How the OH reactivity affects the ozone production efficiency: case studies in Beijing and Heshan, China

Yang, Yudong; Shao, Min; Keßel, Stephan; Li, Yue; Lu, Keding; Lü, Sihua; Williams, Jonathan; Zhang, Yuanhang; Zeng, Liming; Nölscher, A. C.; Wu, Yusheng; Wang, Xuemei; Zheng, Junyu

doi:10.5194/acp-17-7127-2017

Cited by 75 publications

(82 citation statements)

References 73 publications

(73 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Large quantities of ozone can be produced during long-range transport under sunlight influence (Parrish et al, 1998;Akimoto, 2016;Moradzadeh et al, 2019). Consequently, in the 15 seaways around the Arabian Peninsula, ozone mixing ratios were mostly between 50 and 80 ppb, which is the range of daytime values in polluted Beijing (Williams et al, 2016;Yang et al, 2017).…”

Section: Oh Reactivity/ozone Correlations 30mentioning

confidence: 92%

“…When compared to the OH reactivity calculated from all individually measured 5 compounds (termed the speciated OH reactivity), total OH reactivity can be used to infer the occurrence of VOCs that were not measured (termed the unattributed or "missing" OH reactivity). Moreover, total OH reactivity is necessary for a quantitative understanding of ozone production and can help estimating its sensitivity to VOCs and NO x (Kirchner et al, 2001;Sinha et al, 2010; Pusede et al, 2014;Yang et al, 2017). The OH sink also affects the atmospheric residence time of methane and therewith its global budget, which still poses a challenge in models (Zhao et al, 2019).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Shipborne measurements of total OH reactivity around the Arabian Peninsula and its role in ozone chemistry

Pfannerstill¹,

Wang²,

Edtbauer³

et al. 2019

Preprint

Self Cite

View full text Add to dashboard Cite

The Arabian Peninsula is characterized by high and increasing levels of photochemical air pollution. Strong solar irradiation, high temperatures and large anthropogenic emissions of reactive trace gases result in intense photochemical activity, especially during the summer months. However, air chemistry measurements in the region are scarce. In order to assess regional pollution sources and oxidation rates, the first ship-based direct measurements of total OH reactivity were 15 performed in summer 2017 from a vessel travelling around the peninsula during the AQABA (Air Quality and Climate Change in the Arabian Basin) campaign. Total OH reactivity is the total loss frequency of OH radicals due to all reactive compounds present in air and defines the local lifetime of OH, the most important oxidant in the troposphere. During the AQABA campaign, the total OH reactivity ranged from below the detection limit (5.4 s -1 ) over the north-western Indian Ocean (Arabian Sea) to a maximum of 32.8 ± 9.6 s -1 over the Arabian Gulf (also known as Persian Gulf) when air originated 20 from large petroleum extraction/processing facilities in Iraq and Kuwait. In the polluted marine regions, OH reactivity was broadly comparable to highly populated urban centers in intensity and composition. The permanent influence of heavy maritime traffic over the seaways of the Red Sea, Gulf of Aden and Gulf of Oman resulted in median OH sinks of 7.9−8.5 s -1 . Due to the rapid oxidation of direct volatile organic compound (VOC) emissions, oxygenated volatile organic compounds (OVOCs) were observed to be the main contributor to OH reactivity around the Arabian Peninsula (9−35 % by 25 region). Over the Arabian Gulf, alkanes and alkenes from the petroleum extraction and processing industry were an important OH sink with ~9 % of total OH reactivity each, whereas NO x and aromatic hydrocarbons (~10 % each) played a larger role in the Suez Canal, which is influenced more by ship traffic and urban emissions. We investigated the number and identity of chemical species necessary to explain the total OH sink. Taking into account ~100 individually measured chemical species, the observed total OH reactivity can typically be accounted for within the measurement uncertainty, with 30 10 dominant trace gases accounting for 20−39 % of regional total OH reactivity. The chemical regimes causing the intense ozone pollution around the Arabian Peninsula were investigated using total OH reactivity measurements. Ozone vs. OH reactivity relationships were found to be a useful tool for differentiating between ozone titration in fresh emissions and https://doi.photochemically aged air masses. Our results show that the ratio of NO x -and VOC-attributed OH reactivity was favorable for ozone formation almost all around the Arabian Peninsula, which is due to NO x and VOCs from ship exhausts and, often, oil/gas production. Therewith, total OH reactivity measurements help to elucidate the chemical processes underlying the extreme tropospheric ozone concentrations observed in sum...

