<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE article PUBLIC "-//NLM//DTD Journal Publishing DTD v3.0 20080202//EN" "https://jats.nlm.nih.gov/nlm-dtd/publishing/3.0/journalpublishing3.dtd">
<article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" article-type="research-article" dtd-version="3.0" xml:lang="en">
<front>
<journal-meta>
<journal-id journal-id-type="publisher">AMT</journal-id>
<journal-title-group>
<journal-title>Atmospheric Measurement Techniques</journal-title>
<abbrev-journal-title abbrev-type="publisher">AMT</abbrev-journal-title>
<abbrev-journal-title abbrev-type="nlm-ta">Atmos. Meas. Tech.</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">1867-8548</issn>
<publisher><publisher-name>Copernicus Publications</publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/amt-2-193-2009</article-id>
<title-group>
<article-title>Chlorine activation by N&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt;: simultaneous, in situ detection of ClNO&lt;sub&gt;2&lt;/sub&gt; and N&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; by chemical ionization mass spectrometry</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Kercher</surname>
<given-names>J. P.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Riedel</surname>
<given-names>T. P.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Thornton</surname>
<given-names>J. A.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Department of Atmospheric Sciences, University of Washington, Seattle, WA 98195, USA</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Department of Chemistry, University of Washington, Seattle, WA 98195, USA</addr-line>
</aff>
<pub-date pub-type="epub">
<day>26</day>
<month>05</month>
<year>2009</year>
</pub-date>
<volume>2</volume>
<issue>1</issue>
<fpage>193</fpage>
<lpage>204</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2009 J. P. Kercher et al.</copyright-statement>
<copyright-year>2009</copyright-year>
<license license-type="open-access">
<license-p>This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit <ext-link ext-link-type="uri"  xlink:href="https://creativecommons.org/licenses/by/3.0/">https://creativecommons.org/licenses/by/3.0/</ext-link></license-p>
</license>
</permissions>
<self-uri xlink:href="https://amt.copernicus.org/articles/2/193/2009/amt-2-193-2009.html">This article is available from https://amt.copernicus.org/articles/2/193/2009/amt-2-193-2009.html</self-uri>
<self-uri xlink:href="https://amt.copernicus.org/articles/2/193/2009/amt-2-193-2009.pdf">The full text article is available as a PDF file from https://amt.copernicus.org/articles/2/193/2009/amt-2-193-2009.pdf</self-uri>
<abstract>
<p>We report a new method for the simultaneous in situ detection of nitryl chloride
(ClNO&lt;sub&gt;2&lt;/sub&gt;) and dinitrogen pentoxide (N&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt;) using chemical
ionization mass spectrometry (CIMS). The technique relies on the formation
and detection of iodide ion-molecule clusters, I(ClNO&lt;sub&gt;2&lt;/sub&gt;)&lt;sup&gt;&amp;minus;&lt;/sup&gt; and
I(N&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt;)&lt;sup&gt;&amp;minus;&lt;/sup&gt;. The novel N&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; detection scheme is
direct. It does not suffer from high and variable chemical interferences,
