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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>
<abbrev-journal-title abbrev-type="nlm-ta">Atmos. Chem. Phys. Discuss.</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">1680-7375</issn>
<publisher><publisher-name></publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/acp-2016-657</article-id>
<title-group>
<article-title>Urbanization effect on sunshine duration during global dimming and
brightening periods in China</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Wang</surname>
<given-names>Yawen</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>Wild</surname>
<given-names>Martin</given-names>
<ext-link>https://orcid.org/0000-0002-3619-7568</ext-link>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Sanchez-Lorenzo</surname>
<given-names>Arturo</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>Yang</surname>
<given-names>Yonghui</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>Manara</surname>
<given-names>Veronica</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>Ren</surname>
<given-names>Dandan</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, 8092, Switzerland</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, 050021, China</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>nstituto Pirenaico de Ecología, Consejo Superior de Investigaciones Científicas (IPE–CSIC), Zaragoza, 50059, Spain</addr-line>
</aff>
<aff id="aff4">
<label>4</label>
<addr-line>Department of Physics, Università degli Studi di Milano, Milan, 20133, Italy</addr-line>
</aff>
<pub-date pub-type="epub">
<day>05</day>
<month>09</month>
<year>2016</year>
</pub-date>
<volume>2016</volume>
<fpage>1</fpage>
<lpage>20</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2016 Yawen Wang et al.</copyright-statement>
<copyright-year>2016</copyright-year>
<license license-type="open-access">
<license-p>This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit <ext-link ext-link-type="uri"  xlink:href="https://creativecommons.org/licenses/by/3.0/">https://creativecommons.org/licenses/by/3.0/</ext-link></license-p>
</license>
</permissions>
<self-uri xlink:href="https://acp.copernicus.org/preprints/acp-2016-657/">This article is available from https://acp.copernicus.org/preprints/acp-2016-657/</self-uri>
<self-uri xlink:href="https://acp.copernicus.org/preprints/acp-2016-657/acp-2016-657.pdf">The full text article is available as a PDF file from https://acp.copernicus.org/preprints/acp-2016-657/acp-2016-657.pdf</self-uri>
<abstract>
<p>There is an ongoing debate on whether the observed decadal variations in surface solar radiation, known as &quot;dimming and brightening&quot;, are a global or just local phenomenon. We investigated this issue using a comprehensive set of long-term sunshine duration records from China, which experienced a rapid growth in urbanization during past decades. 172 pairs of urban and nearby rural stations were analyzed over the period 1960&amp;ndash;1989 (&quot;dimming phase&quot;) and 1990&amp;ndash;2013 (&quot;brightening phase&quot;). There is a large overlap in urban and rural sunshine duration trends for both dimming (≈&amp;thinsp;86&amp;thinsp;%) and brightening (≈&amp;thinsp;84&amp;thinsp;%) phases. This indicates that rather than urban dimming or rural brightening, the global dimming and brightening phenomena are more of national/regional scale in China. In the dimming phase, sunshine duration significantly declined in both urban and rural areas at an average rate of &amp;minus;0.20&amp;thinsp;h&amp;thinsp;d&lt;sup&gt;&amp;minus;1&lt;/sup&gt;&amp;thinsp;decade&lt;sup&gt;&amp;minus;1&lt;/sup&gt; and &amp;minus;0.14&amp;thinsp;h&amp;thinsp;d&lt;sup&gt;&amp;minus;1&lt;/sup&gt;&amp;thinsp;decade&lt;sup&gt;&amp;minus;1&lt;/sup&gt; respectively, i.e. rural dimming has been around two-thirds of urban dimming. This ratio generally increases from a minimum of 0.39 to a maximum of 0.87 with increasing indices of urbanization, reaching saturation when the urbanization level exceeds 50&amp;thinsp;%, or the urban population exceeds 20 million persons, or the population density becomes higher than 250&amp;thinsp;person&amp;thinsp;km&lt;sup&gt;&amp;minus;2&lt;/sup&gt;. Urbanization can be treated as a useful indicator for anthropogenic air pollution in studying pollution-driven changes in sunshine duration during the dimming phase when pollution control and monitoring were largely absent. After the transition into the brightening phase, the increasing number of environment-related laws and regulations as well as investments in the abatement of environmental pollution might have helped in counteracting air pollutants generated during the urbanization process. Therefore, in the brightening phase, urbanization no longer simply indicates an increase in air pollution and its effect on sunshine duration becomes insignificant. In conclusion, urbanization can give a general indication of pollution-driven sunshine dimming until pollution regulations become effective.</p>
</abstract>
<counts><page-count count="20"/></counts>
<funding-group>
<award-group id="gs1">
<funding-source>National Natural Science Foundation of China</funding-source>
<award-id>41501036</award-id>
</award-group>
</funding-group>
</article-meta>
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