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<front>
<journal-meta>
<journal-id journal-id-type="publisher">ACP</journal-id>
<journal-title-group>
<journal-title>Atmospheric Chemistry and Physics</journal-title>
<abbrev-journal-title abbrev-type="publisher">ACP</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">1680-7324</issn>
<publisher><publisher-name>Copernicus GmbH</publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/acp-6-3211-2006</article-id>
<title-group>
<article-title>Comparison of GOME tropospheric NO&lt;sub&gt;2&lt;/sub&gt; columns with  NO&lt;sub&gt;2&lt;/sub&gt; profiles deduced from ground-based in situ measurements</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Schaub</surname>
<given-names>D.</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>Boersma</surname>
<given-names>K. F.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Kaiser</surname>
<given-names>J. W.</given-names>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Weiss</surname>
<given-names>A. K.</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>Folini</surname>
<given-names>D.</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>Eskes</surname>
<given-names>H. J.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Buchmann</surname>
<given-names>B.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Empa, Swiss Federal Laboratories for Materials Testing and Research,  Ueberlandstrasse 129, CH-8600 Duebendorf, Switzerland</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Royal Netherlands Meteorological Institute (KNMI), P.O. Box 201, 3730  AE, De Bilt, The Netherlands</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>European Centre for Medium-Range Weather Forecasts (ECMWF), Shinfield  Park, Reading, RG2 9AX, UK</addr-line>
</aff>
<pub-date pub-type="epub">
<day>03</day>
<month>08</month>
<year>2006</year>
</pub-date>
<volume>6</volume>
<issue>11</issue>
<fpage>3211</fpage>
<lpage>3229</lpage>
<permissions>
<license xlink:type="simple">
<license-p>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.</license-p>
</license>
</permissions>
<self-uri xlink:href="http://www.atmos-chem-phys.net/6/3211/2006/acp-6-3211-2006.html">This article is available from http://www.atmos-chem-phys.net/6/3211/2006/acp-6-3211-2006.html</self-uri>
<self-uri xlink:href="http://www.atmos-chem-phys.net/6/3211/2006/acp-6-3211-2006.pdf">The full text article is available as a PDF file from http://www.atmos-chem-phys.net/6/3211/2006/acp-6-3211-2006.pdf</self-uri>
<abstract>
<p>Nitrogen dioxide (NO&lt;sub&gt;2&lt;/sub&gt;) vertical tropospheric column densities (VTCs)
retrieved from the Global Ozone Monitoring Experiment (GOME) are compared to
coincident ground-based tropospheric NO&lt;sub&gt;2&lt;/sub&gt; columns. The ground-based
columns are deduced from in situ measurements at different altitudes in the
Alps for 1997 to June 2003, yielding a unique long-term comparison of GOME
NO&lt;sub&gt;2&lt;/sub&gt; VTC data retrieved by a collaboration of KNMI (Royal Netherlands
Meteorological Institute) and BIRA/IASB (Belgian Institute for Space Aeronomy)
with independently derived tropospheric NO&lt;sub&gt;2&lt;/sub&gt; profiles. A first comparison
relates the GOME retrieved tropospheric columns to the tropospheric columns
obtained by integrating the ground-based NO&lt;sub&gt;2&lt;/sub&gt; measurements. For a second
comparison, the tropospheric profiles constructed from the ground-based
measurements are first multiplied with the averaging kernel (AK) of the GOME
retrieval. The second approach makes the comparison independent from the a
priori NO&lt;sub&gt;2&lt;/sub&gt; profile used in the GOME retrieval. This allows splitting the
total difference between the column data sets into two contributions: one that
is due to differences between the a priori and the ground-based NO&lt;sub&gt;2&lt;/sub&gt; profile
shapes, and another that can be attributed to uncertainties in both the remaining
retrieval parameters (such as, e.g., surface albedo or aerosol concentration)
and the ground-based in situ NO&lt;sub&gt;2&lt;/sub&gt; profiles. For anticyclonic clear sky conditions
the comparison indicates a good agreement between the columns (n=157, R=0.70/0.74 for
the first/second comparison approach, respectively). The mean relative difference
(with respect to the ground-based columns) is &amp;minus;7% with a standard deviation of
40% and GOME on average slightly underestimating the ground-based columns.