show abstract

Section: Oh Reactivity/ozone Correlations 30mentioning

confidence: 92%

mentioning

confidence: 99%

Shipborne measurements of total OH reactivity around the Arabian Peninsula and its role in ozone chemistry

Pfannerstill¹,

Wang²,

Edtbauer³

et al. 2019

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…The CRM method is more commonly used than the direct OH measurement techniques because of the commercial availability of PTR-MS instruments. It is applied by the Max Planck Institute Mainz (MPI) (Sinha et al, 2008), IMT Lille Douai, formally called Mines Douai (MDOUAI) Michoud et al, 2015), Laboratoire des Sciences du Climat et de l'Environnement (LSCE) (Zannoni et al, 2015), Indian Institute of Science Education and Research Mohali (Kumar et al, 2014), the Finnish Meteorological Institute (Praplan et al, 2017), Peking University (Yang et al, 2017), the University of Leicester and University of California, Irvine (Kim et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

Comparison of OH reactivity measurements in the atmospheric simulation chamber SAPHIR

Fuchs¹,

Novelli²,

Rolletter³

et al. 2017

Atmos. Meas. Tech.

Self Cite

View full text Add to dashboard Cite

Abstract. Hydroxyl (OH) radical reactivity (k OH ) has been measured for 18 years with different measurement techniques. In order to compare the performances of instruments deployed in the field, two campaigns were conducted performing experiments in the atmospheric simulation chamber SAPHIR at Forschungszentrum Jülich in October 2015 and April 2016. Chemical conditions were chosen either to be representative of the atmosphere or to test potential limitations of instruments. All types of instruments that are currently used for atmospheric measurements were used in one of the two campaigns. The results of these campaigns demonstrate that OH reactivity can be accurately measured for a wide range of atmospherically relevant chemical conditions (e.g. water vapour, nitrogen oxides, various organic compounds) by all instruments. The precision of the measurements (limit of detection < 1 s −1 at a time resolution of 30 s to a few minutes) is higher for instruments directly detecting hydroxyl radicals, whereas the indirect comparative reactivPublished by Copernicus Publications on behalf of the European Geosciences Union. H. Fuchs et al.: OH reactivity comparison in SAPHIRity method (CRM) has a higher limit of detection of 2 s −1 at a time resolution of 10 to 15 min. The performances of the instruments were systematically tested by stepwise increasing, for example, the concentrations of carbon monoxide (CO), water vapour or nitric oxide (NO). In further experiments, mixtures of organic reactants were injected into the chamber to simulate urban and forested environments. Overall, the results show that the instruments are capable of measuring OH reactivity in the presence of CO, alkanes, alkenes and aromatic compounds. The transmission efficiency in Teflon inlet lines could have introduced systematic errors in measurements for low-volatile organic compounds in some instruments. CRM instruments exhibited a larger scatter in the data compared to the other instruments. The largest differences to reference measurements or to calculated reactivity were observed by CRM instruments in the presence of terpenes and oxygenated organic compounds (mixing ratio of OH reactants were up to 10 ppbv). In some of these experiments, only a small fraction of the reactivity is detected. The accuracy of CRM measurements is most likely limited by the corrections that need to be applied to account for known effects of, for example, deviations from pseudo first-order conditions, nitrogen oxides or water vapour on the measurement. Methods used to derive these corrections vary among the different CRM instruments. Measurements taken with a flowtube instrument combined with the direct detection of OH by chemical ionisation mass spectrometry (CIMS) show limitations in cases of high reactivity and high NO concentrations but were accurate for low reactivity (< 15 s −1 ) and low NO (< 5 ppbv) conditions.

