OH reactivity at a rural site (Wangdu) in the North China Plain: contributions from  OH reactants and experimental  OH budget

Fuchs, Hendrik; Tan, Zhaofeng; Lu, Keding; Bohn, Birger; Broch, Sebastian; Brown, Steven S.; Dong, Huabin; Gomm, Sebastian; Häseler, R.; He, Lingyan; Hofzumahaus, A.; Holland, F.; Li, Xin; Liu, Ying; Lü, Sihua; Min, Kyung‐Eun; Rohrer, Franz; Shao, Min; Wang, Baolin; Wang, Ming; Wu, Yusheng; Zeng, Limin; Zhang, Yingson; Wahner, Andreas; Zhang, Yuanhang

doi:10.5194/acp-17-645-2017

Cited by 69 publications

(77 citation statements)

References 56 publications

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“…Fuchs et al, 2017). The maximum error that is caused by the underestimation of the total reactivity measurement by the CRM instrument would be less than 13 % if the results of the experiment of this campaign are extrapolated to atmospheric conditions.…”

Section: Oh Reactivity Measurements In the Presence Of Isoprene Mvkmentioning

confidence: 87%

Comparison of OH reactivity measurements in the atmospheric simulation chamber SAPHIR

Fuchs¹,

Novelli²,

Rolletter³

et al. 2017

Atmos. Meas. Tech.

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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.

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Section: Oh Reactivity Measurements In the Presence Of Isoprene Mvkmentioning

confidence: 87%

Comparison of OH reactivity measurements in the atmospheric simulation chamber SAPHIR

Fuchs¹,

Novelli²,

Rolletter³

et al. 2017

Atmos. Meas. Tech.

Self Cite

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“…The detailed description of the field site and instrumentation can be found in previous publications [14,15]. In short, seven sea containers were used to host most of the instruments.…”

Section: Methodsmentioning

confidence: 99%

“…The spectral actinic photon flux density was measured by spectroradiometers, which could be used to calculate the photolysis frequencies for different photolytic species [16]. In addition, the trace gas compounds were measured by numerous up-to-date instruments in the Wangdu campaign [14,15]. The required model parameters are listed in Table 1. NO was measured by a commercial instrument (Thermo Electron model 42i) utilizing chemiluminescence.…”

Section: Methodsmentioning

confidence: 99%

Explicit diagnosis of the local ozone production rate and the ozone-NOx-VOC sensitivities

et al. 2018

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“…It can be seen that the contribution of OVOCs to OH reactivity is predominant, accounting for 36.86%, 26.79% and 30.74% of the total OH reactivity of NMVOCs in the three cases. The contribution rate of OVOCs to OH reactivity in Case 1 was 6 to 8 percentage points higher 285 than Case 2 and Case 3, illustrating the importance of OVOCs in atmospheric photochemistry and ozone generation (Fuchs et al, 2017). The contribution of alkenes to OH reactivity was the largest in three cases, reaching about 40%, which may be caused by the relatively higher contribution of alkenes emitted by motor vehicles at the urban site, indicating that ozone pollution was severely affected by vehicle emissions in Shanghai (Ling et al, 2014;Guo et al, 2013).…”

Section: Shanghai During (A) Case 1 (B) Case 2 and (C) Casementioning

confidence: 84%

Observationally constrained modelling of atmospheric oxidation capacity and photochemical reactivity in Shanghai, China

Zhu¹,

Wang²,

Wang³

et al. 2019

Preprint

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An observation-based model coupled to the Master Chemical Mechanism (V3.3.1) and constrained by a full suite of observations was developed to study atmospheric oxidation capacity (AOC), OH reactivity, OH chain length, and HOx (= OH + HO2) budget for three different ozone (O3) concentration levels in Shanghai, China. Five months of observation from 1 May to 30 September 2018 showed that 10 days with ozone as the primary pollutant occurred and the days with good air quality 20 (AQI < 100) accounted for 92.2% during this spring-summer time. The levels of ozone and its precursors, as well as meteorological parameters revealed the significant differences among different ozone levels, indicating that the high level of precursors is the premise of ozone pollution, and strong radiation is an essential driving force. By increasing the input JNO 2 value by 40%, the simulated O3 level increased by 30-40% correspondingly under the same level of precursors. The simulation results show that AOC, dominated by reactions involving OH radical during the daytime, has a positive correlation with ozone 25 levels. The reactions with non-methane volatile organic compounds (NMVOCs) (30%-36%), carbon monoxide (CO) (26%-31%), and nitrogen dioxide (NO2) (21%-29%) dominated the OH reactivity under different ozone levels in Shanghai. Among the NMVOCs, alkenes and oxygenated VOCs (OVOCs) played a key role in OH reactivity defined as the inverse of OH lifetime. A longer OH chain length was found in clean condition primarily due to low NO2 in the atmosphere. The high level of radical precursors (e.g., O3, HONO, and OVOCs) promotes the production and cycling of HOx, and the daytime HOx primary 30 source shifted from the HONO photolysis in the morning to the O3 photolysis in the afternoon. For the sinks of radicals, the reaction with NO2 completely dominated radicals termination during the morning rush hour, while the reactions of radicalradical also contributed to the sinks of HOx in the afternoon. Furthermore, the top four species contributing to ozone formation potential (OFP) were HCHO, toluene, ethylene, and m/p-xylene. The concentration ratio (~23%) of these four species is not proportional to their contribution (~55%) to OFP, implying that controlling key VOC species emission is more effective than 35 https://doi.

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OH reactivity at a rural site (Wangdu) in the North China Plain: contributions from OH reactants and experimental OH budget

Cited by 69 publications

References 56 publications

Comparison of OH reactivity measurements in the atmospheric simulation chamber SAPHIR

Comparison of OH reactivity measurements in the atmospheric simulation chamber SAPHIR

Explicit diagnosis of the local ozone production rate and the ozone-NOx-VOC sensitivities

Observationally constrained modelling of atmospheric oxidation capacity and photochemical reactivity in Shanghai, China

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