Both data sets show a similar seasonal behaviour with a distinct maximum of spring
NO&lt;sub&gt;2&lt;/sub&gt; VTCs. Further analysis indicates small GOME columns being systematically
smaller than the ground-based ones. The influence of different shapes in the a
priori and the ground-based NO&lt;sub&gt;2&lt;/sub&gt; profile is analysed by considering AK
information. It is moderate and indicates similar shapes of the profiles for
clear sky conditions. Only for large GOME columns, differences between the
profile shapes explain the larger part of the relative difference. In
contrast, the other error sources give rise to the larger relative
differences found towards smaller columns. Further, for the clear sky cases,
errors from different sources are found to compensate each other partially.
The comparison for cloudy cases indicates a poorer agreement between the
columns (n=60, R=0.61). The mean relative difference between the columns is
60% with a standard deviation of 118% and GOME on average
overestimating the ground-based columns. The clear improvement after
inclusion of AK information (n=60, R=0.87) suggests larger errors in the a
priori NO&lt;sub&gt;2&lt;/sub&gt; profiles under cloudy conditions and demonstrates the
importance of using accurate profile information for (partially) clouded scenes.</p>
</abstract>
<counts><page-count count="19"/></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"> Beyrich, F., Gryning, S.-E., Joffre, S., Rasmussen, A., Seibert, P., and Tercier, P.: Mixing height determination for dispersion modelling &amp;ndash; a test of meteorological pre-processors, Air Pollution Modeling and Its Application, Plenum Press, New York, 1998. </mixed-citation>
</ref>
<ref id="ref2">
<label>2</label><mixed-citation publication-type="other" xlink:type="simple"> Boersma, K. F., Eskes, H. J., and Brinksma, E. J.: Error analysis for tropospheric NO&lt;sub&gt;2&lt;/sub&gt; retrieval from space, J. Geophys. Res., 109, art. no. 4311, doi:10.1029/2003JD003962, 2004. </mixed-citation>
</ref>
<ref id="ref3">
<label>3</label><mixed-citation publication-type="other" xlink:type="simple"> Boersma, K. F., Eskes, H. J., Meijer, W., and Kelder, H. M.: Estimates of lightning NO&lt;sub&gt;x&lt;/sub&gt; production from GOME satellite observations, Atmos. Chem. Phys., 5, 2311&amp;ndash;2221, 2005. </mixed-citation>
</ref>
<ref id="ref4">
<label>4</label><mixed-citation publication-type="other" xlink:type="simple"> Bovensmann, H., Burrows, J. P., Buchwitz, M., Frerick, J., No\&quot;el, S., and Rozanov, V. V.: SCIAMACHY: Mission objectives and measurement modes, J. Atmos. Sci., 56(2), 127&amp;ndash;150, 1999. </mixed-citation>
</ref>
<ref id="ref5">
<label>5</label><mixed-citation publication-type="other" xlink:type="simple"> Brasseur, G. P.: Atmospheric chemistry in a changing world, Springer Verlag, Berlin, 2003. </mixed-citation>
</ref>
<ref id="ref6">
<label>6</label><mixed-citation publication-type="other" xlink:type="simple"> Burrows, J. P., Weber, M., Buchwitz, M., Rozanov, V., Ladstätter-Weissenmayer, A., Richter, A., DeBeek, R., Hoogen, R., Bramstedt, K., Eichmann, K. U., Eisinger, M., and Perner, D.: The global ozone monitoring experiment (GOME): Mission concept and first scientific results, J. Atmos. Sci., 56, 151&amp;ndash;175, 1999. </mixed-citation>
