Night-Time Atmospheric Reactivity of Some Oxygenated Organic Compounds

2014 ◽  
pp. 105-134
Author(s):  
B. Cabañas ◽  
P. Martín ◽  
S. Salgado ◽  
I. Colmenar ◽  
M-P. Gallego Iniesta ◽  
...  
Keyword(s):  
Organic Compounds ◽  
Night Time ◽  
Atmospheric Reactivity

Peroxy radicals from night-time reaction of N03 with organic compounds

Nature ◽  
1990 ◽  
Vol 348 (6297) ◽  
pp. 147-149 ◽  
Author(s):  
U. Platt ◽  
G. LeBras ◽  
G. Poulet ◽  
J. P. Burrows ◽  
G. Moortgat
Keyword(s):  
Organic Compounds ◽  
Peroxy Radicals ◽  
Night Time

scholarly journals Tree water relations trigger monoterpene emissions from Scots pine stem during spring recovery

2015 ◽  
Vol 12 (10) ◽  
pp. 7783-7814 ◽  
Author(s):  
A. Vanhatalo ◽  
T. Chan ◽  
J. Aalto ◽  
J. F. Korhonen ◽  
P. Kolari ◽  
...  
Keyword(s):  
Organic Compounds ◽  
Scots Pine ◽  
Sap Flow ◽  
Environmental Drivers ◽  
Diurnal Pattern ◽  
Night Time ◽  
Tree Diameter ◽  
Tree Canopies ◽  
Volatile Organic ◽  
Winter Time

Abstract. Tree canopies are known to emit large amounts of VOCs (volatile organic compounds) such as monoterpenes to the surrounding air. The main source for these is considered to be the green biomass, i.e. foliage, but emissions from the woody compartments have not been quantified. A VOC emission anomaly has been observed during transition from winter to summer activity. We analyzed if non-foliar components could partially explain the anomaly. We measured the VOC emissions from Scots pine (Pinus sylvestris L.) stems and shoots during the dehardening phase of trees in field conditions in two consecutive springs. We observed a large, transient monoterpene burst from stems, while the shoot monoterpene emissions and transpiration remained low. The burst lasted about 12 h. Simultaneously, an unusual night-time sap flow and an anomalous diurnal pattern of tree diameter were detected. Hence, we suggest that the monoterpene burst was a consequence of the recovery of the stem from winter-time. This indicates that the dominant processes and environmental drivers triggering the monoterpene emissions are different between stems and foliage.

scholarly journals Measurement report: Variability in the composition of biogenic volatile organic compounds in a Southeastern US forest and their role in atmospheric reactivity

2021 ◽  
Vol 21 (20) ◽  
pp. 15755-15770
Author(s):  
Deborah F. McGlynn ◽  
Laura E. R. Barry ◽  
Manuel T. Lerdau ◽  
Sally E. Pusede ◽  
Gabriel Isaacman-VanWertz
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Growing Season ◽  
Mixing Ratio ◽  
Biogenic Volatile Organic Compounds ◽  
Mixing Ratios ◽  
Southeastern Us ◽  
Atmospheric Reactivity ◽  
Volatile Organic ◽  
The Impact

Abstract. Despite the significant contribution of biogenic volatile organic compounds (BVOCs) to organic aerosol formation and ozone production and loss, there are few long-term, year-round, ongoing measurements of their volume mixing ratios and quantification of their impacts on atmospheric reactivity. To address this gap, we present 1 year of hourly measurements of chemically resolved BVOCs between 15 September 2019 and 15 September 2020, collected at a research tower in Central Virginia in a mixed forest representative of ecosystems in the Southeastern US. Mixing ratios of isoprene, isoprene oxidation products, monoterpenes, and sesquiterpenes are described and examined for their impact on the hydroxy radical (OH), ozone, and nitrate reactivity. Mixing ratios of isoprene range from negligible in the winter to typical summertime 24 h averages of 4–6 ppb, while monoterpenes have more stable mixing ratios in the range of tenths of a part per billion up to ∼2 ppb year-round. Sesquiterpenes are typically observed at mixing ratios of <10 ppt, but this represents a lower bound in their abundance. In the growing season, isoprene dominates OH reactivity but is less important for ozone and nitrate reactivity. Monoterpenes are the most important BVOCs for ozone and nitrate reactivity throughout the year and for OH reactivity outside of the growing season. To better understand the impact of this compound class on OH, ozone, and nitrate reactivity, the role of individual monoterpenes is examined. Despite the dominant contribution of α-pinene to total monoterpene mass, the average reaction rate of the monoterpene mixture with atmospheric oxidants is between 25 % and 30 % faster than α-pinene due to the contribution of more reactive but less abundant compounds. A majority of reactivity comes from α-pinene and limonene (the most significant low-mixing-ratio, high-reactivity isomer), highlighting the importance of both mixing ratio and structure in assessing atmospheric impacts of emissions.