which are associated with the typical method of nitrate anion detection. We
address the role of water vapor, CDC electric field strength, and instrument
zero determinations, which influence the overall sensitivity and detection
limit of this method. For both species, the method demonstrates high
sensitivity (&gt;1 Hz/pptv), precision (~10% for 100 pptv in 1 s), and
accuracy (~20%), the latter ultimately determined by the nitrogen
dioxide (NO&lt;sub&gt;2&lt;/sub&gt;) cylinder calibration standard and characterization of
inlet effects. For the typically low background signals (&lt;10 Hz) and high
selectivity, we estimate signal-to-noise (&lt;i&gt;S/N&lt;/i&gt;) ratios of 2 for 1 pptv in
60 s averages, but uncertainty associated with the instrumental zero
currently leads to an ultimate detection limit of ~5 pptv for both
species. We validate our approach for the simultaneous in situ measurement of
ClNO&lt;sub&gt;2&lt;/sub&gt; and N&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; while on board the &lt;i&gt;R/V&lt;/i&gt; Knorr as part of the
ICEALOT 2008 Field Campaign.</p>
</abstract>
<counts><page-count count="12"/></counts>
</article-meta>
</front>
<body/>
<back>
<ref-list>
<title>References</title>
<ref id="ref1">
<label>1</label><mixed-citation publication-type="other" xlink:type="simple"> % vor jede Referenz Aldener, M., Brown, S. S., Stark, H., Williams, E. J., Lerner, B. M., Kuster, W. C., Goldan, P. D., Quinn, P. K., Bates, T. S., Fehsenfeld, F. C., and Ravishankara, A. R.: Reactivity and Loss Mechanisms of NO&lt;sub&gt;3&lt;/sub&gt; and N&lt;sub&gt;2&lt;/sub&gt;O$_5$ in a Polluted Marine Environment: Results from in situ Measurements during New England Air Quality Study 2002, J. Geophys. Res.-Atmos., $111$, D23S73, https://doi.org/10.1029/2006JD007252, 2006. </mixed-citation>
</ref>
<ref id="ref2">
<label>2</label><mixed-citation publication-type="other" xlink:type="simple"> Arsene, C., Bougiatioti, A., Kanakidou, M., Bonsang, B., and Mihalopoulos, N.: Tropospheric OH and Cl levels deduced from non-methane hydrocarbon measurements in a marine site, Atmos. Chem. Phys., 7, 4661–4673, 2007. </mixed-citation>
</ref>
<ref id="ref3">
<label>3</label><mixed-citation publication-type="other" xlink:type="simple"> Atkinson, R.: Atmospheric Chemistry of VOCs and NO&lt;sub&gt;x&lt;/sub&gt;, Atmos. Environm., 34, 2063–2101, 2000. </mixed-citation>
</ref>
<ref id="ref4">
<label>4</label><mixed-citation publication-type="other" xlink:type="simple"> Ayers, J. D. and Simpson, W. R.: Measurements of N&lt;sub&gt;2&lt;/sub&gt;O$_5$ near Fairbanks, Alaska, J. Geophysi. Res.-Atmos., $111$, D14309, https://doi.org/10.1029/2006JD007070, 2006. </mixed-citation>
</ref>
<ref id="ref5">
<label>5</label><mixed-citation publication-type="other" xlink:type="simple"> Behnke, W., George, C., Scheer, V., and Zetzsch, C.: Production and Decay of ClNO&lt;sub&gt;2&lt;/sub&gt; from the Reaction of Gaseous N&lt;sub&gt;2&lt;/sub&gt;O$_5$ with NaCl solution: Bulk and Aerosol Experiments, J. Geophys. Res.-Atmos., $102$, 3795–3804, 1997. </mixed-citation>
</ref>
<ref id="ref6">
<label>6</label><mixed-citation publication-type="other" xlink:type="simple"> Bertram, T. H., Thornton, J. A., and Riedel, T. P.: An experimental technique for the direct measurement of N&lt;sub&gt;2&lt;/sub&gt;O$_5$ reactivity on ambient particles, Atmos. Meas. Tech. Discuss., 2, 689–723, 2009. </mixed-citation>
