scholarly journals Importance of biogenic volatile organic compounds to acyl peroxy nitrates (APN) production in the southeastern US during SOAS 2013

2019 ◽  
Vol 19 (3) ◽  
pp. 1867-1880 ◽  
Author(s):  
Shino Toma ◽  
Steve Bertman ◽  
Christopher Groff ◽  
Fulizi Xiong ◽  
Paul B. Shepson ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Gas Phase ◽  
Organic Compounds ◽  
Model Simulation ◽  
Statistical Correlation ◽  
Organic Nitrates ◽  
Biogenic Volatile Organic Compounds ◽  
The North ◽  
Southeastern Us ◽  
Volatile Organic

Abstract. Gas-phase atmospheric concentrations of peroxyacetyl nitrate (PAN), peroxypropionyl nitrate (PPN), and peroxymethacryloyl nitrate (MPAN) were measured on the ground using a gas chromatograph electron capture detector (GC-ECD) during the Southern Oxidants and Aerosols Study (SOAS) 2013 campaign (1 June to 15 July 2013) in Centreville, Alabama, in order to study biosphere–atmosphere interactions. Average levels of PAN, PPN, and MPAN were 169, 5, and 9 pptv, respectively, and the sum accounts for an average of 16 % of NOy during the daytime (10:00 to 16:00 local time). Higher concentrations were seen on average in air that came to the site from the urban NOx sources to the north. PAN levels were the lowest observed in ground measurements over the past two decades in the southeastern US. A multiple regression analysis indicates that biogenic volatile organic compounds (VOCs) account for 66 % of PAN formation during this study. Comparison of this value with a 0-D model simulation of peroxyacetyl radical production indicates that at least 50 % of PAN formation is due to isoprene oxidation. MPAN has a statistical correlation with isoprene hydroxynitrates (IN). Organic aerosol mass increases with gas-phase MPAN and IN concentrations, but the mass of organic nitrates in particles is largely unrelated to MPAN.

scholarly journals Aerosol mass yields of selected biogenic volatile organic compounds – a theoretical study with nearly explicit gas-phase chemistry

2019 ◽  
Vol 19 (22) ◽  
pp. 13741-13758
Author(s):  
Carlton Xavier ◽  
Anton Rusanen ◽  
Putian Zhou ◽  
Chen Dean ◽  
Lukas Pichelstorfer ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Gas Phase ◽  
Organic Compounds ◽  
Chemical Mechanism ◽  
Biogenic Volatile Organic Compounds ◽  
Gas Phase Chemistry ◽  
Mass Load ◽  
Volatile Organic ◽  
Phase Chemistry ◽  
Good Agreement

Abstract. In this study we modeled secondary organic aerosol (SOA) mass loadings from the oxidation (by O3, OH and NO3) of five representative biogenic volatile organic compounds (BVOCs): isoprene, endocyclic bond-containing monoterpenes (α-pinene and limonene), exocyclic double-bond compound (β-pinene) and a sesquiterpene (β-caryophyllene). The simulations were designed to replicate an idealized smog chamber and oxidative flow reactors (OFRs). The Master Chemical Mechanism (MCM) together with the peroxy radical autoxidation mechanism (PRAM) were used to simulate the gas-phase chemistry. The aim of this study was to compare the potency of MCM and MCM + PRAM in predicting SOA formation. SOA yields were in good agreement with experimental values for chamber simulations when MCM + PRAM was applied, while a stand-alone MCM underpredicted the SOA yields. Compared to experimental yields, the OFR simulations using MCM + PRAM yields were in good agreement for BVOCs oxidized by both O3 and OH. On the other hand, a stand-alone MCM underpredicted the SOA mass yields. SOA yields increased with decreasing temperatures and NO concentrations and vice versa. This highlights the limitations posed when using fixed SOA yields in a majority of global and regional models. Few compounds that play a crucial role (>95 % of mass load) in contributing to SOA mass increase (using MCM + PRAM) are identified. The results further emphasized that incorporating PRAM in conjunction with MCM does improve SOA mass yield estimation.

