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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-8-5373-2008</article-id>
<title-group>
<article-title>Photolysis frequency measurement techniques: results of a comparison within the ACCENT project</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Bohn</surname>
<given-names>B.</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>Corlett</surname>
<given-names>G. K.</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>Gillmann</surname>
<given-names>M.</given-names>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
<xref ref-type="aff" rid="aff11">
<sup>11</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Sanghavi</surname>
<given-names>S.</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>Stange</surname>
<given-names>G.</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>Tensing</surname>
<given-names>E.</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>Vrekoussis</surname>
<given-names>M.</given-names>
</name>
<xref ref-type="aff" rid="aff5">
<sup>5</sup>
</xref>
<xref ref-type="aff" rid="aff12">
<sup>12</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Bloss</surname>
<given-names>W. J.</given-names>
</name>
<xref ref-type="aff" rid="aff6">
<sup>6</sup>
</xref>
<xref ref-type="aff" rid="aff13">
<sup>13</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Clapp</surname>
<given-names>L. J.</given-names>
</name>
<xref ref-type="aff" rid="aff7">
<sup>7</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Kortner</surname>
<given-names>M.</given-names>
</name>
<xref ref-type="aff" rid="aff8">
<sup>8</sup>
</xref>
<xref ref-type="aff" rid="aff14">
<sup>14</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Dorn</surname>
<given-names>H.-P.</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>Monks</surname>
<given-names>P. 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>Platt</surname>
<given-names>U.</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>Plass-Dülmer</surname>
<given-names>C.</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>Mihalopoulos</surname>
<given-names>N.</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>Heard</surname>
<given-names>D. E.</given-names>
</name>
<xref ref-type="aff" rid="aff6">
<sup>6</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Clemitshaw</surname>
<given-names>K. C.</given-names>
</name>
<xref ref-type="aff" rid="aff7">
<sup>7</sup>
</xref>
<xref ref-type="aff" rid="aff15">
<sup>15</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Meixner</surname>
<given-names>F. X.</given-names>
</name>
<xref ref-type="aff" rid="aff8">
<sup>8</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Prevot</surname>
<given-names>A. S. H.</given-names>
</name>
<xref ref-type="aff" rid="aff9">
<sup>9</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Schmitt</surname>
<given-names>R.</given-names>
</name>
<xref ref-type="aff" rid="aff10">
<sup>10</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Institut für Chemie und Dynamik der Geosphäre 2:  Troposphäre, Forschungszentrum Jülich, 52425 Jülich, Germany</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Department of Chemistry, University of Leicester, Leicester LE1 7RH, UK</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>Institut für Umweltphysik, Universität Heidelberg, 69120 Heidelberg, Germany</addr-line>
</aff>
<aff id="aff4">
<label>4</label>
<addr-line>Deutscher Wetterdienst, Meteorologisches Observatorium Hohenpeissenberg, 82383 Hohenpeissenberg, Germany</addr-line>
</aff>
<aff id="aff5">
<label>5</label>
<addr-line>Environmental Chemistry Laboratory, University of Crete, 71003 Voutes, Heraklion, Greece</addr-line>
</aff>
<aff id="aff6">
<label>6</label>
<addr-line>School of Chemistry, University of Leeds, Leeds LS2 9JT, UK</addr-line>
</aff>
<aff id="aff7">
<label>7</label>
<addr-line>Department of Environmental Science and Technology, Imperial College London,  Silwood Park Campus, Ascot SL5 7PY, UK</addr-line>
</aff>
<aff id="aff8">
<label>8</label>
<addr-line>Biogeochemistry Department, Max Planck Institute for Chemistry, 55128 Mainz, Germany</addr-line>