</ref>
<ref id="ref7">
<label>7</label><mixed-citation publication-type="other" xlink:type="simple"> Brown, S. S., Dube, W. P., Osthoff, H. D., Stutz, J., Ryerson, T. B., Wollny, A. G., Brock, C. A., Warneke, C., De Gouw, J. A., Atlas, E., Neuman, J. A., Holloway, J. S., Lerner, B. M., Williams, E. J., Kuster, W. C., Goldan, P. D., Angevine, W. M., Trainer, M., Fehsenfeld, F. C., and Ravishankara, A. R.: Vertical Profiles in NO&lt;sub&gt;3&lt;/sub&gt; and N&lt;sub&gt;2&lt;/sub&gt;O$_5$ Measured from an Aircraft: Results from the NOAA P-3 and Surface Platforms during the New England Air Quality Study 2004, J. Geophys. Res.-Atmos., $112$, D22304, https://doi.org/10.1029/2007JD008883, 2007. </mixed-citation>
</ref>
<ref id="ref8">
<label>8</label><mixed-citation publication-type="other" xlink:type="simple"> Brown, S. S., Neuman, J. A., Ryerson, T. B., Trainer, M., Dube, W. P., Holloway, J. S., Warneke, C., de Gouw, J. A., Donnelly, S. G., Atlas, E., Matthew, B., Middlebrook, A. M., Peltier, R., Weber, R. J., Stohl, A., Meagher, J. F., Fehsenfeld, F. C., and Ravishankara, A. R.: Nocturnal Odd-Oxygen Budget and its Implications for Ozone Loss in the Lower Troposphere, Geophys. Res. Lett., $33$, L08801, https://doi.org/10.1029/2006GL025900, 2006. </mixed-citation>
</ref>
<ref id="ref9">
<label>9</label><mixed-citation publication-type="other" xlink:type="simple"> Brown, S. S., Stark, H., Ciciora, S. J., McLaughlin, R. J., and Ravishankara, A. R.: Simultaneous in situ Detection of Atmospheric NO&lt;sub&gt;3&lt;/sub&gt; and N&lt;sub&gt;2&lt;/sub&gt;O$_5$ via Cavity Ring-Down Spectroscopy, Rev. Sci. Instrum., $73$, 3291–3301, 2002. </mixed-citation>
</ref>
<ref id="ref10">
<label>10</label><mixed-citation publication-type="other" xlink:type="simple"> Cavender, A. E., Biesenthal, T. A., Bottenheim, J. W., and Shepson, P. B.: Volatile organic compound ratios as probes of halogen atom chemistry in the Arctic, Atmos. Chem. Phys., 8, 1737–1750, 2008. </mixed-citation>
</ref>
<ref id="ref11">
<label>11</label><mixed-citation publication-type="other" xlink:type="simple"> Dentener, F. J. and Crutzen, P. J.: Reaction of N&lt;sub&gt;2&lt;/sub&gt;O$_5$ on Tropospheric Aerosols – Impact on the Global Distributions of NO&lt;sub&gt;x&lt;/sub&gt;, O&lt;sub&gt;3&lt;/sub&gt;, and OH, J. Geophys. Res.-Atmos., $98$, 7149–7163, 1993. </mixed-citation>
</ref>
<ref id="ref12">
<label>12</label><mixed-citation publication-type="other" xlink:type="simple"> Evans, M. J. and Jacob, D. J.: Impact of new Laboratory Studies of N&lt;sub&gt;2&lt;/sub&gt;O$_5$ Hydrolysis on Global Model Budgets of Tropospheric Nitrogen Oxides, Ozone, and OH, Geophys. Res. Lett., $32$, L09813, https://doi.org/10.1029/2005GL022469, 2005. </mixed-citation>
</ref>
<ref id="ref13">
<label>13</label><mixed-citation publication-type="other" xlink:type="simple"> Finlayson-Pitts, B. J., Ezell, M. J., and Pitts, J. N.: Formation of Chemically Active Chlorine Compounds by Reactions of Atmospheric NaCl Particles with Gaseous N&lt;sub&gt;2&lt;/sub&gt;O$_5$ and ClONO&lt;sub&gt;2&lt;/sub&gt;, Nature, $337$, 241–244, 1989. </mixed-citation>
</ref>
<ref id="ref14">