scholarly journals Evaporative volatile organic compounds from gasoline in Mexico City: Characterization and atmospheric reactivity

2020 ◽  
Vol 6 ◽  
pp. 825-830 ◽  
Author(s):  
V. Mugica-Alvarez ◽  
C.A. Martínez-Reyes ◽  
N.M. Santiago-Tello ◽  
I. Martínez-Rodríguez ◽  
M. Gutiérrez-Arzaluz ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Mexico City ◽  
Atmospheric Reactivity ◽  
Volatile Organic

Characterization of gaseous and particulate phase organic compounds during a winter-time air pollution event

2020 ◽  
Author(s):  
Julien Kammer ◽  
Niall O’Sullivan ◽  
Elena Gomez Alvarez ◽  
Stig Hellebust ◽  
John Wenger
Keyword(s):  
Air Pollution ◽  
Organic Compounds ◽  
Solid Fuel ◽  
Urban Areas ◽  
Phase Transfer ◽  
Anthropogenic Sources ◽  
Particulate Phase ◽  
Night Time ◽  
Field Campaign ◽  
Pollution Event

&lt;p&gt;&lt;strong&gt;&amp;#160;Abstract&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;Atmospheric particles are known to cause adverse health effects and premature deaths in European cities. To improve air quality, a detailed understanding of particle sources is thus essential in order to reduce their emissions. Secondary organic aerosols (SOA) produced from the oxidation of volatile organic compounds emitted by anthropogenic sources such as road vehicles and solid fuel combustion is an important air pollution source in urban areas. It is demonstrated that SOA contribute significantly to the atmospheric particle loading, and could even be the major contributor at specific locations. Yet, state of the art models are still not able to reproduce SOA formation despite recent advances. Clearly, further work is needed to improve our understanding of the processes related to SOA formation.&lt;/p&gt;&lt;p&gt;In this context, a field campaign has been conducted at a monitoring station in Cork City, Ireland during winter 2019 (26&lt;sup&gt;th&lt;/sup&gt; January to 8&lt;sup&gt;th&lt;/sup&gt; February). The chemical composition of organic compounds in both gas and particle phases was investigated online using a Time-of-Flight Chemical Ionisation Mass Spectrometer (ToF-CIMS) coupled with a Filter Inlet for Gases and Aerosols (FIGAERO). PM&lt;sub&gt;2.5&lt;/sub&gt; concentration, ozone and nitrogen oxides (NO&lt;sub&gt;x&lt;/sub&gt;) were also monitored during the campaign, as well as meteorological parameters. Finally, air mass backward trajectories were computed using the HYSPLIT model.&lt;/p&gt;&lt;p&gt;A strong night-time air pollution event was observed during the field campaign, characterized by PM&lt;sub&gt;2.5&lt;/sub&gt; concentrations up to 180 &amp;#181;g m&lt;sup&gt;-3&lt;/sup&gt;. Using iodide as reagent, the FIGAERO-ToF-CIMS detected hundreds of ions simultaneously in gas and particulate phases. Among the identified compounds were a range of well-known atmospheric tracers of solid fuel burning, including phenolic compounds such as guaiacol and catechol, and numerous oxygenated polycyclic aromatic hydrocarbons (OPAHs). A number of nitrated aromatic compounds were also detected. In this work, the gas/particle partitioning of some of these key compounds has been investigated to provide information on phase transfer of solid fuel emissions over time. The thermograms produced by the FIGAERO analysis are also used to determine the volatility of the species detected. Finally, the FIGAERO-ToF-CIMS data is used to explore the extent to which oxidation of the gaseous emissions by the nitrate radical (NO&lt;sub&gt;3&lt;/sub&gt;) leads to the formation of nitrated compounds in the particulate phase. This work thus provides unique insights into the night-time oxidation processes that can lead to SOA formation from anthropogenic sources.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Acknowledgments&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;This work was supported by the Irish Research Council (GOIPG/2017/1364) and by the European Union&amp;#8217;s Horizon 2020 research and innovation programme (EUROCHAMP-2020, grant no.&amp;#160;730997; Marie Sk&amp;#322;odowska-Curie grant agreement No. 751527).&lt;/p&gt;