</ref>
<ref id="ref7">
<label>7</label><mixed-citation publication-type="other" xlink:type="simple"> BUWAL: NABEL &amp;ndash; Luftbelastung 2003, Schriftenreihe Umwelt Nr. 370, 2004. </mixed-citation>
</ref>
<ref id="ref8">
<label>8</label><mixed-citation publication-type="other" xlink:type="simple"> Choi, Y., Wang, Y., Zeng, T., Martin, R. V., Kurosu, T. P., and Chance, K.: Evidence of lightning NO&lt;sub&gt;x&lt;/sub&gt; and convective transport of pollutants in satellite observations over North America, Geophys. Res. Lett., 32, L02805, doi:10.1029/2004GL021436, 2005. </mixed-citation>
</ref>
<ref id="ref9">
<label>9</label><mixed-citation publication-type="other" xlink:type="simple"> Clemitshaw, K. C.: A review of instrumentation and measurement techniques for ground-based and airborne field studies of gas-phase chemistry, Crit. Rev. in Env. Sc. and Techn., 34, 1&amp;ndash;108, 2004. </mixed-citation>
</ref>
<ref id="ref10">
<label>10</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., 98, 7149&amp;ndash;7163, 1993. </mixed-citation>
</ref>
<ref id="ref11">
<label>11</label><mixed-citation publication-type="other" xlink:type="simple"> Dentener, F. J., van Weele, M., Krol, M., Houweling, S., and van Velthoven, P.: Trends and inter-annual variability of methane emissions derived from 1979&amp;ndash;1993 global CTM simulations, Atmos. Chem. Phys., 3, 73&amp;ndash;88, 2003. </mixed-citation>
</ref>
<ref id="ref12">
<label>12</label><mixed-citation publication-type="other" xlink:type="simple"> Empa: Technischer Bericht zum Nationalen Beobachtungsnetz für Luftfremdstoffe (NABEL), Duebendorf, 2005. </mixed-citation>
</ref>
<ref id="ref13">
<label>13</label><mixed-citation publication-type="other" xlink:type="simple"> Eskes, H. J. and Boersma, K. F.: Averaging kernels for DOAS total-column satellite retrievals, Atmos. Chem. Phys., 3, 1285&amp;ndash;1291, 2003. </mixed-citation>
</ref>
<ref id="ref14">
<label>14</label><mixed-citation publication-type="other" xlink:type="simple"> Eskes, H. J.: Combined retrieval, modeling and assimilation approach to GOME NO&lt;sub&gt;2&lt;/sub&gt;, in GOA final report, European Commission 5th framework programme 1998&amp;ndash;2002, EESD-ENV-99-2, 116&amp;ndash;122, Eur. Comm., De Bilt, Netherlands, 2003. </mixed-citation>
</ref>
<ref id="ref15">
<label>15</label><mixed-citation publication-type="other" xlink:type="simple"> Finlayson-Pitts, B. J. and Pitts, J. N.: Chemistry of the upper and lower Atmosphere &amp;ndash; Theory, Experiments and Applications, Academic Press, San Diego, CA, 2000. </mixed-citation>
</ref>
<ref id="ref16">
<label>16</label><mixed-citation publication-type="other" xlink:type="simple"> Forrer, J., Rüttimann, R., Schneiter, D., Fischer, A., Buchmann, B., and Hofer, P.: Variability of trace gases at the high-Alpine site Jungfraujoch caused by meteorological transport processes, J. Geophys. Res., 105, 12 241&amp;ndash;12 251, 2000. </mixed-citation>
</ref>
<ref id="ref17">