<label>14</label><mixed-citation publication-type="other" xlink:type="simple"> Fuchs, H., Dube, W. P., Cicioira, S. J., and Brown, S. S.: Determination of Inlet Transmission and Conversion Efficiencies for in situ Measurements of the Nocturnal Nitrogen Oxides, NO&lt;sub&gt;3&lt;/sub&gt;, N&lt;sub&gt;2&lt;/sub&gt;O$_5$ and NO&lt;sub&gt;2&lt;/sub&gt;, via Pulsed Cavity Ring-Down Spectroscopy, Anal. Chem., $80$, 6010–6017, 2008. </mixed-citation>
</ref>
<ref id="ref15">
<label>15</label><mixed-citation publication-type="other" xlink:type="simple"> Geyer, A., Alicke, B., Mihelcic, D., Stutz, J., and Platt, U.: Comparison of Tropospheric NO&lt;sub&gt;3&lt;/sub&gt; Radical Measurements by Differential Optical Absorption Spectroscopy and Matrix Isolation Electron Spin Resonance, J. Geophys. Res.-Atmos., $104$, 26097–26105, 1999. </mixed-citation>
</ref>
<ref id="ref16">
<label>16</label><mixed-citation publication-type="other" xlink:type="simple"> Harrison, A. G.: Chemical Ionization Mass Spectrometry, CRC Press, Boca Raton, FL, USA, 1983. </mixed-citation>
</ref>
<ref id="ref17">
<label>17</label><mixed-citation publication-type="other" xlink:type="simple"> Heintz, F., Platt, U., Flentje, H., and Dubois, R.: Long-term Observation of Nitrate Radicals at the Tor Station, Kap Arkona (Rugen), J. Geophys. Res.-Atmos., $101$, 22891–22910, 1996. </mixed-citation>
</ref>
<ref id="ref18">
<label>18</label><mixed-citation publication-type="other" xlink:type="simple"> Huey, L. G.: Measurement of Trace Atmospheric Species by Chemical Ionization Mass Spectrometry: Speciation of Reactive Nitrogen and Future Directions, Mass Spectrom. Rev., $26$, 166–184, 2007. </mixed-citation>
</ref>
<ref id="ref19">
<label>19</label><mixed-citation publication-type="other" xlink:type="simple"> Huey, L. G., Hanson, D. R., and Howard, C. J.: Reactions of SF$_6^-$ and I$^-$ with Atmospheric Trace Gases, J. Phys. Chem., $99$, 5001–5008, 1995. </mixed-citation>
</ref>
<ref id="ref20">
<label>20</label><mixed-citation publication-type="other" xlink:type="simple"> Jacob, D. J.: Heterogeneous Chemistry and Tropospheric Ozone, Atmos. Environ., $34$, 2131–2159, 2000. </mixed-citation>
</ref>
<ref id="ref21">
<label>21</label><mixed-citation publication-type="other" xlink:type="simple"> Logan, J. A., Prather, M. J., Wofsy, S. C., and McElroy, M. B.: Tropospheric Chemistry – A Global Perspective, J. Geophys. Res., 86, 7210–7255, 1981. </mixed-citation>
</ref>
<ref id="ref22">
<label>22</label><mixed-citation publication-type="other" xlink:type="simple"> McNeill, V. F., Patterson, J., Wolfe, G. M., and Thornton, J. A.: The effect of varying levels of surfactant on the reactive uptake of N&lt;sub&gt;2&lt;/sub&gt;O$_5$ to aqueous aerosol, Atmos. Chem. Phys., 6, 1635–1644, 2006. </mixed-citation>
</ref>
<ref id="ref23">
<label>23</label><mixed-citation publication-type="other" xlink:type="simple"> Mentel, T. F., Bleilebens, D., and Wahner, A.: A Study of Nighttime Nitrogen Oxide Oxidation in a Large Reaction Chamber - The Fate of NO&lt;sub&gt;2&lt;/sub&gt; N&lt;sub&gt;2&lt;/sub&gt;O$_5$, HNO&lt;sub&gt;3&lt;/sub&gt;, and O&lt;sub&gt;3&lt;/sub&gt; at Different Humidities, Atmos. Environ., $30$, 4007–4020, 1996. </mixed-citation>
</ref>
<ref id="ref24">
<label>24</label><mixed-citation publication-type="other" xlink:type="simple"> Noxon, J. F., Norton, R. B., and Marovich, E.: NO&lt;sub&gt;3&lt;/sub&gt; in the Troposphere, Geophys. Res. Lett., $7$, 125–128, 1980. </mixed-citation>
