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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-7-10543-2007</article-id>
<title-group>
<article-title>Short- and medium-term atmospheric effects of very large solar proton events</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Jackman</surname>
<given-names>C. H.</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>Marsh</surname>
<given-names>D. R.</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>Vitt</surname>
<given-names>F. M.</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>Garcia</surname>
<given-names>R. R.</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>Fleming</surname>
<given-names>E. 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>Labow</surname>
<given-names>G. 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>Randall</surname>
<given-names>C. E.</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>López-Puertas</surname>
<given-names>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>Funke</surname>
<given-names>B.</given-names>
</name>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>NASA/Goddard Space Flight Center, Greenbelt, MD, USA</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>National Center for Atmospheric Research, Boulder, CO, USA</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>University of Colorado, Boulder, CO, USA</addr-line>
</aff>
<aff id="aff4">
<label>4</label>
<addr-line>Instituto de-Astrofisica de Andalucia, CSIC, Granada, Spain</addr-line>
</aff>
<pub-date pub-type="epub">
<day>23</day>
<month>07</month>
<year>2007</year>
</pub-date>
<volume>7</volume>
<issue>4</issue>
<fpage>10543</fpage>
<lpage>10588</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/7/10543/2007/acpd-7-10543-2007.pdf">The full text article is available as a PDF file from http://www.atmos-chem-phys-discuss.net/7/10543/2007/acpd-7-10543-2007.pdf</self-uri>
<abstract>
<p>Solar eruptions sometimes produce protons, which impact the Earth&apos;s
atmosphere. These solar proton events (SPEs) generally last a few days and
produce high energy particles that precipitate into the Earth&apos;s atmosphere.
The protons cause ionization and dissociation processes that ultimately lead
to an enhancement of odd-hydrogen and odd-nitrogen in the polar cap regions
(&amp;gt;60&amp;deg; geomagnetic latitude). We have used the Whole Atmosphere
Community Climate Model (WACCM3) to study the atmospheric impact of SPEs
over the period 1963&amp;ndash;2005. The very largest SPEs were found to be the most
important and caused atmospheric effects that lasted several months to years
after the events. We present the short- and medium-term (days to a few
months) atmospheric influence of the four largest SPEs in the past 45 years
(August 1972; October 1989; July 2000; and October&amp;ndash;November 2003) as
computed by WACCM3 and observed by satellite instruments. The polar effects
can be summarized as follows: 1) Mesospheric NO&lt;sub&gt;x&lt;/sub&gt; (NO+NO&lt;sub&gt;2&lt;/sub&gt;)
increased by over 50 ppbv and mesospheric ozone decreased by over 30%
during these very large SPEs; 2) upper stratospheric and lower mesospheric
NO&lt;sub&gt;x&lt;/sub&gt; increased by over 10 ppbv and was transported during polar night
down to the middle stratosphere in a few weeks; 3) mid- to upper
stratospheric ozone decreased over 20%; and 4) enhancements of HNO&lt;sub&gt;3&lt;/sub&gt;,
HOCl, ClO, ClONO&lt;sub&gt;2&lt;/sub&gt;, and N&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; were indirectly caused by the
very large SPEs, although the model results suggest impacts at higher
altitudes than indicated by the measurements for the October&amp;ndash;November 2003 SPE
period.</p>
</abstract>
<counts><page-count count="46"/></counts>
</article-meta>
</front>
<body/>
<back>
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