<label>17</label><mixed-citation publication-type="other" xlink:type="simple"> Heland, J., Schlager, H., Richter, A., and Burrows, J. P.: First comparison of tropospheric NO&lt;sub&gt;2&lt;/sub&gt; column densities retrieved from GOME measurements and in situ aircraft profile measurements, Geophys. Res. Lett., 29, 1983, doi:10.1029/2002GL015528, 2002. </mixed-citation>
</ref>
<ref id="ref18">
<label>18</label><mixed-citation publication-type="other" xlink:type="simple"> Herwehe, J. A., McNider, R. T., and Newchurch, M. J.: A numerical study of the effects of large eddies photochemistry in the convective boundary layer, Reprint from the American Meteorological Society&apos;s 14th Symposium on Boundary Layer and Turbulence, Aspen, CO, 2000. </mixed-citation>
</ref>
<ref id="ref19">
<label>19</label><mixed-citation publication-type="other" xlink:type="simple"> Heue, K.-P., Richter, A., Bruns, M., Burrows, J. P., v. Friedeburg, C., Platt, U., Pundt, I., Wang, P., and Wagner, T.: Validation of SCIAMCHY tropospheric NO&lt;sub&gt;2&lt;/sub&gt;-columns with AMAXDOAS measurements, Atmos. Chem. Phys., 5, 1039&amp;ndash;1051, 2005. </mixed-citation>
</ref>
<ref id="ref20">
<label>20</label><mixed-citation publication-type="other" xlink:type="simple"> Holtslag, A. A. M., De Bruin, E. I. F., and Pan, H.-L.: A high resolution air mass transformation model for short range weather forecasting, Monthly Weather Rev., 118, 1561&amp;ndash;1575, 1990. </mixed-citation>
</ref>
<ref id="ref21">
<label>21</label><mixed-citation publication-type="other" xlink:type="simple"> Horowitz, L. W., Walters, S., Mauzerall, D. L., Emmons, L. K., Rasch, P. J., Granier, C., Tie, X. X., Lamarque, J. F., Schultz, M. G., Tyndall, G. S., Orlando, J. J., and Brasseur, G. P.: A global simulation of tropospheric ozone and related tracers: Description and evaluation of MOZART, version 2, J. Geophys. Res., 108, 4784, doi:10.1029/2002JD002853, 2003. </mixed-citation>
</ref>
<ref id="ref22">
<label>22</label><mixed-citation publication-type="other" xlink:type="simple"> Jaeglé, L., Jacob, D. J., Wang, Y., Weinheimer, A. J., Ridley, B. A., Campos, T. L., Sachse, G. W., and Hagen, D. E.: Sources and chemistry of NO&lt;sub&gt;x&lt;/sub&gt; in the upper troposphere over the United States, Geophys. Res. Lett., 25, 1705&amp;ndash;1708, 1998. </mixed-citation>
</ref>
<ref id="ref23">
<label>23</label><mixed-citation publication-type="other" xlink:type="simple"> Koelemeijer, R. B. A., Stammes, P., Hovenier, J. W., and de Hann, J. F.: A fast method for retrieval of cloud parameters using oxygen A-band measurements from Global Ozone Monitoring Experiment, J. Geophys. Res., 106, 3475&amp;ndash;3490, 2001. </mixed-citation>
</ref>
<ref id="ref24">
<label>24</label><mixed-citation publication-type="other" xlink:type="simple"> Kramm, G., Dlugi, R., Dollard, G. J., Foken, T., Mölders, N., Müller, H., Seiler, W., and Sievering, H.: On the dry deposition of ozone and reactive nitrogen species, Atmos. Environ., 29, 3209&amp;ndash;3231, 1995. </mixed-citation>
</ref>
<ref id="ref25">
<label>25</label><mixed-citation publication-type="other" xlink:type="simple"> Lugauer, M., Baltensperger, U., Furger, M., Gäggeler, H. W., Jost, D. T., Schwikowski, M., and Wanner, H.: Aerosol transport to the high Alpine sites Jungfraujoch (3454 m asl) and Colle Gnifetti (4452 m asl), Tellus, 50B, 76&amp;ndash;92, 1998. </mixed-citation>