</ref>
<ref id="ref25">
<label>25</label><mixed-citation publication-type="other" xlink:type="simple"> Osthoff, H. D., Roberts, J. M., Ravishankara, A. R., Williams, E. J., Lerner, B. M., Sommariva, R., Bates, T. S., Coffman, D., Quinn, P. K., Dibb, J. E., Stark, H., Burkholder, J. B., Talukdar, R. K., Meagher, J., Fehsenfeld, F. C., and Brown, S. S.: High Levels of Nitryl Chloride in the Polluted Subtropical Marine Boundary Layer, Nature Geoscience, $1$, 324–328, 2008. </mixed-citation>
</ref>
<ref id="ref26">
<label>26</label><mixed-citation publication-type="other" xlink:type="simple"> Pechtl, S. and von Glasow, R.: Reactive Chlorine in the Marine Boundary Layer in the Outflow of Polluted Continental Air: A Model Study, Geophys. Res. Lett., $34$, L11813, https://doi.org/10.1029/2007GL029761, 2007. </mixed-citation>
</ref>
<ref id="ref27">
<label>27</label><mixed-citation publication-type="other" xlink:type="simple"> Platt, U., Allan, W., and Lowe, D.: Hemispheric average Cl atom concentration from $^13$C/$^12$C ratios in atmospheric methane, Atmos. Chem. Phys., 4, 2393–2399, 2004. </mixed-citation>
</ref>
<ref id="ref28">
<label>28</label><mixed-citation publication-type="other" xlink:type="simple"> Platt, U. and Heintz, F.: Nitrate Radicals in Tropospheric Chemistry, Israel J. Chem., $34$, 289–300, 1994. </mixed-citation>
</ref>
<ref id="ref29">
<label>29</label><mixed-citation publication-type="other" xlink:type="simple"> Simpson, W. R.: Continuous Wave Cavity Ring-Down Spectroscopy Applied to in situ Detection of Dinitrogen Pentoxide (N&lt;sub&gt;2&lt;/sub&gt;O$_5)$, Rev. Sci. Instrum., $74$, 3442–3452, 2003. </mixed-citation>
</ref>
<ref id="ref30">
<label>30</label><mixed-citation publication-type="other" xlink:type="simple"> Slusher, D. L., Huey, L. G., Tanner, D. J., Flocke, F. M., and Roberts, J. M.: A Thermal Dissociation-Chemical Ionization Mass Spectrometry (TD-CIMS) Technique for the Simultaneous Measurement of Peroxyacyl Nitrates and Dinitrogen Pentoxide, J. Geophys. Res.-Atmos., $109$, D19315, https://doi.org/10.1029/2004JD004670, 2004. </mixed-citation>
</ref>
<ref id="ref31">
<label>31</label><mixed-citation publication-type="other" xlink:type="simple"> Smith, N., Plane, J. M. C., Nien, C. F., and Solomon, P. A.: Nighttime Radical Chemistry in the San-Joaquin Valley, Atmos. Environ., $29$, 2887–2897, 1995. </mixed-citation>
</ref>
<ref id="ref32">
<label>32</label><mixed-citation publication-type="other" xlink:type="simple"> Spicer, C. W., Chapman, E. G., Finlayson-Pitts, B. J., Plastridge, R. A., Hubbe, J. M., Fast, J. D., and Berkowitz, C. M.: Unexpectedly High Concentrations of Molecular Chlorine in Coastal Air, Nature, $394$, 353–356, 1998. </mixed-citation>
</ref>
<ref id="ref33">
<label>33</label><mixed-citation publication-type="other" xlink:type="simple"> Stutz, J., Alicke, B., Ackermann, R., Geyer, A., White, A., and Williams, E.: Vertical Profiles of NO&lt;sub&gt;3&lt;/sub&gt;, N&lt;sub&gt;2&lt;/sub&gt;O$_5$, O&lt;sub&gt;3&lt;/sub&gt;, and NO&lt;sub&gt;x&lt;/sub&gt; in the Nocturnal Boundary Layer: 1. Observations during the Texas Air Quality Study 2000, J. Geophys. Res.-Atmos., $109$, D12306, https://doi.org/10.1029/2007JD008883, 2004. </mixed-citation>
</ref>