scholarly journals Measurements of biogenic volatile organic compounds at a grazed savannah-grassland-agriculture landscape in South Africa

2016 ◽  
Author(s):  
Kerneels Jaars ◽  
Pieter G. van Zyl ◽  
Johan P. Beukes ◽  
Heidi Hellén ◽  
Ville Vakkari ◽  
...  
Keyword(s):  
South Africa ◽  
Soil Moisture ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Wind Direction ◽  
Reaction Rates ◽  
Biogenic Volatile Organic Compounds ◽  
Night Time ◽  
Volatile Organic ◽  
Order Of Magnitude

Abstract. Biogenic volatile organic compounds (BVOCs) are important role players in the chemistry of the troposphere, especially in the formation of tropospheric ozone (O3) and secondary organic aerosols (SOA). Ecosystems produce and emit a large number of BVOCs. It is estimated on a global scale that approximately 90 % of annual VOC emissions are BVOCs. In this study, measurements of BVOCs were conducted at the Welgegund measurement station (South Africa), which is considered to be a regionally representative background site situated in savannah grassland. Very few BVOC measurements exist for grassland savannah and results presented in this study are the most extensive for this type of landscape. Samples were collected twice a week for two hours during daytime and two hours during night-time through two long-term sampling campaigns from February 2011 to February 2012 and from December 2013 to February 2015. Individual BVOCs were identified and quantified using a thermal desorption instrument, connected to a gas chromatograph and a mass selective detector. The annual median concentrations of isoprene, 2-methyl-3-butene-2-ol (MBO), monoterpenes and sesquiterpenes (SQT) during the first campaign were 14, 7, 120 and 8 pptv, respectively, and 14, 4, 83 and 4 pptv, respectively, during the second campaign. The sum of the concentrations of the monoterpenes were at least an order of magnitude higher than the concentrations of other BVOC species during both sampling campaigns, with α-pinene being the most abundant species. The highest BVOC concentrations were observed during the wet season and elevated soil moisture was associated with increased BVOC concentrations. However, comparisons with measurements conducted at other landscapes in southern Africa and the rest of the world that have more woody vegetation indicated that BVOC concentrations were, in general, significantly lower. Furthermore, BVOC concentrations were an order of magnitude lower compared to total aromatic concentrations measured at Welgegund. An analysis of concentrations by wind direction indicated that isoprene concentrations were higher from the western direction, while wind direction did not indicate any significant differences in the concentrations of the other BVOC species. Statistical analysis indicated that soil moisture had the most significant impact on atmospheric levels of MBO, monoterpenes and SQT concentrations, while temperature had the greatest influence on isoprene levels. The combined O3 formation potentials of all the BVOCs measured calculated with MIR coefficients during the first and second campaign were 1162 and 1022 pptv, respectively. α-Pinene and limonene had the highest reaction rates with O3, while isoprene exhibited relatively small contributions to O3 depletion. Limonene, α-pinene and terpinolene had the largest contributions to the OH-reactivity of BVOCs measured at Welgegund for all of the months during both sampling campaigns.