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 Importance of Biogenic Volatile Organic Compounds to Peroxyacyl Nitrates (PANs) Production in the Southeastern U.S. during SOAS 2013

2018 ◽  
Author(s):  
Shino Toma ◽  
Steve Bertman ◽  
Christopher Groff ◽  
Fulizi Xiong ◽  
Paul B. Shepson ◽  
...  
Keyword(s):  
Gas Phase ◽  
Atmospheric Chemistry ◽  
Model Simulation ◽  
Statistical Correlation ◽  
Organic Nitrates ◽  
The North ◽  
Aerosol Mass ◽  
Isoprene Oxidation ◽  
D Model ◽  
Atmospheric Concentrations

Abstract. Gas-phase atmospheric concentrations of PAN, PPN, and MPAN were measured at the ground using GC-ECD during the SOAS 2013 campaign (1 June to 15 July 2013) in Centerville, Alabama in order to study biosphere-atmosphere interactions. Average levels of PAN, PPN and MPAN were 169, 5, and 9 pptv respectively, and the sum accounts for an average of 15 % of NOy during the daytime (10 am to 4 pm local time). Higher concentrations were seen on average in air that came to the site from the urban NOx sources to the north. PAN levels were the lowest observed in ground measurements over the past two decades in the Southeastern U.S. Analysis of PAN/NOx indicates PAN production in this region was sensitive to NOx. A multiple regression analysis indicates that biogenic VOCs account for 66 % of PAN formation in this region of the Southeastern U.S. Comparison of this value with a 0-D model simulation of peroxyacetyl radical production indicates that at least 50 % of PAN formation is due to isoprene oxidation. MPAN has a statistical correlation with isoprene hydroxynitrates (IN) with an average MPANppb/INppb ratio of 0.3. Organic aerosol mass increases with gas-phase MPAN and IN concentrations, but the mass of organic nitrates in particles is largely insensitive to MPAN. Isoprene and PAN play a significant role in the atmospheric chemistry in the Southeastern United States.

scholarly journals Aerosol Mass yields of selected Biogenic Volatile Organic Compounds – a theoretical study with near explicit gas-phase chemistry

2019 ◽  
Author(s):  
Carlton Xavier ◽  
Anton Rusanen ◽  
Putian Zhou ◽  
Chen Dean ◽  
Lukas Pichelstorfer ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Gas Phase ◽  
Organic Compounds ◽  
Chemical Mechanism ◽  
Seed Particle ◽  
Biogenic Volatile Organic Compounds ◽  
Gas Phase Chemistry ◽  
Mass Load ◽  
Volatile Organic ◽  
Phase Chemistry

Abstract. In this study we modeled secondary organic aerosols (SOA) mass loadings from the oxidation (by O3, OH and NO3) of five representative Biogenic Volatile Organic compounds (BVOCs): isoprene, endocyclic bond containing monoterpenes (α-pinene and limonene), exocyclic double bond compound (β-pinene) and a sesquiterpene (β-caryophyllene). The simulations were designed to replicate idealized smog chamber and oxidative flow reactors (OFR). The master chemical mechanism (MCM) together with the peroxy radical autoxidation mechanism (PRAM), were used to simulate the gas-phase chemistry. The aim of this study was to compare the potency of MCM and MCM+PRAM in predicating SOA formation. SOA yields were in good agreement with experimental values for chamber simulations when MCM+PRAM mechanism was applied, while a standalone MCM under-predicted the SOA yields. Compared to experimental yields, the OFR simulations using the MCM+PRAM mechanism over-predicted SOA mass yields for BVOCs oxidized by O3 and OH, probably owing to increased seed particle surface area used in the OFR simulations. SOA yields increased with decreasing temperatures and NO concentrations and vice-versa. This highlights the limitations posed when using fixed SOA yields in a majority of global and regional models. Few compounds that play a crucial role (> 95 % of mass load) in contributing to SOA mass increase (using MCM+PRAM) are identified. The results further emphasized that incorporating PRAM in conjunction with MCM does improve SOA mass yields estimation.

scholarly journals Organic nitrate aerosol formation via NO<sub>3</sub> + biogenic volatile organic compounds in the southeastern United States