</ref>
<ref id="ref26">
<label>26</label><mixed-citation publication-type="other" xlink:type="simple"> Lugauer, M., Baltensperger, U., Furger, M., Gäggeler, H. W., Jost, D. T., Nyeki, S., and Schwikowski, M.: Influences of vertical transport and scavenging on aerosol particle surface area and radon decay product concentrations at the Jungfraujoch (3454 m asl), J. Geophys. Res., 105, 19 869&amp;ndash;19 879, 2000. </mixed-citation>
</ref>
<ref id="ref27">
<label>27</label><mixed-citation publication-type="other" xlink:type="simple"> Martin, R. V., Parrish, D. D., Ryerson, T. B., Nicks, D. K., Chance, K., Kurosu, T. P., Jacob, D. J., Sturges, E. D., Fried, A., and Wert, B. P.: Evaluation of GOME satellite measurements of tropospheric NO&lt;sub&gt;2&lt;/sub&gt; and HCHO using regional data from aircraft campaigns in the southeastern United States, J. Geophys. Res., 109, D24307, doi:10.1029/2004JD004869, 2004. </mixed-citation>
</ref>
<ref id="ref28">
<label>28</label><mixed-citation publication-type="other" xlink:type="simple"> MeteoSwiss: Alpine Weather Statistics (Alpenwetterstatistik &amp;ndash; Witterungskalender: Beschreibung der einzelnen Parameter), MeteoSwiss, Switzerland, 1985. </mixed-citation>
</ref>
<ref id="ref29">
<label>29</label><mixed-citation publication-type="other" xlink:type="simple"> Moxim, W. J., Levy II, H., and Kasibhatla, P. S.: Simulated global tropospheric PAN: Its transport and impact on NO&lt;sub&gt;x&lt;/sub&gt;, J. Geophys. Res., 101, 12 621&amp;ndash;12 638, 1996. </mixed-citation>
</ref>
<ref id="ref30">
<label>30</label><mixed-citation publication-type="other" xlink:type="simple"> Navas, M. J., Jiménez, A. M., and Galan, G.: Air analysis: determination of nitrogen compounds by chemiluminescence, Atmos. Environ., 31, 3603&amp;ndash;3608, 1997. </mixed-citation>
</ref>
<ref id="ref31">
<label>31</label><mixed-citation publication-type="other" xlink:type="simple"> Nyeki, S., Kalberer, M., Colbeck, I., De Wekker, S., Furger, M., Gäggeler, H. W., Kossmann, M., Lugauer, M., Steyn, D., Weingartner, E., Wirth, M., and Baltensperger, U.: Convective boundary layer evolution to 4 km asl over high-alpine terrain: airborne lidar observations in the Alps, Geophys. Res. Lett., 27, 689&amp;ndash;692, 2000. </mixed-citation>
</ref>
<ref id="ref32">
<label>32</label><mixed-citation publication-type="other" xlink:type="simple"> Ordó&amp;ntilde;ez, C., Richter, A., Steinbacher, M., Zellweger, C., Nüss, H., Burrows, J. P., and Prévôt, A. S. H.: Comparison of 7 years of satellite-borne and ground-based tropospheric NO&lt;sub&gt;2&lt;/sub&gt; measurements around Milan, Italy, J. Geophys. Res., 111(D5), D05310, doi:10.1029/2005JD006305, 2006. </mixed-citation>
</ref>
<ref id="ref33">
<label>33</label><mixed-citation publication-type="other" xlink:type="simple"> Palmer, P. I., Jacob, D. J., Chance, K., Martin, R. V., Spurr, R. J. D., Kurosu, T. P., Bey, I., Yantosca, R., Fiore, A., and Li, Q.: Air mass factor formulation for spectroscopic measurements from satellites: Application to formaldehyde retrievals from the Global Ozone Monitoring Experiment, J. Geophys. Res., 106, 14 539&amp;ndash;14 550, 2001. </mixed-citation>
</ref>
