What effect does VOC sampling time have on derived OH reactivity?

Sonderfeld, Hannah; White, Iain R.; Goodall, Iain C. A.; Hopkins, James R.; Lewis, Alastair C.; Koppmann, R.; Monks, Paul S.

doi:10.5194/acp-16-6303-2016

Cited by 8 publications

(6 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…PTR-MS measurements have provided valuable insights into VOC emissions and chemistry in urban air. , The highly time-resolved VOC data were reported to be important in accurately constraining OH reactivity of VOC . Additional species measured by PTR-TOF may help to explain “missing” organic carbon, inferred from both carbon-balance studies and OH reactivity work .…”

Section: Research Highlightsmentioning

confidence: 99%

Proton-Transfer-Reaction Mass Spectrometry: Applications in Atmospheric Sciences

et al. 2017

View full text Add to dashboard Cite

Proton-transfer-reaction mass spectrometry (PTR-MS) has been widely used to study the emissions, distributions, and chemical evolution of volatile organic compounds (VOCs) in the atmosphere. The applications of PTR-MS have greatly promoted understanding of VOC sources and their roles in air-quality issues. In the past two decades, many new mass spectrometric techniques have been applied in PTR-MS instruments, and the performance of PTR-MS has improved significantly. This Review summarizes these developments and recent applications of PTR-MS in the atmospheric sciences. We discuss the latest instrument development and characterization work on PTR-MS instruments, including the use of time-of-flight mass analyzers and new types of ion guiding interfaces. Here we review what has been learned about the specificity of different product ion signals for important atmospheric VOCs. We present some of the recent highlights of VOC research using PTR-MS including new observations in urban air, biomass-burning plumes, forested regions, oil and natural gas production regions, agricultural facilities, the marine environment, laboratory studies, and indoor air. Finally, we will summarize some further instrument developments that are aimed at improving the sensitivity and specificity of PTR-MS and extending its use to other applications in atmospheric sciences, e.g., aerosol measurements and OH reactivity measurements.

show abstract

Section: Research Highlightsmentioning

confidence: 99%

Proton-Transfer-Reaction Mass Spectrometry: Applications in Atmospheric Sciences

et al. 2017

View full text Add to dashboard Cite

show abstract

“…A common method to address this issue is to average the constraints to the lowest time frequency available (e.g., 30 minutes). However, this introduces significant uncertainties in the model results and does not allow investigations of the short scale changes in atmospheric composition (Sonderfeld et al, 2016).…”

Section: Variables and Constraintsmentioning

confidence: 99%

“…The advantage of using an interpolation method is that setting up the model is easier and faster, as there is no need to average the constrained data onto a single time base beforehand. More importantly, the constrained data can be used with the original time frequency, thus retaining the important kinetic and mechanistic information that is lost by averaging to the lowest time frequency (Sonderfeld et al, 2016). The disadvantage is that some assumptions are made about the time evolution of the low frequency constraints, which may lead to serious errors if, for example, the gaps in the data are large or the short term variability is high.…”

Section: Variables and Constraintsmentioning

confidence: 99%

AtChem, an open source box-model for the Master Chemical Mechanism

Sommariva

Cox

Martin

et al. 2019

Preprint

Self Cite

View full text Add to dashboard Cite

Abstract. AtChem is an open source zero-dimensional box-model for atmospheric chemistry. Any general set of chemical reactions can be used with AtChem, but the model was designed specifically for use with the Master Chemical Mechanism (MCM, http://mcm.york.ac.uk/). AtChem was initially developed within the EUROCHAMP project as a web application (AtChem-online, https://atchem.leeds.ac.uk/webapp/) for modelling environmental chamber experiments; it was recently upgraded and further developed into a standalone offline version (AtChem2) which allows the user to run complex and long simulations, such as those needed for modelling of intensive field campaigns, as well as to perform batch model runs for sensitivity studies. AtChem is installed, set up and configured using semi-automated scripts and simple text configuration files, making it easy to use even for non-experienced users. A key feature of AtChem is that it can easily be constrained to observational data which may have different timescales, thus retaining all the information contained in the observations. Implementation of a continuous integration workflow, coupled with a comprehensive suite of tests and version control software, makes the AtChem codebase robust, reliable and traceable. The AtChem2 code and documentation are available at https://github.com/AtChem/, under the open source MIT license.

