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<front>
<journal-meta>
<journal-id journal-id-type="publisher">ACPD</journal-id>
<journal-title-group>
<journal-title>Atmospheric Chemistry and Physics Discussions</journal-title>
<abbrev-journal-title abbrev-type="publisher">ACPD</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">1680-7375</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/acpd-11-18433-2011</article-id>
<title-group>
<article-title>Have primary emission reduction measures reduced ozone across Europe?  An analysis of European rural background ozone trends 1996–2005</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Wilson</surname>
<given-names>R. C.</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>Fleming</surname>
<given-names>Z. L.</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>Monks</surname>
<given-names>P. S.</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>Clain</surname>
<given-names>G.</given-names>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Henne</surname>
<given-names>S.</given-names>
</name>
<xref ref-type="aff" rid="aff5">
<sup>5</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Konovalov</surname>
<given-names>I. B.</given-names>
</name>
<xref ref-type="aff" rid="aff6">
<sup>6</sup>
</xref>
<xref ref-type="aff" rid="aff7">
<sup>7</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Szopa</surname>
<given-names>S.</given-names>
</name>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Menut</surname>
<given-names>L.</given-names>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Department of Chemistry, University of Leicester, University Road, Leicester, UK</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>National Centre for Atmospheric Science, Department of Chemistry, University of Leicester, University Road, Leicester, UK</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>Laboratoire de Météorologie Dynamique, École Polytechnique, 91128 Palaiseau, France</addr-line>
</aff>
<aff id="aff4">
<label>4</label>
<addr-line>Laboratoire de Sciences du Climat et de l&apos;Environnement,  Gif-sur-Yvette, 91191 France</addr-line>
</aff>
<aff id="aff5">
<label>5</label>
<addr-line>Empa, Swiss Federal Laboratories for Materials Testing and Research, Dübendorf,  Switzerland</addr-line>
</aff>
<aff id="aff6">
<label>6</label>
<addr-line>Institute of Applied Physics, Russian Academy of Sciences, Nizhniy Novgorod, Russia</addr-line>
</aff>
<aff id="aff7">
<label>7</label>
<addr-line>Laboratoire Inter-Universitaire de Systèmes Atmosphériques, CNRS, Université Paris-Est and Université Paris 7, Créteil, France</addr-line>
</aff>
<pub-date pub-type="epub">
<day>29</day>
<month>06</month>
<year>2011</year>
</pub-date>
<volume>11</volume>
<issue>6</issue>
<fpage>18433</fpage>
<lpage>18485</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>
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<self-uri xlink:href="http://www.atmos-chem-phys-discuss.net/11/18433/2011/acpd-11-18433-2011.pdf">The full text article is available as a PDF file from http://www.atmos-chem-phys-discuss.net/11/18433/2011/acpd-11-18433-2011.pdf</self-uri>
<abstract>
<p>National and European legislation over the past 20 years, and the
      modernisation or removal of industrial sources, have significantly
      reduced European ozone precursor emissions.  This study quantifies
      observed and modelled European ozone annual and seasonal linear trends
      from 158 harmonised rural background monitoring stations over
      a constant time period of a decade (1996–2005).  Mean ozone
      concentrations are investigated, in addition to the ozone
      5th percentiles as a measure of the baseline or
      background conditions, and the 95th percentiles that
      are representative of the peak concentration levels.  This study aims
      to characterise and quantify surface European ozone concentrations and
      trends and assess the impact of the changing anthropogenic emission
      tracers on the observed and modelled trends.
&lt;br&gt;&lt;/br&gt;
      Significant (&lt;i&gt;p&lt;/i&gt; &lt; 0.1) positive annual trends in ozone mean,
      5th and 95th percentiles are
      observed at 54 %, 52 % and 45 % of sites respectively (85 sites,
      82 sites and 71 sites).  Spatially, sites in Central and Northwestern
      Europe tend to display positive annual ozone trends in mean,
      5th and 95th percentiles.
      Significant negative annual trends in ozone mean 5th
      and 95th percentiles are observed at 11 %, 12 %
      and 12 % of sites respectively (18 sites, 19 sites and 19 sites)
      which tend to be located in the eastern and south-western extremities
      of Europe.  European-averaged annual trends have been calculated from
      the 158 sites in this study.  Overall there is a net positive annual
      trend in observed ozone mean (0.16 ±  0.02 ppbv yr&lt;sup&gt;&amp;minus;1&lt;/sup&gt; 2&amp;sigma;
      error)), 5th (0.13 ± 0.02 ppbv yr&lt;sup&gt;&amp;minus;1&lt;/sup&gt;) and
      95th (0.16 ± 0.03 ppbv yr&lt;sup&gt;&amp;minus;1&lt;/sup&gt;) percentiles,
      representative of positive trends in mean, baseline and peak ozone.
      Assessing the sensitivity of the derived overall trends to the
      constituent years shows that the European heatwave year of 2003 has
      significant positive influence and 1998 the converse effect;
      demonstrating the masking effect of inter-annual variability on
      decadal based ozone trends.
&lt;br&gt;&lt;/br&gt;
      The European scale 3-D CTM CHIMERE was used to simulate hourly
      O&lt;sub&gt;3&lt;/sub&gt; concentrations for the period 1996–2005.  Comparisons
      between the 158 observed ozone trends to those equivalent sites
      extracted from regional simulations by CHIMERE better match the
      observed increasing annual ozone (predominantly in Central and
      Northwestern Europe) for 5th percentiles, than for
      mean or 95th ozone percentiles.  The
      European-averaged annual ozone trend in CHIMERE 5th
      percentiles (0.13 ± 0.01 ppbv yr&lt;sup&gt;&amp;minus;1&lt;/sup&gt;) matches the corresponding
      observed trend extremely well, but displays a negative trend for the
      95th percentile (&amp;minus;0.03 ± 0.02 ppbv yr&lt;sup&gt;&amp;minus;1&lt;/sup&gt;) where
      a positive ozone trend is observed.  Inspection of the EU-averaged
      monthly means of ozone shows that the CHIMERE model is overestimating
      the summer month O&lt;sub&gt;3&lt;/sub&gt; levels.
&lt;br&gt;&lt;/br&gt;
      In comparison to trends in EMEP emissions inventories, with the
      exception of Austria-Hungary, we find anthropogenic NO&lt;sub&gt;x&lt;/sub&gt; and
      VOC reductions do not appear to have a substantial effect on observed
      annual mean O&lt;sub&gt;3&lt;/sub&gt; trends in the rest of Europe.</p>
</abstract>
<counts><page-count count="53"/></counts>
</article-meta>
</front>
<body/>
<back>
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