show abstract

“…For example, additional species (such as more reactive NMHCs or more reactive reaction intermediates) and their chemistry could be included in the model. However, observations indicate that this approach would still leave outstanding missing reactivity (Edwards et al, 2013;Elshorbany et al, 2012;Kaiser et al, 2016;Kovacs et al, 2003;Lee et al, 2009;Lou et al, 2010;Mao et al, 2012;Mogensen et al, 2011;Yang et al, 2017). In this work, we have taken a different, simpler approach.…”

Section: Comparison Of Modelled K Oh and Known Oh Sinks With Observatmentioning

confidence: 99%

“…These efforts have been met with mixed results: whilst some managed to reconcile the total k OH with the sum of reactivities once the oxidation intermediates were taken into account (Whalley et al, 2016), others obtained different degrees of improvement on the agreement between the two, leaving different fractions of k OH still unaccounted for (Edwards et al, 2013;Elshorbany et al, 2012;Kaiser et al, 2016;Kovacs et al, 2003;Lee et al, 2009;Lou et al, 2010;Mao et al, 2012;Mogensen et al, 2011;Yang et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

Global modelling of the total OH reactivity: investigations on the “missing” OH sink and its atmospheric implications

et al. 2018

View full text Add to dashboard Cite

Abstract. The hydroxyl radical (OH) plays a crucial role in the chemistry of the atmosphere as it initiates the removal of most trace gases. A number of field campaigns have observed the presence of a "missing" OH sink in a variety of regions across the planet. A comparison of direct measurements of the OH loss frequency, also known as total OH reactivity (k OH ), with the sum of individual known OH sinks (obtained via the simultaneous detection of species such as volatile organic compounds and nitrogen oxides) indicates that, in some cases, up to 80 % of k OH is unaccounted for. In this work, the UM-UKCA chemistry-climate model was used to investigate the wider implications of the missing reactivity on the oxidising capacity of the atmosphere. Simulations of the present-day atmosphere were performed and the model was evaluated against an array of field measurements to verify that the known OH sinks were reproduced well, with a resulting good agreement found for most species. Following this, an additional sink was introduced to simulate the missing OH reactivity as an emission of a hypothetical molecule, X, which undergoes rapid reaction with OH. The magnitude and spatial distribution of this sink were underpinned by observations of the missing reactivity. Model runs showed that the missing reactivity accounted for on average 6 % of the total OH loss flux at the surface and up to 50 % in regions where emissions of the additional sink were high. The lifetime of the hydroxyl radical was reduced by 3 % in the boundary layer, whilst tropospheric methane lifetime increased by 2 % when the additional OH sink was included. As no OH recycling was introduced following the initial oxidation of X, these results can be interpreted as an upper limit of the effects of the missing reactivity on the oxidising capacity of the troposphere. The UM-UKCA simulations also allowed us to establish the atmospheric implications of the newly characterised reactions of peroxy radicals (RO 2 ) with OH. Whilst the effects of this chemistry on k OH were minor, the reaction of the simplest peroxy radical, CH 3 O 2 , with OH was found to be a major sink for CH 3 O 2 and source of HO 2 over remote regions at the surface and in the free troposphere. Inclusion of this reaction in the model increased tropospheric methane lifetime by up to 3 %, depending on its product branching. Simulations based on the latest kinetic and product information showed that this reaction cannot reconcile models with observations of atmospheric methanol, in contrast to recent suggestions.

show abstract

How the OH reactivity affects the ozone production efficiency: case studies in Beijing and Heshan, China

Cited by 75 publications

References 73 publications

Shipborne measurements of total OH reactivity around the Arabian Peninsula and its role in ozone chemistry

Shipborne measurements of total OH reactivity around the Arabian Peninsula and its role in ozone chemistry

Comparison of OH reactivity measurements in the atmospheric simulation chamber SAPHIR

Global modelling of the total OH reactivity: investigations on the “missing” OH sink and its atmospheric implications

Contact Info

Product

Resources

About