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Measurements of Hono During Baqs-met : Volume 10, Issue 6 (21/06/2010)

By Wentzell, J. J. B.

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Book Id: WPLBN0003995440
Format Type: PDF Article :
File Size: Pages 29
Reproduction Date: 2015

Title: Measurements of Hono During Baqs-met : Volume 10, Issue 6 (21/06/2010)  
Author: Wentzell, J. J. B.
Volume: Vol. 10, Issue 6
Language: English
Subject: Science, Atmospheric, Chemistry
Collections: Periodicals: Journal and Magazine Collection, Copernicus GmbH
Historic
Publication Date:
2010
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications

Description
Description: Department of Chemistry, York University, Toronto, Ontario, Canada. Measurements of nitrous acid (HONO) were performed as part of the 2007 Border Air Quality and Meteorology Study (BAQS-Met) at the Harrow Ontario supersite between 20 June and 10 July 2007. Nitrous acid is an important precursor of the hydroxy radical and understanding its chemistry is important to understanding daytime oxidation chemistry. The HONO measurements were made using a custom built Long Path Absorption Photometer (LOPAP). The goal of this work was to shed light on sources of daytime HONO in the border region. During the course of the campaign HONO mixing ratios consistently exceeded expected daytime values by as much as a factor of 6. Mean daytime concentrations of 61 pptv were observed. While HONO decay began at sunrise, minimum HONO values were not measured until the late afternoon. There was little difference between the daytime (mean=1.5%) and night-time (mean=1.7%) ratios of HONO/NO2. Thus there was a very strong daytime source of HONO which is consistent with other recent studies. Correlations of daytime HONO production with a variety of chemical and meteorological parameters indicate that production is dependent on UV radiation, NO2 and water vapour but is not consistent with a simple gas phase process. Apparent rate constants for the production of HONO from photolyticly excited NO2 and water vapour vary from 2.8–7.8×10−3 molec−1 s−1, during the campaign.

Summary
Measurements of HONO during BAQS-Met

Excerpt
Acker, K., Müller, D., Wieprecht, W., Meixner, F. X., Bohn, B., Gilge, S., Plass-Dalmer, C., and Berresheim, H.: Strong daytime production of OH from HNO2 at a rural mountain site, Geophys. Res. Lett., 33, L02809, doi:10.1029/2005GL024643, 2006.; Alicke, B., Geyer, A., Hofzumahaus, A., Holland, F., Konrad, S., Patz, H. W., Schafer, J., Stutz, J., Volz-Thomas, A., and Platt, U.: OH formation by HONO photolysis during the BERLIOZ experiment, J. Geophys. Res., 108, 8247–8264, 2003.; Alicke, B., Platt, U., and Stutz, J.: Impact of nitrous acid photolysis on the total hydroxyl radical budget during the Limitation of Oxidant Production/Pianura Padana Produzione di Ozono study in Milan, J. Geophys. Res., 107, 8196–8213, 2002.; Bejan, I., Abd-el-Aal, Y., Barnes, I., Benter, T., Bohn, B., Wiesen, P., and Kleffmann, J.: The photolysis of ortho-nitrophenols: a new gas phase source of HONO, Phys. Chem. Chem. Phys., 8, 2028–2035, 2006.; Carr, S., Heard, D. E., and Blitz, M. A.: Comment on Atmospheric Hydroxyl Radical Production from Electronically Excited NO2 and H2O, Science, 324, 336 pp., doi:10.1126/science.1166669, 2009.; Crowley, J. N. and Carl, S. A.: OH Formation in the Photoexcitation of NO2 beyond the Dissociation Threshold in the Presence of Water Vapor, J. Phys. Chem. A., 101, 4178–4184, 1997.; George, C., Strekowski, R. S., Kleffmann, J., Stemmler, K., and Ammann, M.: Photoenhanced uptake of gaseous NO2 on solid organic compounds: a photochemical source of HONO?, Faraday Discuss., 130, 195–210, 2005.; Harris, G. W., Carter, W. P. L., Winer, A. M., Pitts, J. N., Platt, U., and Perner, D.: Observations of nitrous acid in the Los Angeles atmosphere and implications for predictions of ozone-precursor relationships, Environ. Sci. Technol., 16, 414–419, 1982.; Wall, K. J., Schiller, C. L., and Harris, G. W.: Measurements of the HONO photodissociation constant, J. Atmos. Chem., 55, 31–54, 2006.; Heland, J., Kleffmann, J., Kurtenbach, R., and Wiesen, P.: A New Instrument To Measure Gaseous Nitrous Acid (HONO) in the Atmosphere, Environ. Sci. Technol., 35, 3207–3212, 2001.; Kleffmann, J.: Daytime sources of nitrous acid (HONO) in the atmospheric boundary layer, Chemphyschem, 8, 1137–1144, 2007.; Kleffmann, J., Gavriloaiei, T., Hofzumahaus, A., Holland, F., Koppmann, R., Rupp, L., Schlosser, E., Siese, M., and Wahner, A.: Daytime formation of nitrous acid: A major source of OH radicals in A forest, Geophys. Res. Lett., 32, L05818, doi:10.1029/2005GL022524, 2005.; Kleffmann, J., Heland, J., Kurtenbach, R., Lörzer, J., and Wiesen, P.: A New Instrument (LOPAP) for the Measurement of Nitrous Acid (HONO), Environ. Sci. Pollut. Res., 4, 48–54, 2002.; Kleffmann, J., Kurtenbach, R., Lörzer, J., Wiesen, P., Kalthoff, N., Vogel, B., and Vogel, H.: Measured and simulated vertical profiles of nitrous acid-Part I: Field Measurements, Atmos. Environ., 37, 2949–2955, 2003.; Kraus, A. and Hofzumahaus, A.: Field Measurements of Atmospheric Photolysis Frequencies for O3, NO2, HCHO, CH3CHO, H2O2, and HONO by UV Spectroradiometry, J. Atmos. Chem., 31, 161–180, 1998.; Li, S., Matthews, J., and Sinha, A.: Atmospheric Hydroxyl Radical Production from Electronically Excited NO2 and H2O, Science, 319, 1657–1660, 2008.; Ndour, M., D'Anna, B., George, C., Ka, O., Balkanski, Y., Kleffmann, J., Stemmler, K., and Ammann, M.: Photoenhanced uptake of NO2 on mineral dust: Laboratory experiments and model simulations, Geophys. Res. Lett., 35, L05812, doi:10.1029/2007GL032006, 2008.; Platt, U., Perner, D., Harris, G. W., Winer, A. M., and Pitts, J. N.: Observations of nitrous acid in an urban atmosphere by differential optical absorption, Nature, 285, 312–314, 1980.; Stemmler

 

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