show abstract

“…Radical reactivity is a measure of the strength of the sinks for the radical (Sonderfeld et al, 2016;Fuchs et al, 2017a;Fuchs et al, 2017b;Tan et al, 2019). Total radical reactivity (s -1 ) is defined as the total radical loss rate, which is the inverse of its lifetime with respect to a radical in the atmosphere (Di Carlo et al, 2004;Mao et al, 2009;Mao et al, 2010;Liebmann et al, 2017;Liebmann et al, 2018b In the above equations, the pseudo first order rate coefficients (in cm 3 molecule -1 s -1 ) for OH- (Atkinson et al, 2004;Atkinson et al, 2006b)…”

Section: Speciated Radical Reactivitymentioning

confidence: 99%

Parameterized reactivity of hydroxy radical, ozone, nitrate radical and atmospheric oxidation capacity during summer at a suburban site between Beijing and Tianjin

Yang

Wang

Yao

et al. 2019

Preprint

View full text Add to dashboard Cite

Abstract. Hydroxyl (OH) radicals, nitrate (NO3) radicals, and ozone (O3) play central roles in the troposphere because they control the lifetimes of many trace gases that resulted from anthropogenic and biogenic origins. To estimate the self-cleaning capacity of the atmosphere, the reactivities of OH, NO3 and O3 was comprehensively analyzed for the first time based on a parameterization method at a suburban site in Xianghe in the North China Plain from 6 July 2018 to 6 August 2018. The total OH reactivity, ROHtotal, NO3 reactivity, RNO3total, and O3 reactivity, RO3total, at the site varied from 8.5 s−1 to 68.1 s−1, 0.7 s−1 to 27.5 s−1, and 3.3 × 10−4 s−1 to 1.8 × 10−2 s−1 with campaign-averaged values of 25.6 ± 9.7 s−1, 2.2 ± 2.6 s−1 and 1.2 ± 1.7 × 10-3 s−1 (± standard deviation), respectively. NOx (NO + NO2) were by far the main contributors to the ROHtotal, RNO3total and RO3total, with average values of 47, 99 and 99 %, respectively. Isoprene dominated the OH and NO3 reactivity towards TVOCs (ROHTVOCs and RNO3TVOCs), accounting for 40 % and 77 %, respectively. However, alkenes dominated the O3 reactivity towards TVOCs (RO3TVOCs), representing 66 % of RO3total. ROHtotal, RNO3total and RO3total displayed a similar diurnal variation with the lowest during the afternoon and the highest during rush hours, and the diurnal profile of NOx appears to be the major driver for the diurnal profiles of ROHtotal, RNO3total and RO3total. The calculated atmospheric oxidative capacity (AOC) was up to 4.4 × 108 molecules cm−3 s−1 with campaign-averaged values of 3.1 × 107 molecules cm−3 s−1 dominated by OH radicals (2.9 × 107 molecule cm−3 s−1, 95 %), O3 (1.2 × 106 molecule cm−3 s−1, 4 %) and NO3 radicals (1.7 × 105 molecule cm−3 s−1, 1 %). The reaction with OH radicals was the dominant volatile organic compounds (VOCs) loss except for trans-2-butene, cis-2-butene, trans-2-pentene, propylene, 1-butene, 1-pentene, 1-hexene, acetone and styrene, where the reaction with O3 was more important for their loss rates. Compared with anthropogenic hydrocarbons, the oxidation by the NO3 radical was more important for the nighttime integral of isoprene loss rates. Overall, the present study may provide some useful suggestions for VOC pollution control in the Xianghe and North China Plain. To better understanding the trace gas reactivity and AOC, further studies, especially direct observations of the OH and NO3 radical concentrations and their reactivities, are required.

show abstract

What effect does VOC sampling time have on derived OH reactivity?

Cited by 8 publications

References 46 publications

Proton-Transfer-Reaction Mass Spectrometry: Applications in Atmospheric Sciences

Proton-Transfer-Reaction Mass Spectrometry: Applications in Atmospheric Sciences

AtChem, an open source box-model for the Master Chemical Mechanism

Parameterized reactivity of hydroxy radical, ozone, nitrate radical and atmospheric oxidation capacity during summer at a suburban site between Beijing and Tianjin

Contact Info

Product

Resources

About