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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>GÃ¶ttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/acp-7-1899-2007</article-id>
<title-group>
<article-title>Connections between atmospheric sulphuric acid and new particle formation during QUEST III&amp;ndash;IV campaigns in Heidelberg and HyytiÃ¤lÃ¤</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Riipinen</surname>
<given-names>I.</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>Sihto</surname>
<given-names>S.-L.</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>Kulmala</surname>
<given-names>M.</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>Arnold</surname>
<given-names>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>Dal Maso</surname>
<given-names>M.</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>Birmili</surname>
<given-names>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>Saarnio</surname>
<given-names>K.</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>TeinilÃ¤</surname>
<given-names>K.</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>Kerminen</surname>
<given-names>V.-M.</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>Laaksonen</surname>
<given-names>A.</given-names>
</name>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
<xref ref-type="aff" rid="aff5">
<sup>5</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Lehtinen</surname>
<given-names>K. E. J.</given-names>
</name>
<xref ref-type="aff" rid="aff6">
<sup>6</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>University of Helsinki, Department of Physical Sciences,  P.O. Box 64, 00014 University of Helsinki, Finland</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Max Planck Institute for Nuclear Physics (MPIK), Atmospheric Physics  Division, P.O. Box 103980, 69029 Heidelberg, Germany</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>Leibniz Institute for Tropospheric Research,  Permoserstrasse 15, 04318 Leipzig, Germany</addr-line>
</aff>
<aff id="aff4">
<label>4</label>
<addr-line>Finnish Meteorological Institute, Erik Palmenin Aukio 1, P.O. Box 503,  00101 Helsinki, Finland</addr-line>
</aff>
<aff id="aff5">
<label>5</label>
<addr-line>University of Kuopio,  Department of Applied Physics, P.O. Box 1627, 70211 Kuopio,  Finland</addr-line>
</aff>
<aff id="aff6">
<label>6</label>
<addr-line>Finnish Meteorological Institute and University of Kuopio, Department of Applied Physics, P.O. Box 1627, 70211  Kuopio, Finland</addr-line>
</aff>
<pub-date pub-type="epub">
<day>17</day>
<month>04</month>
<year>2007</year>
</pub-date>
<volume>7</volume>
<issue>8</issue>
<fpage>1899</fpage>
<lpage>1914</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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<abstract>
<p>This study investigates the connections between atmospheric
sulphuric acid and new particle formation during QUEST III and
BACCI/QUEST IV campaigns. The campaigns have been conducted in
Heidelberg (2004) and HyytiÃ¤lÃ¤ (2005), the first
representing a polluted site surrounded by deciduous forest, and
the second a rural site in a boreal forest environment. We have
studied the role of sulphuric acid in particle formation and
growth by determining 1) the power-law dependencies between
sulphuric acid ([H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;]), and particle concentrations
(&lt;I&gt;N&lt;/I&gt;&lt;sub&gt;3&amp;ndash;6&lt;/sub&gt;) or formation rates at 1 nm and 3 nm (&lt;I&gt;J&lt;/i&gt;&lt;sub&gt;1&lt;/sub&gt; and
&lt;I&gt;J&lt;/I&gt;&lt;sub&gt;3&lt;/sub&gt;); 2) the time delays between [H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;] and
&lt;I&gt;N&lt;/I&gt;&lt;sub&gt;3&amp;ndash;6&lt;/sub&gt; or &lt;I&gt;J&lt;/I&gt;&lt;sub&gt;3&lt;/sub&gt;, and the growth rates for 1&amp;ndash;3 nm particles;
3) the empirical nucleation coefficients &lt;I&gt;A&lt;/I&gt; and &lt;I&gt;K&lt;/I&gt; in relations
&lt;I&gt;J&lt;/I&gt;&lt;sub&gt;1&lt;/sub&gt;=&lt;I&gt;A&lt;/I&gt;[H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;] and
&lt;I&gt;J&lt;/I&gt;&lt;sub&gt;1&lt;/sub&gt;=&lt;I&gt;K&lt;/I&gt;[H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;]&lt;sup&gt;2&lt;/sup&gt;, respectively; 4) theoretical
predictions for &lt;I&gt;J&lt;/I&gt;&lt;sub&gt;1&lt;/sub&gt; and &lt;I&gt;J&lt;/I&gt;&lt;sub&gt;3&lt;/sub&gt; for the days when no
significant particle formation is observed, based on the observed
sulphuric acid concentrations and condensation sinks. In both
environments, &lt;I&gt;N&lt;/I&gt;&lt;sub&gt;3&amp;ndash;6&lt;/sub&gt; or &lt;I&gt;J&lt;/I&gt;&lt;sub&gt;3&lt;/sub&gt; and [H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;] were
linked via a power-law relation with exponents typically ranging
from 1 to 2. The result suggests that the cluster activation
theory and kinetic nucleation have the potential to explain the
observed particle formation. However, some differences between the
sites existed: The nucleation coefficients were about an order of
magnitude greater in Heidelberg than in HyytiÃ¤lÃ¤
conditions. The time lags between &lt;I&gt;J&lt;/I&gt;&lt;sub&gt;3&lt;/sub&gt; and [H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;]
were consistently lower than the corresponding delays between
&lt;I&gt;N&lt;/I&gt;&lt;sub&gt;3&amp;ndash;6&lt;/sub&gt; and [H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;]. The exponents in 
the &lt;I&gt;J&lt;/I&gt;&lt;sub&gt;3&lt;/sub&gt;&amp;#x221D;[H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt; ]&lt;sup&gt;n&lt;sub&gt;J3&lt;/sub&gt;&lt;/sup&gt;-connection were
consistently higher than or equal to the exponents in the relation
&lt;I&gt;N&lt;/I&gt;&lt;sub&gt;3&amp;ndash;6&lt;/sub&gt;&amp;#x221D;[H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt; ]&lt;sup&gt;n&lt;sub&gt;N36&lt;/sub&gt;&lt;/sup&gt;. In the
&lt;I&gt;J&lt;/I&gt;&lt;sub&gt;1&lt;/sub&gt; values, no significant differences were found between the
observed rates on particle formation event days and the
predictions on non-event days. The &lt;I&gt;J&lt;/I&gt;&lt;sub&gt;3&lt;/sub&gt; values predicted by the
cluster activation or kinetic nucleation hypotheses, on the other
hand, were considerably lower on non-event days than the rates
observed on particle formation event days. This study provides
clear evidence implying that the main process limiting the
observable particle formation is the competition between the
growth of the freshly formed particles and their loss by
scavenging, rather than the initial particle production by
nucleation of sulphuric acid. In general, it can be concluded that
the simple models based on sulphuric acid concentrations and
particle formation by cluster activation or kinetic nucleation can
predict the occurence of atmospheric particle formation and growth
well, if the particle scavenging is accurately accounted for.</p>
</abstract>
<counts><page-count count="16"/></counts>
</article-meta>
</front>
<body/>
<back>
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