<ref id="ref34">
<label>34</label><mixed-citation publication-type="other" xlink:type="simple"> Thornton, J. A. and Abbatt, J. P. D.: N&lt;sub&gt;2&lt;/sub&gt;O$_5$ Reaction on Submicron Sea Salt Aerosol: Kinetics, Products, and the Effect of Surface Active Organics, J. Phys. Chem. A, $109$, 10004–10012, 2005. </mixed-citation>
</ref>
<ref id="ref35">
<label>35</label><mixed-citation publication-type="other" xlink:type="simple"> Thornton, J. A., Braban, C. F., and Abbatt, J. P. D.: N&lt;sub&gt;2&lt;/sub&gt;O$_5$ Hydrolysis on Sub-Micron Organic Aerosols: the Effect of Relative Humidity, Particle Phase, and Particle Size, Phys. Chem. Ch. Ph., $5$, 4593–4603, 2003. </mixed-citation>
</ref>
<ref id="ref36">
<label>36</label><mixed-citation publication-type="other" xlink:type="simple"> van Aardenne, J. A., Carmichael, G. R., Levy, H., Streets, D., and Hordijk, L.: Anthropogenic NO&lt;sub&gt;x&lt;/sub&gt; Emissions in Asia in the Period 1990–2020, Atmos. Environ., $33$, 633–646, 1999. </mixed-citation>
</ref>
<ref id="ref37">
<label>37</label><mixed-citation publication-type="other" xlink:type="simple"> Veres, P., Roberts, J. M., Warneke, C., Welsh-Bon, D., Zahniser, M., Herndon, S., Fall, R., and de Gouw, J.: Development of Negative-Ion Proton-Transfer Chemical-Ionization Mass Spectrometry (NI-PT-CIMS) for the Measurement of Gas-Phase Organic Acids in the Atmosphere, Int. J. Mass Spectrom., $274$, 48–55, 2008. </mixed-citation>
</ref>
<ref id="ref38">
<label>38</label><mixed-citation publication-type="other" xlink:type="simple"> Wayne, R. P., Barnes, I., Biggs, P., Burrows, J. P., Canosamas, C. E., Hjorth, J., Lebras, G., Moortgat, G. K., Perner, D., Poulet, G., Restelli, G., and Sidebottom, H.; The Nitrate Radical - Physics, Chemistry, and the Atmosphere, Atmos. Environ. A-Gen., $25$, 1–203, 1991. </mixed-citation>
</ref>
<ref id="ref39">
<label>39</label><mixed-citation publication-type="other" xlink:type="simple"> Wolfe, G. M., Thornton, J. A., McNeill, V. F., Jaffe, D. A., Reidmiller, D., Chand, D., Smith, J., Swartzendruber, P., Flocke, F., and Zheng, W.: Influence of trans-Pacific pollution transport on acyl peroxy nitrate abundances and speciation at Mount Bachelor Observatory during INTEX-B, Atmos. Chem. Phys., 7, 5309–5325, 2007. </mixed-citation>
</ref>
<ref id="ref40">
<label>40</label><mixed-citation publication-type="other" xlink:type="simple"> Wood, E. C., Wooldridge, P. J., Freese, J. H., Albrecht, T., and Cohen, R. C.: Prototype for in situ detection of Atmospheric NO&lt;sub&gt;3&lt;/sub&gt; and N&lt;sub&gt;2&lt;/sub&gt;O$_5$ via Laser-Induced Fluorescence, Environ. Sci. Technol., $37$, 5732–5738, 2003. </mixed-citation>
</ref>
<ref id="ref41">
<label>41</label><mixed-citation publication-type="other" xlink:type="simple"> Yienger, J. J.: An Evaluation of Chemistry&apos;s Role in the Winter-Spring Ozone Maximum found in the Northern Midlatitude Free Troposphere, J. Geophys. Res.-Atmos., $104$, 8329–8329, 1999. </mixed-citation>
</ref>
<ref id="ref42">
<label>42</label><mixed-citation publication-type="other" xlink:type="simple"> Zhu, R. S. and Lin, M. C.: ab initio Studies of ClOx Reactions: Prediction of the Rate Constants of ClO+NO for the Forward and Reverse Processes, Chem. Phys. Chem., $5$, 1864–1870, 2004. </mixed-citation>
</ref>
</ref-list>
</back>
</article>