<ref id="ref34">
<label>34</label><mixed-citation publication-type="other" xlink:type="simple"> Penkett, S. A. and Brice, K. A.: The spring maximum in the photooxidants in the northern-hemisphere troposphere, Nature, 319, 655&amp;ndash;657, 1986. </mixed-citation>
</ref>
<ref id="ref35">
<label>35</label><mixed-citation publication-type="other" xlink:type="simple"> Petritoli, A., Bonasoni, P, Giovanelli, G., Ravegnani, F., Kostadinov, I., Bortoli, D., Weiss, A., Schaub, D., Richter, A., and Fortezza, F.: First comparison between ground-based and satellite-borne measurements of tropospheric nitrogen dioxide in the Po basin, J. Geophys. Res., 109, D15307, doi:10.1029/2004JD004547, 2004. </mixed-citation>
</ref>
<ref id="ref36">
<label>36</label><mixed-citation publication-type="other" xlink:type="simple"> Pisano, J. T., McKendry, I., Steyn, D. G., and Hastie, D. R.: Vertical nitrogen dioxide and ozone concentrations measured from a tethered balloon in the lower Fraser valley, Atmos. Environ., 31, 2071&amp;ndash;2078, 1997. </mixed-citation>
</ref>
<ref id="ref37">
<label>37</label><mixed-citation publication-type="other" xlink:type="simple"> Ridley, B. A., Walega, J. G., Lamarque, J.-F., Grahek, F. E., Trainer, M., Hübler, G., Lin, X., and Fehsenfeld, F. C.: Measurements of reactive nitrogen and ozone to 5-km altitude in June 1990 over the southeastern United States, J. Geophys. Res., 103, 8369&amp;ndash;8388, 1998. </mixed-citation>
</ref>
<ref id="ref38">
<label>38</label><mixed-citation publication-type="other" xlink:type="simple"> Rodgers, C. D.: Inverse methods for atmospheric sounding: theory and practice, Ser. Atmos. Oceanic Planet. Phys., World Scientific Publishing, Singapore, 2000. </mixed-citation>
</ref>
<ref id="ref39">
<label>39</label><mixed-citation publication-type="other" xlink:type="simple"> Schaub, D., Weiss, A. K., Kaiser, J. W., Petritoli, A., Richter, A., Buchmann, B., and Burrows, J. P.: A transboundary transport episode of nitrogen dioxide as observed from GOME and its impact in the Alpine region, Atmos. Chem. Phys., 5, 23&amp;ndash;37, 2005. </mixed-citation>
</ref>
<ref id="ref40">
<label>40</label><mixed-citation publication-type="other" xlink:type="simple"> Seibert, P., Beyrich, F., Gryning, S.-E., Joffre, S., Rasmussen, A., and Tercier, P.: Review and intercomparison of operational methods for the determination of the mixing height, Atmos. Environ., 34, 1001&amp;ndash;1027, 2000. </mixed-citation>
</ref>
<ref id="ref41">
<label>41</label><mixed-citation publication-type="other" xlink:type="simple"> Seinfeld, J. H. and Pandis, S. N.: Atmospheric chemistry and physics &amp;ndash; from air pollution to climate change, John Wiley &amp; Sons, New York, 1998. </mixed-citation>
</ref>
<ref id="ref42">
<label>42</label><mixed-citation publication-type="other" xlink:type="simple"> Solomon, S., Portmann, W., Sanders, R. W., Daniel, J. S., Madsen, W., Bartram, B., and Dutton, E. G.: On the role of nitrogen dioxide in the absorption of solar radiation, J. Geophys. Res., 104, 12 047&amp;ndash;12 058, 1999. </mixed-citation>
</ref>
<ref id="ref43">
<label>43</label><mixed-citation publication-type="other" xlink:type="simple"> Spicer, C. W.: Nitrogen oxide reactions in the urban plume of Boston, Science, 215, 4536, 1095&amp;ndash;1097, 1982. </mixed-citation>
