Document Type

Article

Publication Date

1-13-2017

Publication Title

Atmospheric Chemistry and Physics

ISSN

1680-7324

Volume

17

Issue

1

DOI

http://dx.doi.org/10.5194/acp-17-645-2017

Abstract

In 2014, a large, comprehensive field campaign was conducted in the densely populated North China Plain. The measurement site was located in a botanic garden close to the small town Wangdu, without major industry but influenced by regional transportation of air pollution. The loss rate coefficient of atmospheric hydroxyl radicals (OH) was quantified by direct measurements of the OH reactivity. Values ranged between 10 and 20 s(-1) for most of the daytime. Highest values were reached in the late night with maximum values of around 40 s(-1). OH reactants mainly originated from anthropogenic activities as indicated (1) by a good correlation between measured OH reactivity and carbon monoxide (linear correlation coefficient R-2 = 0 : 33) and (2) by a high contribution of nitrogen oxide species to the OH reactivity (up to 30% in the morning). Total OH reactivity was measured by a laser flash photolysis-laser-induced fluorescence instrument (LP-LIF). Measured values can be explained well by measured trace gas concentrations including organic compounds, oxygenated organic compounds, CO and nitrogen oxides. Significant, unexplained OH reactivity was only observed during nights, when biomass burning of agricultural waste occurred on surrounding fields. OH reactivity measurements also allow investigating the chemical OH budget. During this campaign, the OH destruction rate calculated from measured OH reactivity and measured OH concentration was balanced by the sum of OH production from ozone and nitrous acid photolysis and OH regeneration from hydroperoxy radicals within the uncertainty of measurements. However, a tendency for higher OH destruction compared to OH production at lower concentrations of nitric oxide is also observed, consistent with previous findings in field campaigns in China.

Comments

Hendrik Fuchs1, Zhaofeng Tan2, Keding Lu2, Birger Bohn1, Sebastian Broch1, Steven S. Brown3, Huabin Dong2, Sebastian Gomm1,a, Rolf Häseler1, Lingyan He4, Andreas Hofzumahaus1, Frank Holland1, Xin Li1,b, Ying Liu2, Sihua Lu2, Kyung-Eun Min3,5,c, Franz Rohrer1, Min Shao2, Baolin Wang2, Ming Wang6, Yusheng Wu2, Limin Zeng2, Yinson Zhang2, Andreas Wahner1, and Yuanhang Zhang2,7

1Institute of Energy and Climate Research, IEK-8: Troposphere, Forschungszentrum Jülich GmbH, Jülich, Germany
2College of Environmental Sciences and Engineering, Peking University, Beijing, China
3Chemical Sciences Division, Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO, USA
4Key Laboratory for Urban Habitat Environmental Science and Technology, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen, China
5Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
6School of Environmental Sciences and Engineering, Nanjing University of Information Science and Technology, Nanjing, China
7CAS Center for Excellence in Regional Atmospheric Environment, Chinese Academy of Science, Xiamen, China
anow at: d-fine GmbH, Opernplatz 2, 60313 Frankfurt, Germany
bnow at: College of Environmental Sciences and Engineering, Peking University, Beijing, China
cnow at: School of Environmental Science and Engineering, Gwangju Institute of Science and Technology, Gwangju, Korea

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Creative Commons Attribution 3.0 License
This work is licensed under a Creative Commons Attribution 3.0 License.

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