References

ACP

Atmospheric Chemistry and Physics

ACP

1680-7324

Copernicus GmbH

Göttingen, Germany

10.5194/acp-12-1497-2012

Exploring the atmospheric chemistry of nitrous acid (HONO) at a rural site in Southern China

¹ ² Brauers

² Häseler

² Bohn

² Fuchs

² Hofzumahaus

² Holland

² Lou

² ³ ⁷ Lu

K. D.

¹ ² Rohrer

² Hu

¹ Zeng

L. M.

¹ Zhang

Y. H.

¹ Garland

R. M.

⁴ ⁸ Su

¹ ⁴ Nowak

⁵ ⁹ Wiedensohler

⁵ Takegawa

⁶ Shao

¹ Wahner

College of Environmental Sciences and Engineering, Peking University, Beijing, China

Institute for Energy and Climate Research, IEK-8, Research Center Jülich, Jülich, Germany

School of Environmental Science and Technology, Shanghai Jiaotong University, Shanghai, China

Max Planck Institute for Chemistry, Biogeochemistry Department, Mainz, Germany

Leibniz Institute for Tropospheric Research, Leipzig, Germany

Research Center for Advanced Science and Technology, University of Tokyo, Tokyo, Japan

now at: Shanghai Academy of Environmental Sciences, Shanghai, China

now at: Natural Resources and the Environment, CSIR, Pretoria, South Africa

now at: Physikalisch Technische Bundesanstalt, Braunschweig, Germany

08 02 2012

12 3 1497 1513

This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

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The full text article is available as a PDF file from http://www.atmos-chem-phys.net/12/1497/2012/acp-12-1497-2012.pdf

We performed measurements of nitrous acid (HONO) during the PRIDE-PRD2006 campaign in the Pearl River Delta region 60 km north of Guangzhou, China, for 4 weeks in June 2006. HONO was measured by a LOPAP in-situ instrument which was setup in one of the campaign supersites along with a variety of instruments measuring hydroxyl radicals, trace gases, aerosols, and meteorological parameters. Maximum diurnal HONO mixing ratios of 1–5 ppb were observed during the nights. We found that the nighttime build-up of HONO can be attributed to the heterogeneous NO2 to HONO conversion on ground surfaces and the OH + NO reaction. In addition to elevated nighttime mixing ratios, measured noontime values of ≈200 ppt indicate the existence of a daytime source higher than the OH + NO→HONO reaction. Using the simultaneously recorded OH, NO, and HONO photolysis frequency, a daytime additional source strength of HONO (PM) was calculated to be 0.77 ppb h−1 on average. This value compares well to previous measurements in other environments. Our analysis of PM provides evidence that the photolysis of HNO3 adsorbed on ground surfaces contributes to the HONO formation.

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