MTX2006), using proton transfer reaction mass spectrometry (PTR-MS). Temporal variations of NMVOCs were recorded in mass-scan mode from m/z 17 to m/z 300 during 12–30 June 2006. More than thirty kinds of NMVOCs were detected up to m/z 160, including alkenes, aromatics, alcohols, aldehydes, and ketones. Oxygenated VOCs were the predominant NMVOCs. During the night of 12 June, we observed an episode of high NMVOCs concentrations attributed to the burning of agricultural biomass. The ΔNMVOCs/ΔCO ratios derived by PTR-MS measurements for this episode are compared to emission ratios from various types of biomass burning as reviewed by Andreae and Merlet (2001) and to ratios recently measured by PTR-MS in tropical forests (Karl et al., 2007) and at urban sites (Warneke et al., 2007).

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