</aff>
<aff id="aff9">
<label>9</label>
<addr-line>Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, 5232 Villigen, Switzerland</addr-line>
</aff>
<aff id="aff10">
<label>10</label>
<addr-line>Meteorologie Consult GmbH (Metcon), 61462 Königstein, Germany</addr-line>
</aff>
<aff id="aff11">
<label>11</label>
<addr-line>now at: SIG Plasmax GmbH, 22145 Hamburg, Germany</addr-line>
</aff>
<aff id="aff12">
<label>12</label>
<addr-line>now at: Institut für Umweltphysik, University of  Bremen, 28359 Bremen, Germany</addr-line>
</aff>
<aff id="aff13">
<label>13</label>
<addr-line>now at: School of Geography, Earth &amp; Environmental  Sciences, University of Birmingham, Birmingham B15 2TT, UK</addr-line>
</aff>
<aff id="aff14">
<label>14</label>
<addr-line>now at: Müller-BBM GmbH, 63589 Linsengericht,  Germany</addr-line>
</aff>
<aff id="aff15">
<label>15</label>
<addr-line>now at: Department of Earth Sciences, Royal  Holloway, University of London, Egham TW20 0EX, UK</addr-line>
</aff>
<pub-date pub-type="epub">
<day>10</day>
<month>09</month>
<year>2008</year>
</pub-date>
<volume>8</volume>
<issue>17</issue>
<fpage>5373</fpage>
<lpage>5391</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/8/5373/2008/acp-8-5373-2008.html">This article is available from http://www.atmos-chem-phys.net/8/5373/2008/acp-8-5373-2008.html</self-uri>
<self-uri xlink:href="http://www.atmos-chem-phys.net/8/5373/2008/acp-8-5373-2008.pdf">The full text article is available as a PDF file from http://www.atmos-chem-phys.net/8/5373/2008/acp-8-5373-2008.pdf</self-uri>
<abstract>
<p>An intercomparison of different radiometric techniques measuring atmospheric photolysis
frequencies &lt;i&gt;j&lt;/i&gt;(NO&lt;sub&gt;2&lt;/sub&gt;), &lt;i&gt;j&lt;/i&gt;(HCHO) and &lt;i&gt;j&lt;/i&gt;(O&lt;sup&gt;1&lt;/sup&gt;D) was carried out
in a two-week field campaign in June 2005 at Jülich, Germany.
Three double-monochromator based spectroradiometers (DM-SR), three
single-monochromator based spectroradiometers with diode-array
detectors (SM-SR) and seventeen filter radiometers (FR) (ten
&lt;i&gt;j&lt;/i&gt;(NO&lt;sub&gt;2&lt;/sub&gt;)-FR, seven &lt;i&gt;j&lt;/i&gt;(O&lt;sup&gt;1&lt;/sup&gt;D)-FR) took part in this
comparison. For &lt;i&gt;j&lt;/i&gt;(NO&lt;sub&gt;2&lt;/sub&gt;), all spectroradiometer results agreed
within &amp;plusmn;3%. For &lt;i&gt;j&lt;/i&gt;(HCHO), agreement was slightly poorer
between &amp;minus;8% and +4% of the DM-SR reference result. For the
SM-SR deviations were explained by poorer spectral resolutions and
lower accuracies caused by decreased sensitivities of the
photodiode arrays in a wavelength range below 350 nm. For
&lt;i&gt;j&lt;/i&gt;(O&lt;sup&gt;1&lt;/sup&gt;D), the results were more complex within +8% and
&amp;minus;4% with increasing deviations towards larger solar zenith
angles for the SM-SR. The direction and the magnitude of the
deviations were dependent on the technique of background
determination. All &lt;i&gt;j&lt;/i&gt;(NO&lt;sub&gt;2&lt;/sub&gt;)-FR showed good linearity with
single calibration factors being sufficient to convert from output
voltages to &lt;i&gt;j&lt;/i&gt;(NO&lt;sub&gt;2&lt;/sub&gt;). Measurements were feasible until sunset
and comparison with previous calibrations showed good long-term
stability. For the &lt;i&gt;j&lt;/i&gt;(O&lt;sup&gt;1&lt;/sup&gt;D)-FR, conversion from output voltages
to &lt;i&gt;j&lt;/i&gt;(O&lt;sup&gt;1&lt;/sup&gt;D) needed calibration factors and correction functions
considering the influences of total ozone column and elevation of
the sun. All instruments showed good linearity at photolysis
frequencies exceeding about 10% of maximum values. At larger
solar zenith angles, the agreement was non-uniform with deviations
explainable by insufficient correction functions. Comparison with
previous calibrations for some &lt;i&gt;j&lt;/i&gt;(O&lt;sup&gt;1&lt;/sup&gt;D)-FR indicated drifts of
calibration factors.</p>
</abstract>
<counts><page-count count="19"/></counts>
</article-meta>
</front>
<body/>
<back>
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