</ref>
<ref id="ref44">
<label>44</label><mixed-citation publication-type="other" xlink:type="simple"> Staehelin, J., Prévôt, A. S. H., and Barnes, I.: Photochemie der Troposphäre, in: Handbuch der Umweltveränderungen und Oekotoxikologie &amp;ndash; Atmosphäre, edited by: Guderian, R., Springer Verlag, Berlin, 2000. </mixed-citation>
</ref>
<ref id="ref45">
<label>45</label><mixed-citation publication-type="other" xlink:type="simple"> Stammes, P.: Spectral radiance modelling in the UV-Visible Range, in: IRS 2000: Current problems in Atmospheric Radiation, edited by: Smith, W. L. and Timofeyev, Y. M., A. Deepak Publ., Hampton (VA), 2001. </mixed-citation>
</ref>
<ref id="ref46">
<label>46</label><mixed-citation publication-type="other" xlink:type="simple"> Troen, I. and Mahrt, L.: A simple model of the planetary boundary layer: Sensitivity to surface evaporation, Boundary-Layer Meteor., 37, 129&amp;ndash;148, 1986. </mixed-citation>
</ref>
<ref id="ref47">
<label>47</label><mixed-citation publication-type="other" xlink:type="simple"> Umweltbundesamt: Jahresbericht 2002 aus dem Messnetz des Umweltbundesamtes, 69, Berlin, 2003. </mixed-citation>
</ref>
<ref id="ref48">
<label>48</label><mixed-citation publication-type="other" xlink:type="simple"> Van Noije, T. P. C., Eskes, H. J., Dentener, F. J., et al.: Multi-model ensemble simulations of tropospheric NO&lt;sub&gt;2&lt;/sub&gt; compared with GOME retrievals for the year 2000, Atmos. Chem. Phys., 6, 2943&amp;ndash;2979, 2006. </mixed-citation>
</ref>
<ref id="ref49">
<label>49</label><mixed-citation publication-type="other" xlink:type="simple"> Vandaele, A. C., Fayt, C., Hendrick, F., et al.: An intercomparison campaign of ground-based UV-visible measurements of NO&lt;sub&gt;2&lt;/sub&gt;, BrO, and OClO slant columns: Methods of analysis and results for NO&lt;sub&gt;2&lt;/sub&gt;, J. Geophys. Res., 110, D08305, doi:10.1029/2004JD005423, 2005. </mixed-citation>
</ref>
<ref id="ref50">
<label>50</label><mixed-citation publication-type="other" xlink:type="simple"> Vogelezang, D. H. P. and Holtslag, A. A. M.: Evaluation and model impacts of alternative boundary-layer height formulations, Boundary-Layer Meteor., 81, 245&amp;ndash;269, 1996. </mixed-citation>
</ref>
<ref id="ref51">
<label>51</label><mixed-citation publication-type="other" xlink:type="simple"> Warneck, P.: Chemistry of the natural atmosphere, second edition, Academic Press, London, 2000. </mixed-citation>
</ref>
<ref id="ref52">
<label>52</label><mixed-citation publication-type="other" xlink:type="simple"> York, D.: Least-square fitting of a straight line, Can. J. Phys., 44, 1079&amp;ndash;1086, 1966. </mixed-citation>
</ref>
<ref id="ref53">
<label>53</label><mixed-citation publication-type="other" xlink:type="simple"> Zellweger, C., Forrer, J., Hofer, P., Nyeki, S., Schwarzenbach, B., Weingartner, E., Ammann, M., and Baltensperger U.: Partitioning of reactive nitrogen (NO$_\rm y)$ and dependence on meteorological conditions in the lower free troposphere, Atmos. Chem. Phys., 3, 779&amp;ndash;796, 2003. </mixed-citation>
</ref>
</ref-list>
</back>
</article>