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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>GÃ¶ttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/acpd-11-22075-2011</article-id>
<title-group>
<article-title>Characteristics, sources and formation of aerosol oxalate in an Eastern Asia megacity and its implication to haze pollution</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Jiang</surname>
<given-names>Y.</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>Zhuang</surname>
<given-names>G.</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>Wang</surname>
<given-names>Q.</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>Liu</surname>
<given-names>T.</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>Huang</surname>
<given-names>K.</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>Fu</surname>
<given-names>J. S.</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>Li</surname>
<given-names>J.</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>Lin</surname>
<given-names>Y.</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>Zhang</surname>
<given-names>R.</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>Deng</surname>
<given-names>C.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Center for Atmospheric Chemistry Study, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Department of Civil and Environmental Engineering, The University of Tennessee, Knoxville, TN 37996, USA</addr-line>
</aff>
<pub-date pub-type="epub">
<day>04</day>
<month>08</month>
<year>2011</year>
</pub-date>
<volume>11</volume>
<issue>8</issue>
<fpage>22075</fpage>
<lpage>22112</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/11/22075/2011/acpd-11-22075-2011.pdf">The full text article is available as a PDF file from http://www.atmos-chem-phys-discuss.net/11/22075/2011/acpd-11-22075-2011.pdf</self-uri>
<abstract>
<p>A total of 238 samples of PM&lt;sub&gt;2.5&lt;/sub&gt; and TSP were analyzed to study the
characteristics, sources, and formation pathways of aerosol oxalate in
Shanghai in four seasons of 2007. The concentrations of oxalate were
0.07â€“0.41 Î¼g m&lt;sup&gt;&amp;minus;3&lt;/sup&gt; in PM&lt;sub&gt;2.5&lt;/sub&gt; and 0.10â€“0.48 Î¼g m&lt;sup&gt;&amp;minus;3&lt;/sup&gt; in TSP,
respectively. Oxalate displayed a seasonal variation of
autumn&gt;summer&gt;winter&gt;spring in both PM&lt;sub&gt;2.5&lt;/sub&gt; and TSP and was dominantly
present in  PM&lt;sub&gt;2.5&lt;/sub&gt; in all samples. Correlation between oxalate and
K&lt;sup&gt;+&lt;/sup&gt; and high ratio of oxalate/K&lt;sup&gt;+&lt;/sup&gt; suggested that biomass burning was
a secondary source of aerosol oxalate in Shanghai, in addition to urban VOCs
sources (vehicular and industrial emissions), especially in autumn.
Secondary formation accounted for the majority of aerosol oxalate in
Shanghai, which was supported by the high correlation of oxalate with
nss-SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2&amp;minus;&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt; and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;&amp;minus;&lt;/sup&gt;, proceeding from different
mechanisms. Relatively high ambient RH together with high cloud cover was
found benefiting the secondary formation of aerosol oxalate. The in-cloud
process (aqueous-phase oxidation) was proposed to be likely the major
formation pathway of aerosol oxalate in Shanghai, which was supported by the
high correlation of oxalate with nss-SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2&amp;minus;&lt;/sup&gt; and K&lt;sup&gt;+&lt;/sup&gt; , dominant
residence of oxalate in droplet mode and result of favorable meteorological
condition analysis. High correlation of oxalate and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;&amp;minus;&lt;/sup&gt; reflected
the OH radical involved oxidation chemistry of the two species in the
atmosphere and also suggested that gas-particle surface reactions and
evaporation-condensation process were both possible secondary formation
pathways of aerosol oxalate in coarser particle mode (&gt;1.0 Î¼m).
Aerosol oxalate contributed to the haze pollution and visibility degradation
of the local environment. As a major water-soluble organic compound in
aerosols, concentration of oxalate showed a distinct negative correlation to
the atmospheric visibility, which implied that aerosol organic compounds
could play an important role in air quality in Shanghai.</p>
</abstract>
<counts><page-count count="38"/></counts>
</article-meta>
</front>
<body/>
<back>
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