2015 ◽  
Vol 15 (23) ◽  
pp. 13377-13392 ◽  
Author(s):  
B. R. Ayres ◽  
H. M. Allen ◽  
D. C. Draper ◽  
S. S. Brown ◽  
R. J. Wild ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Organic Nitrate ◽  
Organic Nitrates ◽  
Aerosol Formation ◽  
Biogenic Volatile Organic Compounds ◽  
Aerosol Mass ◽  
Volatile Organic ◽  
Nitrate Aerosol

<p><strong>Abstract.</strong> Gas- and aerosol-phase measurements of oxidants, biogenic volatile organic compounds (BVOCs) and organic nitrates made during the Southern Oxidant and Aerosol Study (SOAS campaign, Summer 2013) in central Alabama show that a nitrate radical (NO<sub>3</sub>) reaction with monoterpenes leads to significant secondary aerosol formation. Cumulative losses of NO<sub>3</sub> to terpenes are correlated with increase in gas- and aerosol-organic nitrate concentrations made during the campaign. Correlation of NO<sub>3</sub> radical consumption to organic nitrate aerosol formation as measured by aerosol mass spectrometry and thermal dissociation laser-induced fluorescence suggests a molar yield of aerosol-phase monoterpene nitrates of 23–44 %. Compounds observed via chemical ionization mass spectrometry (CIMS) are correlated to predicted nitrate loss to BVOCs and show C<sub>10</sub>H<sub>17</sub>NO<sub>5</sub>, likely a hydroperoxy nitrate, is a major nitrate-oxidized terpene product being incorporated into aerosols. The comparable isoprene product C<sub>5</sub>H<sub>9</sub>NO<sub>5</sub> was observed to contribute less than 1 % of the total organic nitrate in the aerosol phase and correlations show that it is principally a gas-phase product from nitrate oxidation of isoprene. Organic nitrates comprise between 30 and 45 % of the NO<sub><I>y</I></sub> budget during SOAS. Inorganic nitrates were also monitored and showed that during incidents of increased coarse-mode mineral dust, HNO<sub>3</sub> uptake produced nitrate aerosol mass loading at a rate comparable to that of organic nitrate produced via NO<sub>3</sub> + BVOCs.</p>

scholarly journals Contributions of individual reactive biogenic volatile organic compounds to organic nitrates above a mixed forest

2012 ◽  
Vol 12 (21) ◽  
pp. 10125-10143 ◽  
Author(s):  
K. A. Pratt ◽  
L. H. Mielke ◽  
P. B. Shepson ◽  
A. M. Bryan ◽  
A. L. Steiner ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Mixed Forest ◽  
Organic Aerosol ◽  
Oxidation Products ◽  
Organic Nitrate ◽  
Organic Nitrates ◽  
Biogenic Volatile Organic Compounds ◽  
Nitrate Production ◽  
Volatile Organic

Abstract. Biogenic volatile organic compounds (BVOCs) can react in the atmosphere to form organic nitrates, which serve as NOx (NO + NO2) reservoirs, impacting ozone and secondary organic aerosol production, the oxidative capacity of the atmosphere, and nitrogen availability to ecosystems. To examine the contributions of biogenic emissions and the formation and fate of organic nitrates in a forest environment, we simulated the oxidation of 57 individual BVOCs emitted from a rural mixed forest in northern Michigan. Key BVOC-oxidant reactions were identified for future laboratory and field investigations into reaction rate constants, yields, and speciation of oxidation products. Of the total simulated organic nitrates, monoterpenes contributed ~70% in the early morning at ~12 m above the forest canopy when isoprene emissions were low. In the afternoon, when vertical mixing and isoprene nitrate production were highest, the simulated contribution of isoprene-derived organic nitrates was greater than 90% at all altitudes, with the concentration of secondary isoprene nitrates increasing with altitude. Notably, reaction of isoprene with NO3 leading to isoprene nitrate formation was found to be significant (~8% of primary organic nitrate production) during the daytime, and monoterpene reactions with NO3 were simulated to comprise up to ~83% of primary organic nitrate production at night. Lastly, forest succession, wherein aspen trees are being replaced by pine and maple trees, was predicted to lead to increased afternoon concentrations of monoterpene-derived organic nitrates. This further underscores the need to understand the formation and fate of these species, which have different chemical pathways and oxidation products compared to isoprene-derived organic nitrates and can lead to secondary organic aerosol formation.

Sign in / Sign up

Export Citation Format

Share Document