scholarly journals Alkyl nitrates in the boreal forest: formation via the NO<sub>3</sub>-, OH- and O<sub>3</sub>-induced oxidation of biogenic volatile organic compounds and ambient lifetimes

2019 ◽  
Vol 19 (15) ◽  
pp. 10391-10403 ◽  
Author(s):  
Jonathan Liebmann ◽  
Nicolas Sobanski ◽  
Jan Schuladen ◽  
Einar Karu ◽  
Heidi Hellén ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Boreal Forest ◽  
Organic Compounds ◽  
High Reactivity ◽  
Anthropogenic Sources ◽  
Reactive Nitrogen ◽  
Biogenic Volatile Organic Compounds ◽  
Night Time ◽  
Alkyl Nitrates ◽  
Volatile Organic

Abstract. The formation of alkyl nitrates in various oxidation processes taking place throughout the diel cycle can represent an important sink of reactive nitrogen and mechanism for chain termination in atmospheric photo-oxidation cycles. The low-volatility alkyl nitrates (ANs) formed from biogenic volatile organic compounds (BVOCs), especially terpenoids, enhance rates of production and growth of secondary organic aerosol. Measurements of the NO3 reactivity and the mixing ratio of total alkyl nitrates (ΣANs) in the Finnish boreal forest enabled assessment of the relative importance of NO3-, O3- and OH-initiated formation of alkyl nitrates from BVOCs in this environment. The high reactivity of the forest air towards NO3 resulted in reactions of the nitrate radical, with terpenes contributing substantially to formation of ANs not only during the night but also during daytime. Overall, night-time reactions of NO3 accounted for 49 % of the local production rate of ANs, with contributions of 21 %, 18 % and 12 % for NO3, OH and O3 during the day. The lifetimes of the gas-phase ANs formed in this environment were on the order of 2 h due to efficient uptake to aerosol (and dry deposition), resulting in the transfer of reactive nitrogen from anthropogenic sources to the forest ecosystem.

scholarly journals The Association between Exposure to Residential Indoor Volatile Organic Compounds and Measures of Central Arterial Stiffness in Healthy Middle-Aged Men and Women

2022 ◽  
Vol 19 (2) ◽  
pp. 981
Author(s):  
Suzanne E. Gilbey ◽  
Christopher M. Reid ◽  
Rachel R. Huxley ◽  
Mario J. Soares ◽  
Yun Zhao ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Arterial Stiffness ◽  
Organic Compounds ◽  
Disease Risk ◽  
Augmentation Index ◽  
Cardiovascular Disease Risk ◽  
Night Time ◽  
Cross Sectional ◽  
Men And Women ◽  
Volatile Organic

It is well reported that individuals spend up to 90% of their daily time indoors, with between 60% to 90% of this time being spent in the home. Using a cross-sectional study design in a population of 111 healthy adults (mean age: 52.3 ± 9.9 years; 65% women), we investigated the association between exposure to total volatile organic compounds (VOCs) in indoor residential environments and measures of central arterial stiffness, known to be related to cardiovascular risk. Indoor VOC concentrations were measured along with ambulatory measures of pulse pressure (cPP), augmentation index (cAIx) and cAIx normalized for heart rate (cAIx75), over a continuous 24-h period. Pulse wave velocity (cfPWV) was determined during clinical assessment. Multiple regression analysis was performed to examine the relationship between measures of arterial stiffness and VOCs after adjusting for covariates. Higher 24-h, daytime and night-time cAIx was associated with an interquartile range increase in VOCs. Similar effects were shown with cAIx75. No significant effects were observed between exposure to VOCs and cPP or cfPWV. After stratifying for sex and age (≤50 years; >50 years), effect estimates were observed to be greater and significant for 24-h and daytime cAIx in men, when compared to women. No significant effect differences were seen between age groups with any measure of arterial stiffness. In this study, we demonstrated that residential indoor VOCs exposure was adversely associated with some measures of central arterial stiffness, and effects were different between men and women. Although mechanistic pathways remain unclear, these findings provide a possible link between domestic VOCs exposure and unfavourable impacts on individual-level cardiovascular disease risk.

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